Triceps

Triceps brachii

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Triceps refers to a group of muscles located in the upper arm, specifically the triceps brachii muscle. The term "triceps" is derived from the Latin words "tri," meaning three, and "ceps," meaning heads, indicating that the muscle has three distinct heads: the long head, the lateral head, and the medial head.

Anatomy

The triceps brachii is a large muscle on the back of the upper limb of many vertebrates. It is the muscle principally responsible for extension of the elbow joint (straightening of the arm).

Heads of the Triceps

• Long Head: The long head of the triceps originates from the infraglenoid tubercle of the scapula. It is the only head that crosses the shoulder joint, and it helps in shoulder extension and adduction.
• Lateral Head: The lateral head originates from the posterior surface of the humerus, superior to the radial groove. It is the strongest of the three heads.
• Medial Head: The medial head originates from the posterior surface of the humerus, inferior to the radial groove. It is the deepest of the three heads and is mostly covered by the long and lateral heads.

Function

The primary function of the triceps is to extend the forearm at the elbow joint. The long head also assists in the extension and adduction of the arm at the shoulder joint. The triceps works in opposition to the biceps brachii, which is responsible for flexing the elbow.

Innervation

The triceps brachii is innervated by the radial nerve, which arises from the brachial plexus. The radial nerve provides motor innervation to the triceps, allowing it to contract and extend the elbow.

Blood Supply

The blood supply to the triceps brachii comes from the deep brachial artery, a branch of the brachial artery. This artery runs alongside the radial nerve in the radial groove of the humerus.

Clinical Significance

Injuries to the triceps can occur due to overuse, trauma, or improper exercise techniques. Common injuries include triceps tendonitis and triceps muscle strain. Proper warm-up and stretching exercises can help prevent these injuries.

Exercises

Strengthening the triceps can be achieved through various exercises, including:

• Triceps dips
• Triceps pushdowns
• Overhead triceps extensions
• Close-grip bench press

See Also

• Biceps brachii
• Elbow joint
• Shoulder joint
• Radial nerve
• Brachial artery