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    Related Topics

    From Musculoskeletal System

    Ribs (12 Pairs)
    12 pairs of bones that form the sides of the thoracic cage.
    Phalanges (14 bones)
    14 bones forming the toes.
    Lumbar Vertebrae (L1 - L5)
    Vertebrae in the lower back (L1-L5).
    Femur
    Thigh bone, the longest and strongest bone in the body.
    Flexor and Extensor Groups
    Muscles responsible for flexing and extending the hand and wrist.
    Skull
    Bony structure of the head that encases the brain.
    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.
    Deltoid
    Shoulder muscle responsible for arm abduction.
    Biceps Tendon
    Tendon that attaches the biceps muscle to the bone.
    Cranial Bones
    Bones of the skull that protect the brain.
    Fibula
    Smaller bone in the lower leg, located alongside the tibia.
    Tarsals (7 bones)
    7 ankle bones.
    Trapezius
    Muscle responsible for moving, rotating, and stabilizing the scapula.
    Wormian Bones
    Sutural bones in the skull.
    Sphenoid Bone
    Bone forming part of the base of the skull and sides of the orbits.
    Sacrum
    Triangular bone at the base of the spine.
    Sartorius
    Longest muscle in the body responsible for hip flexion.
    Sacroiliac Ligaments
    Ligaments connecting the sacrum to the iliac bones.
    Radius
    Forearm bone on the thumb side.
    Levator Ani
    Pelvic floor muscle responsible for lifting the anus.
    Masseter
    Muscle that elevates the mandible.
    Anterior Cruciate Ligament (ACL)
    Knee ligament that stabilizes the joint.
    Annular Ligament
    The annular ligament is a strong fibrous band encircling the head of the radius, stabilizing the proximal radioulnar joint and allowing smooth rotation of the forearm.
    Latissimus Dorsi
    Back muscle responsible for arm adduction and extension.
    Sternocleidomastoid
    Muscle that rotates and flexes the neck.

    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.