Fetal Skeletal Development: Bones Ossified at Birth

The following bones in a fetus have ossified at birth:

Long bones: The shaft (diaphysis) of most long bones is ossified at birth. However, the ends (epiphyses) of these bones remain cartilaginous.

Flat bones: The flat bones of the skull (cranial bones) are largely ossified at birth, except for some areas called fontanelles where ossification is incomplete. The sternum and the bones of the pelvis (hip bone) are also mostly ossified at birth.

Short bones: The short bones of the wrist (carpal bones) and ankle (tarsal bones) are partially ossified at birth, with some still being cartilaginous.

Irregular bones: The irregular bones, such as the vertebrae and the facial bones, are largely ossified at birth, although some areas may still have cartilaginous parts.

It's worth noting that the ossification process continues after birth, with the remaining cartilaginous parts of the bones gradually becoming ossified as the child grows. This process is influenced by factors such as genetics, nutrition, and hormonal regulation.