Lecture16: Control Of Breathing

Question 1

What type of neurons are the DRG group?

Answer 1

Inspiratory

Question 2

What do the DRG group do?

Answer 2

They spontaneously discharge impulses to the inspiratory muscles

Question 3

What happens when DRG stop impulses?

Answer 3

The inspiratory muscles relax and the lungs recoil

Question 4

What does the VRG group do?

Answer 4

They promote expiration during forceful breathing

Question 5

What type of neurons are the VRG group?

Answer 5

Both inspiratory and expiratory

Question 6

What do the pontine centers do?

Answer 6

They adjust the rate and rythym generated by the medullary centers

Question 7

What does the pontine Apneustic center do?

Answer 7

Sends continuous excitatory impulses to the DRG, thus ensuring deep and prolonged inspiration

Question 8

What inhibits the Apneustic center?

Answer 8

Both Vagal nerve and Pneumotaxic center impulses

Question 9

Why does the Pneumotaxic center inhibit the Apneustic center?

Answer 9

To limit inspiration and prevent over inflation of the lungs

Question 10

What is Central Chemoreceptors’ primary function?

Answer 10

The most important for minute-to-minute control

Question 11

What do Central Chemoreceptors respond to?

Answer 11

Changes in pH or brain CSF

Question 12

What stimulates central chemoreceptors?

Answer 12

Arterial PCo2 higher than 35 mm hg

Question 13

When does the Central chemoreceptor stimulation appear?

Answer 13

1-2 minutes

Question 14

What is the main drive of ventilation in quiet breathing?

Answer 14

Normal arterial Pco2

Question 15

When does Central Chemoreceptor sensitivity decrease?

Answer 15

During sleep, via morphine

Question 16

Are Central chemoreceptors affected by H+ in the blood?

Answer 16

No

Question 17

Characteristics of Peripheral Chemoreceptors?

Answer 17

Very small, high blood flow, veryyy high metabolic rate

Question 18

What are Peripheral Chemo receptors sensitive to?

Answer 18

Decreasing PaO2, least sensitive to increasing PaCO2

Question 19

What is decreased PaO2 called?

Answer 19

Hypoxemia

Question 20

Why are Peripheral Chemoreceptors important?

Answer 20

Only mechanism to detect O2 tension in the body

Question 21

What are PSRs?

Answer 21

Slowly adapting pulmonary stretch receptors

Question 22

What do PSRs do?

Answer 22

They inform the brain about the changes in lung volume to optimize respiratory output

Question 23

Where are PSRs found?

Answer 23

In the smooth muscle of the bronchial tree

Question 24

What is the Hering-Breuer reflex?

Answer 24

Inhibits the output of Phrenic motor neurons to prevent lung over-inflation

Question 25

What is the Hering-Breuer reflex important in?

Answer 25

Controlling tidal volume during eupnea in infants

Question 26

What do Rapidly Adapting Pulmonary irritant receptors do?

Answer 26

They detect pathophysiology in the airway AND Histamine

Question 27

What stimulates Rapidly Adapting Pulmonary Irritant receptors?

Answer 27

Ciggy smoke and chemicals along with allergens