3.2 Mass Transport In Animals Flashcards
define mass transport
when substances are carried from lungs and intestines over large distances to individual cells and away from individual cells
where has the higest blood pressure
aorta
what transports oxyhaemoglobin from the lungs to the heart
pulmonary vein
what takes deoxygenated blood away from kidneys
renal vein
what transports deoxygenated blood to lungs
pulmonary artery
what takes blood to righ atrium
vena cava
what takes blood to kidneys
renal artery
features of arterys
thick muscle and elastic tissue layer
small lumen
no valves
high blood pressure
carries bloody away from heart
features of veins
thin muscle and elastic tissue layer
large lumen
valves
low blood pressure
carries blood to heart
structure of cappilaries
no muscle and elastic tissue layer endothelial layer only
small diamter creates lots of friction
why do arteries have elastic tissue
tissue stretches under pressure and recoils to even out pressure
why do arteries have muscle layers
muscles contract and reduce diamter of lumen to change the flow
adaptations of capillaries
THIN: increases rate of diffusion
BRANCHED: increases surface area
PERMEABLE: substances can pass in and out
NARROW DIAMETER: ensures RBC is in contact with wall to reduce diffusion distance
when is tissue fluid formed?
when plasma is forced out of capillaries
what is the purpose of the lymph vessel
to drain excess tissue fluid
Describe how tissue fluid is formed and how it is returned to the circulatory system (6)
FORMATION
high hydrostatic pressure forces water / fluid out
large proteins remain in the capillary
RETURN
low water potential in capillary
due to proteins in capillary
water enters capillary by osmosis
describe the role of hydrostatic pressure of blood and osmosis in the formation and reabsoprtion of tissue fluid (6)
at atrieole end, hydrostatic pressure and blood pressure are high
hydrostatic pressure is higher than effect of osmosis
therefore tissue fluid is forced out
tissue fluid contains small molecules eg (o2 and glucose)
larger proteins remain in the blood as they cant fit through wall spaces in capillary
proteins that remain lower the wp of the blood
tissue fluid moves back into blood via osmosis
diastole
myocardium is relaxed
systole
myocardium is contracted
cardiac output
cardiac output = stroke volume X heart rate
what is an atheroma and how may it cause a myocardial infraction (5)
cholestrol/ fatty materials build up in artery wall
this can lead to a blood clot
which blocks the coronary artery and reduces oxygen supply to cells
cells unable to respire and die
explain how oxygen is loaded transported and unloaded in the blood (6)
haemaglobin carries oxygen in red blood cells
loading of o2 happesn in lungs
at a high po2
unloads at repsiring tissue at a low po2 and higher co2 concentration
partial pressure of oxygen
ammount of oxygen in blood
oxygen dissociation
occurs at respiring tissues
oxygen association
in the lungs
component of harm
