Question

Describe the control of respiration, including the two respiratory groups in the medulla and the 4 factors that affect those groups.

Answer 1

Respiration - It is the transport of gases O2 and CO2 in the blood. The normal rate of respiration in adults is 12-16/ min with tidal volume of approx 500ml.

Two zones for respiration - a. Conducting zone - here only passage of air no exchange of gas takes place . It is also called Dead space.

b.Respiratory zone - zone where exchange of gas takes place .

Respiration is regulated by two mechanisms .

1. Nervous regulatory mechanism.

2. Chemical regulatory mechanism.

1.Nervous regulation of respiration -

Medullary respiratory centre - It is located in ventrolateral medulla.

Neurons discharge during inspiration are I - neurons. This neurons give rhythmic discharge to diaphragm via phrenic nerve. This also receive afferents from chemoreceptors ( aortic and carotid bodies).

neurons that discharge during expiration are e- neurons inner ages the accessory muscles of respiration.

Factors affecting respiratory centre -

A. Chemical stimuli ( aortic and carotid bodies).

B.Non- chemical stimuli - 1.Hering breuer inflation and deflation reflex.