The skeletal system is one of the important systems in the human body. Its main functions are to support the organs, anchor the muscles, and protect the organs such as heart, lungs, and brain. The human skeleton contains fused and individual bones, that are supported by muscles, tendons, ligaments, and cartilage.
Total Number of Bones in the Human Body
At birth, the human body consists of about 300 bones. Babies have more cartilage than bone tissue. As they grow up, some of the bones fuse together to form a single bone. As a result, the adult human skeleton consists of 206 bones. The size and shape of a bone varies according to its location in the body.
Types of Bones
- The human skeleton is divided into two categories, such as, axial skeleton (head and trunk of the body) and appendicular skeleton (limbs and the supporting pectoral and pelvic girdles). The axial skeleton contains 80 bones, while the appendicular skeleton contains 126 bones.
- There are five types of bones, such as, long bones, short bones, flat bones, sesmoid bones, and irregular bones.
- Femur is the longest bone, while stapes bone in the middle ear is the smallest bone in the human body.
- Scapula (shoulder blade), rib bones, os coxae (hip bones), etc., are some examples of flat bones in the body.
- The vertebrae, sacrum, and mandible (lower jaw) are examples of irregular bones.
- Short or irregular bones, situated deep in a tendon are called sesamoid bones. The patella (in the knee), pisiform (smallest of the carpals - wrist bone), and the two small bones at the base of the first metatarsal (foot bones) are sesamoid bones.
- The carpals (wrist bones) and the tarsals (foot bones) are short bones.
Distribution of Bones in Different Body Parts
- 28 skull bones (14 facial, 8 cranial, and 6 ear bones)
- Hyoid bone of the neck (horseshoe-shaped)
- 26 vertebrae (7 cervical, 12 thoracic, 5 lumbar, sacrum made from 5 fused vertebrae, and coccyx made from 3 fused vertebrae)
- 24 ribs, 1 sternum or breastbone, shoulder girdle (2 clavicles and 2 scapulae)
- 2 in arms (humerus), 4 in forearms (2 radius, 2 ulna)
- 54 in the hands (carpus, metacarpus, and digits)
- 2 Hip bones
- 2 in thighs
- 6 in the legs (2 patella, 2 tibia, and 2 fibula)
- 52 in the feet (tarsus, metatarsus, and digits)
All these bones together make the skeleton, support our body, and maintain its shape.