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Human Body
Structure and
Function 1
Book lists:
1
...

3
...


Guyton and Hall Textbook of Medical Physiology
Seeley’s Essentials of Anatomy and Physiology
Ganong’s Review of Medical Physiology
Fundamentals of Anatomy and Physiology
By Martini

1

1
...
In addition, anatomy examines the relationship between the structure of a body part and its function
...
Understanding the relationship between structure and function makes it easier to understand and
appreciate anatomy
...
The major goals
when studying human physiology are to understand and predict the body’s responses to stimuli and to understand how
the body maintains conditions within a narrow range of values in a constantly changing environment
...
This system also includes the hard integumentary derivatives like
hairs, furs and nails etc
...


Formation of framework: Bone forms the strong and rigid endoskeleton or framework of the body and support
the body
...
Protection: The skeleton protects certain vital internal organs such as brain, heart, lungs, liver, spinal cord etc
...
Connecting area of muscles and ligament: It provides area for attachment of muscles and ligaments
...
Formation of lever system: Bones forms a system of levers that multiply the forces generated during the
connection of skeletal muscles and transform them into bodily movement
...
Locomotion: The contraction of skeletal muscles create the movement of the bones
...

6
...
In adults, the blood corpuscles are produced in the bone marrow of only the cranium, ribs, sternum,
vertebrae and heads of the humerus and femur
...

WBC are also produced from the bone marrow
...
Defense: The bone marrow also acts as a defensive agent of the body and also takes part in the re-orientation
of the bones
...
Storage: It serves as a reservoir of calcium, phosphate and other ions and supply them to the blood whenever
necessary
...
Poison inhibitor: It stores led, arsenic etc
...

10
...

11
...
The ear ossicles help in hearing;
the sternum and ribs in breathing
...

Types of animal tissue:
1
...

3
...


Epithelial tissue
Connective tissue
Muscular tissue and
Nervous tissue

They are discussed below:

2

Epithelial tissue: The tissue which constitutes the outer lining of the body or any internal organ is called epithelial
tissue
...

2
...


4
...


6
...

Covers body surfaces: Epithelial tissue covers body surfaces and forms glands that are derived
developmentally from body surfaces
...

Distinct cell surfaces: Most epithelial tissues have one free or apical surface where cells are exposed and not
attached to other cells
...
At the
base of the cells is basal surface attached to a basement membrane
...
The basement membrane is a specialized type of extracellular material secreted by
epithelial and connective tissue cells
...
It plays an important role in supporting and guiding cell migration
during tissue repair
...
A few epithelial tissues, such as those in lymphatic capillaries and liver
sinusoids, do not have basement membranes, and some epithelial tissues, such as those in some endocrine
glands, do not have a free surface or a basal surface with a basement membrane
...

Nonvascular: Blood vessels in the underlying connective tissue do not penetrate the basement membrane to
reach the epithelium; thus, all gases and nutrients carried in the blood must reach the epithelium by diffusing
the from blood vessels across the basement membrane
...

Capable of regeneration: Epithelial tissue has the ability to replace damaged cells with new epithelial cells
...
In some types of epithelial
tissues, such as those in the skin and digestive tract, new cells continuously replace cells that die
...

2
...


4
...


Protecting underlying structures: For example, the outer layer of the skin and the epithelium of the oral cavity
protect the underlying structures from abrasion
...
For example, the skin acts
as barrier and reduces water loss from the body
...

Permitting the passage of substances: Though epithelium acts as a barrier for some substance, it also permits
many other substances to move through it
...
Epithelium acts as a filter in the kidney, allowing many
substances to pass from the blood into the urine but retaining other substances, such as blood cells and proteins
in the blood
...

Absorbing substances: The plasma membranes of certain epithelial tissues contain carrier proteins, which
regulate the absorption of materials
...
Based on the number of cell layers in each:
1
...

2
...

3
...
The prefix pseudo
means false, so this type of epithelium appears to be stratified but is not
...
These appear to be two or more layers of

3

cells because some of the cells are tall and extend to the free surface, whereas others are shorter and
do not extend to the free surface
...
Based on idealized shapes:
1
...

2
...

3
...

In most cases, an epithelium is given two names, such as simple squamous, stratified squamous, simple columnar etc
...
Simple
squamous epithelium consists of one layer of flat or scalelike cells that rest on a basement membrane
...
In the lungs, it facilitates the diffusion of gases;
in the kidney it filters blood; in glands it secrets cellular products and in the intestines it absorbs nutrients
...
The multiple layers of cells in stratified epithelium
are well adapted for a protective role
...

Stratified squamous epithelium is found in areas of body where abrasion can occur, such as the skin, mouth,
throat, esophagus, anus and vagina
...
It underlies the skin, surrounds nerves and muscles, joins bones and muscles to each other and often stores fat
in its cells
...

2
...

4
...


Originates from the mesodermal layer
...

Huge intracellular spaces are there and the space is filled with matrix
...

Several types of fibers are there in the matrix
...

2
...

4
...

6
...

8
...

It constitutes the supporting framework of the body
...

It helps in the movement of the body or organs
...

It provides protection against wounding or bacterial invasions
...

It produces antibody
...


The extracellular fluid (14 L): The fluid outside the cells of the body is called extracellular fluid ECF)
...
It is divided into:
i
...

ii
...
It exchanges substances continuously
with the interstitial fluid through the pores of the capillary membranes
...

Transcellular fluid (1-2 L): The fluids within the cavity lined by epithelium which cannot
communicate with other body fluid compartments and don’t participate in the body fluid homeostasis
is called transcellular fluid
...


⸺ Pericardial cavity
⸺ Peritoneal cavity
⸺ Synovial cavity including joint cavity and bursa
⸺ Cavity of the tunica vaginalis surrounding the testis
...
It is of
the total body fluid
...


3

In a 70 Kg adult man, the total body water is about 60% of the body weight, or about 42 L
...
As a person grows older, the percentage of total body weight that is fluid gradually
decreases
...

Because women normally have a greater percentage of body fat compared to men, their total body water averages about
50% of the body weight
...

Therefore, when discussing ‘average’ body fluid compartments, we should realize that variations exist, depending on
age, gender and percentage of body fat
...
The term ‘milieu interior’ was introduced more than 100 years ago by the great 19 th century
French physiologist Claude Bernard
...

2
...


All the tissues and cells of the organism live in the internal environment
...

Bernard describe the milieu interior as if an organism had placed itself in a greenhouse
...
In premature and newborn babies, the total body water ranges from 70 to 75 percent of
body weight
...
Why ECF is called the internal environment?
The ECF contains all the ions and nutrients needed by the cells for maintenance of cellular life
...
This is why ECF is called the internal
environment
...
W
...
Cannon first coined the term homeostasis
...
For example:
1
...

3
...


The lungs provide O2 to the ECF to replenish the O2 used by the cells
...

GIT provides nutrients
...


Significance of body fluids:
1
...


3
...
Water
not only forms the major constituent of internal environment but also plays an important role in homeostasis
...
Water forms an important medium
by which various enzymes, hormones, vitamins, electrolytes and other substances are carried from one part to
another part of the body
...


5

4
...


In texture of tissues: Water inside the cells is necessary for characteristic form and texture of various tissues
...


Hematocrit (packed red blood cell volume): The hematocrit is the fraction of the blood composed of red blood cells,
as determined by centrifuging blood in a ‘hematocrit tube’ until the cells become tightly packed in the bottom of the
tube
...

In men, the measured hematocrit is normally about 0
...
36
...
10, a value that is barely sufficient to sustain life
...
In these persons, the hematocrit
can rise to 0
...

Edema: Edema refers to the presence of excess fluid in the body tissues
...

Q
...

2
...

4
...


Lymph
Synovial fluid
Aqueous humor
Cerebrospinal fluid (CSF)
Pleural, peritoneal and pericardial fluid

Lymph: It is clear and colorless fluid
...

Solids:
•
•
•
•
•

Proteins: Albumin, globulin, fibrinogen, prothrombin, clotting factors, antibodies and enzymes
...

Carbohydrates: Mainly glucose
...

Electrolytes: Na+, Ca2+, K+, Cl⸺, HCO3⸺
...

2
...

4
...

6
...

Redistribution of fluid
...

Maintain structural and functional integrity of tissue
...

Transport lymphocytes
...

Formation: It is formed by secretion (mainly) and filtration of plasma in the choroid plexuses of the lateral, 3rd and 4th
ventricles
...

CSF secretion:
•
•
•

Na+-K+-ATPase drives Na+ secretion
...

Water is rapidly secreted by osmosis through aquaporin water channels in the cell membranes
...
Some fluids also passes to the central canal of the spinal cord
from 4th ventricle
...
2 mg/100 ml
: 147 milliequivalent/Kg H2O
: 2
...
5 mg/100 ml
: 18 mg/ 100 ml
: 0-3 lymphocytes/ cu mm
...
5 ml/min
Pressure: 60-150 mm of water
...

2
...

4
...

6
...

Provides nutrition to the CNS
...

Serves as a reservoir and helps in the regulation of the contents of the skull
...

Serves as a pathway for spinal secretions to reach the pituitary gland
...
Alimentary and Digestive System
The digestive system consists of the digestive tract and accessory organs
...
It is also called alimentary tract or alimentary canal
...
The associated
accessory organs are primarily glands located outside the digestive tract that secrete fluids into it
...
Alimentary tract: Extends from mouth to anus
...
Mouth or buccal cavity with tongue and teeth
2
...
Esophagus
4
...
Small intestine
a
...
Jejunum
c
...
Large intestine:
a
...
Ascending colon
c
...
Descending colon
e
...
Rectum
g
...
Digestive glands:
1
...

