18. CP Respiratory Control

Question 1

What is the function of the Pre-Botzinger Complex?

Answer 1

“Central pattern generator”

Generates the timing (frequency) of the respiratory rhythm

This is the primary source of the respiratory rhythm, but not the only source

Question 2

Lesion to the Pontine Respiratory Group (PRG) causes what condition?

Answer 2

Apneusis (Inhalation without exhalation)

Question 3

What are the two big players in determining respiratory frequency?

Answer 3

Pre-Botzinger Complex

Pontine Respiratory Group

Question 4

What locations in the brainstem are big players in determining respiratory pattern (depth)?

Answer 4

Dorsal Respiratory Group

Ventral Respiratory Group

Question 5

What nerve is the major synapse target of the Dorsal Respiratory Group?

Answer 5

The phrenic nerve

Question 6

What is the function of the rostral part of the Ventral Respiratory Group?

Answer 6

Activating the muscles of inspiration - somewhat the diaphragm through the phrenic, but moreso the other muscles of inspiration

Question 7

What is the function of the caudal portion of the ventral respiratory group?

Answer 7

Activates muscles of expiration

Question 8

Which of the breathing locations in the brain stem are located in the pons, and which are located in the medulla?

Answer 8

The pontine respiratory group is located in the pons

All others (DRG, VRG, Pre-Botzinger) are located in the medulla

Question 9

What is the primary function of the pontine respiratory group?

Answer 9

Turning off inspiration

Question 10

Apneusis comes from pontine damage. What region of the brain would need to be damaged to result in apnea?

Answer 10

Medulla (or the Spinal Cord)

Question 11

Do chemoreceptors fire faster or slower as a result of increased O2?

Answer 11

Slower

Question 12

What can the central chemoreceptors respond to?

Why only this?

Answer 12

H⁺ (from H₂CO₃ - CO₂ in the CSF)

Because CO2 can cross the blood brain barrier.

Question 13

What neurotransmitter should we associate with the carotid body?

Answer 13

Dopamine

(Don’t worry about why, she just said to associate the two)

Question 14

Where are the peripheral chemoreceptors located?

Answer 14

In the carotid body and the aortic arch

(The aortic arch is a backup)

Question 15

What are the peripheral chemoreceptors sensitive to?

Answer 15

CO2 (directly, unlike the central)

O2

H+ (same as central)

Question 16

What do the slowly adapting stretch receptors respond to?

Answer 16

Tidal volume

Question 17

When are the slowly adapting pulmonary stretch receptors most useful?

Answer 17

In infants who are just learning to breathe

Adults doing exercise

Question 18

What is the function of the rapidly adapting pulmonary stretch receptors?

Answer 18

Protect the airways by responding to irritation and eliciting cough.

Question 19

What nerve do the rapid and slow stretch receptors of the lungs use to communicate to the brain?

Answer 19

Vagus nerve

Question 20

What is the function of the juxtacapillary (J) receptors?

Answer 20

They are sensitive to pulmonary edema, and cause cough and tachypnea.

Question 21

What can override the medullary centers?

Answer 21

Cortical influence

Question 22

Slowly Adapting PSRs

Location

stimulus

effect

role

Answer 22

airways

stretch of lung

inhibit inspir/promote expir.

every breath in infants, exercise/high Vt in adults

Question 23

Rapidly Adapting PSRs

location

stimulus

effect

role

Answer 23

location: airways
stimulus: irritants
effect: cough to clear airway
role: protective (not every breath)

Question 24

J receptors

location

stimulus

effect

role

Answer 24

near capillaries in alveoli

pulmonary edema

cough/tachypnea

protective (not every breath)

Question 25

What two types of stretch receptors override normal control systems and are important for survival?

Answer 25

Rapidly adapting PSR and J receptors

Question 26

Central chemoreceptors

location

sensitive to

influence

effects

Answer 26

ventral brainstem

pH (direct), CO2 (indirect)

respiratory drive or drive to breath

increase resp. rate/depth in response to hypercapnia

Question 27

Peripheral chemoreceptors

location

sensitive to

influence

effects

Answer 27

aortic arch and carotid body

O2, CO2, H (directly)

acute changes in blood gases

increase resp. rate/depth in response to hypercapnia, hypoxia or acidosis

Question 28

central chemoreceptors are sensitive to H ions. does that H cross the BBB or not?

Answer 28

No. That H ion comes from the reaction of CO2 and water with carbonic anhydrase to make H and HCO3

this causes the “drive to breath” to help you breath regularly.

Question 29

Which nuclei is each respiratory group assx with?

DRG

VRG

PRG

Botzinger

Pre-Botzinger

Answer 29

DRG: NTS

VRG: Nucleus Ambiguus

PRG: parabrachial

Botzinger: retrofacial

Pre-Botzinger: b/t VRG and Botzinger (generates rhythm)