Muscles of the Thorax

Question 1

External Intercostal (attachments)

Answer 1

rib to rib oriented from superior-lateral to inferior-medial (down & in)

Question 2

External Intercostal (action)

Answer 2

elevates ribs

Question 3

External Intercostal (innervation)

Answer 3

intercostal n. (segmental)

Question 4

Internal & Innermost Intercostal (attachments)

Answer 4

rib to rib oriented from superior-medial to inferior-lateral (down & out)

Question 5

Internal & Innermost Intercostal (action)

Answer 5

depresses ribs

Question 6

Internal & Innermost Intercostal (innervation)

Answer 6

intercostal n. (segmental)

Question 7

Transversus Thoracis (attachments)

Answer 7

posterior sternum to costal cartilages

Question 8

Transversus Thoracis (action)

Answer 8

depresses ribs

Question 9

Transversus Thoracis (innervation)

Answer 9

intercostal n. (segmental)

Question 10

Diaphragm (attachments)

Answer 10

xiphoid process, inner surface of lower ribs & costal cartilages, lumbar vertebrae via crura to central tendon

Question 11

Diaphragm (action)

Answer 11

inspiration (negative thoracic pressure by inferior displacement)

Question 12

Diaphragm (innervation)

Answer 12

phrenic n. (C3-5)