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    Related Topics

    From Musculoskeletal System

    Ribs (12 Pairs)
    12 pairs of bones that form the sides of the thoracic cage.
    Extensor Tendons
    Tendons that help extend the fingers and toes.
    Hinge Joints
    e.g., elbow, knee
    Syndesmoses
    Fibrous joints where bones are connected by ligaments.
    Sartorius
    Longest muscle in the body responsible for hip flexion.
    Ligamentum Flavum
    Spinal ligament connecting the laminae of adjacent vertebrae.
    Lateral Collateral Ligament (LCL)
    Knee ligament that stabilizes the outer knee.
    Anterior Longitudinal Ligament
    Spinal ligament running along the front of the vertebral column.
    Tarsals (7 bones)
    7 ankle bones.
    Rotator Cuff Muscles
    Supraspinatus, Infraspinatus, Teres Minor, Subscapularis.
    Rotator Cuff Tendons
    Tendons of the rotator cuff muscles.
    Flexor and Extensor Groups
    Muscles responsible for flexing and extending the hand and wrist.
    Coccygeus
    Pelvic floor muscle supporting the coccyx.
    Ball-and-Socket Joints
    e.g., shoulder, hip
    Sutures (in the skull)
    Fibrous joints between skull bones.
    Quadriceps
    Rectus Femoris, Vastus Medialis, Vastus Lateralis, Vastus Intermedius.
    Sternocleidomastoid
    Muscle that rotates and flexes the neck.
    Zygomaticus
    Muscle that raises the corners of the mouth.
    Latissimus Dorsi
    Back muscle responsible for arm adduction and extension.
    Phalanges (14 bones)
    14 bones forming the toes.
    Synchondroses
    Cartilaginous joints where bones are connected by hyaline cartilage.
    Obliques (External and Internal)
    Muscles responsible for torso rotation.
    Adductors
    Muscles that bring the thighs toward the midline.
    Parietal Bones
    Bones forming the sides and roof of the skull.
    Ulna
    Forearm bone on the pinky side.

    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? The sacrum is the foundation of the spine and the pelvis.