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    Related Topics

    From Musculoskeletal System

    Interspinous Ligament
    Spinal ligament between adjacent vertebral spinous processes.
    Pubis
    Part of the pelvis that joins with the opposite side to form the pubic symphysis.
    Maxillae
    Upper jaw bones that house the teeth and form part of the orbit.
    Sternum
    Breastbone located in the center of the chest.
    Pectoralis Major
    Chest muscle responsible for shoulder movement.
    Ulna
    Forearm bone on the pinky side.
    Brachioradialis
    Muscle responsible for forearm flexion.
    Latissimus Dorsi
    Back muscle responsible for arm adduction and extension.
    Anterior Cruciate Ligament (ACL)
    Knee ligament that stabilizes the joint.
    Syndesmoses
    Fibrous joints where bones are connected by ligaments.
    Sternocleidomastoid
    Muscle that rotates and flexes the neck.
    Acetabulum
    The acetabulum is the pelvic socket that connects with the femoral head to form the hip joint, vital for stability, movement, and weight-bearing.
    Posterior Cruciate Ligament (PCL)
    Knee ligament that stabilizes the joint.
    Biceps Tendon
    Tendon that attaches the biceps muscle to the bone.
    Levator Ani
    Pelvic floor muscle responsible for lifting the anus.
    Glenohumeral Ligaments
    Shoulder ligaments that stabilize the shoulder joint.
    Wormian Bones
    Sutural bones in the skull.
    Gastrocnemius
    Calf muscle responsible for plantarflexion of the foot.
    Cranial Bones
    Bones of the skull that protect the brain.
    Inferior Nasal Conchae
    Bones inside the nasal cavity that filter and humidify air.
    Rectus Abdominis
    Abs muscle that flexes the trunk.
    Medial Collateral Ligament (MCL)
    Knee ligament that stabilizes the inner knee.
    Sphenoid Bone
    Bone forming part of the base of the skull and sides of the orbits.
    Coccygeus
    Pelvic floor muscle supporting the coccyx.
    Soleus
    Calf muscle responsible for plantarflexion of the foot.

    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 sternocleidomastoid muscle helps rotate the head.