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    Related Topics

    From Musculoskeletal System

    Maxillae
    Upper jaw bones that house the teeth and form part of the orbit.
    Obliques (External and Internal)
    Muscles responsible for torso rotation.
    Ribs (12 Pairs)
    12 pairs of bones that form the sides of the thoracic cage.
    Scapula
    Shoulder blade providing attachment for muscles of the upper limb.
    Ethmoid Bone
    Bone forming part of the nasal cavity and the orbit.
    Interspinous Ligament
    Spinal ligament between adjacent vertebral spinous processes.
    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.
    Humerus
    Upper arm bone connecting the shoulder to the elbow.
    Fibula
    Smaller bone in the lower leg, located alongside the tibia.
    Annular Ligament
    The annular ligament is a strong fibrous band encircling the head of the radius, stabilizing the proximal radioulnar joint and allowing smooth rotation of the forearm.
    Clavicle
    Collarbone connecting the arm to the body.
    Vertebral Column
    Spinal column consisting of vertebrae.
    Metatarsals (5 bones)
    5 bones forming the mid-foot.
    Symphyses
    Cartilaginous joints where bones are connected by fibrocartilage.
    Metacarpals (5 bones)
    5 bones forming the palm of the hand.
    Tibialis Anterior
    Muscle that dorsiflexes and inverts the foot.
    Coccyx
    Tailbone, the remnant of the tail in humans.
    Thoracic Vertebrae (T1 - T12)
    Vertebrae in the upper and mid-back (T1-T12).
    Glenohumeral Ligaments
    Shoulder ligaments that stabilize the shoulder joint.
    Coracoacromial Ligament
    Ligament that connects the acromion to the coracoid process.
    Lumbar Vertebrae (L1 - L5)
    Vertebrae in the lower back (L1-L5).
    Synchondroses
    Cartilaginous joints where bones are connected by hyaline cartilage.
    Vomer Bone
    Bone forming the nasal septum.
    Saddle Joints
    e.g., thumb joint

    Phalanges (14 bones)

    Reviewed by our medical team

    14 bones forming the toes.

    1. Overview

    The phalanges are the 14 long bones that form the fingers of the hand. Each finger consists of multiple phalanges, which provide the skeletal framework necessary for dexterous hand movements, gripping, and manipulation of objects. These bones are small yet highly mobile and essential for fine motor function.

    2. Location

    The phalanges are located in the distal region of the hand:

    • Proximally: Articulate with the metacarpals at the metacarpophalangeal (MCP) joints.

    • Distally: Form the tips of the fingers (distal phalanges).

    • Each finger (digits 2–5): Has three phalanges – proximal, middle, and distal.

    • Thumb (digit 1): Has only two phalanges – proximal and distal (no middle phalanx).

    3. Structure

    The 14 phalanges are classified based on their position within each digit:

    • Proximal phalanges (5): Articulate with the metacarpals and form the base of each finger.

    • Middle phalanges (4): Present in digits 2–5; absent in the thumb.

    • Distal phalanges (5): Form the tips of the fingers and support the nail bed.

    Each phalanx is a miniature long bone composed of:

    • Base: Proximal end, wider for articulation.

    • Shaft (body): Long cylindrical portion.

    • Head: Distal end, rounded for articulation (except in distal phalanges, which are flattened).

    They are made of cortical and cancellous bone and are lined by periosteum, which supports vascularization and healing.

    4. Function

    The phalanges serve crucial mechanical and functional roles in hand movement:

    • Enable finger motion: Allow flexion, extension, abduction, and adduction at various interphalangeal and metacarpophalangeal joints.

    • Gripping and holding: Essential for precision and power grips.

    • Support fine motor skills: Facilitate tasks like writing, typing, and manipulating small objects.

    • Provide leverage: Serve as attachment points for flexor and extensor tendons, enhancing the effectiveness of muscle contraction.

    5. Physiological role(s)

    Beyond movement, the phalanges contribute to:

    • Tactile sensitivity: Serve as the framework beneath the fingertips, where sensory receptors for touch and temperature are concentrated.

    • Tool interaction: Act as physical extensions of the hand, increasing reach and mechanical advantage.

    • Support nail growth: The distal phalanges anchor nail beds, protecting the tips of the fingers.

    • Force transmission: Transmit forces from fingertips to the hand and wrist during object manipulation or impact.

    6. Clinical Significance

    The phalanges are prone to trauma and overuse injuries due to their size and function:

    • Fractures:

      • Common in contact sports, workplace injuries, or falls; may involve any phalanx and can range from simple to comminuted fractures.

    • Dislocations:

      • Most frequently occur at the interphalangeal or MCP joints, typically from hyperextension injuries.

    • Mallet finger:

      • Avulsion injury of the extensor tendon at the distal phalanx, often due to sudden force to a flexed finger tip.

    • Boutonnière and Swan-neck deformities:

      • Deformities of the interphalangeal joints often associated with rheumatoid arthritis or tendon imbalance.

    • Osteoarthritis and rheumatoid arthritis:

      • Degenerative or inflammatory joint disease affecting the DIP, PIP, or MCP joints, leading to pain, stiffness, and deformity.

    • Congenital anomalies:

      • Conditions such as syndactyly (fusion), polydactyly (extra fingers), or brachydactyly (shortened phalanges) may affect structure and function.

    Did you know? The ilium is the largest part of the hip bone.