mass transport in animals Flashcards
what is the structure of haemoglobin
-4 polypeptide chains
-quarternary protein
-O2 binds to Fe2+
what is affinity of haemoglobin for oxygen?
the ability for oyxgen to attract/bind onto the haemoglobin
what is saturation of oxygen with haemoglobin.
the maximum amount of oxygen that haemoglobin can bind onto.
what is loading/ association of haemoglobin
when oxygen binds onto haemoglobin
what is unloading/dissociation of haemoglobin
when oxygen unbinds from haemoglobin
what is meant by the partial pressure of oxygen
concentration of oxygen
what is the affinity when the partial pressure is low?
small affinity
why is the affinity lower for the 1st O2 molecules
its harder for the oxygen to bind onto the haem group
what does the binding of the 1st oxygen molecule do to haemoglobin
creates a conformational change to the quarternary structure.
what happens when there’s a conformational change to the haem group?
will allow for greater affinity
what is the process in which there is a conformational change in the haem group?
positive co-operativity.
why is the partial pressure low in areas near muscle tissue?
cells use it for respiration
why does it take longer for the fourth oxygen molecule to bind
shortage of the remaining binding sites
which part of the body has a higher affinity for oxygen.
the lungs
what happens to the dissociation graph when CO2 is present?
moves to the right
what happens when there is an increase in CO2?
it lowers the pH.
how does carbon dioxide lower the pH
it produces H+ ions.
what is the equation for when CO2 binds to water?
it produces carbonic acid+hydrogen carbonate ions and H+ ions.
what happens when H+ ions bind to haemoglobin?
it unloads o2 at a greater rrate.
what does it mean when theres a lower affinity?
And why is that?
less oxygen is readily avaliable.
more is being unloaded to the tissues
because the cells are respiring.
what way does curve shift to when theres a lower affinity?
moves to thee right
what is the cardiac output?
volume of blood that pumps out the heart per time
why is the cardiac output higher in athletes/ periods of exercise.
higher cause
more blood is pumped to respiring cells
describe the ventricular walls of an athlete
it would be thicker
what is the stroke volume?
volume of blood pumped out the left ventricle in one cardiac cycle.
how can calculate cardiac cycle?
heart rate x stroke volume
what way does the graph shift to when there is a higher affinity?
it moves to the left
why does the graph move to the left when theres a higher affinity?
shows that at any given pressure there is greater saturation
why is foetal haemoglobin higher.
allows haemoglobin to bind at low pressure.
allowing for more oxygen to be supplied to the respiring cells.
to growing baby.
why do we have a double circulatory system?
manage pressure of blood flow
why does blood flow at low pressure to the lungs
prevents damage in capillaries around aveoli
enables time for gas exchange
why does blood flow at a greater pressure when its pumped to rest of body
so blood reaches respiring cells
what are blood vessels in the kidneys called.
renal veins
renal arteries
why is the heart described as myogenic?
can contract or relax without nervous or hormonal stimulation.
what happens to tthe cornary arteries arre blocked
oxygen isnt supplied to the heart
wont be able to respire
cells die
= heart attack
what is the name of the valve found in the right side of the half
tricuspid Artiroventricular valves
what is the name of the valves found in the left side of the heart
bicuspid atrioventricular valves
where are the semi lunar valves located
to the pulmonary artery
aorta
what is the septum
separates oxygenated and deoxygenated blood
what doees systole mean
contracting
what does diastole mean?
relaxation
what happens when blood enters the atria during the cardiac cycle?
pressure gradient is established cause its higher in atria compared to ventricle
what happens to the atriventricular valves when a pressure gradient is established betwwen atria and ventricles
opens
what happens to the heart when the AV valves open
atrial systole occurs and pushes blood down to ventricles
what happens when the ventricels contarct when blood travels.
(ventricular systole)
pressure gradient formed. higher in ventricles lower in atria
what happens to the valves during ventricular systole?
AV valves close
why does the semi lunar valve in the pulmonary artery and aorta open?
greater pressure in ventricles compared to aorta/pulmonary artery.
cause of a pressure gradient
when does the semi lunar valves close
pressure in aorta/ pulmonary artery is high compared to ventricle.
when does ventricular diastole occur
when blood reaches the aorta
what are the coronary arteries
they supply blood/glucose to the heart
relate the structure to the functions of the artery
when blood moves at high pressure
its elastic walls recoil/ stretch
what happens to the elastic walls of the arteries
they recoil/ stretch at high pressure
explain one advantage of capillaries being narrow
short diffusion pathway
providing for faster diffusion
what factor limits the internal diameter of of the lumen of the capillary
endothelial cells are small
why is the volume of blood leaving the capillaries into the veins lower than inital volume from arteries
used in tissue fluid
what happens when CO2 is produced in the blood
produces H+ ions
lower affinity for oxygen
as there is more CO2
how is tissue fluid formed
when blood is under high hydrostaic pressure from arteries and narrow walls.
molecules are forced from holes in capillaries by ultrafiltration
what type of pressure is blood formed under to make tissure fluid
hydrostatic pressure
what comes out the blood from ultafiltration
amino acids
minerals
water
glucose
what doeesn’t get filtered from the blood
red blood cells
larger proteins
why does the hydrostatic pressure fall towards the veins
loss of water
explain why high blood pressure causes accumulation of tissue fluid
higher hydrostatic pressure
increase of outward pressure frrom arteries
reduces inward pressure of ventricles
explain why the water pressure is high towards thee end of the veins than arteries
presence of proteins
water moves out the blood from capillaries
explain the role of the heart in the formation of tissue fluid
contraction of ventricles produce high hydrostatic pressure
forces water out of capillaries
where is excess tissure flud drained into
lymphatic system
what happens when thers a blockage in the lymphatic system
excess tissure fluid cant be reabsorbed
what does the lympahtic system do
drains excess fluidn n
