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Drinking is the act of
ingesting water
Water (chemical formula ) is an Inorganic compound, inorganic, transparent, tasteless, odorless, and Color of water, nearly colorless chemical substance, which is the main constituent of Earth's hydrosphere and the fluids of all known living ...
or other
liquids into the body through the
mouth,
proboscis
A proboscis () is an elongated appendage from the head of an animal, either a vertebrate or an invertebrate. In invertebrates, the term usually refers to tubular mouthparts used for feeding and sucking. In vertebrates, a proboscis is an elong ...
, or elsewhere. Humans drink by
swallowing, completed by
peristalsis
Peristalsis ( , ) is a radially symmetrical contraction and relaxation of muscles that propagate in a wave down a tube, in an anterograde direction. Peristalsis is progression of coordinated contraction of involuntary circular muscles, whic ...
in the
esophagus
The esophagus ( American English) or oesophagus (British English; both ), non-technically known also as the food pipe or gullet, is an organ in vertebrates through which food passes, aided by peristaltic contractions, from the pharynx to ...
. The physiological processes of drinking vary widely among other
animals
Animals are multicellular, eukaryotic organisms in the biological kingdom Animalia. With few exceptions, animals consume organic material, breathe oxygen, are able to move, can reproduce sexually, and go through an ontogenetic stage in ...
.
Most animals
drink water to maintain
bodily hydration, although many can survive on the water gained from their food. Water is required for many
physiological processes. Both inadequate and (less commonly) excessive water intake are associated with health problems.
Methods of drinking
In humans
When a
liquid enters a human
mouth, the
swallowing process is completed by
peristalsis
Peristalsis ( , ) is a radially symmetrical contraction and relaxation of muscles that propagate in a wave down a tube, in an anterograde direction. Peristalsis is progression of coordinated contraction of involuntary circular muscles, whic ...
which delivers the liquid through the
esophagus
The esophagus ( American English) or oesophagus (British English; both ), non-technically known also as the food pipe or gullet, is an organ in vertebrates through which food passes, aided by peristaltic contractions, from the pharynx to ...
to the
stomach
The stomach is a muscular, hollow organ in the gastrointestinal tract of humans and many other animals, including several invertebrates. The stomach has a dilated structure and functions as a vital organ in the digestive system. The stomach i ...
; much of the activity is abetted by gravity. The liquid may be poured from the hands or
drinkware may be used as vessels. Drinking can also be performed by acts of
inhalation, typically when imbibing hot liquids or drinking from a spoon. Infants employ a method of suction wherein the lips are pressed tight around a source, as in
breastfeeding
Breastfeeding, or nursing, is the process by which human breast milk is fed to a child. Breast milk may be from the breast, or may be expressed by hand or pumped and fed to the infant. The World Health Organization (WHO) recommends that br ...
: a combination of breath and tongue movement creates a vacuum which draws in liquid.
[Flint, pp. 137–138.]
In other land mammals
By necessity,
terrestrial animal
Terrestrial animals are animals that live predominantly or entirely on land (e.g. cats, dogs, ants, spiders), as compared with aquatic animals, which live predominantly or entirely in the water (e.g. fish, lobsters, octopuses), and amphibian ...
s in captivity become accustomed to drinking water, but most free-roaming animals stay hydrated through the fluids and moisture in fresh food,
[Mayer, p. 59.] and learn to actively seek foods with high fluid content.
When conditions impel them to drink from bodies of water, the methods and motions differ greatly among species.
[Broom, p. 105.]
Cats,
canines
Canine may refer to:
Zoology and anatomy
* a dog-like Canid animal in the subfamily Caninae
** ''Canis'', a genus including dogs, wolves, coyotes, and jackals
** Dog, the domestic dog
* Canine tooth, in mammalian oral anatomy
People with the surn ...
, and
ruminants
Ruminants (suborder Ruminantia) are hoofed herbivorous grazing or browsing mammals that are able to acquire nutrients from plant-based food by fermenting it in a specialized stomach prior to digestion, principally through microbial actions. The ...
all lower the neck and lap in water with their powerful tongues.
