Diaphyses

Diaphysis
A long bone, with diaphysis labeled at right.
Identifiers
MeSH	A02.835.232.169
Dorlands /Elsevier	d_15/12293630
TA	A02.0.00.017
FMA	24013
Anatomical terminology []

The diaphysis (/daɪˈæfᵻsᵻs/) is the main or midsection (shaft) of a long bone. It is made up of cortical bone and usually contains bone marrow and adipose tissue (fat).

It is a middle tubular part composed of compact bone which surrounds a central marrow cavity which contains red or yellow marrow. In diaphysis, primary ossification occurs.

Ewing's sarcoma tends to occur at the diaphysis.

Long bone