Controlling breathing like an absolute boss

Question 1

What are the three levels of respiratory control?

Answer 1

• higher centres
• apneustic and pneumotaxic centres in the pons
• respiratory rhythmicity centre

Question 2

What is the role of the Pre-Botzinger?

Answer 2

This is the basal respiratory rhythm generator - pacemaker cells

Question 3

Describe the control of breathing by the Pre-Botzinger complex

Answer 3

This is for normal, restful breathing.
Pacemaker cells in the pre-botzinger complex activate neurons in the dorsal respiratory group to start inspiration. They fire action potentials to activate inspiratory muscles (the diaphragm and the external intercostals).
Then signals from the pacemaker cells stop, neurons in the dorsal respiratory group stop firing. The diaphragm relaxes, inspiration stops and expiration begins

Question 4

What is the role of the apneustic centre?

Answer 4

This can speed up the start of inspiration.
It activates the dorsal respiratory group and so the diaphragm and external intercostals are activated. It also activated the ventral respiratory group and so the accessory inspiratory muscles are activated.

Question 5

What is the role of the pneumotaxic centre?

Answer 5

This speeds up the end of inspiration/start of expiration. This inhibits inspiration and activates the ventral respiratory group so activate the accessory expiratory muscles

Question 5

What is the role of the pneumotaxic centre?

Answer 5

This speeds up the end of inspiration/start of expiration. This inhibits inspiration and activates the ventral respiratory group so activate the accessory expiratory muscles

Question 6

What is the purpose of lung mechanoreceptors?

Answer 6

This is part of the Hiring-Breuer reflex which directly inhibits inspiratory interneurons with large increases in lung volume which helps to terminate inspiration. By speeding up the termination (big tidal volume in exercise), they can increase breathing frequency