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For the industrial process, see anaerobic digestion. Anaerobic digestion is a series of processes in which Microorganisms break down Biodegradable material in the absence of Oxygen.
For the treatment of precipitates in analytical chemistry, see precipitation (chemistry)#Digestion. Precipitation is the formation of a Solid in a Solution during a Chemical reaction.

Digestion is the breaking down of food in the body, into a form that can be absorbed and used or excreted. It is also the process by which the body breaks down food into smaller components that can be absorbed by the blood stream. Blood is a specialized Bodily fluid that delivers necessary substances to the body's cells such as nutrients and oxygen—and transports Waste products In mammals, preparation for digestion begins with the cephalic phase in which saliva is produced in the mouth and digestive enzymes are produced in the stomach. Mammals ( class Mammalia) are a class of Vertebrate Animals characterized by the presence of Sweat glands, including sweat glands The cephalic phase of Gastric secretion occurs even before food enters the Stomach, especially while it is being eaten For the band see Saliva (band; for the village in Azerbaijan see Səliva. The mouth, buccal cavity, or oral cavity is the first portion of the Alimentary canal that receives food and begins digestion by mechanically breaking up Digestion enzymes are Enzymes that break down Polymeric Macromolecules into their smaller building blocks In Human anatomy, the stomach is a J-shaped hollow muscular organ of the Gastrointestinal tract involved in the second phase of Digestion, following Mechanical and chemical digestion begin in the mouth where food is chewed, and mixed with saliva to break down starches. For the band see Saliva (band; for the village in Azerbaijan see Səliva. Starch, CAS # 9005-25-8 Chemical formula (C6H10O5n is a Polysaccharide The stomach continues to break food down mechanically and chemically through the churning of the stomach and mixing with enzymes. Absorption occurs in the stomach and gastrointestinal tract, and the process finishes with excretion. Absorption, in Chemistry, is a physical or chemical Phenomenon or a process in which Atoms Molecules, or Ions enter some Defecation is the final act of Digestion by which organisms eliminate solid semisolid or liquid Waste material ( Faeces) from the Digestive tract [1]

Contents

Overview

Digestion is usually divided into mechanical processing to reduce the size of food particles and chemical action to further reduce the size of particles and prepare them for absorption. In most vertebrates, digestion is a multi-stage process in the digestive system, following ingestion of the raw materials, most often other organisms. Vertebrates are members of the Subphylum Vertebrata, Chordates with backbones or spinal columns The grouping sometimes includes Ingestion 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 The process of ingestion usually involves some type of mechanical and chemical processing. Digestion is separated into four separate processes:

  1. Ingestion: placing food into the mouth
  2. Mechanical digestion & chemical digestion: mastication to tear and crush food, and churning of the stomach. Addition of chemicals (acid, bile, enzymes, and water) to break down complex molecules into simple structures
  3. Absorption: movement of nutrients from the digestive system to the circulatory and lymphatic capillaries through osmosis, active transport, and diffusion
  4. Egestion: Removal of undigested materials from the digestive tract through defecation

Underlying the process is muscle movement throughout the system, swallowing and peristalsis. In Computer science, ACID ( Atomicity Consistency Isolation Durability) is a set of properties that guarantee that Database transactions are Bile or gall is a bitter yellow or green Alkaline fluid secreted by Hepatocytes from the Liver of most Vertebrates In many species Enzymes are Biomolecules that catalyze ( ie increase the rates of Chemical reactions Almost all enzymes are Proteins Osmosis is the Diffusion of a solvent (frequently water through a semi-permeable membrane, from a solution of low solute concentration (high water potential Active transport is the mediated process of moving particles across Biological membrane against the concentration gradient Diffusion is the net movement of particles (typically molecules from an area of high concentration to an area of low concentration by uncoordinated random movement Defecation is the final act of Digestion by which organisms eliminate solid semisolid or liquid Waste material ( Faeces) from the Digestive tract Swallowing, known scientifically as deglutition is the process in the human or animal body that makes something pass from the Mouth, to the Pharynx, into In the Esophagus After food is chewed into a bolus it is swallowed to move it into the esophagus