2
...
Pancreas
4
...
Other digestive glands in the wall of the digestive tract
...

Functions of the digestive tract:
1
...

3
...

5
...

7
...

9
...


Ingestion of food
...

Movement of food
...

Absorption of end products of digestion and H2O, vitamins and salt
...

Regulation of acid base balance
...

Regulation of blood glucose level
...


Gastrointestinal regulation:
The various functions of the GIT, including secretion, digestion and absorption and motility must be regulated in an
integrated way to ensure efficient assimilation of nutrients after a meal
...

1
...

3
...
These hormones travel through the bloodstream to change the activity of a distant segment of the
GIT, an organ draining into it (e
...
the pancreas) or both
...

Neural regulation of GIT: It occurs by –
a
...
Largely autonomous enteric nervous system that comprises both and secreto-motor neurons
...
In some cases, the same substance can mediate regulation by
endocrine, paracrine and neurocrine pathways (e
...
cholecystokinin)
...

2
...
It consists of an outer layer
of simple squamous epithelium and an inner layer of connective tissue
...
These folds allow the mucosa and submucosa to stretch, and the folds disappear
as the stomach volume increases as it is filled
...


Epithelial cells: There are five types of epithelial cells of the stomach:
a
...
Mucous neck cells
c
...
Chief cells
e
...


Surface mucous cells: Surface mucous cells are found on the surface around the gastric pit
...
The cells produce an alkaline mucous
on their surface that neutralizes the acid and is a barrier to the digestive enzymes
...
In addition, when surface mucous cells are damaged, they are rapidly replaced
...
Mucous neck cells: The mucous neck cells are located near the openings of the glands and produce mucus
...
Parietal cells: Parietal cells produce HCl and intrinsic factor
...
Chief cells: Chief cells produce the enzyme pepsinogen
...
Endocrine cells: Endocrine cells produce regulatory hormones and paracrine factors
...

• Gastrin containing cells secrete gastrin
...

Identifying characters of the histology of the stomach:
1
...

3
...


There are five layers in the wall of the stomach
...

Gastric glands are there in the mucosa layer
...


Small intestine
The wall of small intestine is made up of six layers:
1
...

3
...

5
...


Serosa layer: This is the outermost layer of small intestine and is made up of squamous epithelial tissue and
loose connective tissue like blood vessels, lymph vessel and adipose tissue
...

Circular muscle layer: It is the layer of circular muscles and placed under the longitudinal muscle
...

Muscularis layer: It is a very thin layer of smooth muscle
...
Absorptive cells: Absorptive cells are cells with microvilli that produce digestive enzymes and absorb
digestive food
...
Goblet cells: Goblet cells produce a protective mucus
...
Granular cells or Paneth cells: Granular cells or Paneth cells may help protect the intestinal
epithelium from bacteria
...
Endocrine cells: Endocrine cells produce regulatory hormones
...


2
...


Hepatic lobules: The liver is divided into hexagon-shaped hepatic lobules by connective tissue septa with a
portal triad at each corner
...

Hepatic cords: Hepatic cords are strings of cells that radiate out from the central vein of each lobule like the
spokes of a wheel
...

Hepatic sinusoids: The spaces between the hepatic cords and blood channels are called hepatic sinusoids
...

• Hepatic phagocytic cells or Kupffer cells

Hepatocytes have six major functions:
1
...

3
...

5
...


Bile production
Storage
Interconversion of nutrients
Detoxification
Phagocytosis and
Synthesis of blood components

10

Lung
1
...

3
...


Wall: The wall of lung is a two-layered membrane
...

Alveoli: Large number of empty spaces named alveoli are found
...

Trabecula: Alveoli are separated from each other by trabecula
...

Bronchioles: Large sized empty spaces bounded by ciliated epithelium are found
...


Q
...
What are the functions of saliva?
Saliva: Saliva is a viscous, colorless, opalescent fluid which is secreted by three pairs of salivary glands – the parotid,
submandibular and sublingual glands
...

Functions of saliva:
1
...
Keeps the mouth moist and helps in speech
...
Facilitates swallowing
...
Helps in preparing food staffs into a bolus, suitable for deglutination
...
Dilutes hot and irritant food, thus prevents injury to the mucosa
...
Acts as a lubricant
...
Washes down the food debris, thereby prevents bacterial growth
...
Role in taste: Helps in taste by dissolving food staffs
...
Digestive function: It breaks down starch into maltose, maltotriose, α-limit dextrin by ptyalin (salivary α
amylase)
𝑆𝑎𝑙𝑖𝑣𝑎𝑟𝑦 𝑎𝑚𝑦𝑙𝑎𝑠𝑒

4
...


6
...


Starch →
maltose, maltotriose, α-limit dextrin
...
g
...

Role in water balance: By evoking the sensation of thirst, it reflects the need of water intake
...
g
...
So drying up of the mucus membrane of
pharynx and mouth occurs; this sends afferent impulse to hypothalamic center, to be reasoned as thirst
...

Bacteriolytic function: Saliva dissolves the cell wall of many bacteria by the enzyme lysozyme and kills them
...
Name the protective constituents of saliva
...

2
...

4
...

Lysozyme: Kills bacteria
...

Bicarbonate: Neutralizes acid
...
Discuss the regulation of saliva secretion
...


Neural control: Salivary secretion is almost entirely controlled by neural influences
...
It has little influence on volume
...

2
...
Drugs:
a
...

c
...

e
...
Indeed, salivary
secretion can readily be coordinated
...
The amount and quality of the secretion
depends on the nature of the substance placed
...
Dry substances or acids produce copious watery secretion
...
Mouth salivary reflex
b
...
Gastro-salivary reflex
d
...
g
...

Acetylcholine and cholinergic agents: Stimulates salivation
...

Adrenergic agents: Cause salivation
...

Anesthetics like chloroform and ether stimulates salivation
...
Name the cells present in gastric gland with substances secreted by them
...

2
...

4
...

• Activates pepsinogen to pepsin
...

• Kills bacteria
...

•
•

5
...


G cells
Enterochromafin cells

Gastrin
Histamine

Forms mucosal barrier over the mucosal surface
of stomach and duodenum and protects against
acid-peptide digestion
...

• Cause gastric HCl secretion
• Cause gastric HCl secretion
...
Give the functions of gastric juices
...
Digestive function:
a
...

b
...
It is present only in stomach of children
...
Digestion of fat: Gastric lipase digests fat to some extent
...
Antiseptic function: Many bacteria pass into the stomach with food materials
...

3
...

4
...

5
...

6
...
Thus,
stomach is not self-digested
...
Acid base balance: It is responsible for the alkaline tide of blood, during secretion of HCl
...
Excretory function: Some heavy metals (e
...
Bi, Pb etc
...


12

Q
...

Functions of gastric HCl:
1
...

3
...

5
...


Converts inactive pepsinogen into active pepsin
...

Kills many ingested bacteria
...

Keeps the iron in ferrous state for absorption
...


Q
...

Parietal cell of stomach
Synonym: Oxyntic cell
...

Receptors present on the parietal cells:
1
...

3
...

2
...

2
...

Intrinsic factor of Castle: It is essential for the absorption of vitamin B12
...
Write short on Intrinsic factor of Castle
...
It is secreted from the gastric parietal cells,
binds with vitamin B12 and is necessary for its absorption from the small intestine
...
Then, when the intrinsic factor – vitamin B12 complex reaches the terminal ileum, the
intrinsic factor binds with receptors on the surface of the enterocytes
...

Deficiency of intrinsic factor: In the absence of intrinsic factor, only about
to vitamin B12 deficiency and pernicious anemia
...
This leads

Q
...
g
...
Mucosal barrier:
• Mucus secreted from the neck and surface mucus cells forms a flexible gel that coats the mucosa
...

• The surface membrane of mucosal cells and the tight junctions between the cells are also part of the
mucosal barrier that protects the gastric epithelium from damage
...
Mucosal blood flow is very high
...

3
...
It stimulates secretion of mucus and HCO 3— but
inhibits secretion of HCl
...


13

4
...

6
...
This aids the resistance against
autodigestion
...

Some of the resistance of the gastric mucosa to autodigestion is also provided by the presence of trefoil peptides
in the mucosa
...


Q
...

This is because –
1
...


HCl converts inactive pepsinogen to active pepsin
...
HCl makes the medium acidic in which pepsin is highly
proteolytic
...
Write down the functions of gall bladder
...

2
...

4
...

6
...

8
...
The storage function of the gall bladder is very important, as bile, because of its
continuous secretion would have been wasted, except during meal time
...

Gall bladder absorbs water and concentrates bile about 10 – 20 times
...

It absorbs inorganic salts from the bile to some extent and reduces the alkalinity of liver bile
...

It secretes mucus which is the main source of mucin of bile
...


Q
...

2
...

4
...

Fatty acids and amino acids in the duodenum releases CCK, which causes gall bladder contraction
...

Substances that increase the secretion of bile are known as choleretics
...


Q
...

Bile: Bile is the secretory product of liver made up of bile salts, bile pigments and other substances dissolved in an
alkaline solution that resembles the pancreatic juice
...

2
...

4
...

6
...


Yellowish green fluid
...

Reaction: Alkaline
...

Produced by hepatocytes
...

Secreted into the 2nd part of the duodenum along with the pancreatic juice through the hepato-pancreatic duct
...


2
...

It also helps in the absorption of fat soluble vitamins like A, D, E and K
...
Discuss the functions of bile
...


