3.3.4.1 Mass Transport Of Animal Flashcards
3 type of blood vessel
Arteries - arteriole (away from heart)
Capillary
Veins- Venules (toward heart)
Artery structure related function
Muscular wall layer is thick
Maintain and withstand high pressure
Elastic layer is relatively thick
Stretch and recoil as the heart beat - maintain high pressure
Even out the pressure of blood through this vessel
Endothelium is folded
Allow the artery to stretch
Maintain high pressure
No valves
High pressure from heart , where blood will only able to flow in one direct
No need to prevent back flow
arteriole structure related function
arterioles form a network throughout the body
direct the blood to different area of demand in the body
muscles fibre present within arterioles (involuntery)
contract to restrict size of lumen to reduce the blood flow
relax to increase the size of lumen to allow full blood flow
(control blood flow)
to change the lumen size
vasoconstriction vs vasodilation
exam ans (during exercise)
circular smooth muscle relax
dilate of lumen of blood vessel to increase blood flow to area need
vasodilation
vein structure related to function
wider lumen
blood at low pressure , do not need to withstand high pressure
muscle layer and elastic layer are relatively thin
contract to help blood flow
vein contain vales at interval throughout
stop the blood flowing backwards
capillary structure related to function
walls consists mainly of the lining layer (endothelium) - one cell thick
shorter diffusion distance, rapid diffusion / fast exchange between blood to cell
numerous and highly branched
increase surface area for exchange
rapid gas exchange for aerobic respiration to reach all the cell
narrow lumen (7um, size of red blood cell to fit)
short diffusion distance for gas exchange
how efficient exchange of substance in capillary link to rate of blood flow
more time for exchange of substance
explain the pressure, velocity, total area relation to 3 blood vessel
23/4 ppt
Artery
pulsatile due to pumping of heart and elastic recoil of arteries, declining slightly reducing amplitude as distance from heart increase
Arterioles
Friction of arterioles vessel wall cause progressive pressure drop. Arterioles have large total surface area and relatively narrow bore causing substantial reduction from aortic pressure. Their pressure depends on whether they are dilated or contracted
capillary
even greater resistance in the capillary with large cross sectional area. the velocity of blood flow is directly related to the pressure. in the capillary beds the pressure drop further due to leakage from capillaries into tissue.
venules and veins
return flow to the heart is non-rhythmic and the pressure in the veins is low but can be increased by the massaging effect of muscle
what factor minimum internal diameter of the lumen of a capillary
diameter of blood cell
why the volume of blood leaving the capillary network into the veins is less than the volume of blood enter from arteries
leakage of water from plasma from capillary to surrounding tissue in form of tissue fluid
why the pressure of capillary drop
leakage of water from plasma from capillary to surrounding tissue in form of tissue fluid
Cardiac cycle (systole)
Atrial systole
Atrium contract, ventricle, relax
From atrium to ventricle
Tricuspid and bicuspid valve, open semilunar valve closed
Higher pressure in atrium (decrease volume) , lower pressure in ventricle (increase when blood eject from Atrium)
Wall thinner in atrium, less force, used to pump for a short distance from atrim to ventricle
Ventricular systole
Atrium, relax, ventricle contracts
From ventricle to Artery
Tricuspid and bicuspid valve closed to present back flow, semi lunar valve open
Higher pressure in ventricle lower pressure ( decrease volume) in a aorta and pulmonary artery
Diastole
Atrium and ventrical relax
Blood re-enter the atrium via vena cava and pulmonary veins
Tricuspid and bicuspid valve open semi lunar valve closed
Higher pressure in atrium, as ventricle, continue to relax pressure fall below atrium
So bloodflow passively without push by atrial contraction
order of valves open and closed
- AV valves closed (ventricle > atrium)
- Semi lunar open (ventricle > artery)
- Semi lunar close (artery > ventricle)
- Av valves open (atrium > ventricle)
valves movement related to pressure
graph 25/4
definition of double circulatory system
blood flow twice through the heart for each circulation of the body
there are 2 circuit
why we need double circulatory system
blood pressure is high
rate of blood flow to the tissue is greater
delivery of oxygen to the cell is quicker
this is important in mammals as they have high metabolic rate
heart structure (from right to left)
right (deoxygenated)
superior/ inferior vena cava
right atrium
tricuspid valves (right atrioventricular valves)
right ventricle
semilunar valves
pulmonary artery
left (oxygenated)
pulmonary veins
left atrium
bicuspid valves (left atrioventricular valves)
left ventricle
semilunar valves
aorta
blood vessel between kidney and heart
to kidney : renal artery
leave kidney : renal veins
explain how the highest blood pressure is produced in the left ventricle
during ventricular systole, there are strongest ventricle contraction
why baby are unable to get enough oxygen to their tissues if they are born with a hole between the right and left ventricle?
the oxygenated and deoxygenated blood will mixed
low volume of oxygenated blood leave the left ventricle to aorta
so no enough oxygen supply to tissue for muscle respiration
how can cardiac output keep the same while resting heart beat decrease after exercise?
training increase in size/ volume of heart
strengthen heart muscle
increase in stroke volume (more blood leave the heart each beat)
cardiac output = stroke volume x heart rate