Epiphysis bone is the extended end of the long bones in animals, lies between the growth plate and the joint at the end of the bone, which ossifies independently from the bone shaft yet winds up settled to the pole when full growth is accomplished. The epiphysis is made of springy cancellous bone secured by a thin layer of compact bone. It is associated with the bone shaft by the epiphyseal ligament, or plates in immature animals, which helps in the development of bone length and is inevitably replaced by bone.
The articular surface of the distal outspread epiphysis is more inward than that of the primary MT, with a transverse edge that runs anteroposteriorly.
The back border of the distal outspread epiphysis bone is more angled; the average surface of the base of the principal MT is more rounded.
The lateral side is thicker and located along the average border. The anterior one is straight and posterior is rounded.
Anatomy of Epiphysis Bone:
It presents in the joints particularly at the extended end of the long bone surface and secondary center of ossification and located at the end part of the diaphysis.
Bone is formed by alteration of connective tissue and replacement of an endochondral ossification. Intramembranous ossification occurs in flat bone, where it causes development in bone thickness. Endochondral ossification forms development in bone span and also forms the articular surfaces.
The procedure of endochondral ossification creates each of the three noteworthy territories of long bones: diaphysis, epiphysis, and metaphysics. The diaphysis grows first in the fetus. This region is known as the essential hardening focus. Vascular intrusion creates at the supplement foramen. Development factors and multipotent stem cells help in the arrangement of neonatal bone comprising of a focal marrow depression encompassed by a thin periosteum.
The epiphysis is a secondary ossification center in the hyaline cartilage, helps in the formation of the joint surfaces at the proximal and distal ends of the bones.
It is supplied from the choroidal branches of the posterior cerebral artery.
It is innervated from the superior cervical ganglion and parasympathetic innervations from the pterygopalatine and otic ganglia.
Epiphysis bone functions:
It is made of red bone marrow and responsible for the growth of bones. It supports the transmission of weight from the region under great strain and force, relieving the weight of the bone owing to the spongy nature of the larger portion.
There are four types of Epiphysis given below:
Pressure epiphysis is responsible for transmitting the pressures of the body during movement like the head of the femur, humerus, and tibia of the femur.
It doesn’t form joints but it is the nearest part to articular part of bone which makes the non-ossifying part.
Atavistic Epiphysis helps in the growth end of a fusion of some bones in the limbs. It comes in separated joints in four-legged animals.
It is seen in the head of the first metacarpal bone. It does not always exist in some individuals.