Logo

    Related Topics

    From Musculoskeletal System

    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.
    Acromioclavicular Joint
    The acromioclavicular joint connects the clavicle and scapula at the top of the shoulder, enabling smooth scapular motion and stability during arm movements.
    Deltoid
    Shoulder muscle responsible for arm abduction.
    Lacrimal Bones
    Bones forming part of the eye socket and housing the tear ducts.
    Cervical Vertebrae (C1 - C7)
    Vertebrae in the neck region (C1-C7).
    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.
    Scapula
    Shoulder blade providing attachment for muscles of the upper limb.
    Hinge Joints
    e.g., elbow, knee
    Wormian Bones
    Sutural bones in the skull.
    Triceps Brachii
    Muscle responsible for elbow extension.
    Achilles Tendon
    Tendon connecting the calf muscle to the heel bone.
    Lateral Collateral Ligament (LCL)
    Knee ligament that stabilizes the outer knee.
    Sternocleidomastoid
    Muscle that rotates and flexes the neck.
    Parietal Bones
    Bones forming the sides and roof of the skull.
    Soleus
    Calf muscle responsible for plantarflexion of the foot.
    Tibialis Anterior
    Muscle that dorsiflexes and inverts the foot.
    Sartorius
    Longest muscle in the body responsible for hip flexion.
    Quadriceps Tendon
    Tendon that connects the quadriceps to the patella.
    Interspinous Ligament
    Spinal ligament between adjacent vertebral spinous processes.
    Mandible
    Lower jawbone that houses the teeth.
    Metatarsals (5 bones)
    5 bones forming the mid-foot.
    Posterior Longitudinal Ligament
    Spinal ligament running along the back of the vertebral column.
    Palatine Bones
    Bones forming part of the hard palate and nasal cavity.
    Tibia
    Shin bone, the larger bone in the lower leg.
    Iliolumbar Ligament
    Ligament connecting the ilium and lumbar vertebrae.

    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 adult human body contains around 60,000 miles of blood vessels.