List of bones of the human skeleton

The skeleton of an adult human consists of 206 bones. It is composed of 270 bones at birth, which decreases to 206 bones by adulthood after some bones have fused together.^[1] It consists of 80 bones in the axial skeleton (28 in skull and 52 in torso) and 126 bones in the appendicular skeleton (32 x 2 in upper extremities including both arms and 31 x 2 in lower extremities including both legs). Many small and often variable bones, such as some sesamoid bones, are not included in this count.

Introduction

The number of bones in the skeleton changes with age, as multiple bones fuse, a process which typically reaches completion in the third decade of life. In addition, the bones of the skull and face are counted as separate bones, despite being fused naturally. Some reliable sesamoid bones such as the pisiform are counted, while others, such as the hallux sesamoids, are not.

Individuals may have more or fewer bones than this owing to anatomical variations. The most common variations include sutural (wormian) bones, which are located along the sutural lines on the back of the skull, and sesamoid bones which develop within some tendons, mainly in the hands and feet. Some individuals may also have additional (i.e. supernumerary) cervical ribs or lumbar vertebrae.

Bones

Vertebral column

• The spinal vertebrae of the vertebral column (33 bones)
  • The cervical vertebrae (7)
  • The thoracic vertebrae (12)
  • The lumbar vertebrae (5)
    • Extra lumber vertebrae
  • The sacral vertebrae (5 at birth, later fused into one)
  • The coccygeal vertebrae (4 at birth, later fused into one)

Chest

• The sternum (1)
• The ribs (24, in 12 pairs), including:
  • (3) pairs (8th,9th and 10th pairs), also known as false ribs are attached anteriorly to each other and to the 7th rib by cartilages and synovial joints
  • (2) pairs of floating ribs (11th and 12th pairs), have no anterior attachment.
  • Cervical ribs

Skull (there are total 28 bones in skull)

• The cranial bones (8)
  • The occipital bone
  • The parietal bones (2)
  • The frontal bone
  • The temporal bones (2)
  • The sphenoid bone (sometimes counted as facial)
  • The ethmoid bone (sometimes counted as facial)
• The facial bones (14)
  • The nasal bones (2)
  • The maxillae (upper jaw) (2)
  • The lacrimal bone (2)
  • The zygomatic bone OR Chick bones (2);
  • The palatine bone (2)
  • The inferior nasal concha (2)
  • The vomer
  • The mandible (lower jaw)
  • The hyoid bone (It is counted as a separate bone.Not included IN SKULL)
• In the middle ears (6)
  • malleus (2)
  • incus (2)
  • stapes (2)

Arm

• The bones of the upper arm (6 bones, 3 on each side)

1. this is also known as pectoral girdle which includes (except humerus) *The Scapula *The Clavicles

• • The humerus
• The bones of the lower arm (4 bones, 2 on each side)
  • The ulna
  • The radius
• The hand (54 bones, 27 in each hand)
  • The carpals
    • scaphoid bone (2)
    • lunate bone (2)
    • triquetrum bone (2)
    • pisiform bone (2)
    • trapezium (2)
    • trapezoid bone (2)
    • capitate bone (2)
    • hamate bone (2)
  • The metacarpals (5 × 2=10)
  • The phalanges of the hand
    • proximal phalanges (5 × 2=10)
    • intermediate phalanges (4 × 2=8)
    • distal phalanges (5 × 2=10)

Pelvic girdle

• The coxal bone, or hip bones, has three regions: ilium, ischium, and pubis (2)
  • The sacrum and the coccyx attach to the two hip bones to form the pelvis
• LEGS * The femur
• The patella or knee cap
• The tibia
• The fibula
• The foot (52 bones in total, 26 per foot)
  • The tarsus
    • calcaneus or heel bone (2)
    • talus (2)
    • navicular bone (2)
    • medial cuneiform bone (2)
    • intermediate cuneiform bone (2)
    • lateral cuneiform bone (2)
    • cuboid bone (2)
  • The metatarsals (10)
  • The phalanges of the foot
    • proximal phalanges (5 × 2=10)
    • intermediate phalanges (4 x 2= 8)
    • distal phalanges (5 x 2=10)

Sesamoid bones

• Patella
• Pisiform bone
• Fabella
• Cyamella (bone)
• sesamoids in first and second metacarpal bones
• sesamoids in first metatarsal bone
• inconsistent sesamoids on other fingers and toes
• Lenticular process of the Incus bone
• Rider's bone
• inconsistent sesamoids in legs, arms, and buttocks

See also

• List of muscles of the human body

References

• The 206 Bones of the Human Body

1. Mammal anatomy : an illustrated guide. New York: Marshall Cavendish. 2010. p. 129. ISBN 9780761478829.