Central control of respiration

Question 1

What is breathing?

Answer 1

an automatic, rhythmic process

Question 2

What is the basic respiratory rhythm generated?

Answer 2

centres in the medulla

Question 3

What can alter the involuntary mechanism of breathing?

Answer 3

• hyperventilation
• breath holding

Question 4

If there is a severance above the level of the medulla (between the medulla & pons) what happens?

Answer 4

the individual maintains a basic rhythmic pattern of breathing

Question 5

If there is a severance below the level of the medulla (between the medulla & pons) what happens?

Answer 5

the breathing pattern is lost

Question 6

What is DRG (dorsal respiratory group)?

Answer 6

group of neurones
- primary link to inspiration - nerve outputs down to:
- phrenic nerve (to diaphragm)
- spinal nerves (to inter-costal muscles associated with inspiration)

(associated with quiet breathing)

Question 7

What is VRG (ventral respiratory group)?

Answer 7

group of neurones
- links to inspiration & expiratory
- linked to VRG is a small region of neurones known as the “pre-botzinger complex” - which is where the basic pattern of breathing is generated from. This sends signals to the DRG, to control inspiration.
- by moderating this pattern, you can control respiration rate

Question 8

What is VRG (ventral respiratory group) associated to?

Answer 8

mainly associated with forced inspiration & forced expiration

Question 9

What are the 2 centres in the Pons region of the brain?

Answer 9

• pneumotaxic center
• apeustic center

Question 10

Where is the basic pattern of breathing generated from?

Answer 10

pre-botzinger complex

Question 11

What is in the pneumotaxic centre?

Answer 11

increase the rate by shortening inspirations.
- inhibitory effect on inspiration centre

Question 12

What is in the apenustic centre?

Answer 12

increases the depth and reduces the rate by prolonging inspirations.
- stimulates inspiratory centre

Question 13

What is the Hering-Breuer reflex?

Answer 13

stretch receptors in the lung send signals back to the medulla to limit inspiration & prevent over-inflation of the lungs.

Question 14

What is the benefit of the Hering-Breuer reflex?

Answer 14

prevents over-inflation of the lungs

Question 15

Through which nerve does the Hering-Breur reflex tell the inspiration centre to stop inspiration?

Answer 15

vagus nerve

Question 16

What are the central chemoreceptors?

Answer 16

monitor conditions in the cerbro-spinal fluid. Sending CO2 & pH. indirect response to a rise in CO2 - stimulation leads to an increase in ventilation.

Question 17

Where are the peripheral chemoreceptors?

Answer 17

located in the carotid body & aortic arch

Question 18

What do peripheral chemoreceptors respond to?

Answer 18

• increase in CO2
• decrease in pH
• decrease in O2

Question 19

What does stimulation of the central & peripheral chemoreceptors lead to?

Answer 19

stimulation leads to an increase in ventilation