Control of Respiration

Question 0

CSF buffering capabilities

Answer 0

Very low due to the lack of Hb and carbonic anhydrase found in the CSF

=>rapid fluctuation of pCO2 and respiratory drive

Question 1

Central Chemoreceptors

Answer 1

Found in the medulla; respond to fluctuations in pCO2 in the CSF

• Major respiratory drive in a normal person
• Chronic exposure => adaptation

Question 2

Peripheral Chemoreceptors

Answer 2

Respond to fluctuations in pCO2, pH, and pO2 (carotid bodies)

-CANNOT adapt; responds to pO2 levels < 60mmHg; until levels reach here, pCO2 = main driving force

Question 3

Respiratory Drive in a Lung Disease Patient

Answer 3

Respiratory drive is controlled by pO2

• pCO2 is lowered due to excretion from the kidneys
• If patient placed on ventilator, respiratory drive will decrease and pCO2 will increase again

Question 4

DRGs

Answer 4

“Dorsal Respiratory Groups”

These neurons control the basic rhythm off breathing (inspiratory neurons); integrate info from chemoreceptors, stretch receptors, and higher brain centers

Question 5

VRGs

Answer 5

“Ventral Respiratory Groups”

Regulate the diameter of the upper airways during forced breathing; contain inspiratory and expiratory neurons for times of increased stress

Question 6

Apneustic Center

Answer 6

“Normal Respiration Cut-off Switch”

Continually sends information to the VRGs and DRGs

Question 7

Pneumotaxic Center

Answer 7

Area located in the pons that functions to:

1. Prevent aneupsis
2. Enhance and fine-tune the rhythmicity of breathing

Question 8

Apneustic breathing

Answer 8

Respiratory cycle holds in inspiration and is periodically interrupted by expiration

Question 9

Congenital Central Hypoventilation Syndrome

Answer 9

Congenital disorder characterized by a hypoactive Central Pattern Generator

• Insensitive chemoreceptors damage passive respiration, however, active respiration is intact
• Pts. require a tracheotomy for placement of a ventilator to allow them to breathe @ night

Question 10

Altered Respiratory Control by the Medulla

Answer 10

Poliomyelitis

Edema

Barbiturate, opiate, alcohol abuse

Question 11

Deep Hypothermia

Answer 11

Depresses ventilation thru the general suppression of neural activity

Question 12

Mild hypothermia

Answer 12

Increases ventilation due to stimulation of the sympathetic nervous system

Question 13

Eupnea

Answer 13

Normal breathing

Question 14

Cheyne-Stokes Breathing

Answer 14

10-30s of abnormal breathing followed by increased volume and frequency until another abnormal period occurs; is waning w/ gradual increase and decrease

*Depth of breathing corresponds w/ neural pCO2 levels; found in cardiac failure or brain damage

Question 15

Obstructive Sleep Apnea

Answer 15

Excess fat around the pharynx leads to periods of apnea

Question 16

Central Sleep Apnea

Answer 16

Normal deep inspiratory cycle followed by periods of cessation of breathing; thought to be due to faulty neural control