[ Cats and canines lap up water with the tongue in a spoon-like shape.][Smith, p. 238.] Canines lap water by scooping it into their mouth with a tongue which has taken the shape of a ladle. However, with cats, only the tip of their tongue (which is smooth) touches the water, and then the cat quickly pulls its tongue back into its mouth which soon closes; this results in a column of liquid being pulled into the cat's mouth, which is then secured by its mouth closing. Ruminants and most other herbivores partially submerge the tip of the mouth in order to draw in water by means of a plunging action with the tongue held straight.[Smith, p. 237.] Cats drink at a significantly slower pace than ruminants, who face greater natural predation hazards.[
Many ]desert animals
A xerocole (), is a general term referring to any animal that is adapted to live in a desert. The main challenges xerocoles must overcome are lack of water and excessive heat. To conserve water they avoid evaporation and concentrate excretions (i. ...
do not drink even if water becomes available, but rely on eating succulent plants.[ In cold and frozen environments, some animals like ]hares
Hares and jackrabbits are mammals belonging to the genus ''Lepus''. They are herbivores, and live solitarily or in pairs. They nest in slight depressions called forms, and their young are able to fend for themselves shortly after birth. The gen ...
, tree squirrels
Tree squirrels are the members of the squirrel family (Sciuridae) commonly just referred to as "squirrels." They include more than 100 arboreal species native to all continents except Antarctica and Oceania.
They do not form a single natural, or ...
, and bighorn sheep
The bighorn sheep (''Ovis canadensis'') is a species of sheep native to North America. It is named for its large horns. A pair of horns might weigh up to ; the sheep typically weigh up to . Recent genetic testing indicates three distinct subspec ...
resort to consuming snow and icicles. In savannas
A savanna or savannah is a mixed woodland-grassland (i.e. grassy woodland) ecosystem characterised by the trees being sufficiently widely spaced so that the canopy does not close. The open canopy allows sufficient light to reach the ground to ...
, the drinking method of giraffes
The giraffe is a large African hoofed mammal belonging to the genus ''Giraffa''. It is the tallest living terrestrial animal and the largest ruminant on Earth. Traditionally, giraffes were thought to be one species, '' Giraffa camelopardal ...
has been a source of speculation for its apparent defiance of gravity; the most recent theory contemplates the animal's long neck functions like a plunger pump
A plunger pump is a type of positive displacement pump where the high-pressure seal is stationary and a smooth cylindrical plunger slides through the seal. This makes them different from piston pumps and allows them to be used at higher pressures. ...
. Uniquely, elephants draw water into their trunks and squirt it into their mouths.[
]
In birds
Most birds scoop or draw water into the buccal areas of their bills, raising and tilting their heads back to drink. An exception is the common pigeon which can suck in water directly by inhalation.[
]
In insects
Most insects obtain adequate water from their food: When dehydrated from a lack of moist food, however, many species will drink from standing water. Additionally, all terrestrial insects constantly absorb a certain amount of the air's humidity through their cuticles
A cuticle (), or cuticula, is any of a variety of tough but flexible, non-mineral outer coverings of an organism, or parts of an organism, that provide protection. Various types of "cuticle" are non- homologous, differing in their origin, structu ...
. Some desert insects, such as ''Onymacris unguicularis
''Onymacris unguicularis'', the head-stander beetle, is a species of fog basking beetle that is native to the Namib Desert
The Namib ( ; pt, Namibe) is a coastal desert in Southern Africa. The name is of Khoekhoegowab origin and means " ...
'', have evolved to drink substantially from nighttime fog.
In marine life
Amphibians and aquatic animal
An aquatic animal is any animal, whether invertebrate or vertebrate, that lives in water for most or all of its lifetime. Many insects such as mosquitoes, mayflies, dragonflies and caddisflies have aquatic larvae, with winged adults. Aquatic ani ...
s which live in freshwater do not need to drink: they absorb water steadily through the skin by osmosis
Osmosis (, ) is the spontaneous net movement or diffusion of solvent molecules through a selectively-permeable membrane from a region of high water potential (region of lower solute concentration) to a region of low water potential (region o ...
.[Curtis, p. 569.] Saltwater fish
Saltwater fish, also called marine fish or sea fish, are fish that live in seawater. Saltwater fish can swim and live alone or in a large group called a school.
Saltwater fish are very commonly kept in aquariums for entertainment. Many saltwater f ...
, however, drink through the mouth as they swim, and purge the excess salt through the gills.[ Saltwater fishes do drink plenty of water and excrete a small volume of concentrated urine.
]
Hydration and dehydration
Like nearly all other life forms, humans require water for tissue hydration
Tissue hydration is the process of absorbing and retaining water in biological tissues.
Plants
Land plants maintain adequate tissue hydration by means of an outer waterproof layer. In soft or green tissues, this is usually a waxy cuticle over th ...
. Lack of hydration causes thirst
Thirst is the craving for potable fluids, resulting in the basic instinct of animals to drink. It is an essential mechanism involved in fluid balance. It arises from a lack of fluids or an increase in the concentration of certain osmolites, suc ...
