Logo

    Related Topics

    From Musculoskeletal System

    Sutures (in the skull)
    Fibrous joints between skull bones.
    Occipital Bone
    Bone forming the back and base of the skull.
    Gastrocnemius
    Calf muscle responsible for plantarflexion of the foot.
    Ribs (12 Pairs)
    12 pairs of bones that form the sides of the thoracic cage.
    Sphenoid Bone
    Bone forming part of the base of the skull and sides of the orbits.
    Zygomatic Bones
    Cheekbones that form part of the orbit.
    Diaphragm
    Primary muscle for breathing.
    Cervical Vertebrae (C1 - C7)
    Vertebrae in the neck region (C1-C7).
    Soleus
    Calf muscle responsible for plantarflexion of the foot.
    Palatine Bones
    Bones forming part of the hard palate and nasal cavity.
    Humerus
    Upper arm bone connecting the shoulder to the elbow.
    Posterior Cruciate Ligament (PCL)
    Knee ligament that stabilizes the joint.
    Scapula
    Shoulder blade providing attachment for muscles of the upper limb.
    Hinge Joints
    e.g., elbow, knee
    Pivot Joints
    e.g., atlanto-axial joint
    Sartorius
    Longest muscle in the body responsible for hip flexion.
    Iliolumbar Ligament
    Ligament connecting the ilium and lumbar vertebrae.
    Triceps Brachii
    Muscle responsible for elbow extension.
    Latissimus Dorsi
    Back muscle responsible for arm adduction and extension.
    Thoracic Cage
    Ribs and sternum forming the protective cage for the heart and lungs.
    Gliding (Plane) Joints
    e.g., between carpals
    Nasal Bones
    Bones forming the bridge of the nose.
    Glenohumeral Ligaments
    Shoulder ligaments that stabilize the shoulder joint.
    Lumbar Vertebrae (L1 - L5)
    Vertebrae in the lower back (L1-L5).
    Ischium
    Part of the pelvis that supports weight while sitting.

    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? Ligaments hold bones together and are tough yet flexible.