“Inflation of lungs induces further inflation” is explained by:
A. Hering-Breuer inflation reflexB. Hering-Breuer deflation reflex
C. Heads paradoxical reflex
D. J-reflex
The
Answer is ‘C’
1.
Hering-Breuer Reflexes:
a. Hering-Breur Inflation reflex is an
increase in the duration of expiration - produced by steady lung inflation.
b. Hering-Breuer deflation reflex is a
decreased in the duration of expiration produced by marked deflation of the
lung.
2. J-Receptors
(Juxtracapillary):
They
are stimulated by hyperinflation of the lung, but they respond as well to intravenous
or intracardiac administration of chemicals such as Capsaicin. The reflex
response that is produced is apnea followed by rapid breathing, bradycardia and
hypotension (pulmonary chemoreflex)
3. Head's
paradoxical reflex:
·
With
the completion of second stage of labour, certain events play a major role in
the initiation of respiration
·
Clamping
of umbilical cord results in a fall in arterial oxygen and slight rise in
carbon dioxide tension. These factors taken
together stimulate the respiratory centre directly and via the
chemoreceptors in carotid body.
·
Sensory
impulses from changes in skin temperature and proprioceptive impulse from
joints directly stimulate the respiratory centre.
·
With
inflation of the lungs there is augmentation of respiratory effort - Head's
paradoxical reflex.