, a desire to drink which is regulated by the hypothalamus
The hypothalamus () is a part of the brain that contains a number of small nuclei with a variety of functions. One of the most important functions is to link the nervous system to the endocrine system via the pituitary gland. The hypothalamu ...
in response to subtle changes in the body's electrolyte levels and blood volume. A decline in total body water
In physiology, body water is the water content of an animal body that is contained in the tissues, the blood, the bones and elsewhere. The percentages of body water contained in various fluid compartments add up to total body water (TBW). This ...
is called dehydration
In physiology, dehydration is a lack of total body water, with an accompanying disruption of metabolic processes. It occurs when free water loss exceeds free water intake, usually due to exercise, disease, or high environmental temperature. Mil ...
and will eventually lead to death by hypernatremia
Hypernatremia, also spelled hypernatraemia, is a high concentration of sodium in the blood. Early symptoms may include a strong feeling of thirst, weakness, nausea, and loss of appetite. Severe symptoms include confusion, muscle twitching, and b ...
. Methods used in the management of dehydration
The management of dehydration typically involves the use of oral rehydration solution (ORS). Standard home solutions such as salted rice water, salted yogurt drinks, vegetable and chicken soups with salt can be given. Home solutions such as water ...
include assisted drinking or oral rehydration therapy
Oral rehydration therapy (ORT) is a type of fluid replacement used to prevent and treat dehydration, especially due to diarrhea. It involves drinking water with modest amounts of sugar and salts, specifically sodium and potassium. Oral rehydrat ...
.
An overconsumption of water can lead to water intoxication
Water intoxication, also known as water poisoning, hyperhydration, overhydration, or water toxemia, is a potentially fatal disturbance in brain functions that results when the normal balance of electrolytes in the body is pushed outside safe li ...
, which can dangerously dilute the concentration of salts in the body. Overhydration sometimes occurs among athletes and outdoor laborers, but it can also be a sign of disease or damage to the hypothalamus. A persistent desire to drink inordinate quantities of water is a psychological condition termed polydipsia
Polydipsia is excessive thirst or excess drinking.Porth, C. M. (1990). ''Pathophysiology: Concepts of altered health states''. Philadelphia: J.B. Lippincott Company. The word derives from the Greek () "very thirsty", which is derived from (, "mu ...
. It is often accompanied by polyuria
Polyuria () is excessive or an abnormally large production or passage of urine (greater than 2.5 L or 3 L over 24 hours in adults). Increased production and passage of urine may also be termed diuresis. Polyuria often appears in conjunction wit ...
and may itself be a symptom of diabetes mellitus
Diabetes, also known as diabetes mellitus, is a group of metabolic disorders characterized by a high blood sugar level ( hyperglycemia) over a prolonged period of time. Symptoms often include frequent urination, increased thirst and increased ...
or diabetes insipidus
Diabetes insipidus (DI), recently renamed to Arginine Vasopressin Deficiency (AVP-D) and Arginine Vasopressin Resistance (AVP-R), is a condition characterized by large amounts of dilute urine and increased thirst. The amount of urine produced ...
.[Provan, p. 129.]
Human water requirements
A daily intake of water is required for the normal physiological functioning of the human body. The USDA
The United States Department of Agriculture (USDA) is the federal executive department responsible for developing and executing federal laws related to farming, forestry, rural economic development, and food. It aims to meet the needs of com ...
recommends a daily intake of ''total water'': not necessarily by drinking but by consumption of water contained in other beverage
A drink or beverage is a liquid intended for human consumption. In addition to their basic function of satisfying thirst, drinks play important roles in human culture. Common types of drinks include plain drinking water, milk, juice, smoo ...
s and foods. The recommended intake is 3.7 liters (appx. 1 gallon) per day for an adult male, and 2.7 liters (appx. 0.75 gallon) for an adult female.
Other sources, however, claim that a high intake of fresh drinking water
Drinking water is water that is used in drink or food preparation; potable water is water that is safe to be used as drinking water. The amount of drinking water required to maintain good health varies, and depends on physical activity level, a ...
, separate and distinct from other sources of moisture, is necessary for good health – eight servings per day of eight fluid ounces (1.8 liters, or 0.5 gallon) is the amount recommended by many nutritionist A nutritionist is a person who advises others on matters of food and nutrition and their impacts on health. Some people specialize in particular areas, such as sports nutrition, public health, or animal nutrition, among other disciplines. In many ...
s, although there is no scientific evidence supporting this recommendation.
