2. The Heart As A Pump Flashcards
1
Q
What is the difference between capacitance vessels and resistance vessels?
A
Resistance vessels
- in arterial system - high pressure
- restrict blood flow to drive supply to hard to perfuse areas of the body
Capacitance vessels
- in venous system - low pressure
- enable system to vary amount of blood pumped around body (act as blood store)
2
Q
What are the 2 types of cardiovascular circulations and what is the pressure like in each?
A
- pulmonary circulation: low pressure
- systemic circulation: high pressure
3
Q
Describe the typical pressures in the heart chambers as in the aorta and pulmonary artery
A
In mmHg
- RA = 4
- RV = 25 systole/3 diastole
- pulmonary artery = 25 systole/10 diastole
- LA = 10
- LV = 120 systole/9 diastole
- aorta = 120 systole/80 diastole
4
Q
What are systole and diastole?
A
- Systole = contraction & ejection of blood from ventricles
- Diastole = relaxation & filling of ventricles
5
Q
What is the stroke volume at rest?
A
70 ml/beat
6
Q
name the 4 valves of the heart
A
- Triscupid valve (RA to RV)
- Pulmonary valve (RV to pulmonary artery)
- Mitral valve (LA to LV)
- Aortic valve (LV to aorta)
7
Q
what determines whether heart valves are open/closed?
A
differential blood pressure on each side
8
Q
what prevents the inversion of mitral/tricuspid valves on systole?
A
leaflets are attached to papillary muscles via chordae tendinae
