What serves to extend the humerus?
Attachments: The deltoid muscle originates from the scapula and clavicle and attaches to the lateral surface of the humerus. extension.
Where do the triceps attach to?
It extends downward and inserts on (attaches to) the upper part of the ulna, in the forearm. Its major action is extension of the forearm upon the elbow joint, in opposition to the biceps brachii.
Does the triceps extend the shoulder?
It works in shoulder (humeral) extension, although there are several other muscles (e.g., latissimus dorsi, posterior fibers of the deltoid, and teres major and minor) that contribute to this action.
What is triceps brachii?
Introduction. The triceps brachii is a large, thick muscle on the dorsal part of the upper arm. It often appears as the shape of a horseshoe on the posterior aspect of the arm. The main function of the triceps is the extension of the elbow joint.
Where does triceps attach to humerus?
Triceps brachii muscle
|Origins||Long head – infraglenoid tubercle of the scapula Medial head – posterior surface of the humerus (inferior to radial groove) Lateral head – posterior surface of the humerus (superior to radial groove)|
|Insertion||Olecranon of ulna and fascia of forearm|
What Innervates the triceps?
Nerve. All the three heads of triceps brachii are innervated by the four branches of the radial nerve (C7, C8). … Some research reveals that the long head of triceps is actually innervated by the axillary nerve.
Is the triceps muscle an extensor or flexor?
The opposing muscle of a flexor is called the “extensor” muscle. Your triceps is an extensor. When you contract your triceps your arm straightens and the angle between the forearm and the upper arm increases.