Skeletal Anatomy

• The adult human skeleton is divided into:

  1. Axial skeleton
  2. Appendicular skeleton
• Axial Skeleton


  it includes all bones that lie on or near the central axis of the body
• The adult axial skeleton consists of

  80 bones (includes the skull, vertebral column, ribs, and sternum.
• Skull

  Cranium - 8

  Facial bones - 14
• Hyoid

  1
• Auditory ossicles (small bones in each ear)

  6
• Vertebral column

  Cervical - 7

  Thoracic - 12

  Lumbar - 5

  Sacral - 1

  Coccyx - 1
• Thorax

  Sternum - 1

  Ribs - 24
• Appendicular Skeleton

  • Second division
  • It consists of all bones of the upper and lower limbs (extremities) and the shoulder and pelvic girdles.
  • It attaches to the axial skeleton
• The adult appendicular skeleton comprises

  126 separate bones
• Shoulder girdles

  Clavicle - 2

  Scapula/ae - 2
• Upper limbs

  Humerus (humeri) - 2

  Ulna/ae - 2

  Radius (radii) - 2

  Carpals - 16

  Metacarpals - 10

  Phalanges - 28
• Pelvic girdle

  Hip bones (innominate bones) - 2
• Lower limbs

  Femur (femora) - 2

  Tibia - 2

  Fibula/ae - 2

  Patella/ae - 2

  Tarsals - 14

  Metatarsals - 10

  Phalanges - 28
• Sesamoid bones


  a special type of small, ova-shaped bone that is embedded in certain tendons.
• Patellae


  Two, the largest sesamoid bones, only counted part of the axial or appendicular skeleton.
• Where are the most common sesamoid bones located?

  posterior foot at the base of the first toe.
• In the upper limb, sesamoid bones are found most commonly in?

  tendons near the anterior (palmar) surface of the hand at the base of the thumb.
• any sesamoid bone can be:

  fractured by trauma; may be demonstrated radiographically or by CT.