Mechanism of Breathing

Phrenic muscles contract to increase the volume of the thoracic chamber resulting in inspiration.

Phrenic muscles are present in the _____ (diaphragm/sternum) helps to maintain the volume of thoracic chamber.

Which one of the following is called inspiratory muscle in mammals?

During inspiration, the diaphragm

During expiration the diaphragm becomes

Which of the following statements is correct?

Which structures are responsible for the breathing process?

During inspiration

Explain the mechanism of respiration and the importance of respiration in human.

Explain the mechanism of expiration.

Explain the mechanism of inspiration.

The rate of breathing in an adult during resting condition is 

What happens during expiration?

What happens during inspiration?

Find the incorrect statement about the mechanism of ventilation.

Select the correct order of sequence required to initiate inspiration.

(i) The contraction of external intercostalmuscles raises the ribs and sternum.
(ii) Volume of thorax increases in the dorso-ventral axis.
(iii) Intrapulmonary pressure decreases.
(iv) Diaphragm contraction.
(v) Air rushes into lungs.
(vi) Volume of thorax increases in the anterior-posterior axis.

Involuntary breathing is controlled by the

The amount of air exchanged in breathing can be measured with a

Read the following statements (A – D).

(A) The movement of air in and out of the lungs is carried out by creating a pressure gradient between the lungs and atmosphere.
(B) Inspiration can occur if the pressure within the lungs is more than the atmospheric pressure.
(C) Expiration takes place when the intrapulmonary pressure is lesser than the atmospheric pressure.
(D) The diaphragm and a specialized set of intercostal muscles in between the ribs help in the generation of such pressure gradients for breathing.

How many of the following statements are correct?

Which of the following changes occur in diaphragm and intercostal muscles when expiration of air takes place?