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Human Body
Structure and
Function 2

Book List
1
...

Elsevier publication
2
...

Pearson publication
3
...

McGraw Hill Publication

1

Renal system
Q
...
What are the functions of nephrons?
Nephron: Nephron is the structural and functional unit of kidney
...

Classification of nephrons: Two types:
1
...

3
...
They have short loop of Henle
...
They have long loop of Henle
...
Their loops of Henle are of intermediate length
...
Renal corpuscle:
• Glomerulus: It is the tuft of capillaries arising from the afferent arteriole and again converging to
efferent arteriole
...

• Bowman’s capsule: It is the cup-shaped dilated and invaginated proximal end of ranal tubule
...
Renal tubule:
• Proximal convoluted tubule (PCT)
• Descending limb of loop of Henle
• Ascending limb of loop of Henle
• Distal convoluted tubule (DCT)
• Collecting tubule (CT)
Functions of nephron: Formation of urine by1
...

3
...


Glomerular filtration
...

Tubular secretion
...


Q
...

From Blueprint Physiology Page- 403
...
What is juxtaglomerular apparatus?
Juxtaglomerular apparatus: The Juxtaglomerular cells (JG cells), the
macula densa and the lacis cells are collectively known as the
Juxtaglomerular apparatus
...
JG cells
2
...
Lacis cells (mesangial cells)

Location
Afferent arteriole (in tunica media)
Distal tubule
At the junction between afferent and efferent arteriole

Function:
1
...

3
...

JG cells secrete erythropoietin, which stimulates erythropoiesis
...


2

4
...
Mesangial
cells secrete the extracellular matrix, take up immune complexes and are involved in the progression of
glomerular disease
...
Enumerate the functions of kidney
...
Formation of urine: By this way it helps to maintain1
...
Electrolyte balance
3
...
Acid-base balance
...
Excretory function:
1
...
g
...
Non-protein nitrogenous substance:
• Urea (from the metabolism of amino acids)
• Uric acid (from the catabolism of purines)
• Creatinine (from muscle creatinine)
b
...

c
...
g
...

2
...
g
...

3
...
g
...

4
...

C
...
Formation of erythropoietin in response to hypoxia
...
It secretes renin, which converts angiotensinogen to angiotensin I
...


E
...


G
...
Formation of active form of vitamin D: 1,25-dihydroxycholecalciferol under the influence of
parathyroid hormone
...
It also produces prostaglandin (PG): PGI2, PGE2 synthesized by mesangial cells of glomeruli and
interstitial cells of medulla
...

Metabolic function:
1
...

2
...

Regulation of blood pressure: The kidneys play the dominant role in the long-term regulation of blood
pressure by1
...

2
...

Conservation of nutrients: When blood comes into the kidney through vessels, kidney first selects the
nutrients and also waste products
...
Thus, kidney conserves the nutrients such as glucose, amino acid
...
It maintains blood glucose level during prolonged fasting condition by gluconeogenesis
...
It is the important site for degradation of several polypeptide hormones i
...
, insulin, glucagon and
parathyroid hormone
...
What happens to kidneys when there is a deprivation of water?
Response of water deprivation:
Water is continuously lost from the body in sweat gland and in water vapor from the mouth and nose (called
insensible water loss)
...
The increase
in osmolarity stimulates osmoreceptors in the anterior hypothalamus, which are exquisitely sensitive and are
stimulated by increase in osmolarity of less than 1 mOsm/L
...

It also stimulates secretion of ADH from the posterior pituitary gland
...
ADH circulates in the blood to the kidneys, where it produces an
increase in water permeability of the principle cells of the late distal tubule and collecting duct
...
As more
water is reabsorbed by these segments, urine osmolarity increases and urine volume decreases
...
Coupled with increased thirst
and drinking behavior, plasma osmolarity is decreased, back toward the normal value
...

Q
...

When a person drinks water, the ingested water is distributed throughout the body fluids
...
The decrease in plasma osmolarity inhibits osmoreceptors in the anterior hypothalamus
...

It also inhibits secretion of ADH from the posterior pituitary gland
...

As a result of the lower ADH levels, there is a decrease in water permeability of the principle cells of the late distal
tubule and collecting ducts
...
The water that is not reabsorbed by these segments is excreted, decreasing urine osmolarity and increasing
urine volume
...
Coupled with the inhibition
of thirst and the suppression of water drinking, plasma osmolarity increased back toward the normal value
...
Give the histological characteristics of urinary bladder
...


2
...


Mucosa layer: The innermost layer of the bladder is the mucosa layer that lines the hollow lumen
...
The transitional epithelium also
provides protection to the underlying tissues from acidic or alkaline urine
...

Muscularis layer: The visceral muscles of the muscularis layer surround the submucosa and provide the
urinary bladder with its ability to expand and contract
...
The muscularis also forms
the internal urethral sphincter, a ring of muscle that surrounds the urethral opening and holds urine in the
urinary bladder
...


Q
...

Functions of urinary bladder:
1
...
The ureter, which are 8 to10-inch-long tubes, are lined with muscles that contract and
relax to help move the urine from the kidney to the bladder
...
This tube is
controlled by the internal ureter sphincter, a circular muscle located between the neck of the bladder and
the urethra
...

The bladder wall is able to stretch, making it a perfect storage area
...
As it gets full, stretch receptors in the bladder wall signal the brain
...


3
...
When the bladder is full, the nerves send a signal through the nerves, up the
spinal cord and to the brain
...

Voiding: As the detrusor muscle of the bladder contracts, the pressure inside the bladder becomes higher
than the pressure in the urethra, allowing urine to flow out the relaxed internal urethral sphincter
...
Although
the brain automatically regulates the voiding of urine, people have the ability to delay voiding, thus giving
them time to reach a restroom
...
What is micturition and micturition reflex? Describe the pathway of micturition reflex
...

Micturition reflex: Micturition reflex is a spinal reflex facilitated and inhibited by higher brain centers and subject
to voluntary facilitation and inhibition and which causes voiding of urine from the urinary bladder when it becomes
filled
...

↓
If this inhibition is more potent in the brain than the voluntary constrictor signals to the external sphincter, urination
will occur
...


5

Endocrine System
Q
...

Hormone: A hormone is a chemical substance that is secreted into the internal body fluid by one cell or group of
cells and has a physiological control effect on other cells of the body
...
On the basis of chemical nature:
a
...


Amine hormones:
T3, T4, Epi, Nor, Dop
T3: Triiodothyronine
T4: Thyroxine
Epi: Epinephrine
Nor: Norepinephrine
Dop: Dopamine or prolactin inhibiting factor
...


c
...


3
...
Local Hormones: Act locally near the site of secretion
...

b
...
Examples are
insulin and aldosterone
...
Tropic Hormones: Specialized type of general hormones secreted by one ecdocrine gland and
acts on other glands to control their secretions
...

On the basis of location of receptor:
a
...

c
...


Peptide Hormones: TSH, ADH, insulin etc
...

In the nucleus: Thyroid hormones
...
Group I Hormones: They bind to intracellular receptors
...
Examples are thyroid hormones, steroid hormones
...
Group II Hormones: These are the hormones that bind to cell surface receptors
...
Examples are• Proteins and polypeptides
• Glycoproteins and
• Catecholamines

Q
...

General characteristics of protein and polypeptide hormones:
1
...

2
...
g
...
g
...

3
...

4
...

5
...

6
...

7
...

8
...


6

9
...


Q
...

General characteristics of steroid hormones:
1
...

2
...

3
...
They are therefore produced continually and synthesis and secretion increase on
demand
...
Because steroid hormones are lipid-soluble, they must circulate bound to plasma proteins
...
As steroid hormones are protein-bound, they are not freely filtered by the kidney, which contributes to
their long half-life relative to most peptide hormones
...
They are primarily metabolized by the liver
...

• Adrenal steroids: Cortisol and aldosterone
...
What do you mean by first and second messenger?
First messenger: The extracellular ligands are called first messengers
...

Second messenger: The intracellular mediators which are produced as a result of binding of the first messengers
with the receptors are called second messengers
...

Q
...

Mechanism of action of hormones: The first step of hormone’s action is to bind to its specific receptors at the
target cells to form hormone-receptor complex
...
By changing membrane permeability
...
By activating intracellular enzymes
...
By activating genes
...
By changing membrane permeability: Neurotransmitters (e
...
, acetylcholine), a few of the circulating
hormones, such as epinephrine and norepinephrine secreted by the adrenal medulla act by this way
...

B
...
Activation of the enzymatic part of the receptor itself
...

2
...
g
...
The second messengers in turn
cause the subsequent effects of the hormone
...

a
...
If the G protein stimulates the adenylyl cyclase-c
AMP system, it is called a Gs protein, denoting a stimulatory G protein
...
This then activates c AMPdependent protein kinase, which phosphorylates specific cell proteins, triggering biochemical
reactions that ultimately lead to the cell’s response to the hormone
...
Thus, depending on the coupling of the hormone receptor to an
inhibitory or a stimulatory G protein, a hormone can either increase or decrease the concentration
of c AMP and phosphorylation of key proteins inside the cell
...


Cell membrane phospholipid second messenger system: Some hormones activate
transmembrane receptors that activate the enzyme phospholipase C attached to the inside
projections of the receptors
...
The IP3 mobilizes
calcium ions from mitochondria and the endoplasmic reticulum, and the calcium ions then have
their own second messenger effects, such as smooth muscle contraction and changes in cell
secretion
...
In addition to these
effects, the lipid portion of DAG is arachidonic acid, which is the precursor for the prostaglandins
and other local hormones that cause multiple effects in tissues throughout the body
...


