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    Related Topics

    From Musculoskeletal System

    Scapula
    Shoulder blade providing attachment for muscles of the upper limb.
    Pivot Joints
    e.g., atlanto-axial joint
    Metacarpals (5 bones)
    5 bones forming the palm of the hand.
    Zygomatic Bones
    Cheekbones that form part of the orbit.
    Iliolumbar Ligament
    Ligament connecting the ilium and lumbar vertebrae.
    Hamstrings
    Biceps Femoris, Semitendinosus, Semimembranosus.
    Tibialis Anterior
    Muscle that dorsiflexes and inverts the foot.
    Wormian Bones
    Sutural bones in the skull.
    Synchondroses
    Cartilaginous joints where bones are connected by hyaline cartilage.
    Metatarsals (5 bones)
    5 bones forming the mid-foot.
    Vertebral Column
    Spinal column consisting of vertebrae.
    Lacrimal Bones
    Bones forming part of the eye socket and housing the tear ducts.
    Patellar Tendon
    Tendon connecting the patella to the tibia.
    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.
    Ball-and-Socket Joints
    e.g., shoulder, hip
    Soleus
    Calf muscle responsible for plantarflexion of the foot.
    Sacroiliac Ligaments
    Ligaments connecting the sacrum to the iliac bones.
    Nasal Bones
    Bones forming the bridge of the nose.
    Pubis
    Part of the pelvis that joins with the opposite side to form the pubic symphysis.
    Extensor Tendons
    Tendons that help extend the fingers and toes.
    Sternum
    Breastbone located in the center of the chest.
    Buccinator
    Muscle that helps with chewing and blowing air out.
    Posterior Cruciate Ligament (PCL)
    Knee ligament that stabilizes the joint.
    Brachioradialis
    Muscle responsible for forearm flexion.
    Maxillae
    Upper jaw bones that house the teeth and form part of the orbit.

    Frontal Bone

    Reviewed by our medical team

    Bone forming the forehead and upper part of the orbits.

    1. Overview

    The frontal bone is a flat, unpaired cranial bone that forms the forehead, the superior part of the orbits (eye sockets), and the anterior part of the cranial floor. It plays a vital role in protecting the frontal lobes of the brain and contributes to the shape and structure of the upper face. The frontal bone is part of the neurocranium and has both protective and structural functions.

    2. Location

    The frontal bone is located in the anterior region of the skull:

    • Superiorly: Forms the forehead and part of the anterior cranial vault.

    • Inferiorly: Contributes to the roof of the orbits and the nasal cavity.

    • Laterally: Articulates with the parietal bones at the coronal suture and with the zygomatic bones at the frontozygomatic suture.

    • Posteriorly: Connects with the parietal bones via the coronal suture.

    3. Structure

    The frontal bone is a flat bone with distinct anatomical features:

    • Squamous part (forehead region): Broad and flat; extends upward from the orbits.

    • Orbital part: Forms the roof of each orbit and part of the floor of the anterior cranial fossa.

    • Nasal part: Articulates with the nasal bones and the frontal processes of the maxillae.

    • Glabella: Smooth area between the eyebrows, just above the nasal bridge.

    • Supraorbital margin: The superior rim of the orbit, containing the supraorbital foramen or notch for passage of vessels and nerves.

    • Frontal sinuses: Paired air-filled cavities within the bone, located above the orbits; variable in size and shape.

    • Sutures: The frontal bone fuses with the parietal bones at the coronal suture and may have a persistent metopic suture in some adults (normally fuses during childhood).

    4. Function

    The frontal bone serves several key structural and protective functions:

    • Protects the brain: Shields the frontal lobes from trauma.

    • Forms the forehead: Provides the contour and shape of the upper face.

    • Supports the orbits: Contributes to the orbital roof and thus protects the eyes.

    • Attachment point for facial muscles: Especially for muscles involved in facial expression (e.g., frontalis).

    5. Physiological role(s)

    Besides structural and protective roles, the frontal bone has several physiological contributions:

    • Frontal sinuses: Reduce the weight of the skull, produce mucus to humidify air, and contribute to voice resonance.

    • Neurovascular passage: The supraorbital foramen allows passage of the supraorbital nerve and vessels supplying the forehead and scalp.

    • Muscle interface: Supports the function of the epicranius muscle, which is responsible for forehead movement and facial expressions like raising the eyebrows.

    6. Clinical Significance

    The frontal bone is associated with several clinical considerations:

    • Fractures:

      • Frontal bone fractures, especially involving the frontal sinus or orbital roof, are often the result of high-impact trauma and may be associated with brain injury or CSF leaks.

    • Frontal sinusitis:

      • Inflammation or infection of the frontal sinuses can lead to headache, facial pain, and nasal congestion; may require drainage or antibiotics.

    • Persistent metopic suture:

      • In some adults, the metopic suture fails to fuse completely, which can be mistaken for a skull fracture on radiographs.

    • Craniotomy site:

      • The frontal bone is commonly accessed during neurosurgical procedures (e.g., frontal craniotomy) to reach the frontal lobes of the brain.

    • Congenital anomalies:

      • Craniosynostosis (premature fusion of cranial sutures) involving the coronal suture can lead to abnormal forehead shape and brain development issues.

    Did you know? Bone marrow is the site where red blood cells are made.