Regulation of Breathing

Question 1

Controller of Breathing

Answer 1

behavioural / voluntary control - higher centres (cerebral cortex, hypothalamus and other areas)

automatic control (central pattern generator located here) - respiratory centre (brainstem-medulla…receives input from pons and other parts of brain)

effectors (respiratory muscles)

sensors (chemoreceptors, stretch receptors, proprioceptors and others)

Question 2

regulation of breathing

Answer 2

rhythm generator:
- dorsal respiratory group (inspiration; chiefly to diaphragm)
- ventral respiratory group (inspiration and forced expiration)

rhythm tuners (making it precise):
- regulates duration, fine tuning
- integrates higher centre activity

Question 3

Quiet Breathing

Answer 3

inhalation (2 seconds)
- dorsal respiratory group active ->
- inspiratory muscles contract ->
- inspiration occurs ->

exhalation
- dorsal respiratory group inhibited ->
- inspiratory muscles relax ->
- passive expiration occurs ->

REPEATS

Question 4

Forced Breathing (exercise etc.)

Answer 4

Inhalation
- Expiratory centre of VRG inhibited and DRG and inspiratory centre of VRG active ->
- Inspiratory muscles contract and expiratory muscles relax ->
- Inspiration occurs ->

Exhalation
- DRG and inspiratory centre of VRG inhibited and expiratory centre of VRG active ->
- Inspiratory muscles relax and expiratory muscles contract ->
- Active expiration occurs ->

REPEATS

Question 5

what modulates breathing?

Answer 5

• higher brain centres (cerebral cortex - volunatary control over breathing)
• respiratory centres (medulla and pons)
• stretch receptors in lungs
• irritant receptors
• receptors in muscles and joints
• central chemoreceptors
• peripheral chemoreceptors
• other receptors (pain) and emotional stimuli acting through hypothalamus