2
...

4
...


6
...


Digestive function: Bile helps in the digestion of fat with the help of bile salt which acts:
• By reducing surface tension
...

• By solvent action and dissolve fat and lipase
...

Choleratic: It increases the secretion of bile from liver
...

Excretory function: Certain substances are excreted through bile:
• Heavy metals, Cu, Hg, Zn
...
g
...

• Cholesterol
• Toxin, bacteria
Mucin of bile acts as buffer and lubricant
...


Q
...

Name of bile salts:
1
...

3
...


Na taurocholate
K taurocholate
Na glycocholate
K glycocholate

Functions of bile salts:
1
...

3
...

5
...

7
...


Digestive function: Bile salts emulsify the large fat particles into many minute particles that can be attacked
by pancreatic lipase enzymes
...

Choleratic: Increase the secretion of bile from liver
...

Bile salts keep the cholesterol in soluble form and thus prevent gall stone formation
...

They increase intestinal motility
...


Q
...

Functions of liver:
1
...


3
...
It is the main site for alcohol metabolism
...

• Vitamins (mainly vit-A, D, B12)
• Iron as ferritin
...

• Acute phase proteins
...

• Clotting factors II, VII, IX and X
...


15

4
...

6
...

8
...


• Urea
...

• 25 – Hydroxycholecalciferol
...

Excretory function: Heavy metals (Bi, Pb, As), cholesterol, bile pigment, calcium are excreted through liver
...
g
...
g
...

• Drugs such as penicillin, ampicillin
...

Detoxifying reactions in the liver convert xenobiotics and other toxins to inactive, less lipophilic
metabolites, which are easily excreted through the kidney and bile
...
But in adult,
liver is an organ for the destruction of RBC
...

Liver acts as a blood reservoir
...

A
...
Total protein concentration (Normal: 6-8 gm/dl)
2
...
Serum albumin-globulin ratio (Normal: 1
...
6 : 1)
4
...
It assays the production factors II, VII, IX and X by the
liver
...

B
...
To see CHO metabolism:
• Glucose tolerance test
• Galactose tolerance test
b
...
To see protein metabolism:
• Total protein concentration
• Serum albumin and globulin level
• Albumin globulin ratio
C
...
Serum bilirubin level by van den Berg reaction
...
In urine: Urine urobilinogen, bilirubin
...
In stool: Stercobilinogen
...
Tests for hepatocellular damage: Done by measurement of the following serum enzymes
...
Alanine aminotransferase (ALT) / Serum glutamate pyruvate transaminase (SGPT): Increased in
hepatocellular damage
...
Aspartate aminotransferase (AST) / Serum glutamate oxaloacetate transaminase (SGOT):
Increased in hepatocellular damage
...
Gamma (γ) glutamyl transferase: Increased in alcoholic liver diseases
...
Lactate dehydrogenase
...
Tests for cholestasis (biliary tract obstruction): Done by measurement of the following serum enzymes
...
Alkaline phosphate: Increased in biliary obstruction, cirrhosis of liver
...
γ glutamyl transferase
...
5/ nucleotide
F
...


NH3 concentration in the blood: In liver disease, NH3 cannot be converted to urea
...

2
...

G
...
Serum ferritin: Increased in liver disease
...
Iron binding capacity saturation
...
α – 1 antitrypsin
...
α fetoprotein (normally produced by fetal liver
...

5
...

6
...

Clinical importance or indications of liver function tests: Liver function tests are important in –
1
...

3
...

5
...


Differential diagnosis of jaundice
...

Assessment of severity of liver disease
...

Monitoring treatment
...


Q
...

Classification of digestive enzymes:
A
...
Ptyalin (salivary α amylase)
2
...
Sucrase
4
...
Lactose
6
...
Isomaltase
8
...
Proteolytic enzymes:
1
...
Trypsin, Chymotrypsin, Carboxypolypeptidase, Elastase
...
Aminopeptidase, dipeptidases, tripeptidases, enteropeptidase, endopeptidase
...
Fat splitting enzymes or lipolytic enzymes:
1
...
Lingual lipase
3
...

4
...
Lecithinase
D
...
DNAase
2
...
Other enzymes:
1
...

2
...
Enterokinase
Q
...

Absorption: Absorption may be defined as a process by which the end products of digestion pass through the intestinal
epithelium to enter the lymph or blood stream
...
In hydrolysis, water molecules are added to
the complex food particles with the help of specific enzymes and complex food particles are broken into smaller ones
...

2
...


Active transport
Diffusion
Solvent drug: Transport by solvent drug means that any time a solvent is absorbed because of physical
absorptive forces, the flow of the solvent will drag dissolved substances along with the solvent
...
Describe carbohydrate or starch digestion and absorption
...


In the mouth: Salivary α amylase (ptyalin) hydrolyzes starch into a disaccharide maltose and oligosaccharides
– matotriose and α-limit dextrins
...
0
...


𝑆𝑎𝑙𝑖𝑣𝑎𝑟𝑦 𝑎𝑚𝑦𝑙𝑎𝑠𝑒

In the stomach: In the acid media, the function of ptyalin is lost
...
HCl hydrolyzes some sucrose only
...


Glucose + Fructose

In the duodenum: The acidity of the chyme is neutralized by the help of secretin which facilitates the action
of pancreatic α-amylase
...


Maltose, Maltotriose and α-limit dextrin

→

𝑃𝑎𝑛𝑐𝑟𝑒𝑎𝑡𝑖𝑐 𝛼−𝑎𝑚𝑦𝑙𝑎𝑠𝑒

Maltose, maltotriose and α-limit dextrin

In the small intestine: The carbohydrate splitting enzymes of small intestine digest the carbohydrates as
follows:
Maltose
Lactose

𝑀𝑎𝑙𝑡𝑎𝑠𝑒

→
→

Sucrose →

Glucose + Glucose

𝐿𝑎𝑐𝑡𝑎𝑠𝑒
𝑆𝑢𝑐𝑟𝑎𝑠𝑒

Maltotriose →
α limit dextrin →

Glucose + Galactose
Glucose + Fructose

𝑀𝑎𝑙𝑡𝑎𝑠𝑒

Glucose

𝛼 𝑙𝑖𝑚𝑖𝑡 𝑑𝑒𝑥𝑡𝑟𝑖𝑛𝑎𝑠𝑒

Glucose

Absorption of carbohydrate: Carbohydrates are absorbed as glucose (80%), galactose, fructose and a few pentoses
...
The sugar molecules pass from the mucosal cells to
the blood in the capillaries draining into the portal vein
...
This is
because these sugars and Na+ share the same contraceptor or symport, the sodium-dependent glucose transporter
...
Short note: Lactose intolerance
Lactose or milk intolerance: Intolerance to milk and some dairy products containing lactose is called lactose
intolerance
...


18

Cause: It is caused by lactose deficiency
...
Unhydrolyzed lactose enters the colon, where bacterial
fermentation produces volatile short chain fatty acids, H2 and CO2
...

Types:
1
...


Primary: In this case, lactose deficiency is racially determined and jejunal morphology is normal
...
g
...


Clinical features:
1
...

2
...

2
...


Q
...

Digestion of protein:
1
...


In the mouth: No digestion occurs
...
Pepsin is most active at pH 2
...
0
...

Protein →

𝑃𝑒𝑝𝑠𝑖𝑛

Proteoses, Peptone, Polypeptide
...
In the small intestine:
a
...
Only a small percentage of the proteins are digested all the way to
their constituent amino acids by the pancreatic juices
...

Protein →

𝑇𝑟𝑦𝑝𝑠𝑖𝑛, 𝐶ℎ𝑦𝑚𝑜𝑡𝑟𝑦𝑝𝑠𝑖𝑛
𝐶𝑎𝑟𝑏𝑜𝑥𝑦𝑝𝑜𝑙𝑦𝑝𝑒𝑝𝑡𝑖𝑑𝑎𝑠𝑒

Polypeptide →
Elastin

→

𝐸𝑙𝑎𝑠𝑡𝑎𝑠𝑒

Polypeptide
Amino acids

Polypeptide, Dipeptide
...
In the brush border of enterocytes lining the villi:
𝐴𝑚𝑖𝑛𝑜𝑝𝑜𝑙𝑦𝑝𝑒𝑝𝑡𝑖𝑑𝑎𝑠𝑒, 𝐷𝑖𝑝𝑒𝑝𝑡𝑖𝑑𝑎𝑠𝑒

Polypeptide →
few amino acids
...


In the cytosol of enterocytes: Dipeptides, tripeptides and amino acids are easily transported to the
interior of the enterocytes
...

Di and tripeptides

→

𝐼𝑛𝑡𝑟𝑎𝑐𝑒𝑙𝑙𝑢𝑙𝑎𝑟 𝑝𝑒𝑝𝑡𝑖𝑑𝑎𝑠𝑒𝑠

Amino acids

Absorption of protein:
1
...

a
...


2
...

➢ Five of these require Na+ and transport amino acid into enterocytes
...


From enterocytes into ECF and then to blood: In enterocytes, di and tripeptides are hydrolyzed into amino
acids by intracellular peptides
...


Amino acids then enter into hepatic portal blood
...
Describe the fat digestion and absorption
...

2
...

4
...

2
...


In the mouth: No digestion occurs
...
Lingual lipase secreted
by Ebner’s gland of tongue is active in stomach and can digest 30% dietary triacylglycerol
...
At first, bile salts and lecithin emulsify
fat globules into small particles
...

