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    Related Topics

    From Musculoskeletal System

    Tibialis Anterior
    Muscle that dorsiflexes and inverts the foot.
    Gliding (Plane) Joints
    e.g., between carpals
    Humerus
    Upper arm bone connecting the shoulder to the elbow.
    Coccygeus
    Pelvic floor muscle supporting the coccyx.
    Radius
    Forearm bone on the thumb side.
    Sphenoid Bone
    Bone forming part of the base of the skull and sides of the orbits.
    Lumbar Vertebrae (L1 - L5)
    Vertebrae in the lower back (L1-L5).
    Pivot Joints
    e.g., atlanto-axial joint
    Acromioclavicular Ligament
    Ligament that connects the acromion to the clavicle.
    Rotator Cuff Tendons
    Tendons of the rotator cuff muscles.
    Scapula
    Shoulder blade providing attachment for muscles of the upper limb.
    Masseter
    Muscle that elevates the mandible.
    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.
    Extensor Tendons
    Tendons that help extend the fingers and toes.
    Metatarsals (5 bones)
    5 bones forming the mid-foot.
    Rectus Abdominis
    Abs muscle that flexes the trunk.
    Nasal Bones
    Bones forming the bridge of the nose.
    Sutures (in the skull)
    Fibrous joints between skull bones.
    Wormian Bones
    Sutural bones in the skull.
    Brachioradialis
    Muscle responsible for forearm flexion.
    Synchondroses
    Cartilaginous joints where bones are connected by hyaline cartilage.
    Rotator Cuff Muscles
    Supraspinatus, Infraspinatus, Teres Minor, Subscapularis.
    Adductors
    Muscles that bring the thighs toward the midline.
    Sacroiliac Ligaments
    Ligaments connecting the sacrum to the iliac bones.
    Parietal Bones
    Bones forming the sides and roof of the skull.

    Hyoid Bone

    Reviewed by our medical team

    U-shaped bone in the neck that supports the tongue.

    1. Overview

    The hyoid bone is a small, U-shaped bone located in the anterior neck. Uniquely, it is the only bone in the human body that does not articulate directly with any other bone. Instead, it is suspended in place by muscles and ligaments. The hyoid serves as a crucial anchoring structure for the tongue, supports the larynx (voice box), and plays a vital role in swallowing and speech. It is often studied in anatomy due to its functional and forensic significance.

    2. Location

    The hyoid bone is located in the anterior midline of the neck:

    • Superiorly: Lies below the mandible (lower jaw).

    • Inferiorly: Positioned above the thyroid cartilage (Adam's apple).

    • At the level of: Cervical vertebra C3 in a neutral position.

    • Surrounding structures: Connected to the floor of the oral cavity, pharynx, larynx, and epiglottis by muscle and ligament attachments.

    3. Structure

    The hyoid bone has a characteristic horseshoe or U-shape and consists of three parts:

    • Body: The central part, thick and rectangular in shape.

    • Greater horns (cornua): Project posteriorly and laterally from the body; attachment sites for several muscles (e.g., middle constrictor, hyoglossus).

    • Lesser horns (cornua): Small, conical projections superior to the body; serve as attachment points for the stylohyoid ligament.

    The hyoid bone is made of compact bone and has a dense outer cortex with a medullary cavity. It is anchored by the suprahyoid and infrahyoid muscle groups.

    4. Function

    The hyoid bone serves as a dynamic anchor and support for several functions:

    • Supports the tongue: Acts as the base for tongue movement, aiding in speech and swallowing.

    • Assists in swallowing: Serves as a platform for the elevation of the larynx and movement of the pharynx during deglutition.

    • Facilitates speech: Supports vocalization by maintaining airway patency and stabilizing the larynx.

    • Acts as a muscle attachment site: Anchors over a dozen muscles involved in jaw, neck, and throat movement.

    5. Physiological role(s)

    Despite its small size, the hyoid bone plays critical physiological roles:

    • Respiration: Keeps the airway open by supporting the upper respiratory tract and indirectly preventing airway collapse during breathing.

    • Speech modulation: Works with the laryngeal cartilages and vocal cords to modulate pitch and volume.

    • Swallowing reflex: Coordinates with pharyngeal muscles to initiate and complete the swallowing mechanism safely.

    • Muscle coordination: Coordinates movements between the jaw, tongue, and larynx, critical in chewing and phonation.

    6. Clinical Significance

    The hyoid bone is associated with various clinical and forensic considerations:

    • Hyoid fracture:

      • Rare in accidental trauma but may occur in cases of manual strangulation or hanging, making it significant in forensic investigations.

    • Dysphagia (difficulty swallowing):

      • Can result from dysfunction of muscles attached to the hyoid, particularly in neurological or post-surgical conditions.

    • Speech disorders:

      • Abnormal positioning or injury to the hyoid can affect tongue movement and vocal cord tension, impacting speech clarity.

    • Thyroglossal duct cysts:

      • Embryological remnants can form cysts near the hyoid, often requiring surgical excision that includes part of the hyoid bone (Sistrunk procedure).

    • Obstructive sleep apnea:

      • Inferior positioning of the hyoid is sometimes associated with upper airway obstruction, contributing to sleep apnea.

    Did you know? The smallest joint in the body is the stapes in the ear.