该 肱三头肌 is a first-rate muscle of the higher arm within the human body. The triceps run along the humerus (the principal bone of the top arm) among the shoulder and the elbow. Alongside the biceps, it permits extension and retraction of the forearm.
While the triceps are reduced in size, the forearm extends and the elbow straightens; if the triceps are comfy and the biceps flexed, the forearm retracts and the elbow bends.
The triceps moreover serve to stabilize the shoulder joint at the top of the humerus. The shoulder has the best range of motion of any joint inside the body, possessing the capability to reveal and rotate in many directions.
但, this movability approach that the shoulder is a fairly risky joint and the triceps plays a vital position in stabilizing it.
The distal quantities of the triceps also are concerned in retracting the pill of the elbow joint whilst the forearm extends, thereby permitting the elbow joint to be straightened effectively.
此外, via branches of the deep brachial arterythe muscle is supplied with oxygen and nutrients. It’s also innervated by using four branches of the radial nerve. Each the artery and the nerve hold into the decrease forearm past the triceps.
Origin of triceps brachii
The long head originates on the Infraglenoid tubercle 的 肩胛骨. The lateral head originates on the posterior surface of the humerus above a bony ridge known as the spiral groove. The medial head also originates on the posterior ground of the humerus. 然而, attaches below the spiral groove.
Insertion of triceps brachii
The tendinous insertion of the triceps brachii muscle is shaped by means of the olecranon of the ulna. The insertion tendon already starts within the center of the muscle. It includes two combined Aponeurosis, of which one covers the lower part of the muscle to the out of doors, while the opposite one is passing deep into the muscle tissue.
What actions does the triceps brachii do?
Triceps is pretty a good deal in direct competition to the Biceps brachii muscle, both in phrases of its area in addition to its function. In a number of movements, they may be adverse to one another.
The triceps cross joints, the shoulder and elbow joints. The number one action of the triceps brachii is the extension of the elbow. It’s some distance the most powerful extensor of the elbow.
All three heads are answerable for this movement. 此外, the lengthy head of the triceps can contribute to adduction and extension of the humerus at the shoulder joint.