Fat (triacylglycerol) →
Emulsified fat →

𝐵𝑖𝑙𝑒+𝐴𝑔𝑖𝑡𝑎𝑡𝑖𝑜𝑛

𝑃𝑎𝑛𝑐𝑟𝑒𝑎𝑡𝑖𝑐 𝑙𝑖𝑝𝑎𝑠𝑒

1-monoacylglycerol →

Emulsified fat

Free fatty acid and 2-monoacylglycerol

𝐼𝑛𝑡𝑒𝑠𝑡𝑖𝑛𝑎𝑙 𝑙𝑖𝑝𝑎𝑠𝑒 𝑖𝑛 𝑡ℎ𝑒 𝑒𝑛𝑡𝑒𝑟𝑜𝑐𝑦𝑡𝑒𝑠

20

Glycerol + Fatty acid

Digestion of cholesterol esters and phospholipids:
Most of the cholesterol in the diet is in the form of cholesterol esters
...


Cholesterol ester
Phospholipid

→

→

𝐶ℎ𝑜𝑙𝑒𝑠𝑡𝑒𝑟𝑜𝑙 𝑒𝑠𝑡𝑒𝑟𝑎𝑠𝑒

𝑃ℎ𝑜𝑠𝑝ℎ𝑜𝑙𝑖𝑝𝑎𝑠𝑒 𝐴2

Cholesterol + Fatty acid

Fatty acid + Lysophosphatids

Absorption of lipid: Fat is absorbed mainly as –
1
...

3
...

5
...
Fatty acid, cholesterol, monoacylglycerol are dissolved
in the micelle
...

1
...

3
...


Glycerol and fatty acids containing less than 10-12 carbon atom pass through the enterocyte directly into portal
blood
...

Fatty acids also esterify cholesterol into choesteryl ester
...
Short note: Emulsification
Emulsification: Bile salts and lecithin reduce surface tension of fat globules and break them into small particles
...

Mechanism:
Hydrophobic protein of bile salt and lecithin are dissolved in fat globules
↓
Decreased surface tension of fat globules
↓
Fat globules are broken down into small particles
↓
Increased total surface area of fat

21

↓
Emulsification of fat occurs
...
Emulsification
increases the total surface area of the fat and this causes more exposure of the lipase to the fat particle
...
So fat digestion is also increased
...
What is chyme?
Chyme: After the food has become mixed with the stomach secretion, the resulting mixture that passes down the gut
is called chyme
...
The appearance of chyme is that of a murky, milky
semisolid or paste
...
Short note: Glycemic index
...

Examples:
1
...

3
...


Glucose and galactose have an index of 1, as do lactose, maltose, isomaltose and trehalose, which give rise to
these monosaccharides on hydrolysis
...

GI of starch varies between near 1 to 0 due to variable rates of hydrolysis
...


Importance of GI: Foods that have a low glycemic index are considered to be more beneficial since they cause less
fluctuation in insulin secretion
...
State the functional types of movements of GI tract
...

2
...

Mixing movement: It keeps the intestinal contents thoroughly mixed at all times
...
Name the movements of alimentary tract
...
Movement of mouth: Mastication of chewing
...
Movement of pharynx and esophagus: Deglutition or swallowing
...
Movements of GIT:
a
...
Movements of small intestine:
• Mixing movement – Segmentation contraction
• Propulsive movement – Peristalsis
• Antiperistalsis
• Pendular movement
c
...


Mixes the food particles with digestive juices
...


Helps in absorption by constant bringing of chyme with absorptive surface
...

2
...

Helps in partial mixing of the food particles with digestive juices
...
Mention the functions of stomach
...


2
...
Reservoir function: Stomach stores large quantities of food until the food can be processed in the
stomach, duodenum and lower intestinal tract
...
Mechanical function: Mixing of this food with gastric secretions until it forms a semifluid mixture
called chyme
...
Slow emptying: Stomach causes slow emptying of the chyme from the stomach into the small
intestine at a rate suitable for proper digestion and absorption by the small intestine
...

4
...


Secretion

Peptic cell (chief cell)

Pepsinogen

Parietal (oxyntic) cell

HCl, intrinsic factor of Castle

Mucus neck cell

Mucus

G cells

Gastrin

Digestive function: Pepsin initiates digestion of protein up the stage of peptone
...
HCl hydrolyzes some sucrose
...

Hemopoietic function: Stomach secretes intrinsic factor of Castle that is required for vitamin B12 absorption
...
Blood and Immunity
Q
...
Give the composition of blood
...

Composition:
Blood

Formed elements (45%)

•
•
•

Fluid portion (plasma) (55%)

Red blood cells or
erythrocytes
White blood cells or
leukocytes
Platelets or
thrombocytes

Organic substances (7
...
1%)

Solid (8-9%)

Water (91-92%)

Inorganic substances (0
...

Non-protein nitrogenous substances: Urea, uric acid,
xanthine, hypoxanthine, creatinine, ammonia, amino
acids
...

Lipids: Phospholipids, cholesterol, natural fat etc
...

Others: Hormones, vitamins, enzymes (amylase, protease,
lipase, phosphatase
...
List the life span of blood cells
...

In the tissues: 4 to 5 days
...


Granulocytes

Monocytes
Macrophages
Lymphocytes
Platelets

In times of serious tissue infection, this total life span is often shortened to only a few hours because, the granulocytes
proceed even more rapidly to the infected area, perform their functions, and in the process, are themselves destroyed
...

Q
...

Cellular elements of human blood with their values:
Cellular elements
RBC
WBC
Platelet

Normal values in SI units
In adult male: 4
...
5 ×1012 /L
...
4-5
...
9-5
...
4-5
...
Enumerate the functions of blood
...

2
...


Respiration: Transport of O2 from the lungs to the tissues and of CO2 from the tissues to the lungs
...

Excretion: Transport of metabolic waste products to the kidneys, lungs, skin and intestines for removal from
the body
...
Maintenance of normal acid-base balance in the body
...
Regulation of water balance through the effects of blood on the exchange of water between the circulating
blood and tissue fluid
...
Regulation of body temperature by the distribution of body heat
...
Transport of hormones and regulation of metabolism
...
Transport of metabolites
...
Defense against infection by the white blood cells and circulating antibodies
...
Coagulation
...
Storage: Blood serves as the ready-made source for water and certain electrolytes such as glucose, Na+, K+ etc
...

Q
...

Red bone marrow: Active cellular bone marrow is called red bone marrow
...
That is, at birth,
all the marrow is red bone marrow
...
The process starts first in the distal bones
of the limbs (tarsus and carpus), then in the intermediate (tibia, fibula, radius, ulna) and finally in the proximal
bones (femur, humerus)
...

In the adult, red bone marrow persists mainly in the vertebrate, sternum, ribs and bones of the skull and pelvis
...

2
...

4
...

Formation of granulocytes and to a less extent of monocytes and lymphocytes
...

Destruction of red cells by macrophages which constitute part of the lining of the blood sinus
...
What are the differences between plasma and serum?
Differences between plasma and serum:
1
...


Plasma
It is the non-cellular fluid portion of the blood
...


1
...


3
...


3
...


Plasma can clot because it has all the blood
clotting factors
...


4
...


5
...

It does not contain fibrinogen, factors II, V and
VII
...

Serum cannot clot due to lack of some of the
clotting factors
...


Q
...

Plasma proteins with their normal values:

1
...

3
...


Major plasma
proteins
Albumin
Globulin
Fibrinogen
Prothrombin

Normal value (g/dl)
4
...
3
0
...
1

Q
...

Site of synthesis of plasma proteins:
A
...

2
...

4
...
In embryo, plasma proteins are derived from the mesangial cells
...
In starvation, plasma protein formation is reduced and occurs chiefly from the tissue proteins
...
Enumerate the functions of plasma proteins
...

2
...

4
...


Maintains 80% of the total colloidal osmotic pressure of blood
...

Acts as a buffer and maintains acid-base balance
...

Acts as a protein reservoir
...

2
...

4
...

6
...

Maintains viscosity of blood
...

α2 globulin transports Cu as ceruloplasmin
...

γ globulin acts as antibody
...

2
...


It is essential for blood coagulation
...

It helps to maintain viscosity of blood
...


It is essential for blood coagulation
...
All cellular blood
components are derived from haematopoietic stem cells
...

Blood forming cells may be divided into four groups; depending on their capacity for self-renewal, cell division and the
ability to form different cell types:
1
...

3
...


Pluripotent hematopoietic stem cells: These are very few in number and are capable of forming any type of
blood cell
...

Committed progenitor cells: These are capable of self-renewal but are able to form only one or two cell types
...

Maturing cells: These do not divide again and undergo structural differentiation to form a specific c type of
blood cell
...
Erythropoiesis is
the process of red blood cell formation
...

•
•
•
•

Red blood cells develop from proerythroblasts
...

Monocytes develop from monoblasts
...


All these ‘blast’ cells are developed from or originated from myeloid stem cell
...
What are the stages of erythropoiesis?
Stages of steps of erythropoiesis:
Pluripotent hematopoietic stem cells
↓
Committed stem cells (colony forming unit – erythrocyte)
↓
Pro erythroblast (Pronormoblast)
↓
Basophil erythroblast (early normoblast)
↓

PC PB PO RE

27

Polychromatiphil erythroblast (Intermediate normoblast)
↓
Orthochromatic erythroblast (Late normoblast)
↓
Reticulocyte → enters into circulation
↓
Erythrocyte
...

5 days up to stage of reticulocyte from proerythroblast
...


