Venous return and blood redistribution Flashcards
what is the sympathetic nervous system?
is controlled by the CARDIAC CONTROL CENTRE (CCC) found in the MEDULLA OBLONGATA. It sends signals via sympathetic nerves and is responsible for increasing heart rate.
what is venous return
the volume of blood that returns to the right side of the heart via ventricles and veins
what is Starling’s Law
increase in venous return
=
increase in stroke volume
=
increase cardiac output
what is vascular shunt mechanism
redistribution of blood using network of blood vessels to control where the blood in the body goes
5 mechanisms of venous return
1) pocket values
2) muscle pump
3) respiratory pump
4) smooth muscle
5) gravity
what do pocket valvules do?
prevent back flow of blood and direct it towards the heart
what is vasometer control centre (VCC)
controls blood redistribution
is located in the MEDULLA OBLONGATA.
what is pre-capillary sphincters?
little muscles rings at the end of arterioles
- vasodilation
- vasoconstriction
what is vasodilation?
allows blood flow
what is vasoconstriction?
prevents/restricts blood flow
why do baroreceptors detect?
the increase in blood pressure
what do chemoreceptors detect?
- an increase in CO2 and lactic acid
- a decrease in in O2 and blood pH
