Chapter 17

Functional residual capacity can be represented as (a) \(\mathrm{TV}+\mathrm{ERV}\) (b) \(\mathrm{ERV}+\mathrm{RV}\) (c) \(\mathrm{RV}+\mathrm{IRV}\) (d) ERV + TV + IRV

The volume of air involved in breathing movements can be estimated by using a which helps in clinical assessment of pulmonary functions (a) Osmometer (b) Potometer (c) Spirometer (d) Sphygmomanometer

A spirometer cannot be used to measure (a) IC (b) RV (c) ERV (d) IRV

Inspiratory air in lungs ultimately reaches (a) Trachea (b) Alveoli (c) Bronchi (d) Bronchioles

Which is not true? (a) \(\mathrm{pCO}_{2}\) of deoxygenated blood is \(95 \mathrm{~mm} \mathrm{Hg}\). (b) \(\mathrm{pCO}_{2}\) of alveolar air is \(40 \mathrm{~mm} \mathrm{Hg}\). (c) \(\mathrm{pO}_{2}\) alveolar air is \(104 \mathrm{~mm} \mathrm{Hg}\). (d) \(\mathrm{pO}_{2}\) of oxygenated blood is \(95 \mathrm{~mm} \mathrm{Hg}\). (e) \(\mathrm{pO}_{2}\) of deoxygenated blood is \(40 \mathrm{~mm} \mathrm{Hg}\).

Which of the following factors affect the rate of diffusion of gases? (a) Partial pressure/concentration gradient of diffusing gases (b) Solubility of gases (c) Thickness of diffusion membrane (d) All the above

Lung alveoli of mammals have a thin wall composed of (a) Simple cuboidal epithelium (b) Simple squamous epithelium (c) Stratified cuboidal epithelium (d) Stratified squamous epithelium

The mode of respiration in rabbit is (a) Cutaneous (b) Mucosal (c) Tracheal (d) Pulmonary

The respiratory diffusion membrane is majorly made of layers (a) 2 (b) 3 (c) 4 (d) 5

Select the incorrect statement from the following: (a) Diffusion of \(\mathrm{O}_{2}\) occurs from alveoli to tissue. (b) Diffusion of \(\mathrm{CO}_{2}\) occurs from tissue to alveoli. (c) Amount of \(\mathrm{CO}_{2}\) diffused through membrane is higher than that of \(\mathrm{O}_{2}\). (d) Partial pressure of \(\mathrm{O}_{2}\) is higher in pulmonary artery than that of pulmonary vein.

The total thickness of respiratory diffusion membrane is (a) Less than \(\mathrm{fm}\) (b) Less than micrometer (c) Much less than \(\mathrm{mm}\) (d) Less than \(\mathrm{nm}\)

Diffusion membrane is made up of (a) Thin squamous epithelium of alveoli (b) Endothelium of alveolar capillaries (c) Basement membrane between the two layers (d) All the above

Partial pressures (in \(\mathrm{mmHg}\) ) of \(\mathrm{O}_{2}\) in atmospheric air, alveoli, deoxygenated blood, oxygenated blood and tissues are (a) \(159,104,40,95,40\) (b) \(104,40,40,95,159\) (c) \(0.3,40,45,40,45\) (d) \(159,104,45,95,40\)

Partial pressure (in \(\mathrm{mmHg}\) ) of \(\mathrm{CO}_{2}\) in atmospheric air, alveoli, deoxygenated blood, oxygenated blood and tissues are (a) \(159,104,40,95,40\) (b) \(104,40,40,95,159\) (c) \(0.3,40,45,40,45\) (d) \(159,104,45,95,40\)

The total percentage of \(\mathrm{O}_{2}\) transported by haemoglobin or \(\mathrm{RBC}\) is (a) \(3 \%\) (b) \(97 \%\) (c) \(70 \%\) (d) \(7 \%\)

Besides RBC blood plasma also carries \(\mathrm{O}_{2}\) in dissolved state. The percentage is (a) \(3 \%\) (b) \(97 \%\) (c) \(70 \%\) (d) \(7 \%\)

\(\mathrm{CO}_{2}\) is transported (a) By RBC (b) As bicarbonates (c) In dissolved state through plasma (d) All of these

Blood entering the lung is rich in (a) Oxygen (b) Carbon dioxide (c) Urea (d) More RBCs

The majority of \(\mathrm{CO}_{2}\) is transported as (a) Carbonates (b) Bicarbonates (c) Carbaminohaemoglobin (d) Dissolved state in blood

Oxygen is transported in blood mainly by (a) Blood plasma (b) Leucocytes (c) Thrombocytes (d) Erythrocytes

