Tag: respiration in humans

Questions Related to respiration in humans

Inspiration occurs when there is a negative pressure in the lungs with respect to atmospheric pressure. This negative pressure is achieved when

  1. intrapulmonary pressure is less than the atmospheric pressure

  2. intrapulmonary pressure is greater than the atmospheric pressure

  3. intrapulmonary pressure is equal to the atmospheric pressure

  4. intrapleural pressure becomes more than the intra-alveolar pressure.


Correct Option: A
Explanation:

Because of the pressure gradient between the lungs and the atmosphere, the air moves into and out of the lungs. Inspiration occurs if the pressure within the lungs (intra-pulmonary pressure) is less than the atmospheric pressure i.e. there is a negative pressure in the lungs with respect to atmospheric pressure.

Choose the correct answer from the alternatives given.
The lung is enclosed in a double layered membrane called

  1. pericardium

  2. pleura

  3. periosteum

  4. perichondrium


Correct Option: B
Explanation:

The pleura refers to the double-layered membrane that covers the lungs. The space between the two membranes is called the pleural cavity. It is filled with a thin, lubricating liquid called pleural fluid, which acts as a lubricant and allows the pleurae to slide effortlessly against each other by reducing friction during respiratory movements. So, the correct option is 'pleura'.

The exchange of gases in human beings takes place in-

  1. In skin

  2. In mouth

  3. In nostrils

  4. In lungs.


Correct Option: D