Muscles of thoracic wall

Question 1

Intercostal Muscle Fiber Directions-3

Answer 1

External Intercostal-inferoanteriorly

Internal Intercostal-inferoposteriorly

Innermost Intercostal-inferoposteriorly

Question 2

Intercostal muscles (Superior/Inferior attachment, Innervation, Action)

Answer 2

Superior Attachment: Inferior border of ribs

Inferior Attachment: Superior border of ribs below

Innervation: Intercostal nerve

Action: Elevate ribs

Question 3

Transversus thoracis (Superior/Inferior attachment, Innervation, Action)

Answer 3

Superior attachment:
Posterior surface of lower sternum

Inferior Attachment: Internal surface of costal cartilages 2-6

Innervation: Intercostal nerve

Action: Weakly depresses ribs

Question 4

Subcostal (Superior/Inferior attachment, Innervation, Action)

Answer 4

Superior attachment:
Internal surface of lower ribs near their angles

Inferior attachment:
Superior borders of 2nd or 3rd ribs below

Innervation: Intercostal nerve

Action: Probably same as internal intercostal muscles?

Question 5

Levatores Costarum (Superior/Inferior attachment, Innervation, Action)

Answer 5

Superior attachment: Transverse processes of T7-T11

Inferior attachment:
Subajacent ribs between tubercle and angle

Innervation:
Posterior rami of C8-T11 nerves

Action: Elevate ribs