SKELETAL SYSTEM

The skeletal system comprises all the bones in the body. There are 206 bones in the normal human adult.

The axial skeleton includes the skull, auditory ossicles, hyoid bone, vertebral column, ribs and sternum.

The appendicular skeleton includes the shoulder girdles and arms, and the hip girdle and legs.

The 206 bones are:

- 28 bones in the skull

• cranial cavity

• frontal bone
• occipital bone
  
• parietal bone (paired)
  
• temporal bone (paired)
  
• sphenoid bone
  
• ethmoid bone

• face and nasal cavity

• zygomatic bone (paired)
• maxilla (paired)
• nasal bone (paired)
• lacrimal bone (paired)
• palatine bone (paired)
• inferior nasal concha (paired)
• vomer
• mandible

• middle ear
  

• malleus = hammer (paired)
• incus = anvil (paired)
• stapes = stirrup (paired)

- 1 hyoid bone in the neck

- 26 vertebral bones in the vertebral column:

• 7 cervical vertebrae
• 12 thoracic vertebrae
• 5 lumbar vertebrae
• sacrum
• coccyx

- 25 bones in the chest: 12 ribs on each side, and the sternum.

- 4 bones in the pectoral girdle: 1 scapula and 1 clavicle on each side.

- 6 bones in the arms and forearms: 1 humerus, 1 radius, and 1 ulna on each side.

- 54 bones in the hands, 27 in each hand:

• 8 wrist (carpal) bones

• scaphoid
• lunate
• triquetrum
• pisiform
• hamate
• capitate
• trapezoid
• trapezium

• 5 metacarpal bones
• 14 phalanges of the hand

- 2 bones in the pelvic girdle or pelvis.

- 8 boes in the legs: 1 femur, 1 patella, 1 tibia, and 1 fibula on each side

- 52 bones in the feet, 26 in each foot:

• 7 ankle (tarsal) bones

• talus
• calcaneus
• navicular
• cuboid
• medial cuneiform
• intermediate cuneiform
• lateral cuneiform

• 5 metatarsal bones
• 14 phalanges of the foot