transport systems Flashcards
double circulatory system
blood passes through heart twice on one complete circuit of body
closed circulatory system
circulatory system made up of vessels containing blood
endothelium adaptations
smooth, single layer of squamous epithelial cells
muscles in artery
for constriction and dilation
allow wall to stretch as pulses of blood surge through at high pressure
plasma
flows through capillaries and some plasma leaks out through gaps in endothelium flowing into spaces between cells of tissue
tissue fluid
less proteins than plasma fluid as they are too large to pass through capillary endothelium. wbc can fit roc too large
bohr shift
decrease in affinity of haemoglobin for oxygen that occurs when co2 is present
cardiac cycle steps
atrial systole
ventricular systole
ventricular diastole
atrial systole
atria contract
blood flows from atria into ventricles
back flow stopped by closure of valves in veins
ventricular systole
ventricles contract
atrioventricular valves pushes shut by pressurised blood in ventricles
semilunar valves in aorta and palomanry artery pushed open
blood flows from ventricles to arteries
co2 conc dissociation curve
more co2 shift to the right
co2 journey
produced by respiring cells
it diffuses from the cells into the blood plasma and then diffuses into rbc
carbonic anhydrase catalyses reaction with co2 and water to make carbonic acid H2co3
carbonic acid dissociates into h+ions and HCO3-
haemoglobin combines with hydrogen ions making haemoglobin acid HHb and oxygen is released
chloride shift
chloride ions move into rbc from blood plasma down electrochemical gradient to balance the movement of hydrogencarbonate ions into the plasma from the red blood cells
fetal haemoglobin
needs to be better at absorbing oxygen as by the time oxygen reaches placenta oxygen saturation has decreased
higher affinity to survive at low partial pressure
shift to left
how is the tunica media of a muscular artery different to that of an elastic one
Muscular artery has a thicker tunic media with more smooth muscle(vaso constrict and dialate), less elastin (less stretch and recoil) and a narrower lumen
is the aorta a muscular or elastic artery
elastic
Why does elastic artery need more elastin and collagen in thinner tunic media
To let artery stretch in response to each pulse
How does a vein differ from an artery
One way valves
Wider lumen
Less smooth muscle
Lots of collagen
which has a thinner tunica media vein or artery
vien
what tissues are in the tunica intima in arteries
endothelium cells (squamous epithelium)
tunic media of arteries
elastic fibres and collagen and smooth muscle
tunica externa of arteries
collagen and some elastic fibres
tunica media of vein
smooth muscle and elastic fibre
tunica externa of vein
mostly collagen fibres
what does smooth muscle do vs elastic tissue
smooth muscle is for vasoconstriction and vasodilation to reduce blood flow or increase pressure but elastic tissue is so blood vessel can stretch and recoil and does not burst