Calcium-calmodulin second messenger system: Local hormones act by this way
...

↓
Opening of Ca2+ channel
↓
Ca2+ enters into the cell
↓
Ca2+ binds with calmodulin
↓
Conformational changes in the calmodulin
↓
Activation or inhibition of protein kinases
↓
Cell’s response

For example, calmodulin activates myosin kinase, which acts directly on the myosin to cause
smooth muscle contraction
...
By activating genes: Steroid and thyroid hormones act by this way
...
Then translation of mRNA creates new protein, which controls cell function
...
Discuss the role of hypothalamus in regulation of pituitary secretion
...

Hypothalamus produces releasing and inhibiting hormones
↓
Through hypothalamic-hypophysial portal vessels, the hormones go to the anterior pituitary
...

Hypothalamic control of posterior pituitary secretion: Secretion from the posterior pituitary is controlled by nerve
signals that originate in the hypothalamus and terminate in the posterior pituitary
...

↓
Via hypothalamic-hypophysial tract, these hormones are transported to the posterior pituitary
...

↓
When nerve impulses are transmitted downward along the nerve fibers from the supraoptic and paraventricular
nuclei to the posterior pituitary, the hormones are secreted from the posterior pituitary by exocytosis and enters
into systemic circulation
...
Give the mechanism of action of insulin
...

↓
Activation of tyrosine kinase activity of the intracellular portion of the β subunit
↓
Phosphorylation of some cytoplasmic enzymes and dephosphorylation of others
↓
Activation of some of these enzymes and inactivation of others
↓
Effects of insulin
...
Which hormone is called the ‘life saving hormone’ and why is it so called?
Aldosterone is called the life-saving hormone
...
Without mineralocorticoids, K + concentration in the extracellular
fluid rises markedly, Na+ and Cl- are rapidly lost from the body, and the total ECF volume and blood volume
become greatly reduced
...
The entire sequence can be prevented by the administration of aldosterone or some other
mineralocorticoids
...

Q
...

Any type of stress such as trauma, infection, intense heat or cold, surgery causes immediate and marked increase
in ACTH secretion, which within minutes greatly increases cortisol secretion
...
Indeed, the damaged tissues that
are depleted of proteins can use the newly available amino acids to form new proteins that are essential to the lives
of the cells
...
This is why, cortisol is called emergency hormone or stress hormone
...
Write down the functions of the following hormones:
1
...
ADH
3
...
Calcitonin
5
...
Glucagon
7
...
Oxytocin
9
...
Aldosterone
11
...
Progesterone
Functions of Growth Hormone:
1
...


9

2
...
Most important one is somatomedin C or insulin-like growth factor 1 which causesa
...

b
...

c
...

d
...

Thus, increased growth hormone secretion before fusion of epiphysis with diaphysis increases length and thickness
of bone and increased GH secretion after fusion of epiphysis with diaphysis increases thickness of bone
...
Metabolic function:
a
...

Increased transport of amino acid into the cell
...

Increased transcription of DNA to form mRNA
...

Increased translation of mRNA to cause protein synthesis
...

Decreased breakdown of protein and amino acid
...
Increases fat utilization for energy: Under the influence of GH, fat is used for energy in
preference to use of carbohydrates and proteins
...

Increased fatty acid mobilization from the adipose tissue
...

Increased conversion of fatty acids into acetyl Co-A, which is used for energy production
...

Ketogenic effect of growth hormone: Increased GH increases plasma Free Fatty Acids
(FFA), which increases acetyl Co-A and acetoacetic acid
...

c
...

Decreased glucose uptake in tissue
...

Increased glucose production by liver
...

Increased insulin secretion, but also produces ‘insulin resistance’ and therefore decreases
insulin’s action
...
Electrolyte metabolism:
i
...

ii
...

iii
...

iv
...

Functions of ADH (antidiuretic hormone):
1
...
Increases water reabsorption from the distal and collecting tubule of the kidney
...
Makes urine hypertonic and decreases urine volume
...
Decreases osmolarity and Na+ concentration of ECF by increasing water reabsorption
...
Pressure effect: When vasopressin (ADH) secretion is increased by any of the stimuli, the higher
concentration of vasopressin causes vasoconstriction and thus, increases blood pressure
...
Other functions:
a
...

b
...

c
...

d
...

Mechanism of action of ADH:
In the absence of ADH, the collecting tubules and ducts become almost impermeable to water, which prevents
significant reabsorption of water and therefore allows extreme loss of water into the urine, also causing extreme
dilution of the urine
...

Without ADH, the luminal membranes of the tubular epithelial cells of the collecting ducts are almost impermeable
to water
...
When ADH acts on the cell, it first combines with membrane receptors
that activate adenylyl cyclase and cause formation of cAMP inside the tubular cell cytoplasm
...
All this occurs within 5 to 10 minutes
...
Thus, this process temporarily
provides many new pores that allow free diffusion of water from the tubular fluid through the tubular epithelial
cells and into the renal interstitial fluid
...


10

Physiological functions of Thyroid Hormones (T3 and T4):
1
...

The general effect of thyroid hormone is to activate nuclear transcription of large number of genes
...
The net result is a generalized increase in functional activity throughout the body
...
Thyroid hormones activate nuclear receptors
...
Thyroid hormones increase cellular metabolic activity
...
Thyroid hormones increase the number and activity of mitochondria
...
Thyroid hormones increase transport of ions through cell membranes
...
Effect of thyroid hormones on growth: Thyroid hormone has both general and specific effects on growth
...

In humans, the effect of thyroid hormone on growth is manifest mainly in growing children
...
In children with hyperthyroidism, excessive
skeletal growth often occurs, causing the child to become considerably taller at an earlier age
...

An important effect of thyroid hormone is to promote growth and development of the brain during fetal
life and for the first few years of postnatal life
...
Without specific thyroid therapy within days or weeks after birth, the
child without a thyroid gland will remain mentally deficient throughout life
...
Effects of thyroid hormones on specific body functions:
a
...

b
...

c
...

d
...

e
...

f
...

g
...

h
...

i
...

j
...

k
...
Conversely, lack of thyroid hormone causes the muscles to
become sluggish, and they relax slowly after a contraction
...
Effect on sleep:
i
...

ii
...

m
...

n
...
In
man, lack of thyroid hormones causes loss of libido and a great excess of hormone causes
impotence
...

Functions of Calcitonin:
1
...
Calcium being lost from the bones can make them brittle, fragile and prone to fracture
...
Calcitonin helps maintain normal level of blood calcium, mainly by preventing the calcium level from
rising above normal after a meal
...

3
...

4
...
Osteoclasts dissolve bone tissue,
which is replaced by new tissue formed by cells called osteoblasts
...
Under the microscope, the binding of
calcitonin to its receptor appears to cause the osteoclasts to lose their ‘ruffled border’, which refers to the
compactly folded cell membrane that aids bone removal by increasing the cell’s surface area for resorption
...

6
...


Calcitonin always regulates the level of calcium and other mineral levels in the kidneys
...

In some mammals, calcitonin seems to play a role in hunger and satiety
...


Functions of Insulin:
1
...
Increases transport and uptake of glucose by the cells
...
Promotes peripheral utilization of glucose: Insulin promotes the peripheral utilization of
glucose
...
The rate of
utilization depends upon the intake of glucose
...
Promotes storage of glucose: Insulin promotes the rapid conversion of glucose into glycogen
(glycogenesis), which is stored in the muscle and liver
...
Insulin activates the enzymes which are necessary for glycogenesis
...

d
...
e
...

e
...
e
...

2
...
Insulin stimulates transport of many of the amino acids into the cells
...
Thus,
insulin shares with growth hormone the capacity of increasing uptake of amino acids into cells
...

b
...
In some
unexplained way, insulin turns on the ribosomal machinery
...

c
...

d
...
Presumably this results from the ability of insulin to diminish
the normal degradation of proteins by cellular lysosomes
...
In the liver, insulin depresses the rate of gluconeogenesis by decreasing activity of enzymes that
promote gluconeogenesis
...

In summary, insulin promotes formation of protein and prevents degradation of proteins
...
Fat metabolism:
a
...
After the liver glycogen
concentration reaches 5 to 6 percent, further glycogen synthesis is inhibited
...
The glucose is
first split to pyruvate in the glycolytic pathway, and the pyruvate subsequently is
converted to acetyl coenzyme A (acetyl CoA), the substrate from which fatty acids are
synthesized
...
These ions then have a direct effect to activate
acetyl CoA carboxylase, the enzyme require to carboxylate acetyl CoA to form malonyl
CoA, the first stage of fatty acid synthesis
...

• Insulin inhibits the action of hormone-sensitive lipase
...
Therefore, release of fatty acids
from the adipose tissue into the circulating blood is inhibited
...
Some of this glucose is then used to
synthesize minute amounts of fatty acids, but more important, it also forms large

12

4
...
This substance supplies the glycerol that combines
with fatty acids to form triglycerides, which are the storage form of fat in adipose cells
...

On growth: Along with growth hormone, insulin promotes growth of body by its anabolic action on
proteins
...
It also
has the protein-sparing effect, i
...
, it causes conservation of proteins by increasing the glucose utilization
by the tissues
...
Effects on glucose metabolism: The major effects of glucagon in glucose metabolism are• Breakdown of liver glycogen via glycogenolysis and
• Increased gluconeogenesis in the liver
...

Mechanism of glycogenolysis by glucagon:
The most dramatic effect of glucagon is its ability to cause glycogenolysis in the liver, which in turn increases the
blood glucose concentration within minutes
...
Glucagon activates adenylyl cyclase in the hepatic cell membrane,
2
...
Which activates protein kinase regulator protein,
4
...
Which activates phosphorylase b kinase,
6
...
Which promotes the degradation of glycogen into glucose-1-phosphate,
8
...