Each molecule of haemoglobin can carry at the maximum of \(\quad\) molecules of \(\mathrm{O}_{2}\). (a) 1 (b) 2 (c) 3 (d) 4

Under a given oxygen concentration in blood, dissociation of oxyhaemoglobin will increase if (a) \(\mathrm{pH}\) of blood falls (b) \(\mathrm{pH}\) of blood rises (c) \(\mathrm{CO}_{2}\) concentration in blood falls (d) Free fatty acid concentration in blood falls

The blood coming out of lungs is richer than that one entering into lungs in (a) \(\mathrm{CO}_{2}\) (b) \(\mathrm{O}_{2}\) (c) Both (a) and (b) (d) None of these

When partial pressure of \(\mathrm{CO}_{2}\left(\mathrm{pCO}_{2}\right)\) rises, the oxygen dissociation curve of haemoglobin at \(37^{\circ} \mathrm{C}\) will (a) Shift towards right (b) Shift towards left (c) Become irregular (d) Remains unchanged

Dissociation curve is connected with (a) Myoglobin (b) \(\mathrm{CO}\) (c) \(\mathrm{O}_{2}\) (d) Oxyhaemoglobin

A large proportion of oxygen is left unused in the human blood even after uptake by the body tissue. This oxygen (a) Is enough to keep oxyhaemoglobin saturation at \(96 \%\) (b) Helps in releasing more oxygen to epithelial tissues. (c) Acts as reserve during muscular exercise. (d) Raise \(\mathrm{pCO}_{2}\) of blood to \(75 \mathrm{~mm} \mathrm{Hg}\).

Oxygen dissociation curve is (a) Parabola (b) Sigmoid (c) Hyperbola (d) Straight line

Binding of oxygen with haemoglobin can be affected by (a) \(\mathrm{pCO}_{2}\) (b) \(\mathrm{H}+\mathrm{conc}\) (c) Temperature (d) All of these

Oxygen binding to haemoglobin is (a) Directly proportional to \(\mathrm{CO}_{2}\) concentration (b) Directly proportional to CO concentration (c) Inversely proportional to \(\mathrm{CO}_{2}\) concentration (d) Independent of CO concentration

The most characteristic feature of haemoglobin is (a) Its red colour (b) Presence of iron (c) Its ability to combine reversibly with oxygen (d) Presence of basic protein globin

Factors at tissue level favours the dissociation of oxygen from oxyhaemoglobin (a) Low \(\mathrm{pO}_{2}\), low \(\mathrm{pCO}_{2}\), high \(\mathrm{H}^{+}\), low temperature (b) High \(\mathrm{pO}_{2}\), high \(\mathrm{pCO}_{2}\), low \(\mathrm{H}^{+}\), high temperature (c) Low \(\mathrm{pO}_{2}\), high \(\mathrm{pCO}_{2}\), high \(\mathrm{H}^{+}\), high temperature (d) Low \(\mathrm{pO}_{2}\), high \(\mathrm{pCO}_{2}\), high \(\mathrm{H}^{+}\), low temperature

\(\mathrm{CO}_{2}\) dissociates from Carbaminohaemoglobin when (a) Low \(\mathrm{PO}_{2}\), low \(\mathrm{PCO}_{2}\) (b) High \(\mathrm{PO}_{2}\), high \(\mathrm{PCO}_{2}\) (c) Low \(\mathrm{PO}_{2}\), high \(\mathrm{PCO}_{2}\) (d) High \(\mathrm{PO}_{2}\), low \(\mathrm{PCO}_{2}\)

The enzyme essential for transport of \(\mathrm{CO}_{2}\) as bicarbonate in blood is (a) Carboxypeptidase (b) Succinic dehydrogenase (c) Carbonic anhydrase (d) Thrombokinase (e) Lactase

What is correct about human respiration? (a) About 90 per cent of \(\mathrm{CO}_{2}\) is carried by haemoglobin as carbaminohaemoglobin. (b) Neural signals from pneumotaxic centre of pons can increase the duration of inspiration. (c) Workers in grinding and stone breaking industries may suffer from lung fibrosis. (d) Cigarette smoking leads to inflammation of bronchi.

