Definition

1. Noun:
   • A small endocrine gland in the brain: The epiphysis, also known as the pineal gland, is a small, pinecone-shaped endocrine gland located in the brain. It is situated beneath the posterior part of the corpus callosum and is responsible for secreting the hormone melatonin, which regulates sleep-wake cycles.
   • The end of a long bone: In anatomy, an epiphysis is the rounded end of a long bone. Initially, it is separated from the main shaft of the bone (the diaphysis) by a layer of cartilage (the epiphyseal plate or growth plate). This cartilage eventually ossifies (turns to bone) and fuses with the diaphysis, signaling the end of bone growth.

Usage Examples

• Referring to the brain gland:
  • The epiphysis, or pineal gland, plays a crucial role in regulating circadian rhythms.
  • Melatonin secretion from the epiphysis helps signal to the body that it is time to sleep.
• Referring to the bone end:
  • A fracture in the epiphysis of a child's femur requires careful medical attention.
  • The epiphysis fuses with the diaphysis during late adolescence.

Advanced Usage

• "Epiphyseal plate" (or growth plate): The area of cartilage between the epiphysis and diaphysis in a growing bone.
  • Damage to the epiphyseal plate can stunt bone growth.
• "Epiphyseal fusion": The process where the epiphyseal plate ossifies and the epiphysis joins with the diaphysis.
  • Epiphyseal fusion is used to estimate skeletal age.

Variants and Related Words

• Epiphyseal (adj): Pertaining to an epiphysis.
  • The doctor examined the epiphyseal region on the X-ray.
• Diaphysis (n): The main or midsection (shaft) of a long bone.
  • The fracture occurred in the diaphysis of the humerus.
• Pineal gland (n): Another name for the epiphysis cerebri (the brain gland).
  • Calcification of the pineal gland is sometimes visible on brain scans.

Synonyms

• For the gland: Pineal gland, pineal body, conarium.
• For the bone end: Bone end, articular end (in some contexts).

Related Terms and Phrases

• "Slipped capital femoral epiphysis (SCFE)": A medical condition where the epiphysis of the femur slips off the neck of the bone.
  • SCFE is a common hip disorder in adolescents.
• "Epiphysis cerebri": The full anatomical term for the pineal gland.
  • The epiphysis cerebri is part of the epithalamus.

Noun

1. a small endocrine gland in the brain; situated beneath the back part of the corpus callosum; secretes melatonin
2. the end of a long bone; initially separated from the main bone by a layer of cartilage that eventually ossifies so the parts become fused