2
...
Glucagon activates adipose cell lipase, making increased quantities of fatty acids available to the
energy systems of the body
...
Glucagon also inhibits the storage of triglycerides in the liver, which prevents the liver from
removing fatty acids available for other tissues of the body
...
Glucagon in high concentration —
i
...

ii
...

iii
...

iv
...

Functions of Testosterone:
In male fetus:
1
...

2
...

3
...

In adult male:
1
...

2
...

3
...

4
...

5
...

6
...

7
...

8
...

9
...

10
...

In female:
1
...

• Enlargement of clitoris
...

2
...


13

Functions of Oxytocin:
1
...

Therefore, many obstetricians believe that this hormone is at least partially responsible for causing birth of
the baby
...
Oxytocin aids in milk ejection by the breasts: Oxytocin also plays an especially important role in
lactation
...

Functions of Cortisol:
1
...

• Increases glycogenesis
...

• Increases blood glucose concentration
...
On protein metabolism:
a
...

• Decreases protein synthesis
...

• Increases amino acid mobilization from extrahepatic tissue into blood
...
In liver:
• Increases amino acid uptake
...

c
...

• Increases plasma amino acid
...
On fat metabolism:
• Increases fatty acid mobilization from adipose tissue
...

• Increases ketone body formation
...

4
...

• Causes resolution of inflammation
...
Anti-allergic effect: Inhibits release of mediators, e
...
, histamine causing allergic reaction
...
Effect on blood cells:
• Increases eosinophil and basophil count
...

7
...

Functions of Aldosterone:
1
...
Therefore, aldosterone causes sodium to be conserved in the extracellular fluid
while increasing potassium excretion in the urine
...
At the same time, potassium loss into the urine transiently increases
severafold
...

Conversely, total lack of aldosterone secretion can cause transient loss of 10 to 20 grams of sodium in the urine
a day, an amount equal to one tenth to one fifth of all the sodium in the body
...

2
...
Both
these glands form a primary secretion that contains large quantities of sodium chloride, but much of the sodium
chloride, upon passing through the excretory ducts, is reabsorbed, whereas potassium and bicarbonate ions are
secreted
...
The effect on the sweat glands is important to conserve body salt in hot environments, and the effect
on the salivary gland is necessary to conserve salt when excessive quantities of saliva are lost
...
Conversely, in the absence of aldosterone, sodium absorption can be poor, leading
to failure to absorb chloride and other anions and water as well
...

Functions of Estrogen:
1
...
Proliferation of stromal cells and epithelial cells (re-epithelialization)
...
Increases thickness of endometrium
...
Causes growth of endometrial cells
...
Increases growth of new blood vessels
...
On Breast:
a
...

b
...

c
...

3
...
Increases size of ovary
...
Increases growth of ovarian follicles
...
On vulva and vagina:
a
...

b
...

5
...
Increases ciliated epithelial cells
...
Increase activity of cilia
...
Increases growth of glandular tissue
...
Endocrine function:
a
...

b
...

c
...
g
...

d
...

7
...
Increases libido
...
Slows the progression of Alzheimer’s disease
...
On skeleton:
a
...

b
...

9
...

10
...
Decreases plasma cholesterol
...
Causes vasodilatation
...
Electrolyte balance: Increases Na+ and H2O retention slightly
...
Increases basal metabolic rate slightly
...
Increases fat deposition in breasts, buttocks and thighs
...
Makes the skin soft, smooth and thicker
...
On uterus:
1
...

• Blood vessels become tortuous
...

• Increases swelling of the endometrium (5-6 mm)
...

2
...

3
...

4
...

B
...
Stimulates the development of lobules and alveoli
...
Support the secretory function of the breast during lactation
...
Causes the breast to swell
...

D
...

F
...

H
...

On ovary: Inhibits ovulation
...

Thermogenic action: Increases basal temperature during ovulation
...

Respiratory effect:
1
...

2
...


Q
...

2
...

4
...

6
...
It
secreted not in a constant and continuous fashion but in a pulsatile pattern; increasing and decreasing
...

1
...
The
hypothalamus secretes growth hormone releasing hormone (GHRH) and growth hormone inhibiting
hormone (GHIH) which are transported to anterior pituitary gland and control growth hormone (GH)
secretion from it
...

2
...
As a
result, GH secretion increases as well as the amount of IGF 1
...
So GH secretion
decreases
...
By plasma osmolarity: The most important variable in regulating antidiuretic hormone secretion is plasma
osmolarity, or the concentration of solutes in blood
...

When plasma osmolarity is below a certain threshold, the osmoreceptors are not activated and secretion
of ADH is suppressed
...

2
...
Changes in blood pressure
and volume are not nearly as sensitive a stimulator as increased osmolarity, but are nonetheless potent in
severe conditions
...

3
...

Regulation of thyroid hormone secretion: The day to day maintenance of thyroid secretion depends on the
feedback interplay of thyroid hormones with TSH and thyrotropin releasing hormone (TRH)
...

1
...

2
...

3
...
TSH secretion is also inhibited by stress
...
The adjustments that appear to be maintained via TRH include the increased secretion of thyroid
hormones produced by cold and the decrease produced by heat
...

5
...


16

Regulation of Insulin secretion:
1
...

2
...

3
...

4
...

5
...

Parasympathetic stimulation associated with food intake acts with the elevated blood glucose levels to
increase insulin secretion
...
Because most tissues, except nervous tissue, require insulin to take up glucose,
sympathetic stimulation maintains blood glucose levels in a normal range during periods of physical
activity or excitement
...

6
...
Somatostatins inhibit insulin and glucagon
secretion, but the factors that regulate somatostatin secretion are not clear
...

Regulation of Glucagon secretion:
Low blood glucose levels stimulate glucagon secretion and high blood glucose levels inhibit it
...
After a high-protein meal, amino acids
increase both insulin and glucagon secretion
...
Both
protein synthesis and the use of amino acids to maintain blood glucose levels result from the low, but simultaneous
secretion of insulin and glucagon induced by meals high in protein
...
Increased potassium ion concentration in the extracellular fluid greatly increases aldosterone secretion
...
Increased angiotensin II concentration in the extracellular fluid also greatly increases aldosterone
secretion
...
Increased sodium ion concentration in the extracellular fluid very slightly decreases aldosterone secretion
...
ACTH from the anterior pituitary gland is necessary for aldosterone secretion but has little effect in
controlling the rate of secretion in most physiological conditions
...
A small percentage increase potassium concentration can cause a
severafold increase in aldosterone secretion
...
In turn, the aldosterone acts on the kidneys (1) to help them excrete the excess potassium ions
and (2) to increase the blood volume and arterial pressure, thus returning the renin-angiotensin system
toward its normal level of activity
...


17

Nervous System
Q
...
Classify neuron
...

Classification: Neuron can be classified according to various traits such asA
...
Unipolar neuron
2
...
Pseudo-unipolar neuron and
4
...
According to the size of axons:
1
...
Golgi type II
C
...
Upper motor neuron and
2
...
According to function:
1
...
Sensory or afferent neurons
E
...
Stellate-cerebral cortex
2
...
Fusiform
4
...
According to the number of processes:
1
...
g
...

2
...
E
...
,
bipolar cells of retina, neurons of cochlear and vestibular ganglia
...
Pseudo-unipolar neurons: Some sensory neurons are in a subclass of bipolar cells called pseudounipolar cells
...
E
...
, neurons in the dorsal
root ganglia
...
Multipolar neurons: Multipolar cells have one axon and many dendrites
...

B
...
Golgi type I: They have a long axon
...
g
...

2
...
The short dendrites that arise from these neurons give
them a star-shaped appearance
...

C
...
Upper motor neuron: The neurons in the cerebral cortex and brainstem, the axons of which form
the descending motor tract, are called upper motor neuron
...
g
...

2
...
E
...
, anterior horn cell, neurons of
oculomotor nerve etc
...
According to function:
1
...
g
...

2
...
g
...

E
...
Stellate-cerebral cortex
2
...
Fusiform and
4
...
Name the motor neurons
...

2
...


4
...

Upper motor neuron: These are neurons in the descending tract, e
...
,
a
...
Purkinje cells
Lower motor neuron:
a
...
Γ motor neuron
c
...


Q
...

A typical neuron cell is composed of the following parts:
1
...

3
...
Cell body: Each neuron cell body contains a single nucleus
...
Extensive rough endoplasmic reticulum (rough
ER), a Golgi apparatus and mitochondria surround the nucleus
...

2
...
Most dendrites are extensions of the neuron cell body, but
dendritic structures also project from the peripheral ends of some sensory axons
...

3
...
The area
where the axon leaves the neuron cell body is called the axon hillock
...
Axons of sensory neurons conduct
action potentials towards the CNS and axons of motor neurons conduct action potentials away from the
CNS
...
An
axon may remain unbranched or may branch to form collateral axons
...


19

Fig: A typical neuron
Q
...

Different parts of brain:

20

Q
...

Classification of nervous system:

Q
...

Differences between axon and dendrites:
Axon
1
...

2
...

3
...

4
...

5
...

6
...

7
...


Dendrites
1
...

2
...

3
...

4
...

5
...

6
...

7
...


Q
...

2
...

4
...

2
...

4
...

Form the blood-brain barrier and thereby regulate the entry of substances from blood into brain tissues
Maintain the chemical environment of ECF (extracellular fluid) around CNS neurons
...


21

5
...


Functions of Oligodendrocytes:
1
...


