Mass transport Animals Flashcards
What is the function of haemoglobin?
Transport oxygen from alveoli in lungs to capillaries where oxygen enters tissue fluid to diffuse into cells.
What is the structure of haemoglobin?
Globular protein
Haem
4 polypeptide chains
Porphyrin ring
What are the differences between haemoglobins in difference organisms and what are the reasons for these differences?
Normal found in humans that live on land at sea level
High altitudes/ bottom of lakes where ppO2 is low: left bohr shift, Hb has higher affinity for oxygen, full HbO2 saturation at lower ppO2 and rapidly unloads into tissues.
Species with a high metabolic rate have a right shift.
What is meant by the loading and unloading of oxygen?
Association/ Dissociation of oxygen with Hb to deliver to tissues from the alveoli at lungs
What are the main features of an oxygen dissociation curve?
Hbo formed/ loading at area of high partial pressure oxygen at lungs, higher affinity here.
Hbo unloading in area of low partial pressure oxygen lower affinity here.
Sigmoidal Shape - positive cooperativity.
1st oxygen binds causes a change in shape tertiary structure, allows 2nd oxygen to bind more readily.
4th is harder due to lower probability of collision.
What does a shift to the right mean?
For high co2, low, o2, low ph, for high metabolic rate
Means Hb has a lower affinity for oxygen at a higher ppo2 so more unloading of oxygen.
What does a shift to the left mean?
For low co2, high ph, higher affinity for oxygen at a lower partial pressure oxygen so more loading of oxygen.
Why do organisms need a transport system?
Small surface Area: volume
Diffusion too slow due to large diff distance.
cannot supply oxygen and glucose for respiration and cannot prevent build up of co2
Active nature also has high oxygen and energy demands.
What are the features of this transport system?
Suitable transport medium (blood)
A mass for transport over longer distances (RBCs)
A closed system of vessels with a branching network (blood vessels)
Mechanism for moving the medium (Heart)
How do we supply the heart muscle with oxygen?
Coronary Arteries
What are risk factors associated with cardiovascular disease?
High BP
Smoking
Sedentary lifestyle
Diet high in sat fats
High salt diet
High alcohol consumption
Can you explain the double pump system?
Blood enters the heart twice for the complete circuit of the body: blood pumped to the lungs back to heart then pumped to the body.
How does the structure of the heart relate to its function?
3x more muscle on left ventricle to produce greater contraction for longer distance blood has to travel.
Can you explain the stages in the cardiac cycle and what happens at each stage:
Diastole: Ventricles relax pressure in ventricles is less than aorta
SL valves close
Blood enters atria vol in atria increases and pressure in atria is higher than ventricle
Systole: Atria contract blood forced into ventricle.
Blood enters ventricle pressure in ventricle is higher than atria so AV valve closes.
Ventricles contract and pressure in ventricle is greater than aorta so SL valves open blood enters aorta and pumped to body.
Can you explain how valves control the flow of blood?
Valves stop backflow
AV valves close when ventricle is greater than atrium
SL close when aorta is greater than ventricle
How do you calculate cardiac output?
Stroke volume x heart rate
How is the arteriole structure related to its function?
Smooth muscle allows contraction into capillaries.
Can you describe the pressure and volume changes and associated valve movements during the cardiac cycle that maintain a unidirectional flow of blood?
1: Blood in atria flows to ventricles and AV valves open, when pressure in ventricles is greater than aorta AV closes.
2: Pressure of ventricles greater than aorta SL valve opens and Blood flows into aorta.
3: Pressure in ventricles is lower than aorta SL valve closes.
4: Pressure in ventricles is lower than atria, blood pushes AV valves open.
Can you describe the structure the blood vessels and how this relates to the function.
Smooth endothelium to reduce friction
Elastic Wall
Muscular Wall
Lumen
Arteries:
Smooth endothelium to reduce friction
Thick Elastic Wall
Thick Muscular Wall
Thin Lumen
Outer collagen layer
elastic recoil.
Veins:
Smooth endothelium to reduce friction
Thin Elastic Wall
Thin Muscular Wall
Wide Lumen
Outer collagen layer
Located near skeletal muscle to aid pressure.
Capillaries:
1 endothelial cell thick
Permeable
Narrow small diameter
Usually many and highly branched
Can you describe the formation of tissue fluid and its return to the circulatory system?
High hydrostatic pressure at arterial end due to proximity to ventricle.
Hydrostatic pressure of blood is greater than hydrostatic and osmotic pressure outside capillaries
net movement out of capillaries H2O glucose amino acids ions forming tissue fluid large proteins don’t fit through fenestrations
excess tissue fluid returns at venous end
osmotic pressure is greater than hydrostatic pressure, water returns by osmosis
Lymph collects excess fluid and returns at subclavian vein
