Flashcards in Introduction To CVS Deck (22):
What does rate of diffusion depend on?
How can diffusion 'resistance' be determined?
Nature of molecule
Nature of barrier
What is the limiting factor in our bodies for diffusion?
The concentration gradient is usually the limiting factor.
How do we maintain the concentration gradients in our bodies?
The faster the blood flows, the easier it is to maintain the concentration gradient. Therefore we control the perfusion rate.
What is the cardiac output of a typical 70kg man?
5 litres per minute
How do we control blood flow?
With arterioles and pre-capillary sphincters
Where does the biggest drop in pressure occur in the circulatory system?
After the arterioles so that the pressure is low when it reaches the capillaries.
What are capillaries composed of?
A single layer of endothelial cells surrounded by a basal lamina.
Breathlessness on lying flat, sign of advanced heart failure
How do we measure a pulse?
Count for 15 seconds than x4
What is the approximate pressure of the RA?
What is the approximate pressure of LA?
What is the approximate pressure of RV?
Systole: 15-30 mmHg
Diastole: 0-5 mmHg
What is the approximate pressure of LV?
Systole: 90-140 mmHg
Diastole: 4-12 mmHg
Where is the best place to hear S1?
Where is the best place to hear S2?
Upper left sternal border
Where would we listen for an aortic valve murmur?
2nd ICS, sternal edge, RHS
Where would we listen for a pulmonary valve murmur?
2nd ICS, sternal edge, LHS
Where would we listen for a mitral valve murmur?
Mid-clavicular line, 5th ICS, LHS
Where would we listen for a tricuspid valve murmur?
5th ICS, left sternal edge