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
What is the reason for the Cushing reflex?
Prevents collapse of cranial vessels
What causes bradycardia (parasympathetic activity) and vasoconstriction (sympathetic activity) except in heart and brain?
Dive reflex
What causes blushing?
Loss of sympathetic to only particular vessels
What is the alerting reaction?
Increased blood pressure caused by what would be expected
What is it called when extreme stress causes fainting?
Vasovagal syncope
What is the CV response to superficial pain?
Increased BP…like alerting response
What is the CV response to deep pain?
Similar to vasovagal syncope…decreased HR, decreased sympathetic, and increased parasympathetic
Think about the regulation of blood volume…
…and its effect on arterial pressure and urinary output
