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    Related Topics

    From Musculoskeletal System

    Cranial Bones
    Bones of the skull that protect the brain.
    Hyoid Bone
    U-shaped bone in the neck that supports the tongue.
    Latissimus Dorsi
    Back muscle responsible for arm adduction and extension.
    Saddle Joints
    e.g., thumb joint
    Patellar Tendon
    Tendon connecting the patella to the tibia.
    Lumbar Vertebrae (L1 - L5)
    Vertebrae in the lower back (L1-L5).
    Acromioclavicular Joint
    The acromioclavicular joint connects the clavicle and scapula at the top of the shoulder, enabling smooth scapular motion and stability during arm movements.
    Syndesmoses
    Fibrous joints where bones are connected by ligaments.
    Ischium
    Part of the pelvis that supports weight while sitting.
    Gluteus Maximus
    Largest muscle in the buttocks responsible for hip extension.
    Pectoralis Major
    Chest muscle responsible for shoulder movement.
    Pubis
    Part of the pelvis that joins with the opposite side to form the pubic symphysis.
    Sartorius
    Longest muscle in the body responsible for hip flexion.
    Gliding (Plane) Joints
    e.g., between carpals
    Temporal Bones
    Bones forming the lower sides of the skull and housing the ears.
    Frontal Bone
    Bone forming the forehead and upper part of the orbits.
    Biceps Tendon
    Tendon that attaches the biceps muscle to the bone.
    Hinge Joints
    e.g., elbow, knee
    Acromioclavicular Ligament
    Ligament that connects the acromion to the clavicle.
    Flexor Tendons
    Tendons that help flex the fingers and toes.
    Diaphragm
    Primary muscle for breathing.
    Thoracic Cage
    Ribs and sternum forming the protective cage for the heart and lungs.
    Ribs (12 Pairs)
    12 pairs of bones that form the sides of the thoracic cage.
    Rotator Cuff Tendons
    Tendons of the rotator cuff muscles.
    Femur
    Thigh bone, the longest and strongest bone in the body.

    Temporalis

    Reviewed by our medical team

    Muscle involved in closing the jaw.

    1. Overview

    The temporalis is a broad, fan-shaped muscle located on the side of the head. It is one of the primary muscles of mastication (chewing) and plays a major role in elevating and retracting the mandible (lower jaw). As a powerful and efficient jaw closer, the temporalis is essential for biting and grinding food.

    2. Location

    The temporalis muscle is located in the temporal fossa of the skull:

    • Origin: Temporal fossa and deep surface of the temporal fascia.

    • Course: Fibers converge downward, passing deep to the zygomatic arch (cheekbone).

    • Insertion: Coronoid process of the mandible and the anterior border of the mandibular ramus.

    3. Structure

    The temporalis muscle has a distinctive fan-shaped morphology:

    • Muscle type: Skeletal muscle (voluntary).

    • Fiber orientation: Posterior fibers run more horizontally, while anterior fibers run vertically, allowing for different movement vectors.

    • Tendon: The tendon passes beneath the zygomatic arch and inserts on the mandible.

    • Innervation: Deep temporal branches of the mandibular nerve (CN V3), a branch of the trigeminal nerve.

    • Blood supply: Deep temporal arteries, branches of the maxillary artery.

    4. Function

    The temporalis muscle has two main actions:

    • Elevation of the mandible: Closes the jaw during biting and chewing.

    • Retraction of the mandible: Posterior fibers pull the mandible backward, especially after protrusion.

    These functions work in coordination with other muscles of mastication like the masseter and medial/lateral pterygoids.

    5. Physiological role(s)

    The temporalis supports important daily and survival functions:

    • Mastication: Enables effective chewing and crushing of food.

    • Speech and articulation: Assists in jaw stabilization required for verbal communication.

    • Postural support of the mandible: Maintains resting tone to prevent jaw from hanging open.

    • Sensory feedback: Via muscle spindles, it contributes to proprioception of jaw position and movement.

    6. Clinical Significance

    The temporalis is involved in several musculoskeletal and neurological conditions:

    • Temporomandibular joint (TMJ) dysfunction:

      • Overactivity or spasm of the temporalis can cause jaw pain, limited range of motion, or headaches.

      • May present with tenderness at the temples or pain radiating toward the ear.

    • Tension-type headaches:

      • Temporalis muscle tension is a common contributor to stress-induced headaches.

    • Bruxism (teeth grinding):

      • Involuntary clenching or grinding of teeth can cause hypertrophy and soreness of the temporalis.

      • Long-term bruxism may lead to dental wear, jaw fatigue, and muscle imbalance.

    • Temporal arteritis (giant cell arteritis):

      • Inflammation of the superficial temporal artery may mimic temporalis-related pain; can lead to serious complications like vision loss.

    • Myofascial pain syndrome:

      • Trigger points in the temporalis can refer pain to the forehead, teeth, and upper jaw.

    Did you know? Your thumb has two phalanges, whereas other fingers have three.