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    Related Topics

    From Musculoskeletal System

    Frontal Bone
    Bone forming the forehead and upper part of the orbits.
    Posterior Longitudinal Ligament
    Spinal ligament running along the back of the vertebral column.
    Sesamoid Bones
    e.g., patella, some found in hands/feet.
    Biceps Tendon
    Tendon that attaches the biceps muscle to the bone.
    Thoracic Vertebrae (T1 - T12)
    Vertebrae in the upper and mid-back (T1-T12).
    Patellar Tendon
    Tendon connecting the patella to the tibia.
    Sphenoid Bone
    Bone forming part of the base of the skull and sides of the orbits.
    Patella
    Knee cap, protecting the knee joint.
    Deltoid
    Shoulder muscle responsible for arm abduction.
    Sacroiliac Ligaments
    Ligaments connecting the sacrum to the iliac bones.
    Humerus
    Upper arm bone connecting the shoulder to the elbow.
    Diaphragm
    Primary muscle for breathing.
    Fibula
    Smaller bone in the lower leg, located alongside the tibia.
    Parietal Bones
    Bones forming the sides and roof of the skull.
    Clavicle
    Collarbone connecting the arm to the body.
    Flexor and Extensor Groups
    Muscles responsible for flexing and extending the hand and wrist.
    Maxillae
    Upper jaw bones that house the teeth and form part of the orbit.
    Nasal Bones
    Bones forming the bridge of the nose.
    Extensor Tendons
    Tendons that help extend the fingers and toes.
    Hamstrings
    Biceps Femoris, Semitendinosus, Semimembranosus.
    Ethmoid Bone
    Bone forming part of the nasal cavity and the orbit.
    Synchondroses
    Cartilaginous joints where bones are connected by hyaline cartilage.
    Zygomaticus
    Muscle that raises the corners of the mouth.
    Rotator Cuff Tendons
    Tendons of the rotator cuff muscles.
    Gluteus Maximus
    Largest muscle in the buttocks responsible for hip extension.

    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 human skeleton is made up of 206 bones at adulthood, but you are born with approximately 270 bones.