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    Related Topics

    From Musculoskeletal System

    Lacrimal Bones
    Bones forming part of the eye socket and housing the tear ducts.
    Lateral Collateral Ligament (LCL)
    Knee ligament that stabilizes the outer knee.
    Gomphoses
    Fibrous joints where a peg fits into a socket (e.g., teeth in jaw).
    Latissimus Dorsi
    Back muscle responsible for arm adduction and extension.
    Nasal Bones
    Bones forming the bridge of the nose.
    Carpals (8 bones)
    8 wrist bones.
    Rotator Cuff Tendons
    Tendons of the rotator cuff muscles.
    Hinge Joints
    e.g., elbow, knee
    Wormian Bones
    Sutural bones in the skull.
    Obliques (External and Internal)
    Muscles responsible for torso rotation.
    Pectoralis Major
    Chest muscle responsible for shoulder movement.
    Quadriceps Tendon
    Tendon that connects the quadriceps to the patella.
    Mandible
    Lower jawbone that houses the teeth.
    Thoracic Vertebrae (T1 - T12)
    Vertebrae in the upper and mid-back (T1-T12).
    Brachioradialis
    Muscle responsible for forearm flexion.
    Pivot Joints
    e.g., atlanto-axial joint
    Humerus
    Upper arm bone connecting the shoulder to the elbow.
    Facial Bones
    Bones forming the structure of the face.
    Inferior Nasal Conchae
    Bones inside the nasal cavity that filter and humidify air.
    Rotator Cuff Muscles
    Supraspinatus, Infraspinatus, Teres Minor, Subscapularis.
    Sacroiliac Ligaments
    Ligaments connecting the sacrum to the iliac bones.
    Maxillae
    Upper jaw bones that house the teeth and form part of the orbit.
    Temporal Bones
    Bones forming the lower sides of the skull and housing the ears.
    Ulna
    Forearm bone on the pinky side.
    Gastrocnemius
    Calf muscle responsible for plantarflexion of the foot.

    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? Your thumb has two phalanges, whereas other fingers have three.