Choose the right sequential phenomena during the passage of \(\mathrm{CO}_{2}\) from blood to tissues: (P) Absorption of \(\mathrm{CO}_{2}\) by blood. (Q) Reaction of \(\mathrm{CO}_{2}\) with water forming \(\mathrm{H}_{2} \mathrm{CO}_{3}\) inside \(\mathrm{RBCs}\) and then \(\mathrm{HCO}_{3}^{-}\) and \(\mathrm{H}^{+}\) ions. (R) Reaction of \(\mathrm{CO}_{2}\) with water forming \(\mathrm{H}_{2} \mathrm{CO}_{3}\) inside plasma followed by conversion into \(\mathrm{H}^{+}\) and \(\mathrm{HCO}_{3}^{-}\) ions. (S) Combination of \(\mathrm{H}^{+}\) with haeme part of \(\mathrm{HbO}_{2}\) to release \(\mathrm{O}_{2}\). (T) Combination of \(\mathrm{HCO}_{3}\) with haeme part of \(\mathrm{HbO}_{2}\) to form reduced haemoglobin and release of \(\mathrm{O}_{2}\) (a) \(\mathrm{P}, \mathrm{R}, \mathrm{S}\) (b) P, Q, T (c) \(\mathrm{P}, \mathrm{Q}, \mathrm{S}\) (d) \(P, R, T\)

The transport of \(\mathrm{CO}_{2}\) by the blood is primarily dependent on the (a) Solubility of \(\mathrm{CO}_{2}\) in blood. (b) Presence of carbonic anhydrase in RBCs. (c) Ability of haemoglobin to bind and transport \(\mathrm{CO}_{2}\). (d) Ability of other blood proteins.

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 \(500 \mathrm{~mL}\) of air per minute. (e) During expiration the interpleural pressure is slightly below the surrounding atmospheric pressure.

Respiratory rhythm centre is present in which part of brain? (a) Pons (b) Medulla oblongata (c) Cerebrum (d) Cerebellum

Pneumotaxic centre is present in (a) Pons (b) Medulla oblongata (c) Cerebrum (d) Cerebellum

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 of these

A (1) sensitive area is situated adjacent to the rhythm centre which is highly sensitive to \((2)_{-}\) and \(_{-}(3) \longrightarrow\) ions. (a) (1)-thermo, (2)- CO \(_{2}\), (3)- hydroxide (b) (1)-chemo, (2) - \(\mathrm{O}_{2}\), (3)-hydroxide (c) (1)-thigmo, (2) \(-\mathrm{O}_{2}\), (3)- -hydrogen (d) (1)-chemo, (2) \(-\mathrm{CO}_{2}\), (3)-hydrogen

All of the following factors play an important role in the regulation of respiratory rhythm except (a) \(\mathrm{CO}_{2}\) (b) \(\mathrm{H}^{+}\) conc (c) \(\mathrm{O}_{2}\) (d) None of these

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) \(\mathrm{CO}_{2}\) is carried by haemoglobin as carbamino-haemoglobin (about \(20-25\) per cent).

Receptors associated with aortic and carotid artery can recognize changes in and concentration and send necessary signal to for remedial action. (a) \(\mathrm{O}_{2}, \mathrm{CO}_{2}\), pneumotaxic (b) \(\mathrm{CO}_{2}, \mathrm{H}^{+}\), rhythm centre (c) \(\mathrm{CO}_{2}, \mathrm{H}^{+}\), apneustic centre (d) \(\mathrm{O}_{2}, \mathrm{H}^{+}\), pneumotaxic

Carbonic anhydrase is found in high concentration in (a) Leucocytes (b) Blood plasma (c) Erythrocytes (d) Lymphocytes

The controlling centre of normal breathing in mammals lies in (a) Cerebrum (b) Cerebellum (c) Midbrain (d) Medulla oblongata

Number of RBCs per unit volume of blood is likely to be higher in a person living at high altitudes, because (a) Air is clean and unpolluted (b) More sunshine is available (c) Air is less dense (d) Vegetation gives out more \(\mathrm{O}_{2}\)

Wheezing sound is produced in (a) Asthma (b) Emphysema (c) Silicosis (d) Pneumonia

Major cause of emphysema is (a) Cigarette smoking (b) Allergy (c) Wine consumption (d) Viral infection

Match the column: Column A Column B 1\. Asthma \- A. Inflammation of bronchi and bronchioles. 2\. Emphysema \- B. Chronic disorder in which alveolar walls are damaged due to which respiratory surface is decreased. 3\. Occupational Respiratory Disorders \(-\) C. Long exposure of chemicals can give rise to inflammation leading to fibrosis (proliferation of fibrous tissues). (a) \(1-\mathrm{A}, 2-\mathrm{B}, 3-\mathrm{C}\) (b) \(1-\mathrm{B}, 2-\mathrm{A}, 3-\mathrm{C}\) (c) \(1-\mathrm{C}, 2-\mathrm{A}, 3-\mathrm{B}\) (d) \(1-\mathrm{C}, 2-\mathrm{B}, 3-\mathrm{A}\)