Chapter 9 Flashcards
What is the structure of haemoglobin?
- quarternary protein
What 2 man things much haemoglobin be able to do?
- readily associate with oxygen at the gas exchange surface
- readily disassociate with oxygen at the cells that need it
What does it mean if haemoglobin has a high affinity for oxygen?
- it easily associates with oxygen
- it does not readily disassociate with it
What does it mean if haemoglobin has a low affinity for oxygen?
- it doesn’t easily associate with oxygen
- it easily disassociates
What is the Bohr effect?
- organism lives in an environment with low oxygen concentration it has a high affinity and the graph shifts to LEFT
- organism lives in environment with high oxygen concentration it has a low affinity and graph shifts to RIGHT
What direct does the artery take blood?
away from the heart
What direction does the vein take blood?
towards the heart
What is the function of the hepatic artery?
takes oxygenated blood to the liver
What is the function of the hepatic vein?
takes deoxygenated blood to the heart from the liver
What is the function of the hepatic portal vein?
takes blood from the intestines to the liver
What is the function of the pulmonary arteries?
takes deoxygenated blood to lungs
What is the function of the pulmonary veins?
takes oxygenated blood to heart from lungs`
How does the structure of the arteries relate to its function?
- thick with muscle and elastic tissues to maintain high pressure
How does the structure of the veins relate to its function?
- wide lumen for lots of blood
- valves to stop back-flow of blood
How is the structure of arterioles related to its function?
- arteries branch off to arterioles
- muscles to direct blood flow to different areas and contract/relax to control blood flow
How does the structure of the capillaries relate to its function?
- thin = short diffusion distance
- gas exchange surface
- high concentration gradient
- large number = large surface area
networks of capillaries called capillary beds
What is the equation for stroke volume, heart rate and cardiac output?
cardiac output = stroke volume x heart rate
What is the first step in the cardiac cycle?
- atria contract = decreases volume - increases pressure
- AV valve opens
- blood moves into ventricles = increases pressure and volume in ventricles
What is the second step in the cardiac cycle?
- ventricles contract = decreasing volume - increases pressure
- forces AV valves shut
- pressure in ventricles = higher than in pulmonary artery and aorta
- SL valves open
What is the third step in the cardiac cycle?
- higher pressure in aorta and pulmonary artery closes SL valves
- blood returns to atria because higher pressure in vena cava and pulmonary vein
- higher pressure in atria forces AV valves open blood flows into ventricles
- atria contract and cycle starts again
How is tissues fluid formed?
- capillaries near arterioles hydrostatic pressure = higher than tissue fluid - pressure forces fluid out of capillaries into space around cells
- hydrostatic pressure in capillaries falls at venule end
- fluid loss = high concentration plasma proteins = lower water potential at venule end than tissue fluid
- water re-enters capillaries (osmosis) excess drained into lymphatic system
What is the structure of the heart?
LEFT SIDE - aorta - pulmonary vein - left ventrical - left atria - left AV valve - left SL valve RIGHT SIDE - pulmonary artery - vena cava - right atria - right ventricles - right AV valve - right SL valve
