Topic 3 - B : more exchange and transport systems Flashcards
Only from the heart onwards
Function of Pulmonary artery
heart to lungs
Pulmonary vein
lungs to heart
Aorta
heart to body
Vena cava
body to heart
Renal artery
body to kidneys
Renal vein
kidneys to vena cava
Function and structure of arteries
carry blood from heart to rest of body
thick elastic wall
small lumen
carry oxygenated blood apart from pulmonary artery which takes deoxygenated blood to lungs
Function and structure of arterioles/capilery
branch from arteries
thin elastic wall
small lumen
Function and structure of vein
take blood back to heart
contain valves to stop backflow
wide lumen meaning low pressure
thin wall
carry deoxygenated blood except for pulmonary veins which carry deoxygenated blood to heart from lungs
Coronary arteries
blood to heart
function of left ventricle
thick wall allowing it to contract more powerfully
Atrioventricular valves
link atria to ventricles and stop blood backflow
Semilunar valves
link ventricles to pulmonary artery and aorta and stop backflow
cords
attach atrioventricular valves to the ventricles to stop them being forced up into the atria when ventricles contract
Cardiac cycle - ventricle relax atria contract
atria contract pushing blood into the ventricle potentially changing the volume and pressure a little bit but not much
Cardiac cycle - ventricle contract atria relax
atria relax
ventricle contract increasing pressure
Atrioventricular valve closes as pressure is higher in ventricle than atria
pressure in ventricle is higher than aorta and pulmonary artery which forces Semi lunar valve to open
Cardiac cycle - Ventricles relax atria relax
both relax
higher pressure in pulmonary and aorta meaning semilunar valve closes
process then repeats
what does the xylem transport
water and ions
what does the phloem transport
sugars
amino acids
cohesion tension theorey
transpiration - water evaporates through stomata at top of xylem
this creates tension, pulling more water to leaf
water molecules are cohesive so they stick together and when one is pulled into leaf, others are
this means all water in the xylem moves up
water then enters the stem through the roots
define transpiration
evaporation of water through the leaves of a plant
water leaves through the stomata and down the water potential gradient
How does light intensity affect transpiration
the lighter it is the faster the transpiration as stomata are open
how does temperature affect transpiration
higher the temperature the faster the transpiration rate as warmer water molecules have more energy so they evaporate quicker
How does humidity affect transpiration
the lower the humidity the faster the transpiration rate as if the air is dry there is a bigger water potential gradient
How does the wind affect transpiration
windier it is the faster the transpiration rate as lots of air movement blows away water molecules from around the stomata increasing the water potential gradient
how are most molecules broken down in digestion
hydrolysis reaction
endopeptidase
hydrolyse peptide bonds within protein
exopeptidase
hydrolyse peptide bonds at end of protein to release single amino acid
how is glucose absorbed
active transport with sodium ions
co transporter (channel protein)
how is galactose absorbed
active transport with sodium ions through co transporter (channel protein
how is fructose absorbed
facilitated diffusion through carrier proteins
how are fatty acids and monoglycerides absorbed
micelles diffuse directly across the epithelial cell membrane
how are amino acids absorbed
similar way to glucose and galactose
