Interactions between the Heart and the Peripheral Vasculature Flashcards
What is venous return?
Rate at which blood returns to the thorax.
What is the central venous pool?
Volume enclosed by the right atrium and the great veins.
What is cardiac output?
Rate at which the blood leaves the central venous pool.
What happens to the central venous pressure as the cardiac output increases?
The CVP will decrease and this will increase the pressure gradient, leading to increased venous return.
What happens when the CVP becomes negative?
It will collapse the large veins of the thorax.
What is the systemic circulatory pressure (mean circulatory pressure [Pmc] )?
It is the mean pressure in the circulatory system when the cardiac output stops.
How do increases in blood volume change the Pmc?
It will increase it.
How do increases in venous tone change the Pmc?
It will increase it.
How do increases in the blood volume and venous tone alter the vascular function curve?
They will shift it up and right.
How does venodilation affect venous return?
Decreases
How does increased respiration (inspiration) affect venous return?
Increases. The negative pressure of inspiration allows the great veins to expand more and fill the RV more.
How does increased blood volume affect venous return?
Increases.
How does venoconstriction affect venous return?
Increases.
How does skeletal muscle contraction affect venous return?
Increases.
What is the Pcm in a normal healthy person?
7 mmHg