Evidence-based hydration experts say that the amount of drinking water needed depends on ambient temperature, activity level, body size, and sweat rate.[How much water do you actually need? Here's the science](_blank)
/ref> Research shows drinking when thirsty will maintain hydration to within about 2% of the needed level. Drinking beyond thirst might be beneficial for people who need to perform tasks that require intense concentration, and those with kidney disease, kidney stones
Kidney stone disease, also known as nephrolithiasis or urolithiasis, is a crystallopathy where a calculus (medicine), solid piece of material (kidney stone) develops in the urinary tract. Kidney stones typically form in the kidney and leave the ...
, urinary tract infection
A urinary tract infection (UTI) is an infection that affects part of the urinary tract. When it affects the lower urinary tract it is known as a bladder infection (cystitis) and when it affects the upper urinary tract it is known as a kidne ...
s, and people with a weak sense of thirst (which may include more older people).
Alcoholic beverages
The term “drinking” is often used metonymically
Metonymy () is a figure of speech in which a concept is referred to by the name of something closely associated with that thing or concept.
Etymology
The words ''metonymy'' and ''metonym'' come from grc, μετωνυμία, 'a change of name ...
for the consumption of alcoholic beverages. Most cultures throughout history have incorporated some number of the wide variety of "strong drinks" into their meals, celebrations, ceremonies, toasts and other occasions. Evidence of fermented drink
This is a list of fermented foods, which are foods produced or preserved by the action of microorganisms. In this context, fermentation typically refers to the fermentation of sugar to alcohol using yeast, but other fermentation processes involv ...
s in human culture goes back as early as the Neolithic
The Neolithic period, or New Stone Age, is an Old World archaeological period and the final division of the Stone Age. It saw the Neolithic Revolution, a wide-ranging set of developments that appear to have arisen independently in several p ...
Period, and the first pictorial evidence can be found in Egypt around 4,000 BC.
Alcohol consumption
An alcoholic beverage (also called an alcoholic drink, adult beverage, or a drink) is a drink that contains ethanol, a type of alcohol that acts as a drug and is produced by fermentation of grains, fruits, or other sources of sugar. The cons ...
has developed into a variety of well-established drinking culture
Drinking culture is the set of traditions and social behaviors that surround the consumption of alcoholic beverages as a recreational drug and social lubricant. Although alcoholic beverages and social attitudes toward drinking vary around the w ...
s around the world. Despite its popularity, alcohol consumption poses significant health risks. Alcohol abuse and the addiction of alcoholism
Alcoholism is, broadly, any drinking of alcohol that results in significant mental or physical health problems. Because there is disagreement on the definition of the word ''alcoholism'', it is not a recognized diagnostic entity. Predomi ...
are common maladies in developed countries worldwide. A high rate of consumption can also lead to cirrhosis
Cirrhosis, also known as liver cirrhosis or hepatic cirrhosis, and end-stage liver disease, is the impaired liver function caused by the formation of scar tissue known as fibrosis due to damage caused by liver disease. Damage causes tissue rep ...
, gastritis
Gastritis is inflammation of the lining of the stomach. It may occur as a short episode or may be of a long duration. There may be no symptoms but, when symptoms are present, the most common is upper abdominal pain (see dyspepsia). Other possi ...
, gout
Gout ( ) is a form of inflammatory arthritis characterized by recurrent attacks of a red, tender, hot and swollen joint, caused by deposition of monosodium urate monohydrate crystals. Pain typically comes on rapidly, reaching maximal intens ...
, pancreatitis
Pancreatitis is a condition characterized by inflammation of the pancreas. The pancreas is a large organ behind the stomach that produces digestive enzymes and a number of hormones. There are two main types: acute pancreatitis, and chronic pancr ...
, hypertension, various forms of cancer
Cancer is a group of diseases involving abnormal cell growth with the potential to invade or spread to other parts of the body. These contrast with benign tumors, which do not spread. Possible signs and symptoms include a lump, abnormal b ...
, and numerous other illnesses.[Fiebach, p. 387.]
See also
* Eating
Eating (also known as consuming) is the ingestion of food, typically to provide a heterotrophic organism with energy and to allow for growth. Animals and other heterotrophs must eat in order to survive — carnivores eat other animals, he ...
* Hydration (disambiguation) Hydration may refer to:
* Hydrate, a substance that contains water
* Hydration enthalpy, energy released through hydrating a substance
* Hydration reaction, a chemical addition reaction where a hydroxyl group and proton are added to a compound
* H ...
References
Bibliography
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External links
"Are You Drinking Enough?"
recommendations by the European Hydration Institute (Madrid)
{{Authority control
Body water
Drinking culture
Ethology
Physiology
Nutrition
Food and drink