Liver
Human Anatomy · Physiology · Biochemistry
Say it: LIV-ur
The liver is the largest gland and internal organ, lying in the upper right abdomen, where it makes bile, processes nutrients and clears toxins.
Definition
What is the liver?
The liver is a large, lobed organ that lies just under the diaphragm in the upper right part of the abdomen. No gland in the body is bigger, and it is also the largest internal organ. Most of its volume is made of cells called hepatocytes, arranged in plates inside tiny six-sided units called lobules.
The liver has an unusual double blood supply. The hepatic artery brings oxygen-rich blood, while the hepatic portal vein carries blood straight from the intestines, so nutrients, drugs and toxins absorbed from the gut pass through the liver before they reach the rest of the body. Hepatocytes store glycogen and vitamins, make plasma proteins and clotting factors, process fats and cholesterol, and break down drugs and wastes. Resident immune cells called Kupffer cells remove bacteria and worn-out blood cells.
The liver also makes bile, which is stored in the gallbladder and helps the small intestine digest fats. It can regrow lost tissue to an unusual degree, which is why part of a liver can be donated by a living person. In pharmacology, the liver's first-pass metabolism explains why some drugs work poorly when swallowed.
Word parts
Where does the word “liver” come from?
- hepat-
- liver; used in words such as hepatocyte and hepatitisGreek hepar
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Terms that go with it
- DigestionDigestion is the process by which the body breaks food down, by chewing, churning and enzymes, into molecules small enough to absorb into the blood.
- MetabolismMetabolism is the full set of chemical reactions in a cell or organism, both those that break molecules down for energy and those that build them up.
- First-pass metabolismFirst-pass metabolism is the breakdown of an oral drug in the gut wall and liver before it reaches the general circulation, reducing how much survives.
- CholesterolCholesterol is a waxy steroid lipid found in animal cell membranes and used to make steroid hormones, vitamin D and the bile salts that digest fat.
- PancreasThe pancreas is a gland behind the stomach that sends digestive enzymes to the small intestine and releases insulin and glucagon into the blood.
- GlucagonGlucagon is a peptide hormone made by alpha cells of the pancreas that raises blood glucose, mainly by making the liver release glucose.
Sources
Checked against
Written for biofideX in plain words, after checking these references:
- OpenStax Anatomy and Physiology 2e, 23.6 Accessory Organs in Digestion: The Liver, Pancreas, and Gallbladder
- MedlinePlus: Liver Diseases
- NIDDK: Location, Location, Location - Cell Position in Maintaining and Regenerating Liver
- NCI Dictionary of Cancer Terms: liver
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