List of bones of the skeleton

List of Bones of the Skeleton

The human skeleton is a complex structure that serves as the framework for the body, providing support, protection for internal organs, and facilitating movement. Comprised of over 200 bones at adulthood, the skeleton is categorized into two main parts: the axial skeleton and the appendicular skeleton. This article provides a comprehensive list of the bones that make up the human skeleton, highlighting their significance and organization within the body.

Axial Skeleton

The axial skeleton forms the central axis of the human body and consists of 80 bones. It is divided into the skull, the vertebral column, and the thoracic cage.

Skull

The skull is composed of 22 bones, divided into the cranial bones and the facial bones. The cranial bones protect the brain, while the facial bones form the structure of the face.

• Frontal bone – forms the forehead.
• Parietal bones (2) – form the sides and roof of the cranium.
• Temporal bones (2) – located at the sides and base of the skull.
• Occipital bone – forms the back and base of the skull.
• Sphenoid bone – forms part of the base of the skull and the floor of the orbit.
• Ethmoid bone – contributes to the walls of the orbits and the nasal cavity.
• Facial Bones:
  • Nasal bones (2) – form the bridge of the nose.
  • Maxillae (2) – form the upper jaw.
  • Zygomatic bones (2) – form the cheeks.
  • Mandible – forms the lower jaw, the only movable bone of the skull.
  • Lacrimal bones (2) – small bones forming part of the orbit.
  • Palatine bones (2) – form part of the hard palate.
  • Vomer – forms part of the nasal septum.
  • Inferior nasal conchae (2) – form part of the lateral walls of the nasal cavity.

Vertebral Column

The vertebral column, or spine, consists of 33 vertebrae that are divided into five regions: cervical, thoracic, lumbar, sacral, and coccygeal.

• Cervical vertebrae (7) – form the neck.
• Thoracic vertebrae (12) – each connects to a pair of ribs.
• Lumbar vertebrae (5) – form the lower back.
• Sacrum – five fused vertebrae forming the back of the pelvis.
• Coccyx – four fused vertebrae, also known as the tailbone.

Thoracic Cage

The thoracic cage, or rib cage, protects the heart and lungs. It is composed of the sternum and 24 ribs.

• Sternum – the breastbone.
• Ribs (24) – twelve pairs of bones forming the protective cage of the thorax.

Appendicular Skeleton

The appendicular skeleton consists of 126 bones and comprises the limbs and the girdles that attach them to the axial skeleton.

Pectoral Girdles

The pectoral girdles, or shoulder girdles, attach the upper limbs to the body trunk.

• Clavicle (2) – collarbones.
• Scapula (2) – shoulder blades.

Upper Limbs

Each upper limb is composed of 30 bones.

• Humerus – upper arm bone.
• Radius and Ulna – forearm bones.
• Carpal bones (8) – wrist bones.
• Metacarpal bones (5) – form the palm of the hand.
• Phalanges (14) – bones of the fingers.

Pelvic Girdle

The pelvic girdle, or hip girdle, supports the lower limbs.

• Pelvis – composed of the ilium, ischium, and pubis.

Lower Limbs

Each lower limb consists of 30 bones.

• Femur – thigh bone, the longest bone in the body.
• Patella – kneecap.
• Tibia and Fibula – lower leg bones.
• Tarsal bones (7) – ankle bones.
• Metatarsal bones (5) – form the sole of the foot.
• Phalanges (14) – bones of the toes.

Conclusion

The human skeleton is a marvel of biological engineering, providing a strong yet flexible framework that supports and protects the body's many organs and tissues. Understanding the list of bones that make up the skeleton is fundamental for students of anatomy, health professionals, and anyone interested in the human body's structure and function.