48.
Dissociation of oxyhaemoglobin can be promoted by
(a) low pCO2
(b) high pCO2
(c) low body temperature (d) high blood pH
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49.
Residual air mostly occurs in
(a) alveoli (b) bronchus
(c) nostrils (d) trachea
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50.
Emphysema developes mainly because of
(a) allergy or hypersensitization.
(b) spasm of the smooth muscles of bronchioles.
(c) cigarette smoking.
(d) inflammation of the alveoli
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51.
The pneumotaxic centre that can moderate the function
of respiratory rhythm centre is located in
(a) dorsal side of medulla
(b) ventral side of medulla
(c) aortic arch and carotid artery
(d) pons varolii
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Section showing-View Explanation with NCERT Reference below all the questions.
48- (b) The higher concentration of pCO2
stimulates
dissociation of oxyhaemoglobin.
49- (a) Residual air is the amount of air that remains in the
lungs after a maximal expiration. This air mostly
occurs in alveoli (the main site of gas exchange).
50-(c) Emphysema is a chronic, irreversible disease of the
lungs. It is characterized by abnormal enlargement of
air spaces in the lungs accompanied by destruction
of the tissue which lines the walls of the air spaces. It
is one of several diseases known collectively as
Chronic Obstructive Pulmonary disease (COPD).
Smoking is the leading cause of emphysema.
10 MIN VIDEO REFERENCE
51-(d) Pneumotaxic center controls medullary respiratory centres, particularly inspiratory centre, so that duration of inspiration is controlled. It is located in pons varolii of brain.
7MIN VIDEO https://youtu.be/9j6BpanhpKY
