Respiratory rhythm centre is present in the medulla and is primarily responsible for regulation of respiration as per demands of the body tissues. This centre is regulated by

1. Pneumotaxic centre present pons region

2. Central chemoreceptor adjacent to rhythm centre

3. Peripheral chemoreceptor present in aortic arch and carotid artery

4. All of these

Maximum volume of air a person can breathe after forceful expiration is termed as

1. Inspiratory capacity

2. Vital capacity

3. Expiratory capacity

4. Functional residual capacity

In the given figure, identify the muscles involved in raising the rib cage

1. External intercostals 

2. Internal intercostals

3. External obliques

4. Abdominal recti

Dissociation of oxygen from blood to tissue is facilitated by

1. Low ${\mathrm{pO}}_2$ at the level of tissue

2. Metabolic activities of the tissue

3. High ${\mathrm{pCO}}_2$ at the level of tissue

4. All of these

Select the incorrectly matched pair

The number of oxygen molecules (O${}_2$) that can conjugate with one molecule of haemoglobin are 

1. 2

2. 4

3. 8 

4. 6

Central chemoreceptors in the brain respond to changes in the

1. Oxygen concentration in blood

2. Carbon dioxide concentration in CSF

3. Oxygen concentration in CSF

4. Rate of oxidation of food content in the cell

In which of the following disorders alveolar walls are damaged, surface area for gaseous exchange is reduced and the air sacs remain filled with air even after expiration?

1. Pneumonia 

2. Coryza

3. Emphysema

4. SARS

The pO${}_2$ in systemic arteries and systemic veins is respectively

1. 95, 40 mmHg

2. 95, 45 mmHg

3. 40, 95 mmHg

4. 104, 40 mmHg

Mark the incorrect combination with respect to pulmonary capacities

1. IC = TV + IRV

2. FRC = RV + ERV

3. VC = TLC + RV

4. EC = TV + ERV