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    Related Topics

    From Musculoskeletal System

    Extensor Tendons
    Tendons that help extend the fingers and toes.
    Sesamoid Bones
    e.g., patella, some found in hands/feet.
    Hinge Joints
    e.g., elbow, knee
    Metatarsals (5 bones)
    5 bones forming the mid-foot.
    Lacrimal Bones
    Bones forming part of the eye socket and housing the tear ducts.
    Metacarpals (5 bones)
    5 bones forming the palm of the hand.
    Phalanges (14 bones)
    14 bones forming the toes.
    Saddle Joints
    e.g., thumb joint
    Obliques (External and Internal)
    Muscles responsible for torso rotation.
    Nasal Bones
    Bones forming the bridge of the nose.
    Abductor Digiti Minimi Muscle
    The abductor digiti minimi muscle is a hypothenar muscle that abducts and flexes the little finger, aiding grip and precision in hand movements.
    Iliolumbar Ligament
    Ligament connecting the ilium and lumbar vertebrae.
    Clavicle
    Collarbone connecting the arm to the body.
    Biceps Tendon
    Tendon that attaches the biceps muscle to the bone.
    Patellar Tendon
    Tendon connecting the patella to the tibia.
    Medial Collateral Ligament (MCL)
    Knee ligament that stabilizes the inner knee.
    Buccinator
    Muscle that helps with chewing and blowing air out.
    Ethmoid Bone
    Bone forming part of the nasal cavity and the orbit.
    Inferior Nasal Conchae
    Bones inside the nasal cavity that filter and humidify air.
    Sphenoid Bone
    Bone forming part of the base of the skull and sides of the orbits.
    Patella
    Knee cap, protecting the knee joint.
    Parietal Bones
    Bones forming the sides and roof of the skull.
    Interspinous Ligament
    Spinal ligament between adjacent vertebral spinous processes.
    Levator Ani
    Pelvic floor muscle responsible for lifting the anus.
    Thoracic Vertebrae (T1 - T12)
    Vertebrae in the upper and mid-back (T1-T12).

    Femur

    Reviewed by our medical team

    Thigh bone, the longest and strongest bone in the body.

    1. Overview

    The femur is the longest, strongest, and heaviest bone in the human body. Commonly known as the thigh bone, it extends from the hip to the knee and forms a critical component of the lower limb skeletal structure. The femur plays a central role in weight-bearing, locomotion, and muscular attachment. Its unique anatomy supports both mobility and stability during walking, running, jumping, and standing.

    2. Location

    The femur is located in the upper leg or thigh region, forming the skeletal framework between the hip and the knee:

    • Proximally: Articulates with the acetabulum of the pelvis at the hip joint.

    • Distally: Articulates with the tibia and patella at the knee joint.

    • Medially: Positioned slightly angled inward to allow for bipedal balance and a narrow base of support.

    3. Structure

    The femur is a long bone composed of several key anatomical parts:

    • Head: A spherical structure that articulates with the acetabulum to form the hip joint; contains the fovea capitis for ligament attachment.

    • Neck: Connects the head to the shaft; a common site for fractures, especially in the elderly.

    • Greater and lesser trochanters: Bony prominences for muscle attachment.

    • Shaft (body): Long cylindrical middle portion that slightly bows anteriorly.

    • Linea aspera: Prominent ridge along the posterior shaft for attachment of thigh muscles.

    • Distal end: Features the medial and lateral condyles, which articulate with the tibia, and the patellar surface anteriorly.

    • Blood supply: Via the nutrient artery, retinacular vessels, and metaphyseal arteries; disruption can lead to avascular necrosis, especially in the femoral head.

    4. Function

    The femur is essential for the following mechanical functions:

    • Weight transmission: Carries the body's weight from the hip to the knee, both during movement and standing.

    • Mobility: Facilitates hip and knee movements through its articulations, allowing for walking, running, sitting, and jumping.

    • Muscle leverage: Serves as an attachment point for powerful thigh and hip muscles, including the gluteals, adductors, quadriceps, and hamstrings.

    5. Physiological role(s)

    The femur contributes to multiple physiological processes:

    • Hematopoiesis: Its medullary cavity contains bone marrow, which plays a role in blood cell formation (especially in children).

    • Mineral storage: Acts as a reservoir for calcium and phosphorus, contributing to mineral homeostasis.

    • Posture and gait: The angle of the femoral neck and alignment with the pelvis help maintain upright posture and efficient bipedal locomotion.

    • Shock absorption: The femur's curved shaft and articulation with cartilage-covered joints allow it to absorb and dissipate mechanical forces effectively.

    6. Clinical Significance

    The femur is frequently involved in orthopedic conditions and trauma:

    • Femoral fractures:

      • High-energy trauma can cause mid-shaft fractures, while low-energy trauma may lead to femoral neck fractures in the elderly.

      • Femoral shaft fractures often require intramedullary nailing; neck fractures may need fixation or hip replacement.

    • Avascular necrosis (AVN):

      • Interruption of blood supply to the femoral head, often after fracture or due to corticosteroid use, may lead to bone death and joint collapse.

    • Developmental dysplasia of the hip (DDH):

      • In infants, improper formation of the femoral head and acetabulum can cause dislocation or instability of the hip joint.

    • Osteoarthritis:

      • Degeneration of cartilage in the femur's joint surfaces (hip or knee) leads to pain, stiffness, and loss of mobility.

    • Limb length discrepancy:

      • Can result from femoral growth plate injury or surgical interventions; may require corrective procedures or orthotics.

    • Hip replacement (arthroplasty):

      • Involves replacing the femoral head with a prosthesis in cases of severe arthritis or fracture.

    Did you know? Ligaments hold bones together and are tough yet flexible.