The movement of air into the lungs occurs due to a pressure gradient between the lungs and the atmosphere. So, inspiration occurs when/due to

1. Intra pulmonary is less than the atmospheric pressure

2. Increase in the volume of the thoracic chamber in the dorso-ventral axis

3. Contraction of external inter-costal muscles and phrenic muscles

4. All of these

The diffusion membrane or respiratory membrane does not include

1. Thin squamous epithelium

2. Pseudostratified ciliated epithelium

3. Endothelium

4. Basement membrane 

Human beings have a significant ability to maintain and moderate the respiratory rhythm. This is done by neural control. Which of the following is not related with respiration ?

1. Pneumotaxic centre

2. Respiratory rhythm centre

3. Hypothalamus

4. Aortic and carotid body receptors

During inspiration, the diaphragm

1. Contracts

2. Expands

3. Does not move

4. Relaxes

A healthy man can inspire or expire approximately _____ of air per breath normally

1. 500 ml

2. 1000 ml to 1100 ml

3. 1100 ml to 1200 ml

4. 6000 ml to 8000 ml

Total volume of air accommodated in the lungs at the end of maximum forceful inspiration includes 

A. ERV + RV

B. IRV + ERV

C. TV + IRV + ERV + RV

D. VC + RV

1. A only

2. A & B only

3. C only

4. C & D only 

What percentage of haemoglobin is saturated with oxygen in the blood at ${\mathrm{pO}}_2$ 30 mm Hg and ${\mathrm{pCO}}_2$ 40 mm Hg ?

1. 50 %

2. 85 %

3. 90 %

4. 98 %

Which of the following statements is correct regarding ${\mathrm{CO}}_2$ $\mathrm{and}$ ${\mathrm{O}}_2$ transport in blood ?

1. 100 ml of oxygenated blood carries 53 ml of ${\mathrm{O}}_2$

2. 100 ml of blood always transport equal amounts of ${\mathrm{O}}_2$ $\mathrm{and}$ ${\mathrm{CO}}_2$

3. 100 ml of oxygenated blood delivers more ${\mathrm{O}}_2$ than ${\mathrm{CO}}_2$ to the tissues

4. ${\mathrm{O}}_2$ $\mathrm{and}$ ${\mathrm{CO}}_2$ are both maximally transported through the blood plasma 

Given below are the partial pressures (in mmHg) of oxygen and carbondioxide at different parts involved in diffusion in comparison to those in atmosphere.

Choose the correct option with respect to the values of partial pressures (in mmHg) marked as A, B, C and D

At 40 mmHg of partial pressure of oxygen haemoglobin is ______ saturated

1. 50 %

2. 75 %

3. 85 %

4. 35 %