In anatomy

Anatomy

Anatomy is a branch of biology and medicine that is the consideration of the structure of living things. It is a general term that includes human anatomy, animal anatomy , and plant anatomy...

, a viscus (icon) is an internal organ

Organ (anatomy)

In biology, an organ is a collection of tissues joined in structural unit to serve a common function. Usually there is a main tissue and sporadic tissues . The main tissue is the one that is unique for the specific organ. For example, main tissue in the heart is the myocardium, while sporadic are...

, and viscera is the plural form. The viscera, when removed from a butchered animal, are known collectively as offal

Offal

Offal , also called, especially in the United States, variety meats or organ meats, refers to the internal organs and entrails of a butchered animal. The word does not refer to a particular list of edible organs, which varies by culture and region, but includes most internal organs other than...

. Internal organs are also known as "innards", or less formally, "guts" (which may also refer to the gastrointestinal tract

Gastrointestinal tract

The human gastrointestinal tract refers to the stomach and intestine, and sometimes to all the structures from the mouth to the anus. ....

).

The adjective visceral, also splanchnic

Splanchnic

Splanchnic, from a Greek word spēn, meaning organ, usually used to describe visceral organs.More specifically, it can also refer to:* An adjective describing the intestines* Splanchnic nerves* Splanchnic mesoderm...

, is used for anything pertaining to the internal organs. Historically, viscera of animals were examined by Roman

Rome

Rome is the capital of Italy and the country's largest and most populated city and comune, with over 2.7 million residents in . The city is located in the central-western portion of the Italian Peninsula, on the Tiber River within the Lazio region of Italy.Rome's history spans two and a half...

 pagan priest

Priest

A priest is a person authorized to perform the sacred rites of a religion, especially as a mediatory agent between humans and deities. They also have the authority or power to administer religious rites; in particular, rites of sacrifice to, and propitiation of, a deity or deities...

s like the haruspices or the augur

Augur

The augur was a priest and official in the classical world, especially ancient Rome and Etruria. His main role was to interpret the will of the gods by studying the flight of birds: whether they are flying in groups/alone, what noises they make as they fly, direction of flight and what kind of...

s in order to divine the future by their shape, dimensions or other factors. This practice remains an important ritual in some remote, tribal societies.

Human viscera

Further information: Organs of the human body by region

Abdomen

• peritoneum
  Peritoneum
  The peritoneum is the serous membrane that forms the lining of the abdominal cavity or the coelom — it covers most of the intra-abdominal organs — in amniotes and some invertebrates...
  
  
• stomach
  Stomach
  The stomach is a muscular, hollow, dilated part of the alimentary canal which functions as an important organ of the digestive tract in some animals, including vertebrates, echinoderms, insects , and molluscs. It is involved in the second phase of digestion, following mastication .The stomach is...
  
  
• duodenum
  Duodenum
  The duodenum is the first section of the small intestine in most higher vertebrates, including mammals, reptiles, and birds. In fish, the divisions of the small intestine are not as clear and the terms anterior intestine or proximal intestine may be used instead of duodenum...
  
  
• intestine
  Intestine
  In human anatomy, the intestine is the segment of the alimentary canal extending from the pyloric sphincter of the stomach to the anus and, in humans and other mammals, consists of two segments, the small intestine and the large intestine...
  
  
• colon
  Colon (anatomy)
  The colon is the last part of the digestive system in most vertebrates; it extracts water and salt from solid wastes before they are eliminated from the body, and is the site in which flora-aided fermentation of unabsorbed material occurs. Unlike the small intestine, the colon does not play a...
  
  
• liver
  Liver
  The liver is a vital organ present in vertebrates and some other animals. It has a wide range of functions, including detoxification, protein synthesis, and production of biochemicals necessary for digestion...
  
  
• spleen
  Spleen
  The spleen is an organ found in virtually all vertebrate animals with important roles in regard to red blood cells and the immune system. In humans, it is located in the left upper quadrant of the abdomen. It removes old red blood cells and holds a reserve of blood in case of hemorrhagic shock...
  
  
• pancreas
  Pancreas
  The pancreas is a gland organ in the digestive and endocrine system of vertebrates. It is both an endocrine gland producing several important hormones, including insulin, glucagon, and somatostatin, as well as a digestive organ, secreting pancreatic juice containing digestive enzymes that assist...
  
  
• kidney
  Kidney
  The kidneys, organs with several functions, serve essential regulatory roles in most animals, including vertebrates and some invertebrates. They are essential in the urinary system and also serve homeostatic functions such as the regulation of electrolytes, maintenance of acid–base balance, and...
  
  
• adrenal gland
  Adrenal gland
  In mammals, the adrenal glands are endocrine glands that sit atop the kidneys; in humans, the right suprarenal gland is triangular shaped, while the left suprarenal gland is semilunar shaped...
  
