Question

Describe the mechanism of breathing

Answer 1

In order for air to be drawn into the lungs during inhalation the volume of the thorax must increase. This is brought about due to the contraction of respiratory muscles. The diaphragm contracts and flattens and the intercostal muscles contract to pull the ribs up and out.

Answer 2

contraction and expansion of chest is called respiratory movement
*inspiration involves two muscle
-Phrenic muscle is extended from diaphragm to ribs and vertebral column by contraction of - phrenic muscle diaphragm becomes flat in structure it increases size of thoracic cavity in interior posterior reason in direction
-external intercostal muscles are 11 paired and present between every to lips by contraction of external intercostal muscle sternum moves upward and ribs pulled out what this increases size of thoracic cavity in dorsal ventral and lateral in direction.
#both phrenic muscle and external question muscle contacts together simultaneously. it increases the size of thoracic cavity in all directions. volume of air in lungs increases and pressure of air in lungs decreases to equalise air rushed from outside of lungs through respiratory tract.

*expiration is a passive process it is caused by requiring power of lungs and relaxation of inspiration muscles but during hard work aspiration is active process and it involves abdominal muscle and internal intercostal muscles
- abdominal muscles is extended from visceral organ to ribs, by contraction of these muscles vital organs move upward due to this reason diaphragm becomes dome shaped instructure it decreases the size of thoracic cavity in interior posters reason
- internal intercostal muscles are also of 11 3rd and present between every two ribs by contraction of these muscle sternum moves downward and dreams pull inward it decreases the size of thoracic cavity in dorsal ventral and Lateral in direction
# both abdominal muscle and internal intercostal muscle contract simultaneously increases the size of thoracic cavity in all direction volume of air inside lungs decreases and pressure increases to equalise the air pressure air comes out of lungs through respiratory tract

THAT'S THE WHOLE MECHANISM OF BREATHING..