Control of Respiration

Question 1

What are the 3 parts involved in the control of respiration?

Answer 1

Central Controller
Sensors
Effectors

Question 2

Where is the central controller of respiration located?

Answer 2

In the brainstem in the medulla and pons

Question 3

What are the parts of the medullary respiratory center?

Answer 3

Dorsal Respiratory Group

Ventral Respiratory Group

Question 4

What is the role of the medullary respiratory group?

Answer 4

Generates the breathing pattern

Question 5

What is the role of the Dorsal Respiratory Group?

Answer 5

Inspiration

Question 6

What is the role of the Ventral Respiratory Group?

Answer 6

Expiration

Question 7

What are the parts of the pontine respiratory group?

Answer 7

Apneusitic Center

Pneumotaxic Center

Question 8

What is the role of the pontine respiratory group?

Answer 8

Controls the breathing pattern

Question 9

What is the role of the Apneusitic Center?

Answer 9

Excitatory effect on the DRG (increases inspiration)

Question 10

What is the role of the

Pneumotaxic Center?

Answer 10

Inhibitory effect on the DRG (decreases inspiration)

Question 11

What is the role of the central chemoreceptor?

Answer 11

It is sensitive to changes in pH of the CSF as the CSF has a lower buffering capacity than blood.

Question 12

What changes in gas does the central chemoreceptor respond to?

Answer 12

It responds to changes in PCO2 but not PO2

Question 13

How does the central chemoreceptor respond to decreased pH?

Answer 13

It will increase in activity and increase ventilation

Question 14

Where are the peripheral chemoreceptors found?

Answer 14

They are located in the aortic and carotid bodies

Question 15

What changes are the peripheral chemoreceptors responsive to?

Answer 15

Decrease in pH (carotid bodies only)
Increase in PCO2
Decrease in PO2

Question 16

What are the only chemoreceptors that respond to changes in PO2?

Answer 16

Peripheral chemoreceptors

Question 17

Where are pulmonary stretch receptors located?

Answer 17

Within the smooth muscle cells of airways

Question 18

What is the function of pulmonary stretch receptors?

Answer 18

Affect the activity of the inspiratory muscles based on stretch

Question 19

What is the Hering-Breuer Inflation Reflex?

Answer 19

Inflation of the lung inhibits inspiratory muscle activity

Question 20

What is the Hering-Breuer Deflation Reflex?

Answer 20

Deflation of the lung activates inspiratory muscle activity

Question 21

Are the Hering-Breuer Reflexes active in adults?

Answer 21

Not so much

Question 22

Where are the irritant receptors located?

Answer 22

Between airway epithelial cells

Question 23

What is the role of irritant receptors?

Answer 23

They are stimulated by things like dust and smoke and are activated through the vagus nerve resulting in bronchoconstriction and hyperpnea

Question 24

What are J receptors?

Answer 24

They are “juxtacapillary” receptors found in alveolar walls near capillaries that can trigger rapid shallow breathing

Question 25

What are bronchial C fibers?

Answer 25

They respond to chemicals injected into bronchial circulation with rapid shallow breathing, bronchoconstriction and mucus secretion

Question 26

What happens to ventilation as PCO2 increases?

Answer 26

It will increase

Question 27

What happens to ventilation at a given PCO2 with lower PO2?

Answer 27

Ventilation will be higher than at a normal PO2

Question 28

How will metabolic acidosis affect the response to CO2?

Answer 28

It will increase the response to CO2 by making the curve steeper

Question 29

What is the most important stimulus for ventilation?

Answer 29

Arterial PCO2

Question 30

At normal PCO2, how does the body respond to decreasing PO2?

Answer 30

PO2 can be reduced to 50 mmHg with normal PCO2 levels before ventilation will be induced. Therefore hypoxic stimulation plays only a small role in the increase in ventilation in healthy people.

Question 31

At high PCO2 how does the body respond to decreasing PO2?

Answer 31

Ventilation will be induced much sooner at 100 mmHg

Question 32

In patients with chronic severe lung disease, what is their primary stimulus for ventilation?

Answer 32

Hypoxia, or low PO2 because most of them will have chronic high PCO2

Question 33

How does the body respond to metabolic acidosis?

Answer 33

Ventilation will be increased despite low PCO2

Question 34

What mediates the ventilatory response to pH?

Answer 34

Peripheral chemoreceptors

Question 35

What happens to the BBB at low pH?

Answer 35

The BBB becomes partly permeable to H+

Question 36

What is the breathing pattern for obstructive sleep apnea?

Answer 36

Airflow is cut off but the pleural pressure continues to cycle, and increases as ventilation is not occurring.

Question 37

What is the breathing pattern for central sleep apnea?

Answer 37

Brain activity to the lungs is stopped so that BOTH airflow and pleural pressure changes are stopped momentarily.

Question 38

What is Kussmaul breathing?

Answer 38

It is deep breathing with normal or reduced frequency that is typical in severe acidosis, e.g diabetic ketoacidosis

Question 39

What is apneustic respiration?

Answer 39

It is sustained periods of inspiration, followed by brief periods of exhalation with loss of input from vagal nerve and pneumotaxic center.

Probable causes are brain damage and intoxication.

Question 40

What is Cheyne-Stokes ventilation?

Answer 40

Cyclic breathing with pauses before a waxing and waning and it repeats.

Often found with severe brain injury and patients near death.

Question 41

What is Biot’s respiration?

Answer 41

Deep breaths with large pauses and is often due to neuronal damage