Thorax - transverse sectionYou selected: tricepsThe triceps muscle is the primary extensor of the elbow. It straightens the arm. The muscle has two heads, one of which inserts on the humerus just below the shoulder joint, and the other of which inserts on the scapula. The two heads can commonly be felt by placing a hand around the back of the arm while holding the elbow in a locked position.lungs | ribs | right atrium | left atrium | right ventricle | left ventricle | serratus anterior | latissimus dorsi | erector spinae | pectoralis major | Information Module Name: thorax Module Title: Thorax - transverse section Image Info: Gross specimen. Created by: Lynn Bry Contact Email:bryl@medicine.wustl.edu Last modified: Dec 12th, 1996 Created with Annotation 1.0 |