Digestion starts in the mouth. In digestion the food we eat is basically broken down into energy that our cells can use. Every organism digests in a very different way and time for digestion could be between minutes or hours depending on the food consumed. Some animals like tigers and lions are mainly able to digest soft food or meat whiles other animals like coyotes may even digest bones. It may seem easy to digest but the entire process of digestion is very complicated. The mouth is the beginning of the digestion tract. Smell of food triggers salivary glands to produces saliva. At the first taste of the food, more saliva will be produced to help with the chewing process. After chewing the food into smaller particles, the food is swallowed down the esophagus into the stomach. The pharynx receives the food from the mouth; the esophagus branching off the pharynx receives the food. The tongue also helps in pushing food down through the pharynx. Peristalsis is a series of contractions that pushes the food through the esophagus to the stomach. The stomach is like a sac, with muscle lining, which doesn’t just hold the food but also grind them (Offei, 95). From the stomach after food is grinded, it moves to the small intestines. At this point in the digestion process the part of the food that cannot be digested are sent through other parts of the intestines to be eliminated. The small intestine is made of the duodenum, the jejunum and the ileum. Peristalsis is also active in this organ. The duodenum breaks the food further whiles the jejunum and ileum absorbs the food into the bloodstream. Also in the small intestines, nutrients in the food diffuse through the wall linings to the bloodstream. Whatever is left is moved to the large intestines or the colon. The colon is a 4 to 7 foot long muscular vessel and connects small intestines to rectum. The large intestines basically process waste before it is defecated to make it easy to come out. Once again, the waste passes through the colon by peristalsis, first in liquid form then the solid. It normally takes about 37 hours for food to get through the colon.

Human digestion process

Phases of Gastric Secretion

Oral cavity

Main article: Mouth (human)
Human Gastrointestinal tract
Human Gastrointestinal tract

In humans, digestion begins in the oral cavity where food is chewed. The mouth, buccal cavity, or oral cavity is the first portion of the Alimentary canal that receives food and begins digestion by mechanically breaking up Human beings, humans or man (Origin 1590–1600 L homō man OL hemō the earthly one (see Humus The mouth, buccal cavity, or oral cavity is the first portion of the Alimentary canal that receives food and begins digestion by mechanically breaking up Saliva is secreted in large amounts (1-1. For the band see Saliva (band; for the village in Azerbaijan see Səliva. 5 litre/day) by three pairs of exocrine salivary glands (parotid, submandibular, and sublingual) in the oral cavity, and is mixed with the chewed food by the tongue. There are two types of saliva. One is a thin, watery secretion, and its purpose is to wet the food. The other is a thick, mucous secretion, and it acts as a lubricant and causes food particles to stick together and form a bolus. The saliva serves to clean the oral cavity and moisten the food, and contains digestive enzymes such as salivary amylase, which aids in the chemical breakdown of polysaccharides such as starch into disaccharides such as maltose. Enzymes are Biomolecules that catalyze ( ie increase the rates of Chemical reactions Almost all enzymes are Proteins Amylase is an Enzyme that breaks Starch down into Sugar. Amylase is present in human Saliva, where it begins the chemical process Hydrolysis is a Chemical reaction during which one or more water molecules are split into hydrogen and hydroxide ions which may go on to participate in further reactions Polysaccharides are relatively complex Carbohydrates They are Polymers made up of many Monosaccharides joined together by Glycosidic bonds Starch, CAS # 9005-25-8 Chemical formula (C6H10O5n is a Polysaccharide A disaccharide is a Sugar (a Carbohydrate) composed of two Monosaccharides 'Disaccharide' is one of the four chemical groupings of carbohydrates ( Maltose, or malt sugar is a Disaccharide formed from two units of Glucose joined with an α(1→4 linkage It also contains mucin, a glycoprotein which helps soften the food into a bolus. Not to be confused with Peptidoglycan. Glycoproteins are proteins that contain Oligosaccharide chains ( Glycans) covalently attached

