PMS Circulation Exam
1. What are the divisions of circulation?: Systemic (greater or peripheral) circulation:
- supplies blood to all body tissues except lungs
- 84% of total blood volume: 64% veins, 13% arteries, 7% arterioles and capillaries
Pulmonary circulation:
- supplies blood to the lungs
- 16% of total blood volume: 7% heart and 9% pulmonary vessels
2. What are the functional parts of the circulatory system and their functions?-
: Arteries
- take blood away from heart
- transport blood under high pressure
- strong vascular walls
- high velocity blood flow
Arterioles:
- control conduits (channels) to capillaries
- strong muscular walls, which is why vasoconstrictors have greater effect on arterioles
- regulate blood flow by constriction/dilation
,Capillaries:
- exchange fluid, nutrients, electrolytes, hormones
- thin walls with capillary pores
- pressure and velocity falls
- KEY FUNCTION: diffusion of substances between blood and tissues
Venules:
- collect blood from capillaries
- merge into larger veins
Veins:
- transport blood back to heart
- major reservoir of extra blood, which means contraction causes venous return to increase and more blood travels back
to heart
, - thin, muscular walls for contraction/expansion
- veins above heart do not have valves
- veins below heart have valves to provide force and allow blood to move against gravity
3. How much of circulation is collapsed at a given time?: about 1/2 of circulation, as there
is a higher % of blood volume in systemic circulation than there is in heart and lungs
4. What is the pressure at the venae cavae and which circulation is it a part
of?: Systemic circulation
- 0 mmHg
5. What is the pressure of the arterioral and venous ends of capillaries and which
circulation are they a part of?: Capillaries (low pressure and velocity)
- Arteriolar end = 35 mmHg
- Venous end = 10 mmHg
- average pressure = 17 mmHg
6. Why must the pressure is kidney glomerular capillaries be high at all times?: -
to cause filtration
1. What are the divisions of circulation?: Systemic (greater or peripheral) circulation:
- supplies blood to all body tissues except lungs
- 84% of total blood volume: 64% veins, 13% arteries, 7% arterioles and capillaries
Pulmonary circulation:
- supplies blood to the lungs
- 16% of total blood volume: 7% heart and 9% pulmonary vessels
2. What are the functional parts of the circulatory system and their functions?-
: Arteries
- take blood away from heart
- transport blood under high pressure
- strong vascular walls
- high velocity blood flow
Arterioles:
- control conduits (channels) to capillaries
- strong muscular walls, which is why vasoconstrictors have greater effect on arterioles
- regulate blood flow by constriction/dilation
,Capillaries:
- exchange fluid, nutrients, electrolytes, hormones
- thin walls with capillary pores
- pressure and velocity falls
- KEY FUNCTION: diffusion of substances between blood and tissues
Venules:
- collect blood from capillaries
- merge into larger veins
Veins:
- transport blood back to heart
- major reservoir of extra blood, which means contraction causes venous return to increase and more blood travels back
to heart
, - thin, muscular walls for contraction/expansion
- veins above heart do not have valves
- veins below heart have valves to provide force and allow blood to move against gravity
3. How much of circulation is collapsed at a given time?: about 1/2 of circulation, as there
is a higher % of blood volume in systemic circulation than there is in heart and lungs
4. What is the pressure at the venae cavae and which circulation is it a part
of?: Systemic circulation
- 0 mmHg
5. What is the pressure of the arterioral and venous ends of capillaries and which
circulation are they a part of?: Capillaries (low pressure and velocity)
- Arteriolar end = 35 mmHg
- Venous end = 10 mmHg
- average pressure = 17 mmHg
6. Why must the pressure is kidney glomerular capillaries be high at all times?: -
to cause filtration
