Viscus

In anatomy, a viscus (plural: viscera /ˈvɪsərə/) is an internal organ of an animal (including humans), in particular an internal organ of the thorax or abdomen. The viscera, when removed from a butchered animal, are known collectively as offal. Internal organs are also known as "innards", or less formally, "guts" (which may also refer to the gastrointestinal tract).

The adjective visceral 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.

Human viscera

Further information: Organs of the human body by region

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

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 (anatomy) corresponding to the spinal segment.

Viscus	Nerves	Origo 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

References

See also

• Anatomical terms of location
• Visceroptosis