Provide myelination around the nerve fibers in CNS where Schwan cells are absent
...


Functions of Microglia:
1
...


Engulf and destroy the microorganisms and cellular debris by means of phagocytosis
...


Functions of Ependyma:
1
...

3
...

Tanycytes transport substances from CSF to hypophyseal-protal system
...


Q
...
In the central
nervous system (CNS), glial cells include1
...

3
...


Oligodendrocytes
Astrocytes
Ependymal cells and
Microglia

In the peripheral nervous system (PNS), glial cells include1
...


Schwann cells and
Satellite cells

Neuroscience currently identifies four main functions of glial cells:
1
...

3
...


To surround neurons and hold them in place
...

To insulate one neuron from another
...


Neuroglial cells of CNS:
1
...
The myelin sheath, composed of lipids and
proteins, functions as an electrical insulator of axons and promotes a more efficient conduction of nerve
impulses
...
Astrocytes: Astrocytes are star-shaped neuroglail cells present in all parts of the brain
...
Few fibrous astrocytes
are seen in gray matter also
...
This
type of astrocytes play an important role in the formation of blood-brain barrier by sending
processes to the blood vesicles of brain, particularly the capillaries, forming tight junction with
capillary membrane
...

• Protoplasmic astrocytes: Protoplasmic astrocytes are present mainly in gray matter
...

Functions:
1
...

2
...

4
...


Maintain the chemical environment of ECF (extracellular fluid) around CNS neurons
...

Regulate recycling of neurotransmitter during synaptic transmission
...
Ependymal cells: Ependymal cells are specialized cells that line the cerebral ventricles and central canal
of the spinal cord
...
These ciliated cells surround
the capillaries of the choroid plexus and form cerebrospinal fluid
...
Microglia: Microglia are the smallest neuroglial cells
...
These phagocytic cells migrate to the site of infection or
injury and are often called the macrophages of CNS
...
Engulf and destroy the microorganisms and cellular debris by means of phagocytosis
...
Migrate to the injured or infected area of CNS and act as miniature macrophages
...
Schwann cells: Schwann cells are neuroglia that wrap around some neuronal axons to form the myelin
sheath in PNS structures
...
Provide myelination (insulation) around the nerve fibers in PNS
...
Play important role in nerve regeneration
...
Remove cellular debris during regeneration by their phagocytic activity
...
Satellite cells: These glial cells cover and protect neurons of the peripheral nervous system
...
Provide physical support to the PNS neurons
...
Help in regulation of chemical environment of extracellular fluid (ECF) around the PNS neurons
...
Define and classify nerve fibers
...

Classification:
A
...
Myelinated fiber
2
...
Functionally
1
...
Sensory or afferent
C
...
Somatic
2
...
Chemically
1
...
Cholinergic (neurotransmitter is acetylcholine)
E
...
Both sensory and motor fibers are divided intoa
...

b
...

c
...

2
...
I (Ia and Ib)
b
...
III
d
...
Name the properties of nerve fibers
...

2
...

4
...

6
...

8
...
Excitability: A hallmark of nerve cells is their excitable membrane
...
Two types of responses are produced:
•
•

Local, non-propagated potentials called, depending on their location, sympathetic, generator or electronic
potentials and
Propagated potentials called action potentials or nerve impulse
...
Conductivity: The propagation of action potential (impulse) from the site of its generation is called conduction
...

3
...

Types: It is of two typesa
...


Absolute refractory period (ARP): The ARP is the time from the beginning of one action potential when
it is impossible to stimulate another action potential
...
ARP corresponds to depolarization plus one-third of repolarization
...
A stronger stimulus is needed because a
small number of Na+ channels have now recovered from inactivation and the membrane is less excitable
due to high K+ conductance
...


Importance of refractory period: Refractory period ensures enough time for recovery of cell by getting nutrition
and O2 supply
...

4
...
If the stimulus is at or above threshold intensity, the action potential develops in the
nerve fiber with constant amplitude and form regardless of the strength of the stimulus
...
The action potential of nerve
fiber is therefore ‘all or none’ in character and is said to obey the all or none law
...
Adaptation or accommodation: A slowly rising current fails to produce action potential (impulse) in a nerve
fiber because the nerve adapts to the applied stimulus, a process called accommodation
...
Antidromic conduction: An axon can conduct impulse in either direction
...

The first impulse which travels along the axon to its termination can cross the next synapse
...
Conduction in the opposite direction is called antidromic
...

7
...
But if the nerve is isolated and is connected to another muscle, usual response is obtained
which indicates indefatigability
...
Summation: Due to summation effect of nerve cell, two or more subthreshold stimuli applied at the same time
may produce impulse
...
What is neurotransmitter? List the neurotransmitters and give criteria of neurotransmitter
...

List of neurotransmitters:
Excitatory
Epinephrine
Glutamate

Inhibitory
GABA
Dopamine
Serotonin
Glycine
Alanine
Taurine

Both excitatory and inhibitory
Acetylcholine
Nor epinephrine
Histamine
Prostaglandin
5 – hydroxytryptamine

Criteria of neurotransmitters:
1
...

3
...

5
...

7
...

They are synthesized from precursor substances
...

They remain stored in synaptic vesicles
...

They have post-synaptic receptor and the chemical is able to bind to them
...


Q
...
It possesses excitatory function
...

Biosynthesis: Acetylcholine is synthesized in the axoplasm of the terminal ending of the cholinergic nerve fiber
...

Release:
Arrival of impulse in the nerve ending
↓
Opening of Ca2+ channels
↓
Ca2+ enters into the nerve ending
↓
Vesicles containing acetylcholine fuse with presynaptic membrane
↓
Release of acetylcholine by exocytosis
...
As a result, depolarization
of the postsynaptic membrane takes place
...

The removal occurs by hydrolysis of acetylcholine to choline and acetate, a reaction catalyzed by the enzyme
acetylcholinesterase
...
Define synapse
...
e
...

Functions of synapse:
1
...

3
...

5
...

Integration of nerve impulse
...

Acts as a connection spot in a neural chain
...


Q
...
They are1
...

3
...


They are discussed below:
1
...


3
...
It is the terminal axonal expansion of the presynaptic neuron
...
Neurotransmitter vesicles
b
...
Lysosomes
Synaptic cleft: It is a space, 200-300 angstrom wide, between presynaptic and postsynaptic membrane
...
Neurotransmitter degrading enzyme, e
...
, COMT, acetylcholine esterase
...
Polysaccharides
...
e
...
It contains receptor proteins that bind the
neurotransmitter and a new impulse is generated
...
Describe the properties of synapse
...


2
...
Since axons conduct in either direction with equal facility, the
one-way gate at the synapses is necessary for orderly neural function
...
Therefore, an impulse arriving at the post-synaptic membrane cannot release any
neurotransmitter and so cannot reach to the presynaptic neuron
...
It is about 0
...

Cause of synaptic delay: Synaptic delay is produced in presence of-

26

a
...

c
...

e
...

Diffusion of the transmitter by the presynaptic terminal
...

Action of the receptor to increase membrane permeability
...


IPSP: Inhibitory post synaptic potential
Importance of synaptic delay:
a
...


By the knowledge of synaptic delay, it can be determined whether a reflex pathway is monosynaptic
or polysynaptic
...
If there are many synapses in the chain of neuron, then the conduction along the chain becomes
slower
...
This is called fatigue of synaptic transmission
...
Exhaustion of store of neurotransmitters in the presynaptic terminal (mainly)
...
Progressive inactivation of postsynaptic receptors
...
Slow development of abnormal concentration of ions inside the postsynaptic neuron
...
For example,
fatigue is probably the most important means by which excess excitability of the brain during an epileptic seizure
is finally subdued so that the seizure ceases
...

2
...


4
...


Synaptic response: At the synapse, impulses are received, integrated and discharged
...

Facilitation: Each time certain types of sensory signals pass through sequences of synapses, these synapses
become more capable of transmitting the same type of signal the next time
...

Occlusion
Summation

Q
...
MT NEC
Classification of synapses:
A
...
Axosomatic: It is the synapse between axon of one neuron and cell body of another, e
...
, synapse
between basket cell and Purkenje cell in the cerebellum
...
Axodendritic: It is the synapse between axon of one neuron and dendrite of another; e
...
,
climbing fibers and dendrites of Purkenje cells
...
Axoaxonal: It is the synapse between axons of two neurons
...
On the basis of synaptic transmission:
1
...

In these synapses, impulse is transmitted through the synapse by a chemical substance called
neurotransmitter
...
Electrical synapses: They are present in some area of the CNS, e
...
, between some of the neurons
in the lateral vestibular nucleus
...
Define and classify sensory receptors
...

Classification:
A
...


Mechanoreceptors: The receptors which detect mechanical compression or stretching of the
receptor or of tissue adjacent to the receptor are called mechanoreceptors
...

b
...
Examples include end organ of Raffini
...
Nociceptors (pain receptors): They detect damage of tissue, whether physical damage or
chemical damage
...

d
...
g
...

e
...
Examples are• Receptors for taste and smell
• Visceral receptors which are sensitive to changes in the plasma level of O2, pH, osmolarity,
blood CO2, blood glucose, amino acids, fatty acids e
...
, carotid body, aortic body
...
According to distribution:
a
...
They are of two types1
...
g
...

2
...
g
...

b
...

1
...
g
...
Visceroceptors: e
...
,
• Chemoreceptor
• Baroreceptor
• Osmoreceptor
C
...
Encapsulated receptors: e
...
,
• Meissner’s corpuscles
• Pacinian corpuscles
• Ruffini’s corpuscles
2
...
g
...
Define reflex
...

