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    Related Topics

    From Musculoskeletal System

    Achilles Tendon
    Tendon connecting the calf muscle to the heel bone.
    Sartorius
    Longest muscle in the body responsible for hip flexion.
    Posterior Cruciate Ligament (PCL)
    Knee ligament that stabilizes the joint.
    Flexor and Extensor Groups
    Muscles responsible for flexing and extending the hand and wrist.
    Masseter
    Muscle that elevates the mandible.
    Sacroiliac Ligaments
    Ligaments connecting the sacrum to the iliac bones.
    Metatarsals (5 bones)
    5 bones forming the mid-foot.
    Anterior Cruciate Ligament (ACL)
    Knee ligament that stabilizes the joint.
    Tarsals (7 bones)
    7 ankle bones.
    Saddle Joints
    e.g., thumb joint
    Tibia
    Shin bone, the larger bone in the lower leg.
    Levator Ani
    Pelvic floor muscle responsible for lifting the anus.
    Posterior Longitudinal Ligament
    Spinal ligament running along the back of the vertebral column.
    Soleus
    Calf muscle responsible for plantarflexion of the foot.
    Glenohumeral Ligaments
    Shoulder ligaments that stabilize the shoulder joint.
    Rotator Cuff Muscles
    Supraspinatus, Infraspinatus, Teres Minor, Subscapularis.
    Gomphoses
    Fibrous joints where a peg fits into a socket (e.g., teeth in jaw).
    Ribs (12 Pairs)
    12 pairs of bones that form the sides of the thoracic cage.
    Vertebral Column
    Spinal column consisting of vertebrae.
    Frontal Bone
    Bone forming the forehead and upper part of the orbits.
    Patella
    Knee cap, protecting the knee joint.
    Ilium
    Uppermost and largest part of the hip bone.
    Sutures (in the skull)
    Fibrous joints between skull bones.
    Coracoacromial Ligament
    Ligament that connects the acromion to the coracoid process.
    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? Sesamoid bones are bones that form within tendons, like the patella.