PHYS20009 Lecture Notes - Lecture 7: Reflex Arc, Baroreceptor, Perfusion

• School: University of Melbourne
• Department: Physiology
• Course: PHYS20009
• Professor: angelina fong

Document Summary

Sitting to standing: blood pressure drops, engaged muscles in legs, changed position in relation to the ground, but then it returns (what brings map back up?) Increase in hr stays elevated but peaks early on. As blood pressure falls, heart rate goes up. Effector = _________ (decreased sympathetic nerve activity)-> causes changes in. Why is it important to maintain arterial blood pressure: blood pressure helps to maintain perfusion of blood to tissues. Aortic arch and carotid sinus: carotid sinus just outside skull. Top of neck (carotid bodies are chemoreceptors: aortic arch right next to aorta (aortic bodies are chemoreceptors) Inside wall of artery: every time the heart beats, the artery stretches -> stretch receptors are stretched -> na+ channels open in the nerve endings -> na+ goes in, increased membrane potential, depolarization -> more activity. Increase volume -> increase pressure -> increase stretch of vessel wall -> increase baroreceptor afferent activity. Tonic (basal) level of activity in baroreceptor afferents.