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    Related Topics

    From Musculoskeletal System

    Thoracic Vertebrae (T1 - T12)
    Vertebrae in the upper and mid-back (T1-T12).
    Adductors
    Muscles that bring the thighs toward the midline.
    Quadriceps
    Rectus Femoris, Vastus Medialis, Vastus Lateralis, Vastus Intermedius.
    Sternum
    Breastbone located in the center of the chest.
    Masseter
    Muscle that elevates the mandible.
    Patellar Tendon
    Tendon connecting the patella to the tibia.
    Ball-and-Socket Joints
    e.g., shoulder, hip
    Quadriceps Tendon
    Tendon that connects the quadriceps to the patella.
    Hinge Joints
    e.g., elbow, knee
    Nasal Bones
    Bones forming the bridge of the nose.
    Frontal Bone
    Bone forming the forehead and upper part of the orbits.
    Lumbar Vertebrae (L1 - L5)
    Vertebrae in the lower back (L1-L5).
    Posterior Longitudinal Ligament
    Spinal ligament running along the back of the vertebral column.
    Achilles Tendon
    Tendon connecting the calf muscle to the heel bone.
    Femur
    Thigh bone, the longest and strongest bone in the body.
    Sutures (in the skull)
    Fibrous joints between skull bones.
    Sacroiliac Ligaments
    Ligaments connecting the sacrum to the iliac bones.
    Zygomaticus
    Muscle that raises the corners of the mouth.
    Ribs (12 Pairs)
    12 pairs of bones that form the sides of the thoracic cage.
    Tarsals (7 bones)
    7 ankle bones.
    Rotator Cuff Tendons
    Tendons of the rotator cuff muscles.
    Saddle Joints
    e.g., thumb joint
    Cervical Vertebrae (C1 - C7)
    Vertebrae in the neck region (C1-C7).
    Gliding (Plane) Joints
    e.g., between carpals
    Flexor Tendons
    Tendons that help flex the fingers and toes.

    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? Bones are responsible for protecting organs like the brain, heart, and lungs.