mass transport in animals Flashcards
define mass transport
bulk movement of substances due to pressure difference
why do large, active, multicellular organisms need a blood transport system
- diffusion is too slow
- the blood and dissolved substances are transported by mass flow
draw and label a double circulatory system
name the blood vessels entering and leaving the heart
entering heart:
- vena cava
- pulmonary vein
leaving heart:
- pulmonary artery
- aorta
name the blood vessels entering and leaving the liver
entering liver:
- hepatic vein
- hepatic portal vein
leaving liver:
- hepatic artery
name the blood vessels entering and leaving the kidneys
entering kidney:
- renal vein
leaving kidney;
- renal artery
describe the structure of the artery and explain how each feature relates to its function
- thick muscle layer: prevents bursting under high pressure
- thick elastic tissue layer: elastic tissue stretches hen ventricles contract and recoil when ventricles relax to maintain blood pressure
- smooth endothelium: reduces friction to allow blood flow
describe the structure of the arterioles and explain how each feature relates to its function
thick layer of smooth muscle: contracts and relaxes to regulate blood flow.
describe the structure of the veins and explain how each feature relates to its function
- wide lumen: reduces resistance to flow under low pressure
- contains valves: prevent back flow of blood under low pressure
describe the structure of the capillary and explain how each feature relates to its function
- endothelium is only one cell thick: short diffusion pathway for exchange of materials
- flattened cells: short diffusion pathway
- many of them: slow food flow so more time for diffusion
- narrow lumen (only one blood cell wide): large surface area.
describe the role of skeletal muscle valves in the one way flow of blood through a vein carrying blood up the leg
- skeletal muscle contracts
- vein above muscle builds pressure
-valve opens - pressure decreases
- valve shuts to prevent backflow
what is tissue fluid
- fluid that surrounds cells
- formed by blood plasma
- where the exchange of substances happens between blood and cells
- contains water and small molecules
describe how tissue fluids formed and returned back to the blood
- there isa high hydrostatic blood pressure at the arteriole end
- this forces water and other small molecules out of the capillary. cells and proteins stay in the blood as they are. too big.
-exchange of nutrients between tissue fluid and cells - at the venue end water re-enters the capillary by osmosis from a high water potential to a low water potential down and water potential gradient due to the proteins in the blood. there’s a lower hydrostatic pressure n the blood.
- excess tissue fluid drains into lymph vessels and back into the blood.
explain the role the heart plays in the formation o tissue fluid
the left ventricle contacts to create a high hydrostatic pressure in the arterioles so water and small molecules are forced out to form tissue fluid.
what are the 3 functions of the lymphatic system
- drains excess tissue fluid
-absorbs lipids from the small intestine - part of the immune system
how are lymph vessels adapted for blood flow.
- contain valves
- contraction of skeletal muscle pump.
what is the evidence that haemoglobin has a quaternary structure
made up of 4 polypeptide chains
what is made when haemoglobin combines with oxygen
oxyhaemoglobin
explain the term partial pressure
a measure of the concentration of a certain substance present in tissues
where Is the partial pressure highest in the body
- in the lungs
- haemoglobin has a high. affinity for oxygen
- soo haemoblobin becomes saturated with oxygen
why is the partial pressure of oxygen lowest in the tissues
- haemoglobin has a low affinity for oxygen so haemoglobin becomes unsaturated with oxygen
explain why the oxygen dissociation curve has a sigmoid shape
- the binding of the first molecule of oxygen to haemoglobin canoes the tertiary and quaternary structure of the haemoglobin
- this uncovers another ham group for oxygen to bind to
- so as oxygen binds to haemoglobin it makes it easier for the next oxygen to bind
sketch a curve to show Bohr shift
explain what is meant by bohr shift and explain the benefits of this
- in the presence of carbon dioxide the oxygen dissociation curve shifts to the right
- because the affinity of haemoglobin for oxygen is reduced
- so at the partial pressures of oxygen found at the tissues, haemoglobin is less saturated
- oxygen unloads more readily to be used for aerobic respiration at the tissues.
- this delays inset of anaerobic respiration at the tissues so less lactic acid is produced
- this happens because the carbon dioxide lowers the pH of the blood which alters the tertiary structure if haemoglobin.
draw an oxygen dissociation curve showing an organism living at sea level
blue line
draw an oxygen dissociation curve showing an organism living at sea level
green line
draw an oxygen dissociation curve showing an organism with a high met bloc rate
red line
label a diagram of the heart including chambers, blood vessels and valves
state function of atrioventricular valves
prevent back flow of blood into atria
state function of semilunar valves
prevent back flow into the ventricles
