AS Booklet 7- Mass Transport in Animals Flashcards
Describe the structure of the mammalian heart
Left and right atria:
Thick muscular walls. Receive low pressure blood returning to heart from veins.
Left and right ventricles:
Thick muscular walls contract to move blood at high pressure into arteries.
Right side receives low pressure deoxygenated blood from around the body through veins. Blood is pumped to lungs.
Left side receives oxygenated blood from lungs, pumps it to body through arteries under high pressure.
Describe the function of the atrioventricular valves
Valve that opens when pressure in atrium is higher than in the left ventricle (when blood flows from atrium to ventricle)
Valve that closes when pressure in ventricle is above atrium (when blood moves from ventricle to artery).
Valves close to stop back-flow of blood due to pressure gradient.
Describe the function of the semilunar valves
Valve that opens when pressure in left ventricle increases above that in aorta.
Valve that closes when pressure in the aorta increases above that in ventricle.
Valves close to stop back-flow of blood due to pressure gradient.
Describe the cardiac cycle
Left atrium contracts, blood flows into left ventricle and atrioventricular valve opens.
Left ventricle contracts, volume down pressure above atrium so atrioventricular valve closes.
Left ventricle pressure above aorta so semilunar valve opens and blood flows into aorta.
Left ventricle pressure lower than in aorta, aortic valve closes.
Left ventricle pressure lower than atrium, atrioventricular valve opens, blood flows in to ventricle.
How do you calculate heart rate?
How do you calculate cardiac output?
Length of one cardiac cycle
—————————————
60
Stroke volume (cm3) x heart rate (min-1) = cardiac output cm3min-1
Stroke volume is volume of blood expelled from left ventricle per contraction.
What are risk factors for cardiac disease?
Diet, age, smoking, sex, occupation
Describe the Circulatory System
Double circulatory system ensures blood is pumped at high pressure to body after pressure is reduced in lungs.
Pulmonary circulatory system = blood from heart - lungs - heart.
Systemic circulatory system = pumped to rest of body.
Right side:
• Upper body + renal vein + hepatic portal vein to hepatic vein + lower body- vena cava.
• Pulmonary artery-lungs-pulmonary veins.
Left side:
• Pulmonary vein
• Aorta- hepatic artery, upper body, lower body, renal artery
List the names blood vessels
Arteries. Arterioles, capillaries, venu les, veins.
Aorta-large arteries-small arteries-arterioles-capillaries-venules-small veins-large viens-vena cava
If graph starts with aorta it’s the left side.
Describe blood vessel graph
Velocity at highest in aorta-arterioles then decreases rapidly and at lowest between arterioles and venules. Increases at small veins and levels off near vena cava but not as high as aorta.
Pressure zigzags rapidly from high and then decreases from aorta to capillaries. Still decreasing, lowest pressure at vena cava.
Total cross-sectional area is lowest at aorta-large arteries and small veins-vena cava, rapidly increases with arterioles and venules, then highest at capillaries.
Describe the function and structure of arteries
Carry blood away from heart at high pressure.
Large amount of elastic tissue so it can stretch and not tear at high pressure.
It retains some blood but when it recoils the blood is forced out.
Provides smooth flow of blood and high pressure.
Has an outer coating to prevent damage under high pressure, smaller lumen than veins. Endothelium so less friction.
Describe the function and structure of veins
Carry blood under low pressure towards heart.
Thin walls, less elastic fibre and smooth muscle as it doesn’t go under high pressure.
Large(r) lumen so blood flows back go heart at same rate it leaves despite low pressures
Contracting muscles in body press on veins to squeeze blood along.
Veins have semilunar valves at intervals to prevent back-flow so blood continues in direction of heart.
What does blood consist of?
What is the function of these components?
Dm
How do arterioles relate to the components of blood?
Jc
How is lymph fluid formed?
Jc
Describe the structure of haemoglobin and the function
Jd
