Mrs H bio 5 Mass Transport in Animals Flashcards
what is the structure of a capillary?
thin endothelial layer only, Small diameter to create lots of friction
what is the uses of the capillaries?
exchange materials between blood and tissues
name 4 adaptations of the capillaries?
single cell thick: decreases diffusion distance
branched: increases surface area
narrow: reduces flow rate giving more time for diffusion + ensures RBC in contact with wall to give short diffusion pathway
permeable: substances can pass in/out
what is the 4 components of the structure of the arteries?
endothelial layer, elastic layer, muscle layer, outer layer
how is the endothelial layer of an artery adapted for its functions?
one cell thick to reduce friction
how is the elastic layer if an artery adapted for its function?
stretches and recoils under pressure
stops pressure getting too high
how id thee muscle layer of the artery adapted for its function?
contracts to maintain pressure
what does the outer layer of the artery do?
gives support and strength
what are the components of the structure of the arterioles?
muscle layer and elastic layer
what are the adaptations of the muscle layer of the arterioles?
thinner than the artery but still relatively thick
contracts to limit blood flow to organs
what are the adaptations of the elastic layer of the arterioles?
thinner than artery as blood is at lower pressure
what are the components of the structure of the vein?
endothelial layer, elastic layer, muscle layer, valves
what are the adaptations of the endothelial layer of the vein?
one cell thick and reduces friction
what are the adaptations of the elastic layer of the vein?
very thin as blood pressure is low. no need to stretch and recoil
what are the adaptations of the muscle layer of the vein?
very thin- no need to contract as all blood -> heart
what are the adaptations of the valves in the veins?
reduce back Flow of blood
in blood that is travelling in the arteries what is the pressure like?
high
what will happen to the water potential of a solution if more solute is added?
decrease
what are the names of the 3 blood vessels associated with the liver?
hepatic artery, hepatic vein, hepatic portal vein
what are the names of the 3 blood vessels associated with the kidney?
renal artery and vein
what are cells in a tissue surrounded by?
numerous spaces filled by tissue fluid formed from water and dissolved nutrients
what two forces act across the capillary wall and affect the movement of fluid into and out of the capillary?
hydrostatic pressure and water potential
what happens at the arterial end of the capillary?
the hydrostatic pressure of the blood is higher than the hydrostatic pressure of the tissue fluid so blood plasma (water and dissolved molecules) is pushed out of the capillary and tissue fluid is formed
what happens at the venous end of the capillary?
the water potential of the blood (mainly due to plasma proteins) is lower than the water potential of the tissue fluid so water potential difference creates a force pulling water back into the capillary venous end
what does tissue fluid contain?
glucose, amino acids, urea, ions, water
why does the blood at the venue end have a low water potential
high conc of protein, low conc of fluid
how does the tissue fluid re-enter the blood stream?
osmosis
what happens to any excess liquid that doesn’t return to the capillary?
the lymph vessel drains away any excess liquid
what remains in the blood stream once the tissue fluid has been forced out?
protein
what causes the water potential in the capillary to lower?
water has passed out with the tissue fluid and the proteins are left in the capillary
explain the role of the heart in the formation of tissue fluid
the ventricles contract
