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The Appendicular Skeleton

Appendicular Skeleton

  • Bones involved in body movements.
  • Includes upper and lower limbs and girdles.

Pectoral (Shoulder) Girdle

  • Consists of clavicle and scapula.
    • Clavicle:
    • S-shaped.
    • Medial end articulates with manubrium of sternum.
    • Lateral end articulates with acromion of scapula.
    • Scapula:
    • Flat bone in posterior thorax between second and seventh ribs.
    • Glenoid cavity: attachment for humerus.

Upper Limb (Extremity)

  • Humerus:
    • Articulates with scapula (glenoid cavity).
    • Articulates with radius and ulna (trochlea with ulna, capitulum with radius).
  • Ulna and Radius:
    • Forearm bones.
    • Ulna: Olecranon and coronoid process form trochlear notch (elbow joint).
    • Radius: Located on thumb side; allows forearm rotation.
  • Carpal Bones:
    • 8 small bones connected by ligaments.
    • Proximal row: scaphoid, lunate, triquetrum, pisiform.
    • Distal row: trapezium, trapezoid, capitate, hamate.
  • Metacarpals:
    • 5 bones in palm and back of hand; numbered I-V (1-5) from thumb.
    • Bases articulate with distal carpals, heads with proximal phalanges.
  • Phalanges:
    • 14 bones of digits.
    • Thumb: 2 (proximal, distal).
    • Other fingers: 3 each (proximal, middle, distal).

Pelvic (Hip) Girdle

  • Two hip bones articulate with sacrum.
  • Each hip bone: ilium, ischium, pubis.
  • Articulate anteriorly via pubic symphysis.
  • Femur head articulates with acetabulum.
  • Pelvis divided by pelvic brim into superior (false) and inferior (true) pelvis.
  • Male vs. female:
    • Male: Larger, heavier bones.
    • Female: Wider, shallower bones.

Lower Limb (Extremity)

  • Femur: Longest, heaviest, strongest bone.
    • Head inserts into acetabulum.
    • Distal end articulates with tibia and patella.
  • Patella: Triangular bone in quadriceps tendon; articulates with femur.
  • Tibia and Fibula:
    • Tibia articulates with femur and talus.
    • Tibial tuberosity: Attachment for patellar ligament.
  • Tarsus: 7 tarsal bones (talus, calcaneus, navicular, 3 cuneiforms, cuboid).
  • Metatarsus: 5 metatarsal bones (I-V or 1-5 from big toe).
    • Articulate with cuneiforms and cuboid proximally and phalanges distally.
  • Phalanges: Like hand; big toe (proximal, distal), other toes (proximal, middle, distal).
  • Arches:
    • Longitudinal (medial and lateral parts) and transverse arches.
    • Support body weight, provide leverage, distribute weight.