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BIOLOGY Term 2 Midterm Review Package
Table of Contents:
Ch
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2 Cell Structure and Function
Ch
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5 Cellular Metabolism
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9 Digestion
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11 Blood
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13 Respiratory System
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1 Chemistry of Life
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an atom is the smallest particle on earth that can not be divided any further
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Ionic bonds form when a metal and non metal come together to form a
compound
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Inorganic compounds usually contain metals and non metals, usually ionic
bonding, contain small number of atoms, often associated with non living
elements

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Organic Compounds always contain carbon and hydrogen, always covalent
bonding, could be quite large with many atoms, often associated with living
organisms
Polar molecules exist in such things like water, where there are hydrogen
bond that are very weak and easily broken
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Acids are molecules that dissociate in water and release hydrogen ions,
bases are molecules that dissociate in water to release OH ions
Buffers help to maintain balance or homeostasis in certain places
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Carbohydrates, fats, nucleic acids, and proteins are large molecules and when
water is added in the hydrolysis reaction, they are broken up into unit
molecules
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Some proteins
will function as
enzymes that
are organic
catalysts that
speed up
reactions in the
body
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These have two components, and amino group H2N and an acid group
COOH
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The specific bond that
bonds two amino acids together is called a peptide bond
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A dipeptide is 2 amino
acids linked, a polypeptide is
anything more than 2, and a
protein is a long chain of about
75 amino acids linked
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amino acids per turn, and tertiary is when the helix bends and winds
randomly and bonding occurs between the R groups
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Monosaccharide’s
are simple sugars only containing one unit, pentose (ribose) is one that has
five carbons and hexose (glucose) has 6 carbons
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A disaccharide is the term to
describe 2 monosaccharide molecules joined together; a common example
would be two glucose molecules coming together to form maltose
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The three common ones are starch, glycogen, and cellulose
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- Starch has few side
branches of glucose from the
main chain, and it is the
storage form of glucose in

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plants
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After an animal eats, the
liver will store glucose in the form
of glycogen, and then in between
eating, the liver will release
glucose into the blood to always
maintain a concentration of 0
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Cellulose is found in plant cell walls and accounts for the sturdy nature of
these walls
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Lipids are organic compounds insoluble in water
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Neutral fats (triglycerides) contain a fatty
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acid group and a glycerol group
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Below a
reaction is illustrated that
demonstrates the process that occurs
when a glycerol group and a fatty acid
group combine to make a lipid
molecule, or fat molecule
Phospholipids are fats that contain a
phosphate group, and this addition of
the phosphate group replaces one of
the three fatty acids groups
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Causing an oil to disperse in water is
called emulsification
- Steroids are similar
in structure to cholesterol
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Steroids count as fats as
well however they have a
completely different
structure from the
triglycerides and

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phospholipids
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They two forms of nucleic acids work
together in the cell to bring about protein synthesis
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Both DNA and RNA are polymers of nucleic acids, which means these nucleic
acids are just chains of nucleotides
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Backbone is
made up of phosphate sugar phosphate sugar
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ATP
(adenosine triphosphate) is a nucleotide that
contains three phosphate groups instead of one
and it is the energy carrier in cells
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2 Cell Structure and Function
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small organisms are unicellular and made up of only one cell while larger
organisms are more complex made up of more cells and therefore called
multicellular
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- Eukaryotic
cells are surrounded
by a cell membrane
as the outer layer, and
within this membrane
are many organelles
that contribute to the
workings of the cell
and these organelles
are suspended within
the cell by the
cytoplasm
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- Organelles
within the cell can be
categorized into 5
main categories: The
nucleus,
membranous canals
and vacuoles, energy
related, cytoskeleton,
and centrioles and
related organelles
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The protein molecules form a pattern (mosaic) within the
phospholipid bilayer which is a fluid (liquid)
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It serves as the control center for
the cell and oversees metabolic functioning, it also determines the cells
characteristics
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When it comes time for cell division, the chromatin will coil up
into chromosomes
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More