Factors necessary for erythropoiesis:
1
...
Proteins: Proteins of high biological value are needed in the formation of hem part
...
Metal ions:
• Iron: Iron is essential for RBC formation because it enters in the formation of hem part
...
It catalyzes the
oxidation of Fe2+ to Fe3+, a reaction that must occur before transferrin can combine and
transport iron
...
So excess Co may produce
polycythaemia
...
Vitamins: Both vitamin B12 and folic acid are essential for final maturation of RBCs because they are
needed in DNA synthesis
...

2
...

• Thyroid hormones: They stimulate the metabolism of all body cells including the bone
marrow cells; thus increasing erythropoiesis
...

• Glucocorticoids: Glucocorticoids stimulate the general metabolism and also stimulate the
bone marrow to produce more RBCs
...

• Pituitary gland: Pituitary gland affects erythropoiesis both directly and indirectly through the
action of several hormones
...

3
...
In chronic liver disease anemia occurs
...

Q
...
They are as follows:
1
...

3
...

5
...
Describe the morphology of RBC
...

2
...

4
...

6
...


Shape: Circular, biconcave disk
...
8µm
...
5 µm at the thickest point and 1 µm or less in the centre
...


Q
...

2
...

4
...

6
...

Acid base balance: The Hb of RBC acts as a buffer and helps to maintain acid-base balance
...
If RBC is increased in plasma
(polycythemia), the viscosity of blood will also be increased
...
g
...

Determination of blood group: It contains antigens e
...
, ABO blood group antigens, Rh antigens which
determine the blood group
...


Q
...
The rate at which this occurs is called
erythrocyte sedimentation rate
...

2
...
Define hemoglobin
...

Hemoglobin: Hemoglobin is a chromoprotein consisting of the protein globin united with the pigment heme
...
5 g/dl

Functions of hemoglobin:
1
...

3
...


Transports O2 from the lungs to the tissues and CO2 from the tissues to the lungs
...

Formation of various pigments e
...
, bilirubin, stercobilin, urobilin etc
...


29

Q
...

Hemoglobin synthesis: Hb synthesis begins in the basophil erythroblast stage and is completed in the orthochromatic
erythroblast stage
...

Site of synthesis: In mitochondria
...

2
...

4
...

2 syccinyl CoA + 2 glycine → Pyrrole
4 pyrrols → Protoporphyrin IX
Protophorphyrin IX + Fe → Heme

Globin synthesis:
Raw materials: Amino acids
...

Steps:
DNA →

𝑡𝑟𝑎𝑛𝑠𝑐𝑟𝑖𝑝𝑟𝑡𝑖𝑜𝑛

mRNA

→

𝑡𝑟𝑎𝑛𝑠𝑙𝑎𝑡𝑖𝑜𝑛

Polypeptide (globin)

Finally:
Heme + Polypeptide → Hemoglobin chain (α/β)
...

Hemoglobin breakdown:
Hemoglobin is broken down by macrophages into heme and globin chains
↓
The globin chains of hemoglobin are broken down to individual amino acids and are metabolized or used to build new
proteins
↓
The heme of hemoglobin releases the iron
...

↓
Blood transports ion in combination with transferrin to various tissues for storage or to the red bone marrow, where it
is used in the production of new hemoglobin
...
Bacteria of the intestine break down the
bilirubin
...

↓
Other bilirubin derivatives are reabsorbed from the intestine into the blood
...

[Seeley’s Anatomy and Physiology, 11th edition]
Anemia
Definition: Anemia may be defined as a clinical condition characterized by pale coloration of skin and mucous
membrane due to qualitative and quantitative deficiency of hemoglobin below the lower limit in the peripheral blood
in respect of age and sex
...
These may be due to –
•
•
•

Decreased production of RBC
Increased destruction of RBC
Excess loss of blood from the body

MCV, MCH and MCHC
•
•
•

MCV (Mean Corpuscular Volume): MCV is the average red blood cell size
...

Normal value: 27⸺33 picograms / red blood cell (1 g = 10⸺12 pcg)
MCHC (Mean Corpuscular Hemoglobin Concentration): MCHC is the amount of hemoglobin relative to
the size of the cell or hemoglobin concentration per red blood cell
...
4⸺35
...


2
...


High MCV: High MCV means that the red blood cells are larger than normal
...
Macrocytic anemia can be caused by –
⸺ Vitamin B12 deficiency
⸺ Folate deficiency
⸺ Chemotherapy
⸺ Pre-leukemias
Low MCV: Low MCV means the red blood cells are too small
...

Microcytic anemia can be caused by –
⸺ Iron deficiency, which can be caused by poor dietary intake of iron, menstrual bleeding or
gastrointestinal bleeding
...
One can have a normal MCV and still
be anemic if there are too few red blood cells or if other red blood cell indices are abnormal
...

Normocytic anemia occurs when the red blood cells are normal in size and hemoglobin content, but there are
too few of them
...

⸺ A prosthetic heart valve
⸺ A tumor
⸺ A chronic disease such as a kidney disease or endocrine disorder
⸺ Aplastic anemia
⸺ A blood infection

MCHC
1
...


High MCHC: High MCHC means that the relative hemoglobin concentration per red blood cell is high
...
The
RBCs will take a lighter colour when viewed under microscope
...

Conditions that can cause low MCHC includes the same conditions that cause low MCV, including –
⸺ Iron deficiency
31

⸺ Chronic disease
⸺ Thalassemia
⸺ Pb poisoning
Generally, a low MCV and a MCHC will be found together
...


Classification:
A
...
Normocytic normochromic anemia: MCV (mean corpuscular volume), MCH (mean corpuscular
hemoglobin) and MCHC (mean corpuscular hemoglobin concentration) is normal; RBC count is
decreased
...
Macrocytic hypochromic anemia: MCV > 96 fL (famto Liter); MCHC is less (cells are of pale colour)
...
Microcytic hypochromic anemia: MCV < 80 fL; MCH < 27 pg; MCHC < 30 g/dL
...
Etiological classification:
1
...

Acute
•
•

Chronic
•
•
•
•
•

Accidental blood loss
Surgical blood loss

Hook worm infection
Menorrhagia
Peptic ulcer
Hemorrhoids
Carcinoma of stomach, colon
...
Hemolytic anemia:
a
...

• Defect in Hb: Thalassemia, sickle cell anemia
...

b
...

• Mechanical trauma to RBC: Disseminated intravascular coagulation
...

• Chemical injury: Lead (Pb) poisoning
...
Anemia due to impaired red blood cell production:
a
...
Due to disturbance of proliferation and differentiation of stem cells:
• Aplastic anemia
• Anemia of renal failure due to erythropoietin deficiency

32

• Anemia of endocrine disorder
Due to replacement of normal bone marrow:
• Leukemia
• Lymphoma
• Myeloma
d
...
Clinical anemia:
1
...
Moderate anemia: When Hb = 9 – 6 gm/dl (++)
3
...


Breakdown of RBC and Jaundice
The life span of and RBC is about 120 days
...
RBC cannot synthesize new enzymes (proteins) due to absence
of nucleus
...

During circulation, the RBC has to pass through the spaces in the red pulp of the spleen
...
So extreme alterations in shape are required for red cells to pass
the spaces successfully
...
The mononuclear phagocytic cells in the spleen phagocytose the RBC and destroy them
...

Q
...
Classify it
...
Any process that causes increased destruction of red blood cells can
cause jaundice, such as damage by toxins, genetic defects in red blood cell plasma membranes, infections and immune
reactions
...

Normal serum bilirubin: 0
...

Clinical jaundice: When bilirubin in plasma exceeds 3 mg/dl (50 μmol/L)
...

Classification:
1
...

3
...

Hepatic: It is caused by hepatocellular damages and defects
...


Blood grouping
If large quantities of blood are lost during surgery or due to injury, the patient can go into shock and die unless red
blood cells are replaced to restore the blood’s oxygen-carrying capacity
...

Transfusion: A transfusion is the transfer of blood or blood components from one individual to another
...


33

It may be surprising that an infusion would be used to treat someone who has lost a large volume of blood, but in many
cases the return of blood volume to normal levels is all that is necessary to prevent shock
...

Early attempts to transfuse blood from one person to another were often unsuccessful because they resulted in
transfusion reactions, characterized by clotting within the blood vessels, kidney damage and death
...
Cells have marker molecules on their
membranes to identify them as normal cells of the body
...
The plasma contains proteins called antibodies, which bind to antigens
...
When the antibodies in the plasma
bind to the antigens on the surfaces of the red blood cells, they form molecular bridges that connect the red blood cells
...
The combination of the antibodies with the antigens can also
initiate reactions that cause hemolysis
...

The antigens on the surface of red blood cells have been categorized into blood groups, and more than 35 blood groups,
most of them rare, have been identified
...

Other well-known groups are the Lewis, Duffy, MNSs, Kidd, Kell and Lutheran groups
...
Note that there are only two possible antigens associated with the ABO blood group:
antigen A and antigen B
...
The ABO blood group is an example of codominance in that
the A and B antigens can be expressed at the same time
...
Anti-A antibodies act against type A antigens and anti-b antibodies
act against type B antigens
...
Instead,
we would expect to find antibodies for the antigens that are not present
...
Type AB blood has neither type of antibody,
and type O blood has both anti-A and anti-B antibodies
...
In the case of
antibodies associated with the ABO blood group, scientists are unsure exactly how this exposure occurs
...

In support of this explanation, anti-A and anti-B antibodies are not found in the blood until about 2 months after birth
...

