Abdominal Muscles and Mediastinum

Question 1

Rectus Abdominus

Answer 1

Most anterior/superficial muscle in trunk of body. Segmented muscle divided into 4 ipsilateral parts.

Origin: pubic symphysis

Insertion: Xiphoid Process, Costal Cartilage of ribs 5-7

Actions: Flexes trunk, Compresses abdomen

Question 2

External Oblique

Answer 2

Lateral superficial abdominal muscles. Fibers run inferiorly and medially (EXtra money pockets).

Origin: 5-12th ribs

Insertion: Linea Alba, Pubis, Anterior Crest

Actions: Lateral flexion, Trunk compression, Opposite side trunk rotation

Question 3

Internal Oblique

Answer 3

Lateral muscles deeper to external obliques. Fibers run superiorly and medially (INternal Pockets).

Origin: Thoracolumbar Fascia, Iliac Crest

Insertion: 10th-12th (floating) ribs, Linea Alba

Actions: Lateral flexion, Trunk compression, Opposite side trunk rotation

Question 4

Transverse Abdominus

Answer 4

Lateral muscle fibers deep to external and internal obliques. Fibers run in the transverse plane. (It’s a belt)

Origin: inner 7-12 costal cartilages, thoracolumbar fascia, iliac crest

Insertion: linea alba, pubis

Actions: Rotates trunk to same side, compression of abdomen

Question 5

R. and L. Vagus Nerve

Answer 5

Runs deep to the jugular vein and common carotid artery.

Origin: Brain (Spinal nerve X)

Insertion: Most visceral organs

Question 6

Aorta

Answer 6

Extension of the left ventricle. Carries blood away from the heart

Question 7

Brachiocephalic Artery

Answer 7

First arterial branch off the aorta. Subdivides into the R. common carotid artery and the R. Subclabian artery later on.

Question 8

R. and L. Subclavian Arteries

Answer 8

The R. one branches off the brachiocephalic artery and the L. one branches directly off the aorta. Ultimately vascularizes the arms.

Question 9

R. and L. Recurrent Laryngeal Nerves

Answer 9

Nerve branches off of the R. and L. Vagus nerves that innervate the larynx. The L. Recurrent Laryngeal nerve swings under the aortic arch. The R. Recurrent Laryngeal nerve swings under the right subclavian artery.

Question 10

R. and L. Phrenic Nerves

Answer 10

Innervates the Diaphragm on both sides. Leads from C-(3-5) to the diaphragm between the lungs and the pericardium

Question 11

Trachea

Answer 11

Windpipe wrapped with circular cartilage pieces

Question 12

R. and L. Primary Bronchi

Answer 12

The first branches off the trachea going toward the lungs

Question 13

Esophagus

Answer 13

Round tube connecting the mouth to the stomach. No cartilage is found on this tube.

Question 14

Heart

Answer 14

Primary mover of blood through the circulatory system

Question 15

Pericardium

Answer 15

A double-walled sac that contains the heart and the roots of the great vessels