How Many Bones Are in the Human Body?
How Many Bones Are in the Human Body?
There are 206 bones in the human skeleton, including the tiniest bones in the middle ear to the longest bone the femur.
Infants are typically born with around 270 bones. As they age, some of those bones fuse together to become 206 separate bones. This number can vary, though, because injury could cause some people to lose ribs, vertebrae or digits.
Picture Reference: https://www.innerbody.com/image/skelfov.html
Picture Reference: https://www.britannica.com/science/human-skeleton
Axial bones include:
- The skull: The skull bones are comprised of 22 interlocking cranial and facial bones. These cranial plates and oddly shaped bones are held together by joints, though these joints don't allow for movement (except for the mandible or jawbone). Deep in your ear is the smallest bone in your body, the stirrup. It's about the size of a grain of rice.
- The sternum: The sternum — or breastbone — protects your heart, lungs and portions of your major arteries from external forces. The sternum starts off as different sections that fuse over time into one unified piece. The sternum also provides stability to the ribs.
- The ribs: These flat bones form a protective shield around your internal organs. There are 24 ribs, 12 on each side of your body. They come in three different types. From the top, the first seven sets of ribs are true ribs. They connect in the back to the spine and connect in the front to the sternum. The next three pairs are the false ribs. They connect in the back to the spine, but in the front, they attach to the seventh true rib, which is the last rib that connects to the sternum. Last are the floating ribs, and these two pairs attach to the spine like all the others, but "float" in the front, meaning they're not attached to the sternum or any other rib.
While the axial bones form the vertical axis of the body, the appendicular bones are the bones that connect to this axis.
Appendicular bones include:
Picture Reference: https://www.theskeletalsystem.net/appendicular-skeleton
- Bones of the shoulder: The bones that make up your shoulder girdle connect your arms to your sternum and rib cage for stability and support. You have two clavicles (collarbones) that attach on one end to the breast plate and, on the other end, support the shoulder blades, or scapulas. Each shoulder blade provides a point of contact for many muscles and the bone of each upper arm.
- Bones of the arm and hand: The arm has three basic components: the upper arm, the lower arm and the hand. The upper arm is one long bone, the humerus. The top fits neatly into the scapula, and the lower end is connected by the elbow joint to the two bones of the lower arm: the ulna (the bone on the same side as your little finger) and the radius (the bone on the side of your thumb). The radius plays a larger role in your mobility and function, while your ulna provides more stability. Both the ulna and the radius connect to the wrist bones in the hand. Each hand has an impressive 27 bones: eight carpal bones that make up the wrist, five metacarpal bones that extend the length of your palm, and 14 phalanges that form four fingers with three bones each along with a single two-boned thumb.
- The pelvic girdle: This tough pair of hip bones protects lower organs such as the bladder and, for women, a fetus when she's pregnant. The dimensions of the pelvis differ significantly for men and women.
- Bones of the thigh, leg and foot: Connecting the pelvic girdle to the lower leg is the femur, the longest and strongest bone in the body. The femur connects through the knee joint (which is covered and protected by the patella, or kneecap) to the shin bone (tibia). Slightly smaller than the tibia is the other bone in the leg, the fibula. Each foot has 26 bones: seven tarsal bones that make up the ankle, five metatarsal bones that make up the body of your foot, and 14 phalanges that form four toes with three bones each with a big toe that has two bones.
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