Meanwhile, an infant with A antigens does not produce antibodies against the A antigens on bacteria or food because
mechanisms exist in the body to prevent the production of antibodies that react with the body’s own antigens
...
When a blood transfusion is performed, the donor is the person who gives blood, and the
recipient is the person who receives it
...
For example, a person with type A blood can receive blood from a person with type A
blood
...

On the other hand, if type A blood were donated to a person with type B blood, a transfusion reaction would occur
because the person with type B blood has anti-A antibodies
...

Type O blood is characterized by the absence of either type A or type B antigens
...
People with O blood are often called universal donors
because they can usually give blood to the other ABO blood types without causing an ABO transfusion reaction
...

The term ‘universal donor’ is misleading, however
...
Second, antibodies in the donor’s
34

blood can react with antigens in the recipient’s blood
...
If
type O blood is transfused into a person with type A blood, the anti-A antibodies (in the type O blood) react against the
A antigens (in the type A blood)
...
Blood banks separate donated
blood into several products, such as packed red blood cells, plasma, platelets and cryoprecipitate, which contains von
Willebrand factor, clotting factors and fibrinogen
...
Type O packed red blood cells are unlikely to
cause an ABO transfusion reaction when given to a person with a different blood type because the transfusion fluid
contains concentrated red blood cells with very little plasma containing anti-A and anti-B antibodies
...
The person with blood group A +ve has antigen A in
his/her and antibody Anti B
...
The
person’s blood group is A+ve
...

Rh factor or Rh antigens: The Rh factor or rhesus factor is an antigen which was first found in the red cells of rhesus
monkey and named after this animal
...
There are 6 common types of Rh antigens,
each of which is called an Rh factor
...
D is the commonest Rh antigen
...

Inheritance of Rh antigen:
•
•
•
•
•
•

Gene for antigen D is called D and gene for antigen d is called d
...

When blood sperm and ovum carry gene D, the resulting genotype of the offspring is DD
...

When both games carry d, result is dd
...


Rh antibody: There are several varieties of Rh antibodies: anti D, anti C, anti E, anti d, anti c, anti e
...
Very rarely anti E antibody may be present in the Rh⸺ persons
...

2
...

Passage of Rh+ blood from fetus to Rh⸺ mother causes anti D production in mother
...

Hazards or Rh incompatibility: Rh incompatibility causes hemolytic transfusion reaction in the following conditions:
1
...


When a Rh⸺ mother carries a Rh+ fetus, hemolytic transfusion reaction occurs in the fetus resulting in two
clinical syndromes:
a
...

b
...
after subsequent transfusion with
Rh+ blood, he/she suffers from hemolytic transfusion reaction, in which anti D antibody binds with Rh
antigen on the RBC membrane causing hemolysis
...
Rh positive person is safer than Rh negative person
...


35

Rh positive person is safer than Rh negative person:
1
...

3
...
after subsequent
transfusion with Rh+ blood, he/she suffers from hemolytic transfusion reaction, in which anti D antibody
binds with Rh antigen on the RBC membrane causing hemolysis
...
As a result, no hemolytic transfusion reaction occurs in the subsequent transfusions
...
In case of Rh+ positive females, there is no chance of erythroblastosis fetalis
...

Erythroblastosis fetalis: When hemolysis and anemia occurs due to Rh-incompatibility in an Rh+ fetus growing in an
Rh⸺ mother, large number of premature red cells (erythroblasts) appear in the peripheral circulation of the fetus to
compensate the anemia
...

Occurrence: Erythroblastosis fetalis occurs in fetuses of second or later pregnancies in cause of a Rh⸺ mother and and
Rh+ father
...
e
...

2
...

4
...


Development of jaundice at birth or within 24 hours
...

Kernicterus, a neurological syndrome in which un-conjugated bilirubin is deposited in the basal ganglia
...

Death due to liver failure
...


Anti-D injection within 72 hours after every delivery
...


Prevent or minimize feto-maternal bleeding during removal of placenta
...

Q
...

2
...

4
...


To find out complete blood group in order to avoid transfusion reaction
...

To determine paternity (by MN system)
...

Various experimental studies in hematological laboratories
...
What is the clinical importance of Rh typing?
Clinical importance of Rh typing:
1
...

3
...

Due to Rh incompatibility, hemolytic transfusion reaction occurs in Rh+ fetus growing in a Rh⸺ mother
...

No Rh⸺ female at any stage before menopause should be given Rh+ positive blood
...
e
...
She is likely to destroy, subsequently any Rh+ fetus
by anti D
...


Q
...

Types:
1
...


Major cross matching: Donor’s antigen (RBC) and recipient’s antibodies (plasma)
...


Procedure:
Blood is collected from both donor’s and recipient’s
↓
Serum and red blood cells are separated from each other of both blood samples
...

↓
The donor’s RBCs are mixed with recipient’s serum
...

↓
Similarly, recipient’s RBCs are mixed with donor’s serum
...

↓
If there is no agglutination in steps 4 and 5, the two bonds are perfectly compatible and transfusion can be
given
...

2
...
Thus, perfectly compatible blood can be found out
...


Q
...
Whole blood
a
...
Severe hemorrhage

37

2
...

4
...

6
...


C
...


E
...


During a major operation
Severe burns when there is excessive hemolysis and dehydration
Postoperatively in severe debilitated and anemic patients
...

As a prophylactic measure preoperatively in hemorrhagic tendencies e
...
ITP, hemophilia,
obstructive jaundice
...
Fresh blood: Thalassemia, DIC, ITP, hemophilia
...
Heparinized blood: In bypass surgery
...
Exchange transfusion:
1
...

2
...

3
...

4
...

5
...

Red cell concentrate:
1
...

2
...

White blood cells:
1
...

2
...

Platelet concentrate:
1
...
Acute leukemia
3
...
Coagulation disorders e
...
hemophilia
2
...
Patient with oral anticoagulant
4
...
Coagulation factor deficiency
2
...


Q
...
Immediate effects:
1
...
Nausea and vomiting
3
...
Pulse and respiratory rate are increased
5
...
Shock
B
...
Inapparent hemolysis
2
...
Hemoglobinemia and hemoglobinuria
4
...
Acute kidney shut down
Q
...


Fever

38

2
...

4
...

6
...

8
...
Hepatitis B and C
b
...
Syphilis
d
...
Transfusion hemosiderosis
10
...
Chemical risks:
a
...

b
...

c
...

Q
...

Measures of safe blood transfusion:
A
...
Blood donors must meet specific criteria:
a
...

b
...

c
...
Donor must be in general good health
...
Some minor health problems such as cold, flu may temporarily disqualify donor
...
Other significant medical histories i
...
major surgery, blood transfusion etc
...

4
...

5
...
Pregnant women or lactating mother with anemia are contraindications for donation
...
Minimum acceptable hemoglobin concentration before donation: 13
...
5
g/dl for woman
...
Volume of donation: Volume of donation should not be more than 13% of total estimated volume to
protect against vasovagal attacks
...

e
...


B
...
Compatibility:
1
...

2
...

3
...

4
...

b
...
Viral hepatitis (hepatitis B and C)
2
...
Syphilis
4
...


Cytomegalovirus

C
...
Proper labeling
...
Check the following things before starting transfusion:
a
...

b
...
and bag no
...
Record following before transfusion: Pulse, BP, temperature, respiration, urinary output
...
Keep the blood at room temperature for 15 – 20 minutes before transfusion (cold blood may cause
rigor)
...
Injection of prothrombin 15 minutes before transfusion
...
At first, blood should be transfused slowly and any allergic reactions should be observed
...
If any reaction is seen, transfusion should be stopped
immediately
...
Name the anticoagulants used in blood collecting bag
...


ACD (Acid Citrate and Dextrose): It is used in blood collecting bag
...
Citrate acts as anticoagulant
...
CPD (Citrate Phosphate and Dextrose)
...
CPD-A (Citrate Phosphate Dextrose and Adenine)
...
Describe the mechanism of acute renal shut down due to mismatched blood transfusion
...
It can begin within a few minutes to few hours and continue until the person dies of renal failure
...

2
...


Renal vasoconstriction: The antigen-antibody reaction of the transfusion reaction releases toxic substances
from the hemolyzed blood that cause powerful renal vasoconstriction
...
The arterial blood pressure falls very
low, and the renal blood flow and urine output decreases
...


Thus, renal vasoconstriction, circulatory shock and renal tubular blockage together cause acute renal shutdown
...

Q
...
This leads to increased bilirubin production
and development of jaundice
...
What is induced erythrocythemia?
Induced erythrocythemia (blood doping): Induced erythrocythemia (blood doping) is the process of increasing the
number of circulating red blood cells, either by transfusing an individual with blood that has been previously removed
or by administrating erythropoietin, in order to increase the oxygen-carrying capacity of the blood for improved athletic
endurance
...
Blood doping
is banned by the World Anti-doping Agency
...
If done correctly, this process can increase hemoglobin level and
RBC count by up to 20%
...
They are formed
typically in the bone marrow (granulocytes and monocytes and a few lymphocytes) and partially in the lymph tissue
(lymphocytes and plasma cells)
...

The real value of the white blood cells is that most of them are specifically transported to areas of serious infection and
inflammation, thereby providing a rapid and potent defense against infectious agents
...

Q
...

Classification of WBC: On the basis of presence of granules in the cytoplasm, WBCs are of two types:
A
...
On the basis of staining of the nucleus and size of the
granules, they are of three types:
1
...
Eosinophil
3
...
Agranulocytes: They have no granules in the cytoplasm
...
Lymphocytes:
a
...
Small lymphocytes
2
...
Classify WBC with their normal values in peripheral blood
...
g
...

