In anatomy, a viscus (pron.: //) 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 
- adrenal gland
- gall bladder
Pelvis and perineum 
- fallopian tube
- urinary bladder
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||T6, T7, T8, T9 and, sometimes, T10|
|duodenum||T5, T6, T7, T8, T9 and, sometimes, T10|
|pancreatic head||T8, T9|
|jejunum and ileum||T5, T6, T7, T8, T9|
||T6, T7, T8|
|gallbladder and liver||T6, T7, T8, T9|
|kidneys and ureters||T11, T12|
See also 
- "Viscus - Definition". Merriam-Webster Online Dictionary. Retrieved 14 December 2009.
- "Viscera". MeSH. Retrieved 14 December 2009.
- Splanchnic at eMedicine Dictionary
- "parietal". Retrieved 9 September 2012.
- Essential Clinical Anatomy. K.L. Moore & A.M. Agur. Lippincott, 2 ed. 2002. Page 199
- Unless else specified in boxes, then ref is: Essential Clinical Anatomy. K.L. Moore & A.M. Agur. Lippincott, 2 ed. 2002. Page 199