The Baroreceptor Reflex

1
The Baroreceptor Reflex

• By
• Amanda Graves
• Judd Hall
• Thang Nguyen

2
Question 1

• Consider a normal individual who goes from supine
  posture to standing. Explain your predictions
  for the immediate changes.

3
Immediate changes
4
What is a Baroreceptor?

• Stretch-sensitive mechanoreceptors.
• Located in the walls of the carotid artery and
  aorta.
• Monitor the pressure of blood flow to brain and
  body
• Action potentials are fired continuously at
  normal blood pressure.

5
Receptors initiate the reflex!

• Sensors pressure sensors in the arteries of the
  upper body
• Carotid sinus sensory nerve cranial nerve IX.
• Aortic arch sensory nerve cranial nerve X.

6
At the Integrating Center

• Medulla oblongata medullary cardiovascular
  control center.
• Centers used to correct blood pressure
• Sympathetic and Parasympathetic nervous systems
• Cardiac accelerator center increases cardiac
  output uses cardiac accelerator nerve.
• Cardiac inhibitor center decreases cardiac
  output uses vagus nerve.
• Vasoconstrictor center constricts arterioles and
  veins uses spinal nerves.

7
Reflex Effectors

• Heart
• SA Node controls heart rate (HR)
• Heart muscle controls stroke volume (SV)
• Arteries veins
• Dilation
• Constriction

8
What changes are made?

• Results
• If pressure is low
• Reflex will increase cardiac output (CO HR X
  SV)
• Reflex will constrict arterioles veins.
• If pressure is high
• Reflex will decrease CO
• Decreased reflex activity will dilate arterioles
  and veins.
• Reflex will restore correct blood pressure
• P CO X R

9
What its Like

• A water balloon fight with your friendswith
  human shaped water balloons.
• Stretch receptors in balloon force water to fill
  up whole balloon, not just pool in legs and feet.