Reflex: Involuntary motor response due to any sensory stimulus is called reflex action
...
Clinical classification:
1
...
Examples:
• Planter reflex
• Abdominal reflex
• Corneal reflex
2
...
Examples:

28

B
...


D
...


• Knee jerk
• Ankle jerk
• Biceps jerk
3
...
Examples:
• Pupillary reflex
• Micturition reflex
• Baroreceptor reflex
• Vomiting reflex
4
...
Examples:
• Babinski’s sign
According to the number of synapses in the reflex arch:
1
...
The stretch reflexes are monosynaptic reflexes
...
Polysynaptic reflexes: The reflexes having more than one synapses between the afferent and efferent
neurons are called polysynaptic reflexes
...

Physiological classification:
1
...
g
...

2
...
g
...

Inborn or acquired:
1
...
Conditional reflex (acquired): e
...
, salivation in sight or smell of food
...
Segmental
2
...
Suprasegmental

Q
...

2
...

4
...

6
...

2
...

4
...

6
...


Determining the intelligence
Determining personality
Motor function
Planning and organization
Touch sensation
Processing sensory information
Language processing

Functions of thalamus:
1
...
Impulses of almost all the sensations
reach the thalamic nuclei, particularly in the ventral posterolateral nucleus
...

2
...
All the peripheral sensory impulses reaching thalamus are integrated and modified before
being sent to specific areas of cerebral cortex
...


29

3
...
e
...
Usually the sensations have two qualitiesa
...

b
...
Determining the affective nature of sensations is the
function of thalamus
...
Center for sexual sensations: Thalamus forms the center for perception of sexual sensations
...
Role in arousal and alertness reactions: Because of its connections with nuclei of reticular formation,
thalamus plays an important role in arousal and alertness reactions
...
Center for reflex activity: Since the sensory fibers relay here, thalamus forms the center for many reflex
activities
...
Center for integration of motor activity: Through the connections with cerebellum and basal ganglia,
thalamus serves as a center for integration of motor functions
...


2
...

4
...


6
...


Autonomic control: The hypothalamus controls the autonomic nervous system
...

Endocrine control: It controls anterior pituitary secretion by producing releasing and inhibiting factors
...

Temperature regulation: The hypothalamus is the principle center for regulation of body temperature
...
The posterior part
(posterior nuclei) responds to cold and increases body temperature
...
Medial nucleus (satiety center) inhibits eating and decreases food intake
...

Control of emotion and behavior: Together with limbic system and prefrontal cortex, hypothalamus
controls emotion and behavior
...
g
...

Stimulation of the lateral hypothalamic nuclei may cause the symptoms and signs of rage, whereas lesions
of these areas may lead to passivity
...

Control of circadian rhythm: It controls many circadian rhythms such as body temperature,
adrenocortical activity, eosinophil count and renal secretion
...
The suprachiasmatic nucleus, which receives afferent fibers from the retina, appears
to play an important role in controlling the biologic rhythms
...

2
...


Archicerebellum or Vestibulocerebellum
Spinocerebellum or Paleocerebellum and
Cerebrocerebellum or neocerebellum

They are discussed below:
1
...
Flocculonodular lobe
lingula constitute the archicerebellum
...
It is also concerned with learning-induced changes in the vestibule-ocular
reflex
...


3
...

Function: It controls tone, posture and crude movements of the limbs
...
By maintaining muscle tone, they help in maintenance of posture
...
They are the newest from a physiological point of view, reaching their greatest
development in humans
...
This region
receives proprioceptive input from the body as well as a copy of the ‘motor plan’ from the motor cortex
...


Functions of pons:
1
...

3
...

5
...

7
...


Axons of pontine nuclei join to form the middle cerebellar peduncle or the branchium pontis
...

Pyramidal tracts pass through the pons
...

Nuclei of 8th, 7th, 6th and 5th cranial nerves are located in pons
...

It also contains the vestibular nuclei, which are already mentioned in medulla oblongata
...
Write short note on: CSF
CSF
It is a clear, colourless, modified tissue fluid present in the cerebral ventricles, spinal canal and subarachnoid spaces
...
Some is formed from ependymal cells lining the ventricles and from the brain substance through
perivascular spaces
...

• K+-Cl- cotransport secrete K+ and Cl- into the CSF
...

Circulation:
Lateral ventricle
Through Foramen of Monro

3rd ventricle
Through cerebral aqueduct

4th ventricle
Through Foramen of Luschka and Magendie

Subarachnoid spaces around the brain and spinal cord
...

Composition:

31

• Protein
: 15-45 mg/dl or 100 ml [ 100 ml = 1 dl ]
• Glucose
: 50-85 mg/dl
• Cholesterol
: 0
...
3 milliequivalent/Kg H2O
• Cl—
: 720-750 mg/dl
• Urea
: 12 mg/ 100 ml
• Creatinine
: 1
...

Physical characteristics:
• Appearance: Clear and colourless
• Volume: 130 ml
• Rate of production: 0
...

Function:
1
...

3
...

5
...


It protects the CNS from injury
...

Provides mechanical buoyance and support for the brain
...

Removes metabolic waste products from the CNS
...


Q
...

Limbic system: Limbic system is the part of brain involved in the control of emotion, behavior and drive
...

Components: It consists of1
...

3
...

5
...

7
...

2
...

4
...
g
...

It controls sexual behavior, motivation
...

It provides pathways for the integration and effective homeostatic responses to a wide variety of
environmental stimuli
...
List the cranial and spinal nerves
...
They are given below:
Name
I
...
Optic
III
...
Trochlear
V
...
Abducens
VII
...
Vestibulocochlear
IX
...
Vegas
XI
...
Hypoglossal

Specific function
Smell
Vision
Motor to four of six extrinsic eye muscles and upper eyelid; parasympathetic:
constricts pupil, thickens lens
...

Sensory to face and teeth; motor to muscles of mastication (chewing)
...

Hearing and balance
...

Sensory to pharynx, larynx and viscera; motor to palate, pharynx and larynx;
parasympathetic to viscera of thorax and abdomen
...

Motor to tongue muscles
...
They are given below: (CTLSC=8 12 5 5 1)
Name
Cervical
Thoracic
Lumber
Sacral
Coccygeal

Number
8
12
5
5
1

33

Reproductive System
Q
...
In male, it is testis and in female, it is ovary
...

Q
...

Time: Sex determination occurs during the fertilization of ovum
...

2
...

4
...


Sex is determined genetically by two chromosomes, called the sex chromosomes (X and Y)
...
Half of the normal sperms produced during spermatogenesis contain X chromosome
and half contain Y chromosome
...
Each normal ovum produced during oogenesis contains a single X chromosome
...

When fertilization occurs with an X chromosome containing sperm, an XX pattern and genetic female
result
...
What do you mean by sex differentiation?
Sex differentiation: Sex differentiation means the development of gonads, accessory sex organs and the
psychological aspects of sex
...

Phases: It takes place in 3 phases
...


2
...


Development of gonads: On each side of the embryo, a primitive gonad arises from the genital ridge
...
Until the 6th week of development, these structures are identical
in both sexes
...
Leydig and Sertoli cells appear and testosterone and Mullerian inhibiting substances are
secreted
...
The
embryonic ovary does not secrete hromones
...

Anatomic development of external genitalia
...
Define puberty
...
What are the fectors affecting
puberty? Describe the control of onset of puberty
...

Characteristic changes in female at puberty:
1
...

3
...


Thelarche: The first event is thelacche, the development of breasts
...

Menarche: The first menstrual period
...


Factors influencing the onset of puberty:
1
...

3
...


Hereditary factors
...

Nutritional factors
...


34

Onset of puberty: 11-16 years
...

Control of onset of puberty: Pulsatile secretion of gonadotrophin releasing hormone (GnRH) brings on puberty
...
The nature of the mechanism inhibiting the GnRH pulse generator is unknown
...

At the onset of puberty,
Secretion of GnRH occurs from the hypothalamus
...

↓
Development of secondary sexual characteristics and final maturation of the reproductive system
(puberty)
...
Define spermatogenesis
...

Spermatogenesis: The process of formation and maturation of spermatozoa (sperm) from primordial germ cells is
called spermatogenesis
...

Temperature needed: 320 C
...

Steps:
Primordial germ cell (2n)
↓
Type A spermatogonia (2n)
↓
Type B spermatogonia (2n)
↓ Mitosis
Primary spermatocyte (2n)
↓ Meiosis I
Secondary spermatocyte (n)
↓ Meiosis II
Spermatids (n)
↓ Spermiogenesis
Spermatozoa (n)
Q
...

Changes in capacitation:
1
...

3
...

Sperms lose much of their cholesterol and as a result, the membrane at the head of the sperm (the
acrosome) becomes much weaker
...

The membrane of the sperm becomes much more permeable to the calcium ions
...


35

Q
...

Hormonal regulation of spermatogenesis:
1
...

3
...

5
...


7
...


From puberty, hypothalamus begins to release GnRH which stimulates anterior pituitary to secrete FSH
and LH
...

Testosterone causes the growth and divisions of the testicular germinal cells which is the first step in
forming the sperms
...

FSH and testosterone stimulates the Sertoli cells, and without this stimulation, the conversion of spermatid
to sperm (the process of spermiogenesis) will not occur
...

When the seminiferous tubules fail to produce sperm, secretion of FSH increases markedly
...
Inhibin acts directly
on the anterior pituitary to inhibit FSH secretion
...

GH promotes early division of spermatogonia
...


Sterility/Infertility: Sterility means loss of reproductive capacity
...