  
• appendix
  Vermiform appendix
  The appendix is a blind-ended tube connected to the cecum , from which it develops embryologically. The cecum is a pouchlike structure of the colon...
  
  
• gall bladder

Pelvis and perineum

• pelvis
• coccyx
  Coccyx
  The coccyx , commonly referred to as the tailbone, is the final segment of the vertebral column. Comprising three to five separate or fused vertebrae below the sacrum, it is attached to the sacrum by a fibrocartilaginous joint, the sacrococcygeal symphysis, which permits limited movement between...
  
  
• ovaries
• fallopian tube
  Fallopian tube
  The Fallopian tubes, also known as oviducts, uterine tubes, and salpinges are two very fine tubes lined with ciliated epithelia, leading from the ovaries of female mammals into the uterus, via the utero-tubal junction...
  
  
• uterus
  Uterus
  The uterus or womb is a major female hormone-responsive reproductive sex organ of most mammals including humans. One end, the cervix, opens into the vagina, while the other is connected to one or both fallopian tubes, depending on the species...
  
  
• vulva
  Vulva
  The vulva consists of the external genital organs of the female mammal. This article deals with the vulva of the human being, although the structures are similar for other mammals....
  
  
• clitoris
  Clitoris
  The clitoris is a sexual organ that is present only in female mammals. In humans, the visible button-like portion is located near the anterior junction of the labia minora, above the opening of the urethra and vagina. Unlike the penis, which is homologous to the clitoris, the clitoris does not...
  
  
• perineum
  Perineum
  In human anatomy, the perineum is a region of the body including the perineal body and surrounding structures...
  
  
• urinary bladder
  Urinary bladder
  The urinary bladder is the organ that collects urine excreted by the kidneys before disposal by urination. A hollow muscular, and distensible organ, the bladder sits on the pelvic floor...
  
  
• testicles
• rectum
  Rectum
  The rectum is the final straight portion of the large intestine in some mammals, and the gut in others, terminating in the anus. The human rectum is about 12 cm long...
  
  

Innervation

The viscera are mainly innervated parasympathetically by the vagus nerve

Vagus nerve

The vagus nerve , also called pneumogastric nerve or cranial nerve X, is the tenth of twelve paired cranial nerves...

 and sympathetic

Sympathetic nervous system

The sympathetic nervous system is one of the three parts of the autonomic nervous system, along with the enteric and parasympathetic systems. Its general action is to mobilize the body's nervous system fight-or-flight response...

ally 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

Referred pain

Referred pain is pain perceived at a location other than the site of the painful stimulus. An example is the case of ischemia brought on by a myocardial infarction , where pain is often felt in the neck, shoulders, and back rather than in the chest, the site of the injury...

, more specifically pain from the dermatome corresponding to the spinal segment.

