Heller Ch. 9 Flashcards
Baroreceptor reflex?
High BP –>activated parasympathetic ganglia–> decreased HR
High BP–>inhibits pre-ganglionic nuclei in the spinal cord–>decreased sympathetic activity
Where are baroreceptors located?
Walls of aorta and carotid arteries
Bifurcation of the carotid
What does the baroreceptor do?
Tries to keep BP steady
Where do afferent signals from the carotid sinus run?
Carotid sinus nerves–>glossopharyngeal nerve
Where do afferent signals from the aorta run?
Vagus nerve
What is the job of cardiopulmonary baroreceptors?
Sense the pressure/volume in the atria and central venous pool
What effect do cardiopulmonary baroreceptors have on the central nervous system?
Increased central venous pressure –> decrease in sympathetic activity
Where are arterial chemoreceptors located?
Carotid arteries
Aortic arch
What is the effect of arterial chemoreceptors?
Low Po2 and/or high Pco2 → increases in respiratory rate and mean arterial pressure
What does strong, sustained static exercise cause?
Increased arterial pressure
What causes bradycardia and hypotension?
Bezold-Jarisch reflex
What causes the Bezold-Jarisch reflex?
A strong stimuli to coronary vessel chemoreceptors concentrated in the posterior wall of the left ventricle–arteries sense low BP creating sympa response, but the heart overrides stimulus due to low venous return…causing the bradycardia
What triggers cerebral ischemic response?
Inadequate blood to the brain (chemoreceptors)
What produces the strongest sympathetic signals (vasoconstriction and cardiac stimulation)?
Cerebral ischemic response
What is the Cushing reflex?
Increased intracranial pressure –> parallel rise in arterial pressure