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than one nucleoli
may be present
within the
nucleus, and this
is where
ribosomal RNA
(rRNA) is
produced
...
Small
granules called
ribosomes are
attached to some
portions of the
endoplasmic
reticulum, if they
are present, it is
called the rough
endoplasmic
reticulum, if the
ribosomes are not
present, it is
called the smooth
endoplasmic reticulum
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These enzymes are
found within vacuoles that attach to the smooth endoplasmic reticulum,
these are called peroxisomes
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Ribosomes contain RNA and protein
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Usually ribosomes are attached to
endoplasmic reticulums, but when a
group of ribosomes all producing the
same protein are floating in a group
within a cell, this is called a polysome
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Then small portions of the ER will break
away and form vesicles (small vacuoles)
that then migrate to the golgi apparatus for
repackaging and export
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- Vacuoles are clear areas in side
with a membrane
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Vesicles are just
smaller vacuoles, and they are sometimes made by the golgi apparatus, if not,
they can be formed from folds in the cell membrane
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Lysosomes are special types of vesicles in which they are formed by the
golgi apparatus
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Following the formation of a lysosome, it may fuse
together with a vesicle that contains material that need to be digested
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Lysosomes also play a key role in cell
maintenance
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Mitochondria can be found in both
plant and animal cells and is a producer
of ATP
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The mitochondria
burns glucose molecules in order to
produce usable energy, ATP
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Mitochondria carry out gas exchange since there is an exchange
of oxygen and carbon dioxide when creating energy
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The inner
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membrane is convoluted into shelf like structures within called cristae
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Thse
structures help maintain the cells shape, anchor organelles, and allows
movement as appropriate
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Microfilaments are long and very
thin fibres that occur in bundles or
groupings
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Microtubules are shaped like
cylinders and are several times
larger than microfilaments
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When both these structures are
disassembled, the cell is able to
change shape into something else
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They help in the movement
of material throughout the cell
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Cilia are hair like
projections able to move cells around
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Cilia are formed from a 9+2 arrangement of
microtubules
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2
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Basal bodies, which are short cylinders with a circular
arrangement of nine microtubule triplets called the 9 + 0 pattern, are believed to organize the structure of cilia and flagella
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3 Cell Membrane and Cell wall
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Proteins can be found within the cell membrane, some are carriers that
promote movements of molecules in and out of the cell, and some are receptors for
molecules that influence the metabolic activity of the cell
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On the cell membrane there are also chains of simple sugars attached to the
proteins and fats (glycoproteins and glycolipids) these help the body to identify
the cell
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Plant cell walls are easily permeable, however the cell membrane in both are
not and regulate entrance and exit of molecules in and out of the cell
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The three general means of entering a cell are: diffusion, transport by
carriers, and endocytosis and exocytosis
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Rate of Diffusion is determined by three things, the size and shape of the
molecules diffusing, temperature, and the concentration gradient (difference in
concentration of diffusing molecules
between the two regions involved
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Lipids
soluble molecules are able to diffuse
through the membrane because the
membrane is composed of phospholipids
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Osmotic Pressure is the pressure caused by the flow of water from areas of
greater concentration to lesser concentration
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If a cell is in an isotonic solution, the concentration of solute in the cell and
around the cell are equal so movement of water is at equilibrium
...

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They get through the membrane via proteins called
carriers
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During facilitated diffusion or transport, there is
no expenditure of energy by the cell, because the
molecules are moving across the
concentration gradient from an area of greater
concentration to an area of lesser concentration
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Meaning the molecules are moving from an area of lesser
concentration to an area of greater concentration
...

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Both active and facilitated
transport work with small
molecules
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This process always
requires energy and it requires the
formation of a vesicle
...
This requires the formation of a vesicle as well
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5 Cellular Metabolism
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constantly occurring chemical reactions within the cell are called
metabolism
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All reactions within a cell can not go through without an enzyme present
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enzymes remain
unaltered after reactions
because only a small
amount is needed in
order to carry out the
reaction
...
See
picture for detail, on the let are substrates and on the right are products
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Enzymes make reactions more easily to occur because they lower the
activation energy for reactions to take place
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Enzymes determine the amount of product formed, if not much
enzyme is present, less product will be put out in a period of time
...

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Enzymes are usually composed of two groups, the apoenzyme (protein)
and the coenzyme (minearls and nonprotein structures)
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Vitamins are usually
coenzymes and they are unable to be
synthesized, they act as helpers
during enzymatic reactions
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NAD is a specific coenzyme
carryin niacin and is used alongside
the enzyme dehydrogenase
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When NAD is reduced it becomes NADH+, and
becomes oxidized when it becomes NAD again
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When energy is needed for anything in the cell
the cell will break down ATP into ADP and a phosphate
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Organic molecules are oxidizes,
releasing hydrogen atoms, this then releases the energy
needed in order to produce ATP
...

