3-4 Anterior Thoracic Wall: Internal View

Question 1

Origin (two)

Answer 1

A ridge on the inner surface of the inferior aspect of each rib; from the corresponding costal cartilage.

Question 2

Insertion

Answer 2

Attach to the upper border of the rib below.

Question 3

Action (two)

Answer 3

• Elevate the ribs (using the portions of the upper 4 or 5 internal intercostal muscles that interconnect with the costal cartilages);
• Depress the ribs ((using the more lateral and posterior portions of the muscles, where the fibres run more obliquely), active during expiration.

Question 4

Innervation

Answer 4

Intercostal nerves.

Question 5

Name

Answer 5

Internal intercostals