What amount of carbon dioxide is delivered by every 100 ml of deoxygenated blood to the alveoli?

1. 4 ml

2. 5 ml

3. 15 ml

4. 20 ml

A center that moderates the functions of the respiratory rhythm center is located in:

1. Dorsal medulla oblongata

2. Ventral medulla oblongata

3. Pons Varolii

4. Pre-central gyrus of the cerebrum

Pneumotaxic centre which can moderate the functions of the respiratory rhythm centre is present at:

1. Pons region of brain

2. Thalamus

3. Spinal cord

4. Right cerebral hemisphere

The following statements refer to gas carriage by blood. Choose the correct statement:

In the given diagram of the oxygen dissociation curve, under normal physiological conditions, the partial pressure of oxygen at the tissue level is represented by :

1. A

2. B

3. C

4. D

The partial pressure of oxygen in the alveoli of the lungs is  

(1) equal to that in the blood

(2) more than that in the blood

(3) less than that in the blood

(4) less than that of carbon dioxide

Name the chronic respiratory disorder caused mainly by cigarette smoking

1. asthma

2. respiratofy acidosis

3. respiratory alkalosis

4. emphysema

Approximately seventy percent of carbon dioxide absorbed by the blood will be

transported to the lungs

1. as bicarbonate ions

2. in the form of dissolved gas molecules

3. by binding to RBC

4. as carbamino-haemoglobin

The figure shows a diagrammatic view of human respiratory system with labels A, B, C

and D. Select the option, which gives correct identification and main function and/or

characteristic.

1. A-trachea-long tube supported by complete cartilaginous rings for conducting

inspired air

2. 8-pleural membrane-surround ribs on both sides to provide cushion against rubbing

3. C-alveoli-thin walled vascular bag-like structures for exchange of gases

4. D-lower end of lungs-diaphragm pulls it down during inspiration

What is true about RBCs in humans?

1. They carry about 20-25 per cent of CO₂

2. They transport 99.5 per cent of O₂

3. They transport about 80 per cent oxygen only and the rest 20 per cent of it is

transported in dissolved state in blood plasma

4. They do not carry CO₂ at all