Nervous Control of Arterial Pressure

  1. Describe short-term regulation of mean arterial pressure (MAP): timing, which pathways, and targets
    • Seconds to minutes
    • Neural pathways
    • Targets heart and blood vessels
  2. Describe long-term regulation of mean arterial pressure (MAP): timing, which pathways, and targets
    • Hours to days
    • Endocrine pathways
    • Targets kidneys and blood vessels
  3. Compare sympathetic and parasympathetic innervation of CV system
    • Sympathethic chain innervates vessels and heart
    • Vagus (parasympathetic) innervates only heart
  4. How does the CNS control systemic circulation?
    • Vasomotor center in brainstem has vasoconstrictor fibers and vasodilator fibers
    • Hypothalamus controls the vasomotor center
  5. What vessels are innervated by the sympathetic nervous system?
    Sympathetic innervation to arteries, arterioles, veins, and venules, but not capillaries
  6. Where are baroreceptors found?
    In the walls of large systemic arteries, like carotid and aortic arch
  7. What are baroreceptors?
    Pressoreceptors that detect changes in blood pressure
  8. How do baroreceptors react to an increase in blood pressure?
    Receptors stretch, increase firing rate, and transmit high blood pressure signal to CNS to initiate baroreceptor reflex
  9. How does the baroreceptor signal get to the CNS? Where in the CNS does it get transmitted to?
    • Through the glossopharyngeal and vagus nerves
    • To the vasomotor center of the brainstem
  10. Where is the vasomotor center located specifically?
    Medulla and lower third of pons
  11. What are the parts of the vasomotor center?
    • Vasoconstrictor area
    • Vasodilator area
    • Sensory area
  12. What do the baroreceptors do after an acute increase or decrease in arterial blood pressure?
    Baroreceptors fire more at high blood pressure and less at low blood pressure
  13. What happens to the vasomotor center if you occlude both carotid arteries?
    • Reduction of baroreceptor firing leads to less inhibition on vasomotor center
    • Vasomotor center makes blood pressure increase
  14. If blood pressure increases, what does the baroreceptor reflex do to SNS, PNS, HR, SV, CO, and TPR?
    • Want to decrease BP back to normal
    • Decreases SNS
    • Increases PNS
    • Decreases HR
    • Decreases SV
    • Decreases CO
    • Decreases TPR
  15. If blood pressure decreases, what does the baroreceptor reflex do to SNS, PNS, HR, SV, CO, and TPR?
    • Want to increase BP back to normal
    • Increases SNS
    • Decreases PNS
    • Increases HR
    • Increases SV
    • Increases CO
    • Increases TPR
  16. How does chronic hypertension alter baroreceptor activity?
    Desensitized baroreceptors so that they fail to detect elevation of BP and will not respond to decrease it
  17. What is the baroreceptor reflex in response to hemorrhage?
    Less blood = less pressure = less baroreceptor activity = increase SNS = increase BP
  18. ____________________ respond to low O2 and CO2 and H+
  19. What is the most powerful of all the activators of the sympathetic vasoconstrictor system?
    Cerebral ischemia
  20. How does cerebral ischemia affect the vasomotor center?
    Increases sympathetic vasoconstriction to increase BP
  21. What is the Cushing reflex?
    When CSF pressure exceeds arterial pressure, blood flow to brain stops
  22. How does contraction of skeletal muscles increase cardiac output and arterial pressure?
    Increase in flow, increase in BP, increase in CO
Card Set
Nervous Control of Arterial Pressure