Hymen

The hymen (plural: hymens) is a thin fold of mucous membrane which extends across the vaginal opening, usually with some form of internal defect, which permits the free passage of normal menses. 

It usually ruptures during coitus with the remnants, usually in the form of small tags of tissue around the vaginal opening, termed the hymenal carunculae. 

Gross anatomy

Anatomically the hymen forms part of the vulva.

The hymen extends across the vaginal opening (also known as the introitus) which is a midline aperture with an anteroposterior long axis whichthat lies posterior to the urethral opening.

There is usually an opening within the hymen which may be single or multiple, and can be located centrally, eccentrically or at the side. If no opening is present, this is termed an imperforate hymen and leads to accumulation of fluid within the vaginal vault and uterus. 

Morphological subtypes

Multiple terms exist for the various morphologies of the hymen ³:

• annular hymen: ring-shaped
• bifenestrated hymen: two small defects interposed by a wide septum
• circular hymen: circular defect (central/eccentric)
• cribriform hymen: multiple small perforations
• denticular hymen: defect with sawtooth-like margins
• falciform/lunar hymen: crescentic
• fenestrated hymen: see cribriform
• septate hymen: defect is subdivided by a septum
  • subseptate hymen: defect is incompletely subdivided by a partial septum

Function

The actual function of the hymen remains unclear ⁴.

History and etymology

Hymen derives from the Ancient Greek word "υμην" (humen) meaning skin or membrane.

Related pathology

• imperforate hymen
• hymenal polyp