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    Related Topics

    From Musculoskeletal System

    Anterior Longitudinal Ligament
    Spinal ligament running along the front of the vertebral column.
    Synchondroses
    Cartilaginous joints where bones are connected by hyaline cartilage.
    Soleus
    Calf muscle responsible for plantarflexion of the foot.
    Trapezius
    Muscle responsible for moving, rotating, and stabilizing the scapula.
    Obliques (External and Internal)
    Muscles responsible for torso rotation.
    Rotator Cuff Muscles
    Supraspinatus, Infraspinatus, Teres Minor, Subscapularis.
    Tibialis Anterior
    Muscle that dorsiflexes and inverts the foot.
    Coracoacromial Ligament
    Ligament that connects the acromion to the coracoid process.
    Glenohumeral Ligaments
    Shoulder ligaments that stabilize the shoulder joint.
    Sesamoid Bones
    e.g., patella, some found in hands/feet.
    Lateral Collateral Ligament (LCL)
    Knee ligament that stabilizes the outer knee.
    Symphyses
    Cartilaginous joints where bones are connected by fibrocartilage.
    Iliolumbar Ligament
    Ligament connecting the ilium and lumbar vertebrae.
    Rectus Abdominis
    Abs muscle that flexes the trunk.
    Sternocleidomastoid
    Muscle that rotates and flexes the neck.
    Posterior Cruciate Ligament (PCL)
    Knee ligament that stabilizes the joint.
    Frontal Bone
    Bone forming the forehead and upper part of the orbits.
    Pubis
    Part of the pelvis that joins with the opposite side to form the pubic symphysis.
    Ulna
    Forearm bone on the pinky side.
    Inferior Nasal Conchae
    Bones inside the nasal cavity that filter and humidify air.
    Anterior Scalene Muscle
    The anterior scalene muscle is a deep neck muscle that elevates the first rib during inspiration and aids in neck flexion and stability, located between key neurovascular structures.
    Zygomaticus
    Muscle that raises the corners of the mouth.
    Buccinator
    Muscle that helps with chewing and blowing air out.
    Acromioclavicular Ligament
    Ligament that connects the acromion to the clavicle.
    Sphenoid Bone
    Bone forming part of the base of the skull and sides of the orbits.

    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.