Castration: Removal of testis is known as castration
...
When the number of sperm falls below 20 million/MI, the person is likely to be infertile
...
What is LH serge?
LH serge: Sharp rise of pH secretion just before ovulation is called LH serge
...
At 36 – 48 hours before ovulation, the estrogen feedback
effect becomes positive, and this initiates the burst of LH secretion
...

Importance: LH serge is essential for ovulation
...
What are the secondary sex characteristics in male?
Secondary sex characteristics in male:
1
...


Internal genitalia

3
...

Scrotum becomes pigmented and rugose
...

Prostate and bulbourethral glands enlarge and secrete
...

Vocal cord increases in length and thickness
...


Hair growth

5
...


Body conformation

7
...

Beard appears
...

Pubic hair grows with male pattern (triangle with apex up)
...

General body hair increases
...

Active attitude
...

Shoulders broaden
...

Sebaceous gland secretion thickens and increases (predisposing to
acne)
...
What are the secondary sex characteristics of female?
Secondary sex characteristics of female:
1
...


Internal genitalia

3
...

5
...


Hair growth

7
...

9
...
Mental

•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•

Secondary sex characteristics
Deposition of fat in the mons pubis
...

Enlargement of labia minora
...

Proliferation endometrial stroma
...

Follicular growth in ovary
...

Onset of menstruation
...

Voice remains high-pitched
...

Less body hair and more scalp hair
...

Thighs converge and arms diverge
...

Occurs in the breasts, buttocks and thighs
...

Increased secretion of subcutaneous gland causes formation of acne
...

Interest in opposite sex
...
Write down the histology of the following organs:
1
...
Fallopian tube
3
...


2
...
We now know that the term germinal epithelium in humans is not
accurate because this layer does not give rise to ova; the name came about because, at one time, people
believed that it did
...

Tunica albuginea: The tunica albuginea is a whitish capsule of dense irregular connective tissue located
immediately deep to the germinal epithelium
...


4
...


6
...


Ovarian cortex: The ovarian cortex is a region just deep to the tunica albuginea
...

Ovarian medulla: The ovarian medulla is deep to the ovarian cortex
...

Ovarian follicles: Ovarian follicles (folliculus = little bag) are in the cortex and consists of oocytes in
various stages of development, plus the cells surrounding them
...
The surrounding cells nourish the developing oocyte and begin to secrete estrogens
as the follicle grows larger
...

Corpus luteum: A corpus luteum (yellow body) contains the remnants of a mature follicle after ovulation
...


Histology of the fallopian tube: Histologically, the uterine tubes are composed of three layers:
1
...

3
...


2
...


Mucosa
Muscularis and
Serosa
Mucosa: The mucosa consists of epithelium and lamina propia (areolar connective tissue)
...
To help move a
fertilized ovum (or secondary oocyte) within the uterine tube toward the uterus, and non-ciliated cells
called peg cells, which have microvilli and secrete a fluid that provides nutrition for the ovum
...
Peristaltic contractions of the
muscularis and the ciliary action of the mucosa help move the oocyte or fertilized ovum toward the uterus
...


Histology of the uterus:
Uterus is divided into three portions:
1
...

3
...

2
...


Serous or outer layer
Myometrium or middle muscular layer
Endometrium or inner mucous layer

1
...
Anteriorly,
it covers the uterus completely, but posteriorly it covers only up to the isthmus
...

Smooth muscle fibers of myometrium are arranged in three layers:
a
...

b
...

c
...

Endometrium or inner mucous layer: Endometrium is smooth and soft with pale red color
...
Surface of the endometrium has minute orifices, thorough which

2
...


38

tubular follicles of endometrium are open
...
Uterine glands are lined by ciliated columnar epithelial cells
...
What is ovulation? Describe the process of ovulation
...
Prior to ovulation, large amount of LH secretion occurs which is called LH serge
...

2
...


A high concentrations of estrogens stimulate more frequent release of GnRH from the hypothalamus
...

GnRH promotes the release of FSH and additional LH by the anterior pituitary
...
The ovulated oocyte and its corona radiata cells are usually swept into the uterine
tube
...
Give the histological characteristics of ureter
...
Mention the
normal storage capacity of bladder
...

1
...


3
...
The secreted
mucous of this layer keeps the inner walls protected with a chronic film
...

Muscular layer: The muscularis layer is the middle layer of the ureters
...
Muscular layer is responsible for
peristalsis in ureter which pushes the urine from kidney to urinary bladder
...
It is called adventitia and is composed of dense irregular connective
tissue
...


Functions of urinary bladder:
4
...


6
...
The ureter, which are 8 to10-inch-long tubes, are lined with muscles that contract and
relax to help move the urine from the kidney to the bladder
...
This tube is
controlled by the internal ureter sphincter, a circular muscle located between the neck of the bladder and
the urethra
...

The bladder wall is able to stretch, making it a perfect storage area
...
As it gets full, stretch receptors in the bladder wall signal the brain
...
When the bladder is full, the nerves send a signal through the nerves, up the
spinal cord and to the brain
...

Voiding: As the detrusor muscle of the bladder contracts, the pressure inside the bladder becomes higher
than the pressure in the urethra, allowing urine to flow out the relaxed internal urethral sphincter
...
Although
the brain automatically regulates the voiding of urine, people have the ability to delay voiding, thus giving
them time to reach a restroom
...

Q
...
Name the hormones secreted from it
...

Structure of thyroid gland:
The thyroid gland is composed of large numbers of closed follicles (100-300 micrometers in diameter) that are filled
with a secretory substance called colloid and lined with cuboidal epithelial cells that secrete into the interior of the
follicles
...
Once the secretion has entered the follicles, it must be absorbed back thorough the follicular epithelium
into the blood before it can function in the body
...

The thyroid gland also contains C cells, that secrete calcitonin, a hormone that contributes to the regulation of
plasma calcium ion concentration
...

1
...


Calcitonin
...

1
...

• TT3: 1
...
6 nmol/L, average: 2
...

• In hyperthyroidism: Increased
...

2
...
02% of the total plasma T4 is free)
...
3 ng/ dl (only 0
...

• In hypothyroidism: Decreased
...
Measurement of serum TSH by RIA:
• Serum TSH: 0
...
5 milliunits/Liter
...

• In hypothyroidism: Increased
...
Measurement of radioactive iodine (either 131I or 123I) uptake by thyroid gland:
• 131I: Most authentic, but result appears after 8 days because half-life of 131I is 8
...

• 123I: It is most commonly used, because its half-life is only 0
...

• 132I: Half-life of 132I is only 2
...
It is used in emergency cases
...
75 µg/day
...

• In hypothyroidism: 20% below normal
...
Determination of BMR:
• Male: 48-52 kcal/m2/hour (average: 40 kcal/m2/hour)
...

• In hyperthyroidism: 20-30% increase of BMR
...

6
...

• Deceased cholesterol level during increased thyroid function
...
TSH stimulation test or TRH stimulation test
...
Measurement of free thyroxine index (FT4I) and free triiodothyronine index (FT3I)
...
Thyroid scan by MRI, CT scan or ultrasonogram
...
Others:
• Thyroid suppression test
...

• Estimation of butanol extractable iodine (BEI) test
...

Q
...
Enumerate the function of fallopian tube
...


2
...


Mucosa: It consists of epithelium and lamina propria (areolar connective tissue)
...

Muscularis: It is the middle layer of the fallopian tube
...
Peristaltic contractions of
the muscularis and ciliary action of the mucosa help move the oocyte or fertilized ovum toward the uterus
...
The serous membrane is
called perimetrium
...
First, the egg is created within the ovary, where it stays until
ovulation occurs
...
At this point in
the journey, the egg is vulnerable because it is no longer contained within the safe ovary
...

The fallopian tube, also known as the oviduct or uterine tube, is responsible for carrying the egg to the uterus
...
The egg is then brought into the fallopian tube where it will travel to the uterus
...

Sperm cells that enter the reproductive system through the vagina travel to the fallopian tube where they fertilize
the egg
...

Medical issues with the fallopian tube
The fallopian tube is a crucial structure involved in successful reproduction and like with all structures in the human
body, sometimes problems occur that hinder the structure’s ability to function properly
...
Three of the most common medical problems that cause obstructions of the fallopian tubes are:
•
•
•

Ectopic pregnancies
Pelvic inflammatory disease
Endometriosis

Ectopic pregnancy: Ectopic pregnancy is the term used to describe a pregnancy that does not occur within the
uterus
...
An ectopic pregnancy can be life-threatening to the mother and, although the egg can
implant, the fetus cannot survive in that location
...
Although surgery is necessary, having the surgery can cause future problems
...

Pelvic inflammatory disease: Pelvic inflammatory disease, also known as PID, is an infection of the female
reproductive organs, including the uterus, fallopian tubes and ovaries
...
The bacteria
enter the vagina during the intercourse and can travel to the fallopian tubes where they infect the tissues
...


Q
...

2
...

4
...

6
...

8
...

10
...


Ovulation
Pancreatic islets
Micturition reflex
Corpus luteum
Nephron
Neuron
Growth hormone
Suprarenal gland
Hypothalamus
Reflex
Urinary bladder

Ovulation: Ovulation is the release of eggs from the ovaries
...
After ovulation, during the luteal phase, the egg will be

42

available to be fertilized by sperm
...

Process: The high levels of estrogens during the last part of the preovulatory phase exert a positive feedback effect
on the cells that secrete LH and gonadotropin-releasing hormone (GnRH) and cause the ovulation as follows:
1
...

3
...
It
also directly stimulates gonadotropins in the anterior pituitary to secrete LH
...

LH causes rupture of the mature (graafian) follicle and expulsion of a secondary oocyte about 9 hours
after the peak of the LH serge
...