Viscus	Nerves	Origin in spinal column
stomach Stomach The stomach is a muscular, hollow, dilated part of the alimentary canal which functions as an important organ of the digestive tract in some animals, including vertebrates, echinoderms, insects , and molluscs. It is involved in the second phase of digestion, following mastication .The stomach is...	anterior Anterior vagal trunk The anterior vagal trunk is a branch of the vagus nerve which contributes to the esophageal plexus. It consists primarily of fibers from the left vagus, but also contains a few fibers from the right vagus.-External links:...  and posterior vagal trunk Posterior vagal trunk The posterior vagal trunk is a branch of the vagus nerve which contributes to the esophageal plexus. It consists primarily of fibers from the right vagus, but also contains a few fibers from the left vagus.-External links:... s greater splanchnic nerves	T6 Thoracic spinal nerve 6 The thoracic spinal nerve 6 is a spinal nerve of the thoracic segment..It originates from the spinal column from below the thoracic vertebra 6 .... , T7 Thoracic spinal nerve 7 The thoracic spinal nerve 7 is a spinal nerve of the thoracic segment..It originates from the spinal column from below the thoracic vertebra 7 .... , T8 Thoracic spinal nerve 8 The thoracic spinal nerve 8 is a spinal nerve of the thoracic segment..It originates from the spinal column from below the thoracic vertebra 8 .... , T9 Thoracic spinal nerve 9 The thoracic spinal nerve 9 is a spinal nerve of the thoracic segment..It originates from the spinal column from below the thoracic vertebra 9 ....  and, sometimes, T10 Thoracic spinal nerve 10 The thoracic spinal nerve 10 is a spinal nerve of the thoracic segment..It originates from the spinal column from below the thoracic vertebra 10 ....
duodenum Duodenum The duodenum is the first section of the small intestine in most higher vertebrates, including mammals, reptiles, and birds. In fish, the divisions of the small intestine are not as clear and the terms anterior intestine or proximal intestine may be used instead of duodenum...	vagus nerve Vagus nerve The vagus nerve , also called pneumogastric nerve or cranial nerve X, is the tenth of twelve paired cranial nerves... s greater splanchnic nerves	T5 Thoracic spinal nerve 5 The thoracic spinal nerve 5 is a spinal nerve of the thoracic segment..It originates from the spinal column from below the thoracic vertebra 5 .... , T6 Thoracic spinal nerve 6 The thoracic spinal nerve 6 is a spinal nerve of the thoracic segment..It originates from the spinal column from below the thoracic vertebra 6 .... , T7 Thoracic spinal nerve 7 The thoracic spinal nerve 7 is a spinal nerve of the thoracic segment..It originates from the spinal column from below the thoracic vertebra 7 .... , T8 Thoracic spinal nerve 8 The thoracic spinal nerve 8 is a spinal nerve of the thoracic segment..It originates from the spinal column from below the thoracic vertebra 8 .... , T9 Thoracic spinal nerve 9 The thoracic spinal nerve 9 is a spinal nerve of the thoracic segment..It originates from the spinal column from below the thoracic vertebra 9 ....  and, sometimes, T10 Thoracic spinal nerve 10 The thoracic spinal nerve 10 is a spinal nerve of the thoracic segment..It originates from the spinal column from below the thoracic vertebra 10 ....
pancreatic head	vagus nerve Vagus nerve The vagus nerve , also called pneumogastric nerve or cranial nerve X, is the tenth of twelve paired cranial nerves... s thoracic splanchnic nerves	T8 Thoracic spinal nerve 8 The thoracic spinal nerve 8 is a spinal nerve of the thoracic segment..It originates from the spinal column from below the thoracic vertebra 8 .... , T9 Thoracic spinal nerve 9 The thoracic spinal nerve 9 is a spinal nerve of the thoracic segment..It originates from the spinal column from below the thoracic vertebra 9 ....
jejunum Jejunum The jejunum is the middle section of the small intestine in most higher vertebrates, including mammals, reptiles, and birds. In fish, the divisions of the small intestine are not as clear and the terms middle intestine or mid-gut may be used instead of jejunum.The jejunum lies between the duodenum...  and ileum Ileum The ileum is the final section of the small intestine in most higher vertebrates, including mammals, reptiles, and birds. In fish, the divisions of the small intestine are not as clear and the terms posterior intestine or distal intestine may be used instead of ileum.The ileum follows the duodenum...	posterior vagal trunk Posterior vagal trunk The posterior vagal trunk is a branch of the vagus nerve which contributes to the esophageal plexus. It consists primarily of fibers from the right vagus, but also contains a few fibers from the left vagus.-External links:... s greater splanchnic nerves	T5 Thoracic spinal nerve 5 The thoracic spinal nerve 5 is a spinal nerve of the thoracic segment..It originates from the spinal column from below the thoracic vertebra 5 .... , T6 Thoracic spinal nerve 6 The thoracic spinal nerve 6 is a spinal nerve of the thoracic segment..It originates from the spinal column from below the thoracic vertebra 6 .... , T7 Thoracic spinal nerve 7 The thoracic spinal nerve 7 is a spinal nerve of the thoracic segment..It originates from the spinal column from below the thoracic vertebra 7 .... , T8 Thoracic spinal nerve 8 The thoracic spinal nerve 8 is a spinal nerve of the thoracic segment..It originates from the spinal column from below the thoracic vertebra 8 .... , T9 Thoracic spinal nerve 9 The thoracic spinal nerve 9 is a spinal nerve of the thoracic segment..It originates from the spinal column from below the thoracic vertebra 9 ....
