Transport in Animals - Blood, Tissue Fluid and Lymph

Question 1

what is blood

Answer 1

the fluid inside blood vessels. It consists of cells floating in yellow plasma

Question 2

what are the components of blood

Answer 2

• plasma (55%)
• platelets
• white blood cells
• red blood cells (44%)

Question 3

what does plasma contain

Answer 3

• water
• carbon dioxide
• mineral ions
• hormones
• urea
• plasma proteins
• glucose and amino acids

Question 4

what is tissue fluid and what is it formed form

Answer 4

• the fluid that bathes cells in tissues
• it is formed from the plasma that leaks out of capillaries

Question 5

what is the function of tissue fluid

Answer 5

it is essential for the exchange of materials between our cells and our blood

Question 6

what do cells absorb from tissue fluid

Answer 6

oxygen and nutrients

Question 7

what do cells release into tissue fluid

Answer 7

carbon dioxide and other metabolic wastes

Question 8

describe the hydrostatic pressure at the arteriole end of the capillary

Answer 8

relatively high

Question 9

what is the result of the relatively high hydrostatic pressure at the arteriole end of the capillary

Answer 9

fluid is pushed through the gaps in the capillary walls

Question 10

what causes some tissue fluid to move back into the capillary at the arteriole end of the capillary

Answer 10

• the relatively small hydrostatic pressure of tissue fluid working in the opposite direction
• oncotic pressure

Question 11

what is oncotic pressure

Answer 11

the pressure created by the osmotic effects of plasma proteins

Question 12

describe the net movement at the arteriole end of the capillary

Answer 12

there is a net hydrostatic pressure forcing fluid out of the capillary

Question 13

describe the hydrostatic pressure at the venule end of the capillary

Answer 13

much lower due to the loss of fluid

Question 14

is there still oncotic pressure at the venule end of the capillary and why

Answer 14

yes, as the plasma proteins are too large to fit out through the gaps in the capillary walls

Question 15

describe the net movement at the venule end of the capillary

Answer 15

net movement of fluid into the capillaries

Question 16

what is the formula for net movement

Answer 16

net hydrostatic pressure + net oncotic pressure (negative)

Question 17

if fluid is moving out of the capillaries, is this shown as positive or negative

Answer 17

positive

Question 18

how does tissue fluid differ from blood

Answer 18

• no platelets
• no red blood cells
• no plasma proteins

Question 19

suggest why a severe lack of protein in the diet can lead to oedema (swelling)

Answer 19

• lack of plasma proteins
• less oncotic pressure
• less tissue fluid reenters the capillaries
• tissue fluid accumulates, causing swelling

Question 20

what happens to 90% of the fluid that leaks from capillaries

Answer 20

it is returned to them

Question 21

what happens to the remaining 10% of fluid that leaks from the capillaries

Answer 21

it is collected and returned to the blood system via a series of tubes called lymph vessels

Question 22

what are lymph vessels

Answer 22

tiny, blind-ending vessels found in almost all tissues in the body

Question 23

what is the function of valves in lymph vessels

Answer 23

allow tissue fluid to flow in, not out, preventing backflow

Question 24

what do the valves in lymph vessels allow through

Answer 24

proteins

Question 25

why is it important that proteins can enter the lymph

Answer 25

- most proteins cannot enter the capillaries as they are too large - proteins made by cells may still need to be transported to other tissues

Question 26

how is the fluid inside lymph vessels different to tissue fluid

Answer 26

- less oxygen - more carbon dioxide - more lymphocytes

Question 27

why are high concentrations of lipid found in the lymph in the walls of the small intestine

Answer 27

lipids are absorbed into lacteals in villi

Question 28

where is lymph eventually transported to

Answer 28

the subclavian veins

Question 29

what helps move lymph through the lymph vessels

Answer 29

contraction of muscles surrounding the lymph vessels

Question 30

describe the speed of lymph flow

Answer 30

slow

Question 31

where are lymphocytes found and where do they divide

Answer 31

lymph nodes

Question 32

is pressure higher in the aorta or vena cava and why

Answer 32

aorta - pumping of heart - loss of volume - resistance to flow - narrower lumen

Question 33

describe glucose concentration in the aorta, tissue fluid, lymph, and vena cava

Answer 33

- aorta: high - tissue fluid: medium - lymph: low - vena cava: high

Question 34

explain the differences in glucose concentrations

Answer 34

- glucose enters blood at small intestine, and is transported in blood - passes through capillary wall into tissue fluid - used in tissues for respiration

Question 35

is the concentration of fats higher in lymph than in blood/tissue fluid

Answer 35

yes, too large to move through capillary walls