From time to time, an oocyte is lost into the pelvic cavity, where it later disintegrates
...


Pancreatic islets: The pancreatic islets or islets of Langerhans ae the regions of the pancreas that contain its
endocrine (hormone producing) cells, discovered in 1896 by German Physiological anatomist Paul Langerhans
...
The pancreatic
islets are arranged in density routes throughout the human pancreas, and are important in the metabolism of
glucose
...
1 mm in diameter
...
The combined mass of the islets is 2
grams
...
The
roundness of islets along the pancreas has also been quantified as an index of sphericity
...

Microanatomy: Hormones produced in the pancreatic islets are secreted directly into the blood flow by various
types of cells
...

2
...

4
...


Function: The pancreatic feedback system of the pancreatic islets has the following structure:
•
•
•

Glucose/insulin: Activates beta cells and inhibits alpha cells
...

Somatostatin: Inhibits alpha cells
...

Pathway of the reflex or Mechanism of action:
The bladder fills progressively until the tension in its wall rises above a threshold level
↓
Stimulation of the sensory stretch receptors in the bladder wall
↓
Sensory signals pass to the sacral segments of the cord through the pelvic nerves
↓
Efferent signals are conducted from the sacral segments of the cord back to the bladder wall through the
parasympathetic nerves
↓

43

Contraction of the detrusor muscles and relaxation of internal sphincter
↓
As the bladder continues to fill, the micturition reflexes become more frequent and cause greater contractions of
the detrusor muscles
↓
Once the micturition reflex becomes powerful enough, it causes another reflex, which passes through the pudendal
nerves to the external sphincter to inhibit it
...
If not, urination will not occur until the bladder fills further and micturition reflex becomes more
powerful
...
They enlarge in diameter two to three times and become filled with lipid inclusions which give them
yellowish appearance
...

Luteinizing function of LH: The change of granulosa and theca interna cells (or luteal cells) is mainly dependent
on LH
...

Types: It is of 2 types:
1
...


Corpus luteum of menstruation or Corpus albicans: If pregnancy does not occur, the corpus luteum
begins to degenerate about 4 days before the next menses (24th day of the cycle) and is eventually
replaced by scar tissue, forming a corpus albicans
...

Corpus luteum of pregnancy: Of pregnancy occurs, corpus luteum persists under the influence of HCG
secreted from the placenta and is called the corpus luteum of pregnancy
...


Function of the corpus luteum: The corpus luteum is the highly secretory organ and secretes both progesterone
and estrogen
...

Structure: A nephron consists of two parts:
3
...
It remains enclosed within the Bowman’s capsule
...

4
...

Classification of nephrons: Two types:
4
...

6
...
They have short loop of Henle
...
They have long loop of Henle
...
Their loops of Henle are of intermediate length
...

6
...

8
...

Tubular reabsorption of wanted substances
...

Excretion of unwanted substances
...

Structure: A typical neuron cell is composed of the following parts:
4
...

6
...
Cell body: Each neuron cell body contains a single nucleus
...
Extensive rough endoplasmic reticulum (rough
ER), a Golgi apparatus and mitochondria surround the nucleus
...

5
...
Most dendrites are extensions of the neuron cell body, but
dendritic structures also project from the peripheral ends of some sensory axons
...

6
...
The area
where the axon leaves the neuron cell body is called the axon hillock
...
Axons of sensory neurons conduct
action potentials towards the CNS and axons of motor neurons conduct action potentials away from the
CNS
...
An
axon may remain unbranched or may branch to form collateral axons
...


Fig: A typical neuron

45

Number: Approximately 10 million
...

2
...

4
...

Process it
...


Growth Hormone: Growth hormone, also called somatotropin or human growth hormone is secreted by the
anterior lobe of the pituitary gland
...

Plasma half-life: 20 minutes
...


5
...

Stimulates bone and cartilage growth: GH stimulates liver and other tissues to form some proteins called
somatomedins
...
Increased chondrogenesis, therefore increases length of cartilage
...
Increased protein and Ca2+ deposition in chondrocyte and osteogenic cell
...
Increased conversion of chrondrocyte at epiphyseal plate into osteogenic cell, therefore increases
length of bone
...
Increased osteoblast formation at periosteum, therefore increases thickness of bone
...


6
...
Increases protein deposition in tissues byv
...

vi
...

vii
...

viii
...

f
...
GH causesiv
...

v
...

vi
...
It leads to ketosis
...
Increases plasma glucose level byiv
...

v
...

vi
...

h
...

Decreases Na+ and K+ excretion through kidney
...

Increases Ca2+ and Mg2+ absorption from GIT
...

Increases plasma phosphorus
...

Decreases blood urea production
...
They are found above the kidneys
...
The adrenal cortex itself
is divided into three zones:
1
...

3
...

Zona fasciculata and
Zona reticularis
...


Mineralocorticoids (such as aldosterone) are produced in the zona glomerulosa and they help in the regulation of
blood pressure and electrolyte balance
...
Their functions include the regulation of metabolism and immune system suppression
...

Diseases associated with suprarenal gland: A number of endocrine diseases involve dysfunctions of the adrenal
gland
...
Congenital adrenal hyperplasia is a genetic disease produced by dysfunction of endocrine
control mechanisms
...

Hypothalamus: The hypothalamus is the portion of the brain that contains a number of small nuclei with a
variety of functions
...

Location: The hypothalamus is located below the thalamus and it is part of the limbic system
...


9
...

11
...


13
...
Stimulation of the
preoptic and anterior nuclei causes parasympathetic response and stimulation of the posterior and lateral
nuclei causes sympathetic response
...

Neurosecretion: Supraoptic and paraventricular nuclei produce ADH and oxytocin
...

The anterior part (anterior nuclei) responds to heat and decreases body temperature
...

Regulation of food and water intake: Lateral nuclei (hunger center) initiates the feeling of hunger and
increases food intake
...
The lateral
region of the hypothalamus except the hunger center increases the desire to drink water and is called thirst
center
...
Hypothalamus brings about the physical expression of emotion, e
...
,
increase in heart rate, blood pressure, dryness of mouth, flushing or pallor of the skin and sweating
...
Stimulation of the ventromedial nucleus may cause passivity, whereas
lesions of this nucleus may lead to rage
...
Control of circadian rhythm: It controls many circadian rhythms such as body temperature,
adrenocortical activity, eosinophil count and renal secretion
...
The suprachiasmatic nucleus, which receives afferent fibers from the retina, appears
to play an important role in controlling the biologic rhythms
...

Site of occurrence: Most reflexes occur in the spinal cord or brainstem rather than in the higher brain centers
...
The reflex arch is the basic functional unit of the
nervous system because it is the smallest, simplest pathway capable of receiving stimulus and yielding a response
...

2
...

4
...


A sensory receptor
A sensory neuron
Interneurons (neurons located between and communicating with two other neurons)
A motor neuron and
An effector organ (muscles or glands)

Example: One example of a reflex occurs when a person’s finger touches a hot stove
...
Clinical classification:
5
...
Examples:
• Planter reflex
• Abdominal reflex
• Corneal reflex
6
...
Examples:
• Knee jerk
• Ankle jerk
• Biceps jerk
7
...
Examples:
• Pupillary reflex
• Micturition reflex
• Baroreceptor reflex
• Vomiting reflex
8
...
Examples:
Babinski’s sign
G
...
Monosynaptic reflex: The reflexes having a single synapse between the afferent and efferent neurons
ae called monosynaptic reflexes
...

4
...
The withdrawal reflex is a typical polysynaptic reflex
...
Physiological classification:
3
...
g
...

4
...
g
...

I
...
Unconditioned reflex (inborn)
4
...
g
...

J
...
Segmental
5
...
Suprasegmental

48

Urinary bladder: The urinary bladder is a hollow muscular organ in humans and some other animals that collects
and stores urine from the kidneys before disposal by urination
...

Histology:
4
...

6
...
Unlike
the mucosa of other hollow organs, the urinary bladder is lined with transitional epithelial tissue that is
able to stretch significantly to accommodate large volumes of urine
...

Submucosa layer: Surrounding the mucosa layer is the submucosa, a layer of connective tissue with blood
vessels and nervous tissue that supports and controls the surrounding tissue layers
...
The muscularis is commonly referred to as the
detrusor muscle and contracts during urination to expel urine from the body
...
During urination, the sphincter relaxes to allow urine to flow into the urethra
...


2
...


Storage: Urine is produced in the kidneys and continually drains into the bladder through the two ureters,
one on each side
...

The bladder has a third tube, the urethra, through which the urine is excreted from the body
...
This sphincter is very important because without it, the bladder would not be able to store
urine; instead urine would just continually pass through the bladder and out the body
...
As urine enters the bladder, the bladder
distends to allow more volume
...

Signaling: The nerves in the bladder are peripheral nerves, meaning they branch from the spinal cord that
then connects to the brain
...
The brain then sends signal back to the bladder that instructs the internal
urethral sphincter to relax and the detrusor muscle to contract
...
All of
these signals must be precisely coordinated for urine to be completely voided from the bladder
...


Q
...

Mechanism of urine formation: To produce urine, nephron and collecting ducts perform three basic processes –
glomerular filtration, tubular reabsorption and tubular secretion
...


2
...


Glomerular filtration: In the first step of urine production, water and most solutes in blood plasma move
across the wall of glomerular capillaries, where they are filtered and move into the glomerular capsule and
then into the renal tubule
...
The water and solutes return
to the blood as it flows through the peritubular capillaries and vasa recta
...
The term absorption, by contrast, means entry of
new substances into the body, as occurs in the gastrointestinal tract
...
Tubular secretion
removes a substance from the blood
...

