Question No:1

CO₂ dissociates from Carbaminohaemoglobin when

[A] low PO₂, low PCO₂
[B] high PO₂, high PCO₂
[C] low PO₂, high PCO₂
[D] high PO₂, low PCO₂



Question No:2

Dissociation of oxyhaemoglobin can be promoted by

[A] Low pCO₂
[B] High pCO₂
[C] Low body temperature
[D] High blood pH



Question No:3

Enzyme essential for transport of CO₂ as bicarbonate in blood is:

[A] Carboxypeptidase
[B] Succinic dehydrogenase
[C] Carbonic anhydrase
[D] Thrombokinase



Question No:4

What is correct about human respiration?

[A] About 90% of CO₂ is carried by haemoglobin as Carbaminohaemoglobin
[B] Neural signals from pneumotaxic centre of pens can increase duration of inspiration
[C] Workers in grinding and stone breaking industries may suffer from lung fibrosis
[D] Cigarette smoking leads to inflammation of bronchi



Question No:5

Choose the right sequential phenomena during passage of CO₂ from blood to tissues:
(P) Absorption of CO₂ by blood.
(Q) Reaction of CO₂ with water forming H₂CO₃ inside RBCs and then and HCO₃ ^– and H⁺ ions.
(R) Reaction of CO₂ with water forming H₂CO₃ inside plasma followed by conversion into H⁺ and HCO₃ ^– ions.
(S) Combination of H⁺ with haeme part of HbO₂ to release O₂
(T) Combination of HCO₃ with haeme part of HbO₂ to form reduced haemoglobin and release of O₂.

[A] P,R,S
[B] P,Q,T
[C] P, Q, S
[D] P,R,T



Question No:6

The transport of CO₂ by the blood in primarily dependent on the

[A] solubility of CO₂ in blood
[B] presence of carbonic anhydrase in RBCs
[C] ability of hemoglobin to bind and transport CO₂
[D] ability of other blood proteins



Question No:7

Pick the correct statement:

[A] Contraction of internal intercostals muscles lifts up the ribs and sternum
[B] RBCs transport oxygen only
[C] Thoracic cavity is anatomically an air tight chamber
[D] Healthy man can inspire approximately 500 mL of air per minute



Question No:8

Respiratory rhythm centre is present in which part of brain?

[A] Pons
[B] Medulla oblongata
[C] Cerebrum
[D] Cerebellum



Question No:9

Pneumotaxic centre is present hi

[A] pons
[B] medulla oblongata
[C] cerebrum
[D] cerebellum



Question No:10

Human beings have a significant ability to maintain and moderate the respiratory rhythm to suit the demands of the body tissues. This is done by

[A] endocrine system
[B] neural system
[C] excretory system
[D] all



Question No:11

All of the following factors play role in the regulation of respiratory rhythm except

[A] CO₂
[B] H⁺conc
[C] O₂
[D] None of the above



Question No:12

Select the incorrect statement from the following:

[A] Neural signal from Pneumotaxic centre can reduce the duration of inspiration
[B] The role of oxygen in the regulation of respiratory rhythm is quite significant
[C] RBCs contain a very high concentration of the enzyme, carbonic anhydrase and minute quantities of the same is present in the plasma too
[D] CO₂ is carried by haemoglobin as carbamino-haemoglobin (about 20-25 per cent)



Question No:13

Receptors associated with aortic and carotid artery can recognize changes in ____ and ___ cone, and send necessary signal to ___ for remedial action,

[A] O₂, CO₂ pneumotaxic
[B] CO₂, H⁺, rhythm centre
[C] CO₂,H⁺, apneustic centre
[D] O₂, H⁺, pneumotaxic



Question No:14

Carbonic anhydrase is found in high concentration in

[A] leucocytes
[B] blood plasma
[C] erythrocytes
[D] lymphocytes



Question No:15

Controlling centre of normal breathing in mammals lies in

[A] Cerebrum
[B] Cerebellum
[C] Midbrain
[D] Medulla oblongata