is the consumption of a substance by an organism
. In animals
, it normally is accomplished by taking in the substance through the mouth
into the gastrointestinal tract
, such as through eating
. In single-celled organisms
, ingestion can take place through taking the substance through the cell wall
Besides nutritional items, other substances which may be ingested include medications, recreational drugs, and substances considered inedible such as foreign bodies or excrement. Ingestion is a common route taken by pathogenic organisms and poisons entering the body.
Ingestion can also refer to a mechanism picking up something and making it enter an internal hollow of that mechanism, e.g. "a grille was fitted to prevent the pump from ingesting driftwood".
via ingestion, including viruses
, and parasites
. Most commonly, this takes place via the fecal-oral route
. An intermediate step is often involved, such as drinking water
contaminated by feces
prepared by workers who fail to practice adequate hand-washing
, and is more common in regions where untreated sewage
is common. Diseases
transmitted via the fecal-oral route include hepatitis A
, and cholera
Some pathogenic organisms are typically ingested by other routes.
- Larvae of the parasite Trichinella encyst within muscles and are transmitted when a new host eats the infected flesh of a former host animal.
- The parasite Dracunculus is ingested in drinking water, which is contaminated with larvae released as the parasite emerges from the host's body.
- The bacterium Salmonella most commonly infects humans via consumption of undercooked eggs.
, also called button cells, are often mistakenly ingested, particularly by children
and the elderly
. They may be mistaken for a medication pill
because of their size and shape, or they may be swallowed after being held in the mouth while the battery is being changed. Battery ingestion can cause medical problems including blocked airway
, persistent drooling
, and rash
(due to nickel
Pica is an abnormal appetite for non-nutritive objects or for food items in a form not normally eaten, such as flour. Coprophagia is the consumption of feces, a behavior common in some animals.