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    Related Topics

    From Musculoskeletal System

    Cervical Vertebrae (C1 - C7)
    Vertebrae in the neck region (C1-C7).
    Ulna
    Forearm bone on the pinky side.
    Coccyx
    Tailbone, the remnant of the tail in humans.
    Sutures (in the skull)
    Fibrous joints between skull bones.
    Rotator Cuff Muscles
    Supraspinatus, Infraspinatus, Teres Minor, Subscapularis.
    Zygomaticus
    Muscle that raises the corners of the mouth.
    Trapezius
    Muscle responsible for moving, rotating, and stabilizing the scapula.
    Thoracic Vertebrae (T1 - T12)
    Vertebrae in the upper and mid-back (T1-T12).
    Palatine Bones
    Bones forming part of the hard palate and nasal cavity.
    Masseter
    Muscle that elevates the mandible.
    Medial Collateral Ligament (MCL)
    Knee ligament that stabilizes the inner knee.
    Anterior Cruciate Ligament (ACL)
    Knee ligament that stabilizes the joint.
    Coccygeus
    Pelvic floor muscle supporting the coccyx.
    Humerus
    Upper arm bone connecting the shoulder to the elbow.
    Glenohumeral Ligaments
    Shoulder ligaments that stabilize the shoulder joint.
    Anterior Longitudinal Ligament
    Spinal ligament running along the front of the vertebral column.
    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.
    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.
    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.
    Sphenoid Bone
    Bone forming part of the base of the skull and sides of the orbits.
    Symphyses
    Cartilaginous joints where bones are connected by fibrocartilage.
    Coracoacromial Ligament
    Ligament that connects the acromion to the coracoid process.
    Obliques (External and Internal)
    Muscles responsible for torso rotation.
    Occipital Bone
    Bone forming the back and base of the skull.
    Pubis
    Part of the pelvis that joins with the opposite side to form the pubic symphysis.

    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 largest muscle in the body is the gluteus maximus, responsible for hip extension.