Viscus

Not to be confused with viscous.

"Viscera" and "Visceral" redirect here. For other uses, see Viscera (disambiguation). For the game studio, see Visceral Games.

Human viscera

In anatomy, a viscus (pron.: /ˈvɪskəs/) is an internal organ, and viscera is the plural form. The viscera, when removed from a butchered animal, are known collectively as offal. Internal organs are also known as "guts" (which may also refer to the gastrointestinal tract), or more formally, "innards".

The adjective visceral, also splanchnic, is used for anything pertaining to the internal organs. Historically, viscera of animals were examined by Roman pagan priests like the haruspices or the augurs in order to divine the future by their shape, dimensions or other factors. This practice remains an important ritual in some remote, tribal societies.

The term "visceral" is contrasted with the term "parietal", meaning "of or relating to the wall of a body part, organ or cavity". The two terms are often used in describing a membrane or piece of connective tissue, referring to the opposing sides.

Human viscera

Abdomen

• peritoneum
• stomach
• duodenum
• intestine
• colon
• liver
• spleen
• pancreas
• kidney
• adrenal gland
• appendix
• gall bladder

Pelvis and perineum

• pelvis
• coccyx
• ovaries
• fallopian tube
• uterus
• vulva
• clitoris
• perineum
• urinary bladder
• testicles
• rectum

Innervation

Autonomic nervous system, showing splanchnic nerves in middle, and the vagus nerve as "X" in blue. The heart and organs below in list to right are regarded as viscera.

The viscera are mainly innervated parasympathetically by the vagus nerve and sympathetically by the splanchnic nerves. The sensory part of the latter reaches the spinal column at certain spinal segments. Pain in any viscera is perceived as referred pain, more specifically pain from the dermatome corresponding to the spinal segment.

Viscus	Nerves	Origin in spinal column
stomach	anterior and posterior vagal trunks greater splanchnic nerves	T6, T7, T8, T9 and, sometimes, T10
duodenum	vagus nerves greater splanchnic nerves	T5, T6, T7, T8, T9 and, sometimes, T10
pancreatic head	vagus nerves thoracic splanchnic nerves	T8, T9
jejunum and ileum	posterior vagal trunks greater splanchnic nerves	T5, T6, T7, T8, T9
colon	vagus nerves and pelvic splanchnic nerves (parasympathetic) greater splanchnic nerves (sympathetic)	T10, T11, T12 (proximal colon) L1, L2, L3, (distal colon)
spleen	greater splanchnic nerves (especially)	T6, T7, T8
vermiform appendix	nerves to superior mesenteric plexus	T10
gallbladder and liver	sympathetic nerves to celiac plexus vagus nerve right phrenic nerve	T6, T7, T8, T9
kidneys and ureters	vagus nerve thoracic and lumbar splanchnic nerves	T11, T12

See also

• Anatomical terms of location
• Visceroptosis