Cross section of the gut. The lumen is the space in the middle also known as the volume.

In biology, a lumen (plural lumina) is the inside space of a tubular structure, such as an artery or intestine. ^[1] It comes from Latin lumen 'an opening'.

It can refer to:

• The interior of a vessel, such as the central space in an artery, vein or capillary through which blood flows.
• The interior of the gastrointestinal tract^[2]
• The pathways of the bronchi in the lungs
• The interior of renal tubules and urinary collecting ducts
• The pathways of the female genital tract, starting with a single pathway of the vagina, splitting up in two lumina in the uterus, both of which continue through the fallopian tubes

In cell biology, a lumen is a membrane-defined space that is found inside several organelles, cellular components, or structures:

• thylakoid, endoplasmic reticulum, Golgi apparatus, lysosome, mitochondrion, or microtubule

Transluminal procedures

Transluminal procedures are procedures occurring through lumina, including:^[3]

• Natural orifice transluminal endoscopic surgery in the lumina of, for example, the stomach, vagina, bladder, or colon
• Procedures through the lumina of blood vessels, such as various interventional radiology procedures:
  • Percutaneous transluminal angioplasty
  • Percutaneous transluminal commissurotomy

See also

• Foramen, any anatomical opening
• Thylakoid lumen

References