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    Related Topics

    From Musculoskeletal System

    Anterior Longitudinal Ligament
    Spinal ligament running along the front of the vertebral column.
    Maxillae
    Upper jaw bones that house the teeth and form part of the orbit.
    Sternum
    Breastbone located in the center of the chest.
    Palatine Bones
    Bones forming part of the hard palate and nasal cavity.
    Gastrocnemius
    Calf muscle responsible for plantarflexion of the foot.
    Femur
    Thigh bone, the longest and strongest bone in the body.
    Interspinous Ligament
    Spinal ligament between adjacent vertebral spinous processes.
    Facial Bones
    Bones forming the structure of the face.
    Ball-and-Socket Joints
    e.g., shoulder, hip
    Hyoid Bone
    U-shaped bone in the neck that supports the tongue.
    Quadriceps
    Rectus Femoris, Vastus Medialis, Vastus Lateralis, Vastus Intermedius.
    Diaphragm
    Primary muscle for breathing.
    Biceps Brachii
    Muscle responsible for elbow flexion.
    Iliolumbar Ligament
    Ligament connecting the ilium and lumbar vertebrae.
    Syndesmoses
    Fibrous joints where bones are connected by ligaments.
    Flexor Tendons
    Tendons that help flex the fingers and toes.
    Gomphoses
    Fibrous joints where a peg fits into a socket (e.g., teeth in jaw).
    Nasal Bones
    Bones forming the bridge of the nose.
    Clavicle
    Collarbone connecting the arm to the body.
    Tibialis Anterior
    Muscle that dorsiflexes and inverts the foot.
    Sternocleidomastoid
    Muscle that rotates and flexes the neck.
    Gluteus Maximus
    Largest muscle in the buttocks responsible for hip extension.
    Vertebral Column
    Spinal column consisting of vertebrae.
    Pivot Joints
    e.g., atlanto-axial joint
    Posterior Longitudinal Ligament
    Spinal ligament running along the back of the vertebral column.

    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? The smallest joint in the body is the stapes in the ear.