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During glycolysis, glucose is roken down into two
molecules of pyruvic acid
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Active
Acetate enters the Krebs cycle =, which is a cyclical series of oxidation reactions
that give off carbon dioxide and 1
ATP molecule
...
Krebs
accounts for 2 ATP per glucose
molecule
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When the
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coenzyme NADH+ enters this, it carries most of the hydrogen atoms picked up from
glycolysis, transition reaction, and Krebs cycle
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The oxygen is then reduced to water
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ATP is to be associated with all three of the systems mentions previously,
however transition reaction + krebs cycle, and glycolysis produce 4 ATP, meanwhile
respiratory chain produces about 34
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Glycolysis occurs outside mitochondria, however other three processes occur
within the mitochondria
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Amino acids can undergo this process as well but they will have to go thru
deamination (removal of amino group) first
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This is
also called fermentation
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8 Human Organization
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Human body tissues can be categorized into four different sections:
epithelial (surfaces and lines body cavities), Connective (Binds and supports
body parts), Muscular (moves body parts), nervous (responds to stimuli and
transmits impulses)
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The body system must remain constant, or
at homeostasis
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Later
when glucose in blood gets used, it can be broken
down and put back into the blood as glucose
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Negative feedback mechanisms are like
thermostat controls
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9 Digestion
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Olfactory receptors in nose are
responsible for smelling, and
the taste buds are responsible
for tasting food
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there are also three pairs of salivary glands that send juices to the mouth
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It helps
create the product Maltose in the reaction (a disaccharide)
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the tongue turns the chewed food along with saliva into a ball called a bolus
and send it to the esophagus to reach he stomach
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Sphincters regulate when and where food can move, cardiac sphincter stops
food from coming out of stomach
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Millions of gastric glads are found in the stomach lining
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This juice contains pepsinogen and hydrochloric acid
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The stomach pH is 3
because of the HCl
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By this time the food has become liquid called acid chyme and enters the
small intestine via the pyloric sphincter
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Liver and Pancreas send secretions to the duodenum for digestion
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The pancreas sends pancreatic juice to the duodenum via the pancreatic
duct
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Small intestine pH
is slightly basic at 8
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Pancreatic juice contains→
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After these reactions are
carried out, the digestion of fat is
complete
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This
juice releases the
following and
completes the break
down of protein and
carbs→
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In the stomach, a hormone produced by the lower part of the stomach called
gastrin is made when a protein rich meal is consumed, so they tell the upper
stomach to produce more pepsinogen
...
This tells the pancreas and the gall bladder to send
secretions to take care of it
...

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Absorption mainly occurs in the small intestine due to its massive length and
millions of villi
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Blood vessels in
the villi will eventually
form the hepatic portal
vein which leads to the
liver
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Ch
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Arteries and arterioles carry blood away from the heart
while veins and venules carry it to the heart
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Arteries have thick walls and elastic properties to accommodate the sudden
changes of blood pressure when the heart beats
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Exchange of nutrients and waste material
occurs between these thin walls
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Carbon dioxide and ammonia diffuse into the
capillaries since they are waste products
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Venules drain blood from
the capillary and join to form a vein
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Myocardium is the main pat of heart made from cardiac muscle tissue
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There are four chambers
within the heart, the upper two thin walled atria, and the lower two thick walled
ventricles
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Valves between the atria and the ventricles are called atrioventricular
valves
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AV valves on the right are
called tricuspid valves because they have three cusps,
and AV valves on left are called bicuspid or mitral
because is has two cusps
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Right side of heart send blood to lungs, and left
side of heart send blood to rest of body
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From heart, oxygenated blood->Left atria->left
ventricle->aortic semilunar valve->aorta->rest of
body
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blood must pass through lungs before ending
up in left side
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SA node is in upper of right atrium, AV node is
at bottom of right atrium, SA node is also called
pacemaker that send out signals to contract atria,
when this impule reaches AV node it tells ventricles to
contract via purkinje fibers

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