2
...

4
...

6
...

Colour: Straw in colour due to urochromes and urobilinogen
...

Sediment: Absent
...
010 – 1
...
Range 400 – 900 mOsm/L
...

2
...

4
...

6
...

8
...


Reaction or pH: Normally urine is acidic (pH is 4
...
0)
...

Protein: Normally protein is excreted in the urine in less than 150 mg/day
...

Bilirubin: Absent
...

Urobilinogen: A small amount is present
...

Chyle: Absent
...


Normal Chemical Composition of Urine
Urine is an aqueous solution of greater than 95% water, with a minimum of these remaining constituents, in order
of decreasing concentration:
•

Urea

9
...


•

Chloride

1
...


•

Sodium

1
...


•

Potassium

0
...


•

Creatinine

0
...


•

Other dissolved ions, inorganic and organic compounds (proteins, hormones, metabolites)
...

Q
...

Functions of spinal cord:
1
...
Electrical currents travel up and down the spinal cord, sending signals which
allow different segments of the body to communicate with the brain
...


Walking
...
The
action of taking step after step may seem incredibly simple to us since we have been doing it all of our lives,
but there are actually a lot of factors that have to be coordinated properly to allow this motion to occur
...


3
...
Reflexes are involuntary responses resulting from stimuli involving the brain, spinal cord, and
nerves of the peripheral nervous system
...
Discuss the phases of female reproductive cycle
...
The female reproductive cycle is generally assumed in 28 days
...

2
...

4
...

Menstrual phase: The menstrual phase, also called menstruation or menses, lasts for roughly for the first 5 days
of the cycle
...


Events in the ovaries: Under the influence of FSH, several primordial follicles develop into primary
follicles and then into secondary follicles
...

Therefore, a follicle that begins to develop at the beginning of a particular menstrual cycle may not reach
maturity and ovulate until several cycles later
...


Events in the uterus: Menstrual flow from the uterus consists of 50 – 150 ml of blood, tissue fluid,
mucus and epithelial cells shed from the endometrium
...
As a result, the cells they supply become oxygen-deprived and start to die
...
At this time the endometrium is very thin, about 2 – 5 mm,
because only stratum basalis remains
...


Preovulatory phase: The preovulatory phase is the time between the end of menstruation and ovulation
...
It lasts from days 6 to 13 in a 28-day cycle
...


Events in the ovaries: Some of the secondary follicles in the ovaries begin to secrete estrogens and
inhibin
...
Estrogens and inhibin secreted by the dominant follicle decreases
the secretion of FSH which causes other, less well-developed follicles to stop growing and undergo
atresia
...

Normally the one dominant follicle becomes the mature (graafian) follicle, which continues to enlarge
until it is more than 20 mm in diameter and ready for ovulation
...
During the final maturation process, the mature
follicle continues to its production of estrogens
...


2
...

As the endometrium thickens, the short, straight endometrial glands develop, and the arterioles coil and
lengthen as they penetrate the stratum functionalis
...
With reference to the uterine cycle, preovulatory phase is also termed the
proliferative phase because the endometrium is proliferating
...
Tortora Page – 1072-1073
...
Tortora Page – 1072-1073
...
What are the sources of sex hormones?
Sources of sex hormones:
Male sex hormone:
Testis

Sources
•
•
•
•

Hormones
Testosterone (mainly)
Dihydrotestosterone
Androtestosterone
Inhibin

Adrenal cortex

•

Adrenal androgens-dehydroepiandrosterone

Female sex hormones:
Sources
Ovary, adrenal cortex and placenta
Ovary, adrenal cortex and placenta
Ovary
Ovary

Hormones
Estrogen
Progesterone
Relaxin
Inhibin

Q
...
Enumerate the placental hormones
...

Fetal membranes:
1
...

3
...


Amnion
Allantois
Chorion
Yolk sac

Amnion: Amniotic membrane is two layers:
•
•

Epiblast derived extraembryonic ectodermal layer
Thin non-vascular extraembryonic mesoderm

As the amnion enlarges it encompasses the embryo on the ventral side, merging around the umbilical cord
...
With embryo growth the amnion obliterates the chorionic cavity
Amnionic sac is fluid filled and it is called amnionic fluid
...

Function:
1
...

3
...


The amnion is the membranous tent around the embryo
...

It allows the embryo to move freely, keeping the embryo free from pressure
...


Allantois: During the embryonic development, certain cells of endoderm and mesoderm of the hind gut forms a
small sac, which gradually increases in the space between the amnion and chorion, is called allantois
...
Later on it fuses with chorion to form
the allantoic-chorion
...

2
...


It takes part in the formation of placenta
...
from the embryo
...


Chorion: During the embryonic development, certain cells of the somatic mesoderm and the outer cells of
trophoblast or ectoderm becomes folded to form the anterior head fold and posterior caudal fold
...
The outermost fold consists of ectoderm at its outer side
and mesoderm at its inner side forms the membrane, known as chorion
...

2
...

It develops complex out-growth known as villi, which penetrate into tissue of the uterus wall and greatly
increases the absorptive surface of the chorion
...

2
...

4
...

6
...

8
...

Nutritive: The placenta supplies all the essential elements of food to fetus, for which it is called the
alimentary system of the fetus
...
CO 2 on the
other hand, passes from the fetus to the mother’s body by the same process
...
passes from the fetus into
placenta
...

Supply of hormones: The hormones like progesterone, thyroxin, insulin etc
...
The placenta also
supplies progesterone, estrogen etc
...

Protection: The placenta supplies some maternal antibodies to the fetus
...

Barriers: The placenta acts as a barrier to the maternal hormones and other chemicals in the blood of the
mother, which can create adverse effect on fetal development
...

The Rhesus antibodies pass from the mother to the fetal circulation and destroy RBC of the fetus and cause
congenital anemia, hydrops-fetalis, erythroblastosis fetalis etc
...

Q
...

Composition of semen:
Color: White, opalescent
Specific gravity: 1
...
35 – 7
...

Physical properties:
•
•
•
•

Typical ejaculate is 2
...

Appearance: Milky appearance and sticky
...

Semen coagulates after ejaculation
...


Chemical properties of semen:
•
•
•
•
•
•
•
•
•

Sodium: 300 mg/dl
Calcium: 27
...
5 mg/dl
Chloride: 142 mg/dl
Citrate: 528 mg/dl
Glucose: 102 mg/dl
Fructose: 272 mg/dl
Lactic acid: 62 mg/dl

53

•
•
•

Potassium: 109 mg/dl
Protein: 5
...

It takes another 14 days to travel through epididymis to the ejaculatory duct
...


Q
...
To maintain fertility, sperm count should be as a minimum
20 million/mL
...

Sperm morphology: For normal fertility, 75-100% sperm must show normal morphology
...
Male infertility
is most commonly caused by low sperm count
...
Write down the overall functions of hormones
...
Hormone signals control the
internal environment of the body through homeostasis
...
Name the functionally important areas of the cerebral cortex
...
Lobes:
• Frontal lobes: Contains the primary motor cortex and involved in speaking and muscle movements
and in making plans and judgements
...

• Parietal lobes: They contain the primary somatosensory cortex
...

• Temporal lobes: Include the auditory areas, each of which receives auditory information primarily
from the opposite ear
...
Association areas: Association areas are involved with more complex functions such as learning,
discussion making and complex movements such as writing
...
Broca’s area: It is the motor speech area and is involved in translating thoughts into speech
...

4
...

5
...

Q
...

2
...

4
...

2
...

4
...
It
appears to act on the same receptor as LH
...

Stimulates the secretion of estrogen and progesterone from corpus luteum
...


Human chorionic somatomammotropin:
Functions:
1
...


3
...

5
...

It has growth stimulating activity
...

Decreases insulin sensitivity in mother
...

Promotes release of free fatty acids from the fat stores of the mother, thus providing alternative source of
energy for the mother’s metabolism during pregnancy
...

2
...


Enlargement of mother’s uterus, breast and female external genitalia
...

Relaxes the pelvic ligament of the mother, which makes the passage of the fetus through the birth canal
...

2
...


Causes the growth of decidual cells in the endometrium and these cells play an important role in the
nutrition of the early embryo
...

Stimulates the development of lobules and alveoli of the breast
...
What is amniotic fluid? Write down the physical properties of amniotic fluid
...

Amniotic fluid: It is a clear, slightly yellowish liquid that surrounds the unborn baby (fetus) during pregnancy
...
It is found within the amniotic sac contained in the mother’s womb
...

pH: Around 7
...

Specific gravity: 1
...
008
...

Functions of amniotic fluid:

55

1
...

3
...

5
...

7
...
This movement allows for bone and
muscle development
...

The fluid also helps to keep the fetus nice and warm by keeping heat in it
...

The fluid offers protection from any blows that may come to the uterus area
...

When the fetus swallows the amniotic fluid, it is practicing using and developing the digestive system
...
A big squeeze would cut off the nutritional
supply from mother to the baby
...
The fetus’ growing baby parts are very fragile and could grow
together, such as in the case of webbed fingers or toes
...
Genetic disease, chromosome abnormalities and birth defects:
• If a genetic disorder or chromosomal abnormality is detected, then the baby will most likely have
the associated condition
...

• Not every chromosomal abnormality is detected through the test
...
Also, a genetic testing is usually performed for
common mutation types
...
Fetal lung maturity:
• Low levels of surfactants (soapy substance that lowers pressure on the lungs) are indicative that
the fetus’s lung have not yet matured
...

• The healthcare provider monitors the level of surfactants
...


56



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