Swallowing transports the chewed food into the esophagus, passing through the oropharynx and hypopharynx. Swallowing, known scientifically as deglutition is the process in the human or animal body that makes something pass from the Mouth, to the Pharynx, into The esophagus or oesophagus (see American and British English spelling differences) sometimes known as the gullet, is an organ in The Oropharynx ( oral part of the Pharynx) reaches from the Soft palate to the level of the Hyoid bone. In human anatomy the hypopharynx (or laryngopharynx) is the bottom part of the Pharynx, and is the part of the Throat that connects to the Esophagus The mechanism for swallowing is coordinated by the swallowing center in the medulla oblongata and pons. The medulla oblongata is the lower portion of the Brainstem. It deals with autonomic functions such as breathing and blood pressure The pons (sometimes pons Varolii after Costanzo Varolio) is a structure located on the Brain stem. The reflex is initiated by touch receptors in the pharynx as the bolus of food is pushed to the back of the mouth.

Esophagus

Main article: Esophagus

The esophagus, a narrow, muscular tube about 30 centimeters (12 inches) long, starts at the pharynx, passes through the larynx and diaphragm, and ends at the cardiac orifice of the stomach. The esophagus or oesophagus (see American and British English spelling differences) sometimes known as the gullet, is an organ in The esophagus or oesophagus (see American and British English spelling differences) sometimes known as the gullet, is an organ in The larynx (plural larynges) colloquially known as the voicebox, is an organ in the Neck of Mammals involved in protection of the For other types of diaphragm see Diaphragm. In the Anatomy of Mammals the thoracic diaphragm is a sheet of Muscle The cardia (also known as Z-line or esophagogastric junction or gastroesophageal junction) is the anatomical term for the junction orifice of In Human anatomy, the stomach is a J-shaped hollow muscular organ of the Gastrointestinal tract involved in the second phase of Digestion, following The wall of the esophagus is made up of two layers of smooth muscles, which form a continuous layer from the esophagus to the rectum and contract slowly, over long periods of time. Smooth muscle is a type of non- Striated muscle, found within the Tunica media layer of large and small Arteries and Veins, the bladder The rectum (from the Latin rectum intestinum, meaning straight intestine) is the final straight portion of the Large intestine in some Mammals The inner layer of muscles is arranged circularly in a series of descending rings, while the outer layer is arranged longitudinally. At the top of the esophagus, is a flap of tissue called the epiglottis that closes during swallowing to prevent food from entering the trachea (windpipe). The epiglottis is a lid-like flap of Elastic cartilage tissue covered with a Mucous membrane, attached to the root of the Tongue. The traceartes, or windpipe, is a tube that has an inner diameter of about 20-25 mm and a length of about 10-16 cm in humans The chewed food is pushed down the esophagus to the stomach through peristaltic contraction of these muscles. In the Esophagus After food is chewed into a bolus it is swallowed to move it into the esophagus It takes only seconds for food to pass through the esophagus, and little digestion actually takes place.

Stomach

Main article: Stomach

The food enters the stomach after passing through the cardiac orifice. In Human anatomy, the stomach is a J-shaped hollow muscular organ of the Gastrointestinal tract involved in the second phase of Digestion, following In Human anatomy, the stomach is a J-shaped hollow muscular organ of the Gastrointestinal tract involved in the second phase of Digestion, following The cardia (also known as Z-line or esophagogastric junction or gastroesophageal junction) is the anatomical term for the junction orifice of In the stomach, food is further broken apart, and thoroughly mixed with a gastric acid and digestive enzymes that break down proteins. Gastric acid is one of the main Secretions of the Stomach, together with several Enzymes and Intrinsic factor. The acid itself does not break down food molecules, rather, the acid provides an optimum pH for the reaction of the enzyme pepsin. Pepsin is a digestive Protease ( released by the chief cells in the Stomach that functions to degrade food Proteins into The parietal cells of the stomach also secrete a glycoprotein called intrinsic factor which enables the absorption of vitamin B-12. Parietal cells (also called oxyntic cells) are the Stomach Epithelium cells that secrete Gastric acid and Intrinsic factor Not to be confused with Peptidoglycan. Glycoproteins are proteins that contain Oligosaccharide chains ( Glycans) covalently attached Intrinsic factor is a Glycoprotein produced by the Parietal cells of the Stomach. Cyanocobalamin is an especially common Vitamer of the B-12 vitamin family. Other small molecules such as alcohol are absorbed in the stomach as well by passing through the membrane of the stomach and entering the circulatory system directly. In Chemistry, an alcohol is any Organic compound in which a Hydroxyl group ( - O[[hydrogen H]]) is bound to a Carbon Digestion is the breaking down of chemicals in the body into a form that can be absorbed This is an article about the rock music band "Circulatory System"

