Control of Breathing

Question 1

What are the three main controls of breathing?

Answer 1

Rhythmic discharge from pons, Chemical control, Nonchemical influences

Question 2

Where is the automatic system for breathing?

Answer 2

Pons and Medulla. Sends impulses to respiratory motor neurons

Question 3

Where is the voluntary system for breathing?

Answer 3

Cerebral Cortex. Sends impulses to respiratory motor neurons in the spinal cord

Question 4

What is the relationship between expiratory muscles and inspiratory muscles?

Answer 4

The motor neurons to the expiratory muscles are inhibited when the insiratory muscles are active, and vice versa

Question 5

Where is there a feedback mechanism in the control of breathing?

Answer 5

The chest wall/diaphragm/conducting airways can send signals to the spinal cord to help regulate the respiratory muscles.

Question 6

What are the main stimuli for breathing control

Answer 6

Increased PCO2 –main one of the three
Decreased PO2
Decreased pH

Question 7

What are the two things that an increase in PCO2 can stimulate?

Answer 7

The Peripheral Chemo receptors and

Central Chemo receptors

Question 8

What has a stronger effect, Increase in PCO2 or decrease in pH?

Answer 8

increase in PCO2

Question 9

What is the range when peripheral chemoreceptors are particularly sensitive to changes in PO2?

Answer 9

60 to 30 mmHg

This is the range when the Hb dissociation curve drops dramatically

Question 10

What does a low PO2 do to alveolar ventilation?

Answer 10

Increases it INDEPENDENT of PCO2

Question 11

What gives rise to most of the H found in blood?

Answer 11

Rise in CO2

Question 12

Does H easily cross the BBB?

Answer 12

NO

Question 13

What has a greater effect on stimulating chemosensitive neurons, H or CO2?

Answer 13

CO2, even though stimulating these neurons happens by CO2 changing the local H concentration

Question 14

Where are the peripheral chemoreceptors located?

Answer 14

Aortic bodies and the Carotid bodies

Question 15

Do the Aortic bodies and carotid bodies respond more to changes in blood O2, CO2, or H more?

Answer 15

O2, and to a lesser extent CO2 and H

Question 16

Are the central chemoreceptors more sensitive to O2, CO2, or H?

Answer 16

CO2 and H.

Question 17

What is the tractus solitarius?

Answer 17

The termination site for the vagal and glossopharyngeal nerves which transmit signals from the
Peripheral chemoreceptors,
Baroreceptors,
Other receptors in the lungs

Question 18

Where do the vagal and glossopharyngeal nerves receive their sensory input from in respiration?

Answer 18

Peripheral chemoreceptors
Baroreceptors
Other receptors in the lungs

Question 19

What is the pre-Botzinger complex?

Answer 19

A part of the brain between the Nucleus ambiguus and the Lateral Reticular nucleus that contains PACEMAKER cells to control the rhythmic respiration. medulla

Question 20

What does the Dorsal Respiratory Group signal?

Answer 20

It sends out repetitive bursts of INSPIRATORY APs

Question 21

What is the Pneumotaxic center?

Answer 21

an area in the upper pons that transmits signals to the inspiraratory area and controls the switch off point in inspiration signals.
Functions to LIMIT INSPIRATION

Question 22

What is the Ventral Respiratory Group?

Answer 22

When respiratory drive for increase pulmonary ventilation increases a lot, the signal spills over into the VRG.
VRG neurons contribute to both inspiration and exhalation
Normally inactive during quiet breathing

Question 23

How does the brain contribute to increased breathing during exercise?

Answer 23

When sending impulses to the muscles for contraction during exercise, the brain also sends COLLATERAL IMPULSES to the respiratory center

Question 24

What do irritant receptors do?

Answer 24

Cause coughing/sneezing. may also cause bronchial constriction.
Located in the trachea, bronchi, bronchioles

Question 25

What are J receptors and where are they?

Answer 25

Located in alveolar walls, they give a feeling of dyspnea when the pulmonary arteries become engorged or in cases of pulmonary edema
Patients with CHF will feel dyspnea when they lay down due to stimulation of these

Question 26

How can brain edema affect the respirator center?

Answer 26

It can compress it.

Hypertonic solutions can be administered to relieve this

Question 27

Where are stretch receptors located and what do they do?

Answer 27

They are located in the muscular portions of the bronchi and bronchioles. When stretched, they send signals to teh DRG via vagal nerves to switch off the inspiratory ramp. They increase the rate of respiration

Question 28

What is the Hering-Breuer inflation reflex?

Answer 28

It is the stretch receptors response. It isnt activated until it is stretched 3x normal. protective

Question 29

What is Kussmaul’s breathing?

Answer 29

Relentless, rapid, deep breathing found in metabolic acidosis

Question 30

What is Cheyne-Stoke’s BreathingL?

Answer 30

Ventilatory oscillations with long cycle times

Found in stroke, encephalopathies, HF

Question 31

What is Biot’s Breathing?

Answer 31

Group of quick shallow inspirations followed by regular or irrregular periods of apnea
Found in medullary trauma, stroke