TC of WBC: 4,000 – 11,000 /mm3 of blood
...

Absolute count of WBC: It is the total number of individual white blood cells per unit volume of blood e
...
, cubic
millimeter
...
List the properties of WBC
...

2
...


Diapedesis
Amoeboid movement
Chemotaxis

41

4
...


Diapedesis: The process by which leukocytes come out of the lumen of the blood vessels into the tissue space
is called diapedesis
...
Eventually, they pass along the basement membrane and
escape into the extravascular space
...


2
...

Maximum rate of movement is 40 μm/min
...


3
...
Leukocytes are attracted
to the site of injury by the chemotactic agents, which include –
a
...

b
...

• Complement C5a
...
g
...

• Products of blood clotting
...


Phagocytosis: It is the process by which WBC (neutrophil and macrophages) engulf the foreign body and
damaged tissues
...
Give the morphology and functions of different types of leukocytes
...


Q
...

Functions of WBC:
A
...
The most important function of the neutrophils is the phagocytosis
...


B
...


D
...


They synthesize and releasea
...

b
...

c
...

Eosinophils:
1
...

2
...

3
...

Basophils:
1
...

2
...

Monocytes: Monocytes enter the tissues from blood and become tissue macrophages
...
Phagocytosis
...
Antigen presentation
...
Production of cytokines such as IL-1, IL-8, TNF
...
Helper T cells activates cytotoxic T cell, B cells, macrophages and other antigen specific helper T cell
...
Cytotoxic T cells kill virus-infected cells, tumor cells and allograft cells
...
B cells produce antibodies
...
Then the plasma cells produce
antibody
...
What is leukocytosis? List the causes of leukocytosis
...

Causes:
Neutrophilic leukocytosis (Neutrophilia):
1
...

3
...

5
...

7
...

Trauma: Surgery, burns
...

Inflammation: Gout, rheumatoid arthritis, ulcerative colitits, Crohn’s disease
...

Myeloproliferative disease: Polycythemia, chronic myeloid leukemia
...


Eosinophilic leukocytosis (Eosinophilia):
1
...

3
...

5
...

7
...

Infection: Parasitic
...
g
...

Skin disease
...

Malignancy: Solid tumors, lymphomas
...


Basophilic leukocytosis (Basophilia):
1
...

3
...

Inflammation: Acute hypersensitivity, ulcerative colitis, Crohn’s disease
...


Monocytosis:
1
...

43

2
...

4
...

6
...


Bacterial endocarditis
...

Malaria
...
g
...

Inflammatory bowel diseases e
...
, ulcerative colitis
...


Lymphocytosis:
1
...

3
...

5
...
g
...

Lymphoproliferative disease: Chronic leukemia, lymphoma
...

Accompanies monocytosis in many disorders associated with chronic immunologic stimulation (tuberculosis,
brucellosis)
...
g
...


Platelet or thrombocytes
Normal count of platelet: Average 300,000/μL of blood
...

2
...

4
...


Cell size: 2 – 4 μm in diameter
...

Nucleus: Absent
...
Hyalomere: A peripheral light blue stained transparent zone
...

b
...
Three types of granules are present in the
cytoplasm: alpha, delta and lysosomes
...


Chemical characteristics:
1
...

3
...

5
...

7
...

2
...

4
...

6
...


It plays important role in hemostasis
...

It has antigenic properties like ABO blood group antigens
...

Storage and transport of 5-HT and histamine
...

Liberates a protein that increase vascular permeability and contribute to the hormonal control of inflammatory
reaction
...
A collection of complex interrelated systemic
mechanisms operates to maintain a balance between coagulation and anticoagulation
...

2
...

4
...


2
...


4
...
This vasoconstriction results from:
• Nervous reflexes: Initiated by pain or other impulses
...

• Local hormonal factors: Released from the traumatized tissue and blood platelets
...

• Conversion of prothrombin into thrombin
...

Fibrous organization or dissolution of blood clot: Once a blood clot is formed, it can follow one of two
courses:
It can become invaded by fibroblast
↓
Formation of connective tissue
↓
The clot is completely organized into fibrous tissue and closes the hole in the vessel
...
This occurs when excess blood has leaked into the tissue and clots are formed in the tissues
where they are not needed
...

↓
The intrinsic pathway of clotting starts when inactive factor XII, which is in the blood, is activated by coming into
contact with a damaged blood vessel
...

↓
Activated factor X, factor V, phospholipids and Ca2+ form prothrombinase
...

↓
Thrombin converts fibrinogen to fibrin (the clot)
...

[Seeley’s Anatomy and Physiology, 11th Edition]
Q
...

Formation of platelet plug in hemostasis: Platelet plug formation involves three phases:
Platelet adhesion: When the endothelium is injured, platelets adhere to the exposed subendothelial collagen by Von
Willebrand factor (vWF)
↓
Platelet activation: After adhesion, platelets undergo morphologic changes and become activated and then release
granules containing ADP, thromboxane A2, serotonin, platelet activation factor (PAF) and thrombin
...
Intracellular Ca2+ increases in these activated platelets
...

Activation of the glycoprotein IIB/IIIa receptors
↓
Glycoprotein IIb/IIIa binds to fibrinogen
↓
One fibrinogen molecule binds to GP IIb/IIIa receptors on two separate platelets, resulting in platelet cross
linking and platelet aggregation
...

Q
...

Role of platelets in hemostasis: Platelets play important role in all steps of hemostasis
...

2
...


4
...

Role played by formation of platelet plug: By forming platelet plug, platelets can stop blood loss if the hole
of the ruptured vessel is small
...

Role in blood coagulation: Platelets act as a clotting factor for blood coagulation
...
Platelet itself is a constituent of blood clot
...


Q
...
Except for the first two steps in the intrinsic
pathway, Ca2+ is required for promotion or acceleration of all the blood clotting reactions
...

Q
...

Vitamin K dependent factors: Vitamin K is required by liver for the activation of 4 clotting factors:
1
...

3
...


Factor II
Factor VII
Factor IX
Factor X

The vitamin K dependent factors II, VII, IX and X are produced as inactive proteins
...
The
carboxylase enzyme responsible for this in the liver requires vitamin K as a co-factor
...

Q
...


Endothelial surface factors: Probably the most important factors for preventing clotting in the normal vessel
are:
a
...

b
...

c
...
It acts by two ways:
• It binds with thrombin and prevents thrombin from clotting
...

2
...

3
...
Heparin: Secreted by basophil and mast cell
...

b
...
The complex of antithrombin III⸺heparin inhibits the activated factors IX, X, XI and XII
...
Fibrin: It has antithrombin action
...
This prevents the spread of thrombin into the remaining
blood and therefore, prevents excessive spread of the clot
...
Protein C: Activated protein C (APC) along with its co-factor protein S, inactivates factor V and VIII
and inactivates an inhibitor of tissue plasminogen activator, increasing the formation of plasmin
...
Protein S: Acts as cofactor for protein C
...
Heparin surface
...
α2 macroglobulin: Binds some clotting factors and prevents their action
...
Plasmin (fibrinolysin): This enzyme lyses fibrin and fibrinogen, with the production of fibrinogen degradation
products that inhibit thrombin
...
Name the agents that prevent blood coagulation
...
Natural anticoagulants:
1
...
Antithrombin II
3
...
Protein S
5
...
Thrombomodulin
7
...
α2 macroglobulin
B
...
Paul Heller’s mixture
2
...
3
...
Heparin
5
...
EDTA (ethylene diamine tetra-acetate)
7
...
Dicumarol

47

4
...
The pulmonary circulation
returns the blood to the left side of the heart
...
From those tissues, CO 2 and other
waste products are carried back to the right side of the heart
...


2
...

(the right side of the heart pumps blood from the heart to the lungs
...
The O2-rich blood goes into the left side of the heart)
...
O2-poor blood returns to the right side of the heart)
...

2
...

4
...

6
...
All or none law
b
...


Autorhythmicity: Autorhythmicity = Automaticity + Rhythmicity
Specialized cardiac muscle cell (i
...
junctional tissue) can initiate its own impulse without any external
stimulus
...
Specialized cardiac muscle cell can generate its impulse at a regular
interval of time
...
The rhythmicity of –
Cardiac tissues
SA node
AV node
AV bundle or Bundle of His
Purkinje fibers

2
...
Conduction velocities in the cardiac tissues are as follows:
Cardiac tissues
SA node
Atrial pathways
AV node
Bundle of His

Conduction velocities
0
...
05
1

Purkinje system
Ventricular muscle

4
1

48

3
...


Excitability: Heart muscle shows excitability; that is when a stimulus of adequate strength and duration is
applied to it, it develops an action potential
...

Contractility: After excitation, heart muscle contracts due to chemical and mechanical changes in the actin
and myosin
...
All or none law: If myocardial fibers are stimulated by a stimulus at or above threshold level, there
will be maximum contraction of heart muscle
...
This is called all or none law
...
Frank Starling’s law: ‘Force of contraction of heart is proportional to the initial length of the cardiac
muscle fiber’
...
e
...

Importance of Frank Starling’s law:
• This law ensures equal stroke volume of two ventricles
...
g
...

↓
Accumulation of blood in the left ventricle
...

↓
Increased initial length of the cardiac muscle fiber
↓
Increased force of contraction
↓
Increased cardiac output
↓
Proper blood supply to vital organs is ensured
...

6
...


Refractory period: The refractory period of the heart is the interval of time during which a normal cardiac
impulse cannot re-excite an already excited area of cardiac muscle
...

