Viscus

Not to be confused with viscous.

In anatomy, a viscus ( /ˈvɪskəs/) is an internal organ, and viscera is the plural form.[1][2] 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,[3] 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.

Contents

Human viscera

Further information: Organs of the human body by region

Abdomen

Pelvis and perineum

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 corresponding to the spinal segment.[4]

Viscus Nerves [5] Origin in spinal column[5]
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
colon
spleen T6, T7, T8
vermiform appendix T10
gallbladder and liver T6, T7, T8, T9
kidneys and ureters T11, T12

See also

References

  1. ^ "Viscus - Definition". Merriam-Webster Online Dictionary. http://www.merriam-webster.com/dictionary/Viscus. Retrieved 14 December 2009. 
  2. ^ "Viscera". MeSH. http://www.ncbi.nlm.nih.gov/mesh?term=viscera. Retrieved 14 December 2009. 
  3. ^ Splanchnic at eMedicine Dictionary
  4. ^ Essential Clinical Anatomy. K.L. Moore & A.M. Agur. Lippincott, 2 ed. 2002. Page 199
  5. ^ 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
TA 2–4:
MS
Bone (Carpus · Collar bone (clavicle) · Thigh bone (femur) · Fibula · Humerus · Mandible · Metacarpus · Metatarsus · Ossicles · Patella · Phalanges · Radius · Skull (cranium) · Tarsus · Tibia · Ulna · Rib · Vertebra · Pelvis · Sternum) · Cartilage
TA 5–11:
splanchnic/
viscus
mostly
Thoracic
TA 12–16
peripheral (Artery, Vein, Lymphatic vessel) · Heart
primary (Bone marrow, Thymus) · secondary (Spleen, Lymph node)
Blood
(Non-TA)
General anatomy: systems and organs, regional anatomy, planes and lines, superficial axial anatomy, superficial anatomy of limbs