exchange and transport (the circulatory system)

Question 1

why do multicellular organisms need a circulatory system?

Answer 1

have a low surface area to volume ratio so need a transport system to exchange materials

Question 2

what does the vena cava transport?

Answer 2

deoxygenated blood to the heart

Question 3

what does the aorta transport?

Answer 3

oxygenated blood to the body

Question 4

what does the pulmonary artery transport?

Answer 4

deoxygenated blood to the lungs

Question 5

which blood vessels are attached to the heart?

Answer 5

vena cava, aorta, pulmonary artery and pulmonary vein

Question 6

which blood vessels are attached to the lungs?

Answer 6

pulmonary artery and pulmonary vein

Question 7

which blood vessels are attached to the kidneys?

Answer 7

renal artery and renal vein

Question 8

what do arteries do?

Answer 8

carry blood from the heart to the rest of the body

Question 9

what is the structure of an artery?

Answer 9

thick, muscular walls 
elastic tissue to stretch and recoil to maintain high pressure 
inner lining (endothelium) folded, so the artery can stretch

Question 10

what do arterioles do?

Answer 10

form a network throughout the body, blood directed to areas in demand

Question 11

what do veins do?

Answer 11

take blood back to the heart under low pressure

Question 12

what is the structure of a vein?

Answer 12

wude lumen
little elastic or muscle tissue
valves to stop blood flowing backwards

Question 13

what do capillaries do?

Answer 13

exchange substances

Question 14

how are capillaries adapted?

Answer 14

short diffusion pathway as found near cells in exchange tissues
one cell thick which shortens the diffusion pathway
large number of capillaries to increase surface area for gas exchange

Question 15

what is tissue fluid?

Answer 15

fluid which contains water, glucose, amino acids, fatty acids, ions and oxygen
surrounds tissues

Question 16

how is tissue fluid formed?

Answer 16

high hydrostatic pressure at the arteriole end of the capillary
fluid passes out, large molecules remain
which lowers the water potential
water move back into the venous end of the capillary by osmosis
lymph system collects excess tissue fluid which is returned to the blood