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    Related Topics

    From Musculoskeletal System

    Glenohumeral Ligaments
    Shoulder ligaments that stabilize the shoulder joint.
    Sacroiliac Ligaments
    Ligaments connecting the sacrum to the iliac bones.
    Medial Collateral Ligament (MCL)
    Knee ligament that stabilizes the inner knee.
    Clavicle
    Collarbone connecting the arm to the body.
    Vertebral Column
    Spinal column consisting of vertebrae.
    Inferior Nasal Conchae
    Bones inside the nasal cavity that filter and humidify air.
    Ethmoid Bone
    Bone forming part of the nasal cavity and the orbit.
    Hyoid Bone
    U-shaped bone in the neck that supports the tongue.
    Lacrimal Bones
    Bones forming part of the eye socket and housing the tear ducts.
    Pubis
    Part of the pelvis that joins with the opposite side to form the pubic symphysis.
    Parietal Bones
    Bones forming the sides and roof of the skull.
    Temporalis
    Muscle involved in closing the jaw.
    Zygomatic Bones
    Cheekbones that form part of the orbit.
    Humerus
    Upper arm bone connecting the shoulder to the elbow.
    Frontal Bone
    Bone forming the forehead and upper part of the orbits.
    Sutures (in the skull)
    Fibrous joints between skull bones.
    Skull
    Bony structure of the head that encases the brain.
    Sesamoid Bones
    e.g., patella, some found in hands/feet.
    Saddle Joints
    e.g., thumb joint
    Rectus Abdominis
    Abs muscle that flexes the trunk.
    Hamstrings
    Biceps Femoris, Semitendinosus, Semimembranosus.
    Pivot Joints
    e.g., atlanto-axial joint
    Patellar Tendon
    Tendon connecting the patella to the tibia.
    Ellipsoidal (Condyloid) Joints
    e.g., wrist
    Biceps Brachii
    Muscle responsible for elbow flexion.

    Triceps Brachii

    Reviewed by our medical team

    Muscle responsible for elbow extension.

    1. Overview

    The triceps brachii is a large, three-headed skeletal muscle located on the posterior aspect of the upper arm. As the primary extensor of the elbow joint, it plays a crucial role in straightening the forearm. The triceps is also important for shoulder joint stability and movement. Its powerful action is essential in pushing, throwing, and weight-bearing activities.

    2. Location

    The triceps brachii occupies the posterior compartment of the arm:

    • Proximally: Originates from both the scapula and the humerus.

    • Distally: Inserts on the olecranon process of the ulna.

    • Superficial to: The humerus and deep fascia of the upper arm.

    • Adjacent to: Biceps brachii (anteriorly) and deltoid (superiorly).

    3. Structure

    The triceps brachii has three distinct heads:

    • Long head: Originates from the infraglenoid tubercle of the scapula.

    • Lateral head: Originates from the posterior surface of the humerus, superior to the radial groove.

    • Medial head: Originates from the posterior surface of the humerus, inferior to the radial groove.

    All three heads converge into a common tendon that inserts on the olecranon process of the ulna.

    • Innervation: Radial nerve (C6–C8).

    • Blood supply: Deep brachial artery (profunda brachii) and collateral branches of the brachial artery.

    4. Function

    The triceps brachii has two main actions:

    • Elbow extension: All three heads extend the forearm at the elbow joint.

    • Shoulder extension and adduction: The long head also assists in extension and adduction of the arm at the shoulder joint.

    These actions are essential in movements such as pushing open a door, rising from a chair, or performing a push-up.

    5. Physiological role(s)

    The triceps brachii contributes to several important physiological functions:

    • Upper limb mobility: Allows full range of elbow motion in combination with the biceps brachii.

    • Postural support: Assists in maintaining arm and shoulder posture during load-bearing tasks.

    • Force generation: As a powerful muscle, it generates the force required for explosive movements like throwing or punching.

    • Joint stability: Helps stabilize the shoulder joint, particularly when the arm is adducted or extended behind the body.

    6. Clinical Significance

    The triceps brachii can be affected by various injuries and conditions:

    • Triceps strain or tear:

      • Results from sudden or excessive loading, often seen in athletes performing overhead or pushing motions.

    • Radial nerve palsy:

      • Injury to the radial nerve may weaken or paralyze the triceps, leading to difficulty in elbow extension and “wrist drop.”

    • Tendonitis:

      • Repetitive strain can lead to inflammation of the triceps tendon, especially near the olecranon.

    • Triceps reflex testing:

      • Used clinically to assess the integrity of the C7 and C8 spinal cord segments and radial nerve function.

    • Rehabilitation importance:

      • Commonly targeted in strengthening programs for upper limb recovery, especially after injury or surgery.

    Did you know? Your skeleton is 5 times stronger than steel.