10.1 Regulation of Respiration

Question 1

what are the sensory inputs into the controller of respiration

Answer 1

central and peripheral chemoreceptors
mechanoreceptors of lung and airways
exercise and respiration

Question 2

what are the types of chemoreceptors

Answer 2

central 
peripheral (less important but take over if CO2 is chronically high)

Question 3

What are the tracho-bronchial receptors

Answer 3

Stretch receptors, irritant receptors and j receptors

Question 4

Where are the central chemoreceptors and what do they respond to

Answer 4

Ventrolateral medulla: rostral, intermediate and caudal

They respond to CO2. The PaCO2 drives the pH in the CSF quickly

Question 5

Where are the peripheral sensors and what do they respond to?

Answer 5

Glomus cells in the carotid body signal O2 changes via CN IX

Respond to PaO2 and pH

Question 6

Where is the central pattern generator of respiration?

Answer 6

Mainly in the medulla but also in the pons and other ares of the brainstem

Question 7

Which nuclei drive inspiration?

Answer 7

Intermediate ventral respiratory group (nucleus ambiguous and nucleus paraambigualis)

Question 8

Which nuclei drive expiration?

Answer 8

Rostral ventral respiratory group (nucleus retrofacialis)

Question 9

Which are the expiratory pre-motor nuclei?

Answer 9

caudal ventral respiratory group (nucleus retroambigualis)

Question 10

which nuclei are the inhibitory and exictatory interneurones to the ANS

Answer 10

Dorsal respiratory group (nucleus tractus solitaries)

Question 11

How is tonic inspiratory activity controlled?

Answer 11

Activity routed via the nucleus tracts solitaries to various motor nuclei

Question 12

How is phasic expiratory activity controlled?

Answer 12

activity amplified in nucleus retroambigualis to drive expiratory motor nuclei

Question 13

how does the central pattern generator work and what is the interaction between the nuclei?

Answer 13

The Nucleus tractus solitaries (NTS) send tonic inspiratory output to motor neurones and to nucleus ambiguous and nucleus paraambiguous which causes additional stimulation of inspiratory neurones and also sends signals to neucleus retroambiguous and nucleus retrofacialis which sitmulates phasic expiratory output to motor neurones and inhibition of the NTS

Question 14

What is the order of muscle recruitment

Answer 14

1. Innervation of upper airway muscles (nares, larynx, pharynx, tongue)
2. Diaphragm and muscles of the rib cage
3. Opening of the glottis ahead of decrease in tracheal pressure

Question 15

What is seen in vagal breathing?

Answer 15

bradypnoea and large volumes

Question 16

What patterns of breathing is seen in Cheyne-strokes breathing

Answer 16

periods of apnoea folowed by hyperventilation