Triceps brachii is a three-headed (tri - three, cep - head) muscle of the arm. It represents the only constituent of the posterior muscle group of the arm, spanning almost the entire length of the humerus. The triceps, or triceps brachii (Latin for " three-headed muscle of the arm "), is a large muscle on the back of the upper limb of many vertebrates. It consists of three parts: the medial, lateral, and long head. The upper arm is located between the shoulder joint and elbow joint. It contains four muscles - three in the anterior compartment (biceps brachii, brachialis, coracobrachialis), and one in the posterior compartment ( triceps brachii). The triceps, also known as the triceps brachii , is a big muscle found on the back of many vertebrates' upper limbs. It is the muscle that is primarily responsible for elbow joint extension (straightening of the arm).
