BIOL 121 Lecture Notes - Lecture 19: Cardiac Output, Vasodilation, Acetylcholine
Document Summary
Substances (hormones) in the blood cause vasoconstriction or vasodilation. Branches of the autonomic nervous system can induce changes in blood flow by causing vasodilation or vasoconstriction: the autonomic nervous system & control of blood flow. Ans can rapidly induce changes in blood flow by causing vasodilation or vasoconstriction by directly innervating blood vessels. Parasympathetic nervous system: small and indirect effect on blood vessels causing a weak vasodilation throughout the body. Indirect because it is caused by the parasympathetic nervous system shutting off the sympathetic nervous system: the baroreceptor reflex. A negative feedback system that works to maintain mean arterial pressure for proper perfusion of tissue throughout the body. Baroreceptors are located in : the carotid sinus and aortic arch, cardiovascular centers in the brain stem which includes the cardioregulatory centre and the vasomotor centre. Baroreceptors are stretch sensitive sensors which monitor blood pressure. Regulates cardiac output by regulating cardiac output and total peripheral resistance.
