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15 Cards in this Set
- Front
- Back
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What are haemoglobin's? |
Molecule, oxygen binding sites, similar in all organisms (although different affinities depend on different shape) |
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What molecule is haemoglobin? |
Protein with quaternary structure |
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Describe the role of haemoglobin and red blood cells in the transport of oxygen? |
haem (or heme) group which is an inorganic group containing one iron ion. 4 iron ions in each haemoglobin molecule, and iron ions are directly responsible for binding the oxygen molecules
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Describe the role the loading, transport and unloading of oxygen in relation the oxyhaemglobin dissociation? |
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Coordination of heartbeat |
1. SAN sends wave of electrical activity / impulses (across atria) causing atrial contraction;Accept excitation2. Non-conducting tissue prevents immediate contraction of ventricles / prevents impulses reaching the ventricles;3. AVN delays (impulse) whilst blood leaves atria / ventricles fill;4. (AVN) sends wave of electrical activity / impulses down Bundle of His;4. Allow Purkyne fibres / tissue5. Causing ventricles to contract from base up; |
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Left ventricle to aorta |
1. Atrium has higher pressure than ventricle (due to filling / contraction) causing atrioventricular valves to open;Start anywhere in sequence, but events must be in the correct order.1. Accept bicuspid, reject tricuspid1. Allow: blood passes through the valve = valve open / blood stopped from passing through the valve = valve closed2. Ventricle has higher pressure than atrium (due to filling / contraction) causing atrioventricular valves to close;3. Ventricle has higher pressure than aorta causing semilunar valve to open;Points 1, 2 and 3 must be comparative: eg higher 3. Allow aortic valve4. Higher pressure in aorta than ventricle (as heart relaxes) causing semilunar valve to close;4. Allow aortic valve5. (Muscle / atrial / ventricular) contraction causes increase in pressure; |
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What is the general pattern of circulation in an organism? |
Mammals have closed, double circulatory system (reduction in pressure in the lungs) Arteries, capillaries and veins Pulmonary viens and arteries Renal vein and artery Vena cava and Aorta Diffusion within tissues (due to large surface area) |
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Describe the gross structure of the human heart? |
Blood is supplied by the coronary arteries Blood flow is controlled by atria-ventiruclar valves (bicuspid, left, tricuspid, right) Left deoxygenated, right oxygenated Two chambers, atrium, ventricle |
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Why do organisms require a circulatory system? |
Large, multi-cellular Low S/A volume ratio Transport system Raw materiais Specialised exchange surfaces High enough rate maintained |
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What do the valves do? |
Maintain a unidirectional flow of blood |
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What is the structure of an artery in relation to it's function? |
1. thickest wall, enabling it to carry blood at high pressure / withstand pressure surges; 2. most elastic tissue, which smoothes out flow / maintains pressure; 3. most muscle which maintains pressure; 4. muscle in wall to control blood flow; |
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What is the structure of a vein in relation to it's function? |
Thin wall does not have to withstand high pressure |
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What is the structure of the capillary in relation to function? |
Thin wall, allowing diffusion/exchange; only endothelium present, allowing short diffusion pathway; |
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What do all blood vessels have in common? |
Have endothelium that reduces friction; |
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How is tissue fluid formed? |
Arterial end High hydrostatic pressure Net movement out Small molecules (ultrafiltration) Exchange of metabolic substances Water potential lowers in capillary and higher in tissues Osmosis Loss of hydrostatic pressure in the venous end Lymph vessels Hydrostatic pressure Contraction of body muscles (aided by valves in the lymph vessels) |
