Respiratory muscles
A- Diaphragm
Musculo-tendineous dome between the thoracic and abdominal cavities.
It has openings for passage of the
1. Inferior vena cava (T8),
2. Esophagus (T10),
3. Aorta lymphatic vessels and nerves. (T12),
Action: prime mover of inspiration
Nerve supply - phrenic nerve & intercostal nerves.
B- External Intercostal:
Actions: : elevatesthe ribs during inspiration. (increases antero posterior
diameter of thorax)
C- Internal Intercostal:
Actions: : depress and pull in the ribs, expelling air during forceful
expiration. (decreases antero posterior diameter of thorax)
Nerve supply to both muscles - Intercostal nerve
A- Diaphragm
Musculo-tendineous dome between the thoracic and abdominal cavities.
It has openings for passage of the
1. Inferior vena cava (T8),
2. Esophagus (T10),
3. Aorta lymphatic vessels and nerves. (T12),
Action: prime mover of inspiration
Nerve supply - phrenic nerve & intercostal nerves.
B- External Intercostal:
Actions: : elevatesthe ribs during inspiration. (increases antero posterior
diameter of thorax)
C- Internal Intercostal:
Actions: : depress and pull in the ribs, expelling air during forceful
expiration. (decreases antero posterior diameter of thorax)
Nerve supply to both muscles - Intercostal nerve
