Respiratory Physiology 5

Question 1

Identify the 2 parameters that can be controlled to alter ventilation

Answer 1

Respiratory rate

How deep breathing (tidal volume)

Question 2

Describe the control and regulation of breathing

Answer 2

Autonomic nervous system
Neural inputs
- central chemo receptors H+
Peripheral chemoreceptors O2, CO2, H+
Pulmonary receptors - stretch and irritants
Joint and muscle receptors - stretch and tension
All these are sent to a respiratory control centre, then the centres send an efferent signal to res muscles

Question 3

Identify the respiratory control centres

Answer 3

Three groups this is bilateral

Medulla oblongata
dorsal respiratory group (inspiration)
Ventral respiratory group (inspiration and expiration)

Pons (which is in two parts)
pneumotaxic centre
Apneustic centre

Question 4

Compare and describe the inspiration and expiration processes

Answer 4

Dorsal respiratory group set general pattern
Ventral respiratory group provides powerful expiration signals to muscles during heavy breathing
Pneumataxic centres control the duration of each breath to prevent over inflation (strong = short, weak = long)
Apneustic centre control for gasping by inhibiting DRG delaying inspiratory off and then it self inhibited by pulmonary stretch receptors
Cerebral cortex and somatic control of res muscles override the 4 above
Hypothalamus and limbic system - sympathetic fight or flight and holding your breath override of 4 above

Question 5

Explain the importance of central chemoreceptors in breathing

Answer 5

Provide on the most importance feedback loops with the dorsal respiratory group

Question 6

Describe the importance of hydrogen ions in the proper functioning of central chemoreceptors

Answer 6

Charged ions cannot cross the blood brain barrier, but CO2 can. When it crosses over the carbonic anhydrase reaction occurs. DRG and VRG are influenced by the increase of H+ ions from the reaction (the decreasing pH)

Question 7

Identify the location of peripheral chemoreceptors

Answer 7

Carotid bodies and aortic bodies

Question 8

Describe the function of peripheral chemoreceptors

Answer 8

Detect O2 changes in the blood
Respond to CO2 and H = ions
Receive afferent signals from the autonomic nervous system
Type 1 glomus cells

Carotid bodies send signals via the CNXI
Aortic bodies send signals via CNX

Fx, L type voltage gated Ca2+

Question 9

Describe the effect of anaesthesia on respiration

Answer 9

Anaesthetic drugs at on specific ion Chanels and receptors
If ventilation is not occurring properly sympathetic response occurs which includes tachycardia and increased blood pressure.