Week #5 Muscles of the Neck and Trunk

slide 4 of muscles of the neck and trunk PPT

Sternocephalicus m.

• Forms the jugular groove along with the brachiocephalicus m.

• Action

• Draws head and neck side to side, and downward movement of head

External Intercostal m.

• Superficial layer of the intercostal muscles

• Lie between the ribs

• Action

• Expands the rib cage → inspiration

Internal Intercostal m.

• Deep layer of the intercostal muscles

• Lie between the ribs

• Action

• Compresses the rib cage → expiration

slide 8

Linea Alba

• The left and right abdominal muscles meet on ventral midline forming an aponeurosis called the linea alba (white line)

External Abdominal Oblique m.

• Most superficial

• Runs caudoventrally toward the pelvis

External Abdominal Oblique m.

Internal Abdominal Oblique m.

• Lies deep to the external abdominal oblique m.

• Runs cranioventrally toward the sternum

Transverse Abdominis m.

• Lies deep to the internal abdominal oblique m. '

• Runs across lateral to medial

Rectus Abdominis m.

• Lies deep to the transverse abdominis m. on the ventral abdomen

• Runs straight cranial to caudal