Transport in Animals - Blood, Tissue Fluid and Lymph Flashcards
what is blood
the fluid inside blood vessels. It consists of cells floating in yellow plasma
what are the components of blood
- plasma (55%)
- platelets
- white blood cells
- red blood cells (44%)
what does plasma contain
- water
- carbon dioxide
- mineral ions
- hormones
- urea
- plasma proteins
- glucose and amino acids
what is tissue fluid and what is it formed form
- the fluid that bathes cells in tissues
- it is formed from the plasma that leaks out of capillaries
what is the function of tissue fluid
it is essential for the exchange of materials between our cells and our blood
what do cells absorb from tissue fluid
oxygen and nutrients
what do cells release into tissue fluid
carbon dioxide and other metabolic wastes
describe the hydrostatic pressure at the arteriole end of the capillary
relatively high
what is the result of the relatively high hydrostatic pressure at the arteriole end of the capillary
fluid is pushed through the gaps in the capillary walls
what causes some tissue fluid to move back into the capillary at the arteriole end of the capillary
- the relatively small hydrostatic pressure of tissue fluid working in the opposite direction
- oncotic pressure
what is oncotic pressure
the pressure created by the osmotic effects of plasma proteins
describe the net movement at the arteriole end of the capillary
there is a net hydrostatic pressure forcing fluid out of the capillary
describe the hydrostatic pressure at the venule end of the capillary
much lower due to the loss of fluid
is there still oncotic pressure at the venule end of the capillary and why
yes, as the plasma proteins are too large to fit out through the gaps in the capillary walls
describe the net movement at the venule end of the capillary
net movement of fluid into the capillaries
what is the formula for net movement
net hydrostatic pressure + net oncotic pressure (negative)
if fluid is moving out of the capillaries, is this shown as positive or negative
positive
how does tissue fluid differ from blood
- no platelets
- no red blood cells
- no plasma proteins
suggest why a severe lack of protein in the diet can lead to oedema (swelling)
- lack of plasma proteins
- less oncotic pressure
- less tissue fluid reenters the capillaries
- tissue fluid accumulates, causing swelling
what happens to 90% of the fluid that leaks from capillaries
it is returned to them
what happens to the remaining 10% of fluid that leaks from the capillaries
it is collected and returned to the blood system via a series of tubes called lymph vessels
what are lymph vessels
tiny, blind-ending vessels found in almost all tissues in the body
what is the function of valves in lymph vessels
allow tissue fluid to flow in, not out, preventing backflow
what do the valves in lymph vessels allow through
proteins
why is it important that proteins can enter the lymph
- most proteins cannot enter the capillaries as they are too large
- proteins made by cells may still need to be transported to other tissues
how is the fluid inside lymph vessels different to tissue fluid
- less oxygen
- more carbon dioxide
- more lymphocytes
why are high concentrations of lipid found in the lymph in the walls of the small intestine
lipids are absorbed into lacteals in villi
where is lymph eventually transported to
the subclavian veins
what helps move lymph through the lymph vessels
contraction of muscles surrounding the lymph vessels
describe the speed of lymph flow
slow
where are lymphocytes found and where do they divide
lymph nodes
is pressure higher in the aorta or vena cava and why
aorta
- pumping of heart
- loss of volume
- resistance to flow
- narrower lumen
describe glucose concentration in the aorta, tissue fluid, lymph, and vena cava
- aorta: high
- tissue fluid: medium
- lymph: low
- vena cava: high
explain the differences in glucose concentrations
- glucose enters blood at small intestine, and is transported in blood
- passes through capillary wall into tissue fluid
- used in tissues for respiration
is the concentration of fats higher in lymph than in blood/tissue fluid
yes, too large to move through capillary walls
