Viscus

Not to be confused with viscous.

"Viscera" redirects here. For other uses, see Viscera (disambiguation).

In anatomy, a viscus (IPA: /ˈvɪskəs/) (plural: viscera /ˈvɪsərə/) is an internal organ of an animal, 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, also splanchnic,^[1] 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.

1 Human viscera
2 References
3 See also

Human viscera

Further information: Organs of the human body by region

Abdomen

Pelvis and perineum

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 (anatomy) corresponding to the spinal segment.^[2]

Viscus	Nerves ^[3]	Origo in spinal column^[3]
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

^ Splanchnic at eMedicine Dictionary
^ Essential Clinical Anatomy. K.L. Moore & A.M. Agur. Lippincott, 2 ed. 2002. Page 199
^ ^a ^b Unless else specified in boxes, then ref is: Essential Clinical Anatomy. K.L. Moore & A.M. Agur. Lippincott, 2 ed. 2002. Page 199