Unit 1.Lec 8-Baroreceptor & Chemoreceptor Regulation

Question 1

Define Baroreceptors

Answer 1

A type of mechanoreceptors allowing for relaying information derived from blood pressure within the autonomic nervous system.

Question 2

Define chemoreceptors

Answer 2

Are special nerve cells that detect changes in the chemical composition of the blood and send information to the brain to regulate cardiovascular and respiratory functions.

Question 3

What is a short term regulation of blood pressure?

Answer 3

Vascular reflexes

Question 4

Explain Vascular reflexes

Answer 4

• An internal sensory-feedback systems that “sense” or detect change in important circulatory parameters
• Responses via feedback (negative) pathways that alter the automic control lof the heart and vasculature

Important circulatory parameters-blood pressure, O2 and CO2 levels, pH, temperature

Question 5

What is the goal of vascular reflexes?

Answer 5

To work to maintain and optimize cardiovascular performance in rapidly changing physiological situations

Question 6

List the types (5) of vascular reflexes

Answer 6

• Peripherial Baroreceptors
• Peripheral Chemoreceptors
• Central Chemoreceptors
• Pulmonary stretch receptors
• Hypothalamus (temp. sensors)

Question 7

What is the role of the arterial baroreceptors?

Answer 7

Play a key role in the short term (secs to min) adjustment of blood pressure when abrupt chances occur in blood volume, cardiac output, or peripheral resistance

Question 8

What causes (3) abrupt changes in blood volume, cardiac output, or peripheral resistance that activates arterial baroreceptors?

Answer 8

1. Posture changes
2. Exercise
3. Hemorrphage (an escape of blood from a ruptured blood vessel)

Question 9

Where are stretch receptors located?

Arterial Baroreceptors

Answer 9

• Carotid sinuses
• Aortic arch

Question 10

What do strech receptors detect?

Aterial Baroreceptors

Answer 10

Physical deformations in the vessel wall due to blood pressure changes

Question 11

Where are stretch receptor changes relayed to?

Arterial Baroreceptors

Answer 11

Relayed to the nucleus tractus solitarius (NTS) in the medulla via afferent nerve fibers

Question 12

What is the pathway of cartoid sinus (stretch) baroreceptors innervation?

Answer 12

Carotid baroreceptors afferent nerve fibers travels to the sinus nerve to the glossopharyngeal nerve to NTS

Question 13

What is the pathway of aortic (stretch) baroreceptors innervation?

Answer 13

Aortic barorecptors afferent nerve fibers travel along the vagus nerve to the NTS

Question 14

At normal arterial pressure when does afferent firing occurs?

Answer 14

Systole

Question 15

At normal arterial pressure when does decreasing afferent firing occurs?

Answer 15

Late systole and diastole

Question 16

What occurs to carotid sinus afferent firing when blood pressure increases?

Answer 16

It increases