3.4.1 Mass Transport in Animals Flashcards
Describe co-operative binding
- After the first oxygen binds, the second one binds easier
- The first oxygen binding changes the quaternary strucutre of the hameoglobin, so it changes shape
- This uncovers another haem binding site for the second oxygen to bind to
Describe and explain the level and type of protein comprising haemoglobin
- Globular (specific shape for binding)
- Quaternary
- 4 polypeptide chains, and 4 haem binding groups
Describe and explain the process of oxygen loading to haemoglobin
- Occurs in lungs, where p(O2) is high
- Haemoglobin has a high affinity for oxygen
- Oxygen will load/associate with haemoglobin more readily
- Forming oxyhaemoglobin
Describe and explain the process of oxygen unloading from haemoglobin
- Occurs at respiring tissues, where p(O2) is low
- As oxygen is required by respiring tissues for aerobic respiration, to release energy
- Haemoglobin has a low affinity for oxygen
- Oxygen will unload/dissociate with haemoglobin more readily
- Unloading is linked to a high concentration of carbon dioxide - Bohr effect
Describe the red curve
- Foetal haemoglobin
- Oxygen transferred to foetus from mother at placenta
- Haemoglobin has a higher affinity for oxygen
- Oxygen will load/associate more readily with haemoglobin
Describe the blue curve
- Haemoglobin for a smaller mammal
- Haemoglobin has a lower affinity for oxygen
- Oxygen unloads/dissociates more readily
- To supply respiring tissues with more oxygen for increased rate of aerobic respiration
- To release more energy
Blood vessel taking blood into left atrium
Pulmonary vein
Blood vessel taking blood into right atrium
Vena cava
Blood vessel taking blood out of left ventricle
Aorta
Blood vessel taking blood out of right ventricle
Pulmonary artery
Valves seperating atria and ventricles
AV Valves
Valves seperating ventricles and arteries
Semi-Lunar Valves
Function of the coronary arteries
Supply the heart muscle cells with oxygen and glucose for respiration
Why does the left ventricle have the thickest wall
- Produce a stronger contraction
- To create a high blood pressure
- As aorta supplies whole body with blood
Blood vessel taking blood to liver
Hepatic artery
Blood vessel taking blood away from liver
Hepatic vein
Blood vessel taking blood into kidney
Renal artery
Blood vessel taking blood away from kidneys
Renal vein
How does blood flow remain unidirectional
- Blood moves from high to low pressure
- AV and semi-lunar valves close to prevent backflow
Describe and explain atrial systole
- Atria contract
- Causing an increase in pressure in the atria
- So pressure greater in atrium than pressure in ventricle
- So AV valve opens
- Semi-lunar closed
- Blood flows from atrium to ventricle
- Ventricular volume increases, atrial volume decreases
Describe and explain ventricular systole
- Ventricle contracts
- Causing an increase in pressure in ventricles
- So pressure in ventricle is greater than pressure in artery
- So semi-lunar valve opens
- AV valve closed
- Blood moves from ventricle to artery
- Volume of ventricle decreases, volume of artery increases
Cardiac output equation
State the features of the arteries
- Thick muscular layer
- Thick elastic layer
- Thick wall
- Narrow lumen
- Smooth endothelium
State the features of the arterioles
- Thick muscular layer
- Thick elastic layer
- Narrow lumen
- Smooth endothelium
State the features of veins
- Thin muscular layer
- Thin elastic layer
- Wide lumen
- Smooth endothelium
- Valves
Explain the function of the thick muscular wall in arteries
Can contract to maintain pressure (vasoconstriction)
Explain the function of the thick elastic layer in arteries
- Stretch when ventricles contract
- Recoil when ventricles relax
- Maintains blood pressure
Explain the function of the thick wall in arteries
Withstand high blood pressure to prevent bursting
Explain the function of narrow lumen in arteries
Maintain blood pressure
Explain the function of smooth endothelium in arteries
Reduce friction
Explain the function of thick muscular layer in arterioles
Can constrict (vasoconstriction) and relax (vasodilation) to control changes in rate of blood flow
Explain the function of thick elastic layer in arterioles
Stretch and recoil to accomodate changes in blood pressure
Explain the function of narrow lumen in arterioles
Maintain blood pressure
Explain the function of smooth endothelium in arterioles
Reduce friction
Explain the function of thin muscular layer in veins
Some ability to contract (vasoconstriction) to maintain pressure
Explain the function of thin elastic layer in veins
Some ability to stretch and recoil to accommodate changes in blood pressure
Explain the function of wide lumen in veins
Reduce friction
Explain the function of smooth endothelium in veins
Reduce friction
Explain the function of valves in veins
Close to prevent backflow
Why is blood slowed in capillaries
More time for exchange of substances
Why is the capillary comprised on a single endothelial cell
Short diffusion pathway, so quick exchange of substances
Explain the formation of tissue fluid
- Ventricle contracts to produce a high blood pressure
- High blood pressure = high hydrostatic pressure
- Hydrostatic pressure is higher at capillary arteriole end than capillary venuole end
- This pushes water and other small molecules (like glucose) out of capillaries arteriole end, forming tissue fluid
Explain the return of tissue fluid
- Plasma proteins remain in blood, as** too large to leave**
- So their concentration at the venule end of the capillary increases
- This decreases the water potential of the blood
- So water moves into the capillaries venule end by osmosis
- Excess tissue fluid is reabsorbed by the lymphatic system
