Epiphysis

Not to be confused with Apophysis.
This article is about the rounded end of a bone. For information on the endocrine gland also referred to as epiphysis, see pineal gland.
See also: epiphyseal plate

Epiphysis
Structure of a long bone, with epiphysis labeled at top and bottom.
Details
Pronunciation/ɛˈpɪfɪsɪs/[1][2]
Part ofLong bones
Identifiers
MeSHD004838
TA98A02.0.00.018
TA2393
FMA24012
Anatomical terminology

An epiphysis (from Ancient Greek ἐπί (epí) 'on top of' and φύσις (phúsis) 'growth'; pl.: epiphyses) is one of the rounded ends or tips of a long bone that ossify from one or more secondary centers of ossification.[3][4] Between the epiphysis and diaphysis (the long midsection of the long bone) lies the metaphysis, including the epiphyseal plate (growth plate). During formation of the secondary ossification center, vascular canals (epiphysial canals) stemming from the perichondrium invade the epiphysis, supplying nutrients to the developing secondary centers of ossification.[5][6] At the joint, the epiphysis is covered with articular cartilage; below that covering is a zone similar to the epiphyseal plate, known as subchondral bone. The epiphysis is mostly found in mammals but it is also present in some lizards.[7] However, the secondary center of ossification may have evolved multiple times, having been found in the Jurassic sphenodont Sapheosaurus as well as in the therapsid Niassodon mfumukasi.[8][9]

The epiphysis is filled with red bone marrow, which produces erythrocytes (red blood cells).

  1. ^ OED 2nd edition, 1989 as /εˈpɪfɪsɪs/.
  2. ^ Entry "epiphysis" in Merriam-Webster Online Dictionary.
  3. ^ Chaurasia BD (2009). B D Chaurasia's Handbook of General Anatomy (4th ed.). Delhi, India: CBS. p. 41. ISBN 978-8123916545. OCLC 696622496.
  4. ^ "Epiphysis | Definition, Anatomy, & Function". www.britannica.com. Retrieved 2023-01-28.
  5. ^ Xie M, Chagin AS (January 2021). "The epiphyseal secondary ossification center: Evolution, development and function". Bone. 142: 115701. doi:10.1016/j.bone.2020.115701. PMID 33091640.
  6. ^ Estefa J, Tafforeau P, Clement AM, Klembara J, Niedźwiedzki G, Berruyer C, et al. (March 2021). Tautz D, Blumer M, Woodward H (eds.). "New light shed on the early evolution of limb-bone growth plate and bone marrow". eLife. 10: e51581. doi:10.7554/eLife.51581. PMC 7924947. PMID 33648627.
  7. ^ Haines RW (April 1941). "Epiphysial structure in lizards and marsupials". Journal of Anatomy. 75 (Pt 3): 282–294. PMC 1252641. PMID 17104861.
  8. ^ Xie M, Chagin AS (January 2021). "The epiphyseal secondary ossification center: Evolution, development and function". Bone. 142: 115701. doi:10.1016/j.bone.2020.115701. PMID 33091640.
  9. ^ Castanhinha R, Araújo R, Júnior LC, Angielczyk KD, Martins GG, Martins RM, et al. (2013-12-04). "Bringing dicynodonts back to life: paleobiology and anatomy of a new emydopoid genus from the Upper Permian of Mozambique". PLOS ONE. 8 (12): e80974. Bibcode:2013PLoSO...880974C. doi:10.1371/journal.pone.0080974. PMC 3852158. PMID 24324653.