Lab Guidelines-Thoracic Wall

Question 1

Pectoralis Major

Answer 1

Large fan-shaped muscle running from humerus, to sternal margin

Question 2

Pectoralis Minor

Answer 2

Small muscle immediately deep to pectoralis major, running from coracoid process to ribs

Question 3

Where are the Medial and Lateral Pectoral nerves easily seen?

Answer 3

Pectoralis MINOR muscle

Question 4

External Intercostal Muscles and Membrane

Answer 4

Fibers of both run in an infero-anterior direction (\\\\///////)

Question 5

Where can you see the external intercostal muscles and membrane?

Answer 5

Starting approx. 10 cm from sternum

Question 6

Internal Intercostal Muscles and Membrane

Answer 6

Fibers run infero-posterior (///////\\\).

Question 7

Where can you see the internal intercostal muscles fibers?

Answer 7

Below the external intercostal membrane near sternum. (cannot see its membrane)

Question 8

Where does the Innermost Intercostal Muscle run?

Answer 8

The intercostal VAN runs between the innermost and internal intercostal muscles.

Question 9

What is the deepest kayer of intercostal muscles?

Answer 9

Innermost Intercostal Muscle

Question 10

Transverse Thoracic Muscles

Answer 10

Small strips of muscle on the interior surface of the anterior thoracic wall, running from sternal margin in a superior-lateral direction. Usually they span two ribs.

Question 11

Subcostal Muscles

Answer 11

Small strips of muscle (similar to transverse thoracic), but they will be found on the interior surface of the posterior thoracic wall. Span two ribs

Question 12

Sternal Angle

Answer 12

Junction between the manubrium and body of sternum.

Question 13

Internal Thoracic (Mammary Artery)

Answer 13

A long artery on the interior surface of the anterior thoracic wall running along the lateral margin of the sternum. Accompanied by internal thoracic vein.

Question 14

Anterior Intercostal VAN

Answer 14

Very small so may not be seen, but if present, found on the interior surface of the anterior thoracic wall running on the inferior margin of each rib.

Question 15

Parietal Pleura

Answer 15

Thin connective tissue forming the deepest layer of the thoracic wall. Would be intimately associated with visceral pleura on the lungs

Question 16

Costodiaphragmatic Recess

Answer 16

Cavity along inferior margins of thoracic margins of thoracic space, created by the dome of diaphragm protruding into thoracic space. Recess is shallow anteriorly getting progressively deeper as it runs lateral and then posteriorly