colon	vagus nerve Vagus nerve The vagus nerve , also called pneumogastric nerve or cranial nerve X, is the tenth of twelve paired cranial nerves... s and pelvic splanchnic nerves (parasympathetic) greater splanchnic nerves (sympathetic Sympathetic nervous system The sympathetic nervous system is one of the three parts of the autonomic nervous system, along with the enteric and parasympathetic systems. Its general action is to mobilize the body's nervous system fight-or-flight response... )	T10 Thoracic spinal nerve 10 The thoracic spinal nerve 10 is a spinal nerve of the thoracic segment..It originates from the spinal column from below the thoracic vertebra 10 .... , T11 Thoracic spinal nerve 11 The thoracic spinal nerve 11 is a spinal nerve of the thoracic segment..It originates from the spinal column from below the thoracic vertebra 11 .... , T12 Thoracic spinal nerve 12 The thoracic spinal nerve 12 is a spinal nerve of the thoracic segment..It originates from the spinal column from below the thoracic vertebra 12 ....  (proximal colon) L1 Lumbar spinal nerve 1 The lumbar spinal nerve 1 is a spinal nerve of the lumbar segment..It originates from the spinal column from below the lumbar vertebra 1 .The two terminal branches of this nerve is the iliohypogastric and the ilioinguinal nerves-Muscles:... , L2 Lumbar spinal nerve 2 The lumbar spinal nerve 2 is a spinal nerve of the lumbar segment..It originates from the spinal column from below the lumbar vertebra 2 .-Muscles:... , L3 Lumbar spinal nerve 3 The lumbar spinal nerve 3 is a spinal nerve of the lumbar segment..It originates from the spinal column from below the lumbar vertebra 3 .-Muscles:... , (distal colon)
spleen Spleen The spleen is an organ found in virtually all vertebrate animals with important roles in regard to red blood cells and the immune system. In humans, it is located in the left upper quadrant of the abdomen. It removes old red blood cells and holds a reserve of blood in case of hemorrhagic shock...	greater splanchnic nerves (especially)	T6 Thoracic spinal nerve 6 The thoracic spinal nerve 6 is a spinal nerve of the thoracic segment..It originates from the spinal column from below the thoracic vertebra 6 .... , T7 Thoracic spinal nerve 7 The thoracic spinal nerve 7 is a spinal nerve of the thoracic segment..It originates from the spinal column from below the thoracic vertebra 7 .... , T8 Thoracic spinal nerve 8 The thoracic spinal nerve 8 is a spinal nerve of the thoracic segment..It originates from the spinal column from below the thoracic vertebra 8 ....
vermiform appendix Vermiform appendix The appendix is a blind-ended tube connected to the cecum , from which it develops embryologically. The cecum is a pouchlike structure of the colon...	nerves to superior mesenteric plexus Superior mesenteric plexus The superior mesenteric plexus is a continuation of the lower part of the celiac plexus, receiving a branch from the junction of the right vagus nerve with the plexus....	T10 Thoracic spinal nerve 10 The thoracic spinal nerve 10 is a spinal nerve of the thoracic segment..It originates from the spinal column from below the thoracic vertebra 10 ....
gallbladder Gallbladder In vertebrates the gallbladder is a small organ that aids mainly in fat digestion and concentrates bile produced by the liver. In humans the loss of the gallbladder is usually easily tolerated....  and liver Liver The liver is a vital organ present in vertebrates and some other animals. It has a wide range of functions, including detoxification, protein synthesis, and production of biochemicals necessary for digestion...	sympathetic Sympathetic nervous system The sympathetic nervous system is one of the three parts of the autonomic nervous system, along with the enteric and parasympathetic systems. Its general action is to mobilize the body's nervous system fight-or-flight response...  nerves to celiac plexus Celiac plexus The celiac plexus or coeliac plexus, also known as the solar plexus, is a complex network of nerves located in the abdomen, where the celiac trunk, superior mesenteric artery, and renal arteries branch from the abdominal aorta... vagus nerve Vagus nerve The vagus nerve , also called pneumogastric nerve or cranial nerve X, is the tenth of twelve paired cranial nerves... right phrenic nerve Phrenic nerve The phrenic nerve originates mainly from the 4th cervical nerve, but also receives contributions from the 5th and 3rd cervical nerves in humans....	T6 Thoracic spinal nerve 6 The thoracic spinal nerve 6 is a spinal nerve of the thoracic segment..It originates from the spinal column from below the thoracic vertebra 6 .... , T7 Thoracic spinal nerve 7 The thoracic spinal nerve 7 is a spinal nerve of the thoracic segment..It originates from the spinal column from below the thoracic vertebra 7 .... , T8 Thoracic spinal nerve 8 The thoracic spinal nerve 8 is a spinal nerve of the thoracic segment..It originates from the spinal column from below the thoracic vertebra 8 .... , T9 Thoracic spinal nerve 9 The thoracic spinal nerve 9 is a spinal nerve of the thoracic segment..It originates from the spinal column from below the thoracic vertebra 9 ....
kidney Kidney The kidneys, organs with several functions, serve essential regulatory roles in most animals, including vertebrates and some invertebrates. They are essential in the urinary system and also serve homeostatic functions such as the regulation of electrolytes, maintenance of acid–base balance, and... s and ureter Ureter In human anatomy, the ureters are muscular tubes that propel urine from the kidneys to the urinary bladder. In the adult, the ureters are usually long and ~3-4 mm in diameter.... s	vagus nerve Vagus nerve The vagus nerve , also called pneumogastric nerve or cranial nerve X, is the tenth of twelve paired cranial nerves... thoracic and lumbar splanchnic nerves	T11 Thoracic spinal nerve 11 The thoracic spinal nerve 11 is a spinal nerve of the thoracic segment..It originates from the spinal column from below the thoracic vertebra 11 .... , T12 Thoracic spinal nerve 12 The thoracic spinal nerve 12 is a spinal nerve of the thoracic segment..It originates from the spinal column from below the thoracic vertebra 12 ....