Functional syncytium: Cardiac muscle fibers are electrically connected with one another by gap junctions
...
It is called functional syncytium
...
Briefly discuss the refractory period with its significance
...

Types: Two types
...


Absolute refractory period (ARP): The period during which a second action potential cannot be elicited, even
with a strong stimulus, is called the absolute refractory period
...

Period of ARP: The whole depolarization, initial period repolarization, plateau, about half of the late rapid
repolarization is the ARP
...
25 – 0
...


2
...
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
...
RRP of ventricular muscle is 0
...


49

Importance of refractory period:
1
...

3
...

5
...
Of course, tetanization of cardiac muscle for any
length of time would have lethal consequences, and in this sense, the fact that cardiac muscle cannot be
tetanized, is a safety feature
...

Ensures enough time for recovery of cardiac muscle by getting nutrition and O 2 supply
...

If the ventricular rate is excessive, there is insufficient time between beats for the ventricles to fill
...
It is larger in physically active adults than in other healthy adults
...
The blunt, rounded
part of the heart is the apex; the larger, flat part at the opposite end of the heart is the base
...

The heart lies obliquely in the mediastinum, with its base directed posteriorly and slightly interiorly
...
The apex is pointed and is directed posteriorly but
the base is broad and directed towards the anterior side, to locate in the space of the fifth thoracic rib
...
The outer
layer is called the parietal and inner layer is called visceral pericardium
...
This cavity is filled with a fluid, known as pericardia fluid
...


50

The heart is four chambered with two upper chambers known as atreia (singular atrium) or auricles and two lower
chambers known as ventricles
...

The auricular part is smaller and consists of right and left auricles, which are separated from each other by interauricular septum
...
Such the
ventricles are separated from each other by inter-ventricular septum
...
The right
auriculo-ventricular aperture is guarded by a valve, known as tricuspid valve
...
These valves are attached with the papillary muscles or columnae
carneae, of the ventricle through chordae tendineae
...
A membranous fold, the Eustachian valve, guards the opening of the post caval,
situating between the left pre-caval and post-caval
...


Functions
Forces oxygenated blood from left auricle to
left ventricle and prevents the back-flow of
blood from left ventricle to left auricle
...

Situated at the junction of the
right ventricle and pulmonary
trunks
...


Helps the blood to flow from right auricle to
right ventricle and prevents the backflow of
blood from right ventricle to right auricle
...

Helps the blood to flow from inferior vena
cava to right auricle and prevents the backflow
of it
...


Pulmonary semilunar valve
Eustachian valve

51

Coronary
valve
Thebesian valve

or

Situated just behind the aortic
valve at the junction of the
coronary sinus and heart
...


Blood flow through the heart:
Blood leaves the heart in arteries and blood returns to the heart in veins
...

↓
Oxygenated blood leaves the left ventricle through the aortic valve to the aorta, which is the largest artery of our body
...

↓
Deoxygenated blood returns from the top of our body through the superior vena cava and from the bottom of our body
through the inferior vena cava to the right atrium
...

↓
Deoxygenated blood leaves the right ventricle through the pulmonary valve to the pulmonary arteries
...

The path of blood
Blood enters into the atria of the heart, separated from the ventricles by valves, preventing backflow of blood keeping
the blood flowing in one direction
...

↓
When the ventricles contract, the valves close preventing the blood from flowing back into the atria and blood flows
out of the heart
...

Q
...

2
...


Na+
Ca2+
K+

Q
...

Skeletal muscles could be fatigued but cardiac muscle never:
1
...


Cardiac muscle has plateau in action potential
...
This ensures enough
time for recovery of cardiac muscle by getting nutrition and O 2 supply
...

On the other hand, skeletal muscles have no plateau in their action potential
...


Junctional tissues of the heart: There are some specialized fibers in the cardiac muscle which can generate cardiac
impulses and transmit them to all parts of the myocardium
...

Name of the junctional tissues:
1
...


SA node (Sino-atrial node)
The intermodal pathways –
⸺ Anterior
⸺ Middle
52

3
...

5
...
Why is SA node called pace maker of the heart?
Pacemaker of the heart: Pacemaker makes or determines the pace of the race
...
SA node is called the pacemaker of the heart because its rate of discharge makes or determines the pace (rate) at
which the heart is beating
...
SA node normally discharges most rapidly:
Mechanism:
SA discharges most rapidly
↓
This impulse is transmitted to the AV node and other parts of the conductive system before they discharge
spontaneously
↓
As a result, these parts cannot generate impulse at their own rate rather they discharge at the rate of the SA
node discharge
↓
Then the impulse is transmitted to the myocardium
↓
So, myocardium discharges at the rate of the SA nodal discharge
↓
Thus the rate of discharge of SA node determines the rate at which the heart is beating
...


The rate of impulse produced by the SA node is greater than any other part of the heart
...
Therefore, SA node is called
the pacemaker of the heart
...
This is called pacemaker potential
...

Mechanism of production: There are two types of Ca2+ channels in the heart, the T (for transient) channels and the L
(for long lasting) channels
...
This slowly rising membrane potential is called pacemaker potential
...
After depolarization, K + efflux begins and
brings about repolarization
...

Tissues having pacemaker potential: SA node, AV node and other junctional tissues of the heart
...
Thus, this potential enables the cell to
discharge spontaneously
...
Name the pacemaker tissues
...

2
...


Sinoatrial node
Atrioventricular node and
Purkinje fibers

53

Cardiac cycle: The rhythmic contraction (systole) and relaxation (diastole) of the ventricles is called the cardiac cycle
...

↓
Blood is pumped out of the ventricles and into the aorta and pulmonary artery
...

↓
The ventricles fill with blood
...
Enumerate the events of cardiac cycle
...
Systole
a
...
Ventricular systole
2
...
Arterial diastole
b
...
Arterial systole (0
...
About 30% of ventricular
filling occurs actively during arterial systole
...

1
...
05 sec): During the first half of arterial systole, there is maximum contraction of
arterial muscles and intra-arterial pressure rises
...

2
...
05 sec): The second half of the arterial systole is called adynamic phase because
during this period force of contraction of arterial muscles decreases and intra-arterial pressure
decreases
...
Arterial diastole (0
...
During the first half of the arterial diastole, arteria
collect blood from vena cava and pulmonary veins and atrio-ventricular valves remain closed
...
About 70% of the ventricular
filling occurs passively during arterial diastole
...
Ventricular systole (0
...
It has three phases:
1
...

3
...
05 sec): It is the interval between the closure of the AV valves and
opening of the semilunar valves
...
The ventricular muscles contract but muscle length does not shorten
which is called isometric contraction
...
The intraventricular pressure rises sharply as the myocardium presses on the blood in the
ventricle
...

Importance: In this period, there is sharp rise of intraventricular pressure which helps large amount of
blood to be pumped out the ventricles in the next phase
...
11 sec): In this phase, ventricles pump about 80% of the blood
...
14 sec): In this phase, ventricles pump about 20% of the blood
...
Ventricular diastole (o
...
It has 5 phases:
1
...
04 sec): It is the interval between the onset of diastole and the closure of the
semilunar valves
...
So, the intraventricular pressure falls
...

2
...
08 sec): It is the interval between the closure of the semilunar valves
and opening of the AV valves
...
So the intraventricular pressure falls sharply
...

3
...
113 sec): It begins with the opening of the AV valves
...

4
...
167 sec): The amount of filling in this phase is minimum
...

• Arterial pressure falls and ventricular pressure slowly rises
...

5
...
1 sec): It coincides with the arterial systole
...


Heart sound: The vibration motion of the heart produced during different events of the cardiac cycle conducts through
the structures surrounding the heart and produces special audible sound called heart sound
...

2
...

4
...
3 rd heart sound is heard
in many normal young individuals
...
All sounds can be recorded
by phonocardiogram
...
Discuss the significance of 1st and 2nd heart sound
...
Physiological significance:
1
...

2
...

3
...

b
...

2
...


Loud sound indicates hyperdynamic circulation
...

Soft sound indicates heart failure, mitral regurgitation
...
Physical significance:
1
...

2
...

b
...
Palpable and loud 2nd heart sound indicates pulmonary hypertension
...
Fixed wide splitting indicates arterial septal defense
...
Wide but variable splitting indicates delayed right heart emptying e
...
, right bundle branch block
...
Reversed splitting due to delayed left heart emptying e
...
, left bundle branch block
...

Normal range: Normal BP = 120/80 mmHg (in young adult)
Types of blood pressure:
Types
Systolic
pressure

Definition
It is the maximum
pressure during systole of
the heart
...


60 – 90
Average: 80

Pulse
pressure

It is the difference
between systolic and
diastolic pressures

30 – 40
Average: 40

Mean
pressure

It is the average pressure
throughout the cardiac
cycle
...


78 – 98

Significance
It indicates the –
• Extent of work done by heart
...

• Degree of pressure which the arterial walls
have to withstand
...
It increases during exercise, excitement, meal
etc
...
It decreased during sleep, rest etc
...
It indicates the constant load against which
the heart works
...
Increased diastolic pressure indicates that the
heart is approaching failure
...
It is the index of peripheral resistance
...
It indicates the cardiac output
...

2
...

Increased mean pressure means increased chance of
development of hypertension
...


Bradycardia: The term bradycardia means a slow heart rate, usually defined as fewer than 60 beats per minute
...
Parasympathetic nerve (vagus) releases acetylcholine which
acts on heart and causes bradycardia
...
The excessive quantities
of blood pumped into the arterial tree with each beat initiate feedback circulatory reflexes or other effects to cause
bradycardia when the athlete is at rest

---