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    Related Topics

    From Musculoskeletal System

    Flexor Tendons
    Tendons that help flex the fingers and toes.
    Occipital Bone
    Bone forming the back and base of the skull.
    Frontal Bone
    Bone forming the forehead and upper part of the orbits.
    Deltoid
    Shoulder muscle responsible for arm abduction.
    Zygomatic Bones
    Cheekbones that form part of the orbit.
    Hyoid Bone
    U-shaped bone in the neck that supports the tongue.
    Hamstrings
    Biceps Femoris, Semitendinosus, Semimembranosus.
    Scapula
    Shoulder blade providing attachment for muscles of the upper limb.
    Femur
    Thigh bone, the longest and strongest bone in the body.
    Thoracic Vertebrae (T1 - T12)
    Vertebrae in the upper and mid-back (T1-T12).
    Posterior Cruciate Ligament (PCL)
    Knee ligament that stabilizes the joint.
    Rectus Abdominis
    Abs muscle that flexes the trunk.
    Parietal Bones
    Bones forming the sides and roof of the skull.
    Posterior Longitudinal Ligament
    Spinal ligament running along the back of the vertebral column.
    Cranial Bones
    Bones of the skull that protect the brain.
    Iliolumbar Ligament
    Ligament connecting the ilium and lumbar vertebrae.
    Symphyses
    Cartilaginous joints where bones are connected by fibrocartilage.
    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.
    Ball-and-Socket Joints
    e.g., shoulder, hip
    Synchondroses
    Cartilaginous joints where bones are connected by hyaline cartilage.
    Ellipsoidal (Condyloid) Joints
    e.g., wrist
    Sacrum
    Triangular bone at the base of the spine.
    Sesamoid Bones
    e.g., patella, some found in hands/feet.
    Patellar Tendon
    Tendon connecting the patella to the tibia.
    Achilles Tendon
    Tendon connecting the calf muscle to the heel bone.

    Temporal Bones

    Reviewed by our medical team

    Bones forming the lower sides of the skull and housing the ears.

    1. Overview

    The temporal bones are paired, irregular bones located on the lateral sides and base of the skull. Each temporal bone houses critical structures of the ear and contributes to cranial protection, mastication, and hearing. These bones play a major role in forming the cranial vault, cranial base, and temporal region of the face.

    2. Location

    Temporal bones are situated on the lateral sides of the skull, inferior to the parietal bones and posterior to the sphenoid bones:

    • Superiorly: Articulates with the parietal bone via the squamous suture.

    • Anteriorly: Meets the sphenoid bone.

    • Posteriorly: Joins the occipital bone.

    • Inferiorly: Forms part of the base of the skull and supports the mandible via the temporomandibular joint (TMJ).

    3. Structure

    Each temporal bone is divided into four main parts:

    • Squamous part: Flat, thin portion forming part of the lateral wall of the skull; contains the zygomatic process that forms the zygomatic arch.

    • Tympanic part: Surrounds the external acoustic meatus and contributes to the ear canal walls.

    • Mastoid part: Contains the mastoid process, a site for muscle attachment and mastoid air cells that connect to the middle ear.

    • Petrous part: Dense, pyramid-shaped portion that houses the inner ear structures (cochlea and vestibular apparatus); forms part of the cranial base.

    Important foramina and features include the external acoustic meatus, internal acoustic meatus, styloid process, jugular foramen, and carotid canal.

    4. Function

    The temporal bones have both protective and functional purposes:

    • Protect intracranial structures: Encase and shield the temporal lobe of the brain and delicate structures of the ear.

    • House hearing and balance organs: The petrous part protects the cochlea and semicircular canals.

    • Anchor for muscles: Provide attachment points for muscles involved in chewing (masseter), facial expression, and neck movement.

    • Articulate with the mandible: Form the temporomandibular joint (TMJ), enabling jaw movement.

    5. Physiological role(s)

    Beyond their structural role, the temporal bones are involved in essential physiological processes:

    • Hearing: Transmit sound from the external ear to the inner ear via the tympanic membrane and auditory ossicles (within the middle ear cavity).

    • Balance: House the vestibular system (semicircular canals and vestibule), critical for detecting head position and maintaining equilibrium.

    • Speech and mastication: Support the mandible and muscles that control chewing and articulation of speech.

    6. Clinical Significance

    The temporal bone is involved in a range of medical conditions and surgical interventions:

    • Temporal bone fractures:

      • Can result from blunt head trauma; classified as longitudinal or transverse based on fracture orientation.

      • May cause hearing loss, facial nerve paralysis, cerebrospinal fluid (CSF) leak, or vertigo.

    • Otitis media and mastoiditis:

      • Infection can spread from the middle ear to mastoid air cells, leading to mastoiditis, especially in children.

    • Cholesteatoma:

      • An abnormal skin growth in the middle ear that can erode the temporal bone and ossicles if left untreated.

    • Temporomandibular joint (TMJ) disorders:

      • Dysfunction of the TMJ can cause pain, clicking sounds, and jaw movement limitations.

    • Surgical access:

      • Neurosurgeons and ENT specialists may access the petrous part of the temporal bone to reach the inner ear, facial nerve, or brainstem in specific procedures.

    Did you know? The longest muscle in the body is the sartorius, which helps you cross your legs.