epiphyseal closure

(noun)

The fusion of the epiphysis to the diaphysis.

Related Terms

Examples of epiphyseal closure in the following topics:

  • Postnatal Bone Growth

    • Secondary ossification occurs after birth at the epiphyses of long bones and continues until skeletal maturity.
    • It forms the epiphyses of long bones and the extremities of irregular and flat bones.
    • The diaphysis and both epiphyses of a long bone are separated by a growing zone of cartilage (the epiphyseal plate).
    • When a child reaches skeletal maturity (18 to 25 years of age), all of the cartilage is replaced by bone, fusing the diaphysis and both epiphyses together (epiphyseal closure).
    • Between the epiphysis and diaphysis (the long midsection of the long bone) lies the metaphysis, including the epiphyseal plate (growth plate).

  • Stages of Bone Development

    • Secondary ossification occurs after birth, and forms the epiphyses of long bones and the extremities of irregular and flat bones.
    • The diaphysis and both epiphyses of a long bone are separated by a growing zone of cartilage (the epiphyseal plate).
    • When the child reaches skeletal maturity (18 to 25 years of age), all of the cartilage is replaced by bone, fusing the diaphysis and both epiphyses together (epiphyseal closure).

  • Hormonal Abnormalities and Height

    • Acromegaly is a syndrome that results when the anterior pituitary gland produces excess growth hormone (GH) after epiphyseal plate closure at puberty.
    • The distinction between gigantism (occurring in children) and acromegaly (occurring in adults) can be made by the occurrence of the adenoma in relation to the closure of the epiphyses.
    • If elevated growth hormone levels occur before the closure of the epiphyses (i.e. in prepubertal children), then gigantism ensues.
    • If it occurs after the closure of the epiphyses (i.e., in adults), then acromegaly ensues.

  • Cartilaginous Joints: Synchodroses

    • The epiphyseal plate is a hyaline cartilage plate in the metaphysis at each end of a long bone.
    • The epiphyseal plate is found in children and adolescents.
    • This process leaves only a thin epiphyseal scar that later disappears.
    • In adults who have stopped growing, the plate is replaced by an epiphyseal line.
    • Those with achondroplasia (a form of dwarfism) have premature closure of the epiphyseal growth plates, which results in shorter than average arms and legs.

  • Pituitary Gland Disorders

    • The distinction between gigantism (occurring in children) and acromegaly (occurring in adults) can be made by the occurrence of the adenoma in relation to the closure of the epiphyses.
    • If elevated growth hormone levels occur before the closure of the epiphyses (i.e. in prepubertal children), then gigantism ensues.
    • If it occurs after the closure of the epiphyses (i.e., in adults) then acromegaly ensues.

  • Puberty

    • The male "growth spurt" also begins later, accelerates more slowly, and lasts longer before the epiphyses fuse.
    • While estradiol promotes growth of breasts and uterus, it is also the principal hormone driving the pubertal growth spurt and epiphyseal maturation and closure.

  • Development of Joints

    • Between the epiphysis and diaphysis (the long midsection of the long bone) lies the metaphysis, including the epiphyseal plate (growth plate) .
    • 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.
    • For example, the head of the femur (which is a part of the hip joint complex) is a pressure epiphyses.
    • These epiphyses assist in transmitting the weight of the human body and are the regions of the bone which is under pressure during movement or locomotion; hence, their name.
    • Image shows the location of the epiphyseal plates (or lines) and the articular surfaces of long bones.

  • Nerve and Blood Supply

    • The articular and epiphyseal branches of the neighboring arteries form a periarticular arterial plexus.
    • It supplies the capsule, synovial membrane, and the epiphyses.
    • After epiphyseal fusion in the growth of long bones, communication between the circulosus vasculosus and the end arteries of the metaphysis is established.

  • Heart Sounds

    • The two major heart sounds are 'lub' (from the closure of AV-valves) and 'dub' (from the closure of aortic and pulmonary valves).
    • It is caused by the closure of the mitral, and tricuspid valves as ventricular systole begins.
    • There is a very slight split between the closure of the mitral and tricuspid valves, however it is not long enough to create multiple sounds.
    • It is caused by the closure of the semilunar (aortic and pulmonary) valves following ventricular systole.
    • S2 is split because aortic valve closure occurs before pulmonary valve closure.

  • Supply of Blood and Nerves to Bone

    • Near the epiphysis, they anastomose with the metaphyseal and epiphyseal arteries.
    • Epiphyseal and metaphyseal arteries enter on both sides of the growth cartilage, with anastamoses between them being few or absent.
    • Image shows the location of the epiphyseal plates (or lines) and the articular surfaces of long bones.