question_answer 22)

  Mark the correct pair of muscles involved in the normal breathing in humans. (a) External and internal inter costal muscles (b) Diaphragm and abdominal muscles (c) Diaphragm and external inter costal muscles (d) Diaphragm and inter costal muscles

Answer:

                  (d) The diaphragm and a specialised set of muscles, called external muscles present between the ribs are involved in the normal breathing in humans. They are involved in generating pressure gradient of air between the lungs and the atmosphere, so as to facilitate the intake of air.