Main article: Histology of stomach

The transverse section of the alimentary canal reveals four distinct and well developed layers called serosa, muscular coat, submucosa and mucosa. In Human anatomy, the stomach is a J-shaped hollow muscular organ of the Gastrointestinal tract involved in the second phase of Digestion, following Serosa: It is the outermost thin layer of single cells called mesothelial cells. In Anatomy, a serous membrane (or serosa) is a smooth membrane consisting of a thin layer of cells which excrete Serous fluid Muscular coat: It is very well developed for churning of food. The muscular coat ( muscular layer, muscular fibers, muscularis propria, muscularis externa) is a region of Muscle in many organs It has outer longitudinal, middle smooth and inner oblique muscles. Submucosa: It has connective tissue containing lymph vessels, blood vessels and nerves. In the Gastrointestinal tract, the submucosa is the layer of Loose connective tissue that supports the Mucosa, as well as joins the mucosa to the bulk Mucosa: It contains large folds filled with connective tissue. The mucous membranes (or mucosae; singular mucosa) are linings of mostly endodermal origin covered in Epithelium, which are involved in The gastric glands have a packing of lamina propria. Gastric glands may be simple or branched tubular secreting mucus, hydrochloric acid, pepsinogen and renin.

Small intestine

Main article: Small intestine

After being processed in the stomach, food is passed to the small intestine via the Pyloric sphincter. In Biology the small Intestine is the part of the Gastrointestinal tract (gut between the Stomach and the Large intestine, and comprises In Biology the small Intestine is the part of the Gastrointestinal tract (gut between the Stomach and the Large intestine, and comprises The pylorus (from Greek πυλωρος = "gate guard" is the region of the Stomach that connects to the Duodenum. The majority of digestion and absorption occur here as chyme enters the duodenum. Digestion is the breaking down of chemicals in the body into a form that can be absorbed Chyme is the semifluid mass of partly digested food expelled by the stomach into the duodenum In Anatomy of the Digestive system, the duodenum is a hollow jointed tube about 25-30 cm (10-12 in long connecting the Stomach to the Jejunum Here it is further mixed with three different liquids:

  1. bile, which emulsifies fats to allow absorption, neutralizes the chyme, and is used to excrete waste products such as bilin and bile acids (which has other uses as well). Bile or gall is a bitter yellow or green Alkaline fluid secreted by Hepatocytes from the Liver of most Vertebrates In many species An emulsion ( IPA: /ɪˈmʌlʃən/ is a mixture of two Immiscible (unblendable liquids Fats consist of a wide group of compounds that are generally soluble in organic solvents and largely insoluble in water Bilins or bilanes are biological pigments formed in many organisms as a metabolic product of certain Porphyrins Bilin (also called bilichrome was named as a Bile acids (also known as bile salts are Steroid Acids found predominantly in the Bile of Mammals. It is not an enzyme, however. The bile juice is stored in a small organ called the gall bladder. The gallbladder (or cholecyst sometimes gall bladder is a small organ whose function in the body is to store Bile and aid in the digestive process
  2. pancreatic juice made by the pancreas. Pancreatic juice is a juice produced by the Pancreas. It contains a variety of Enzymes, including Trypsinogen, Chymotrypsinogen, Elastase The pancreas is a Gland organ in the digestive and Endocrine system of Vertebrates.
  3. intestinal enzymes of the alkaline mucosal membranes. The enzymes include: maltase, lactase and sucrase, to process sugars; trypsin and chymotrypsin are also added in the small intestine

Most nutrient absorption takes place in the small intestine. Maltase ( (acid maltase alpha-14-glucosidase is an Enzyme produced by the cells lining the Small intestine that breaks down the Disaccharide Maltose Lactase (LCT a part of the β-galactosidase family of Enzymes is a Glycoside hydrolase involved in the Hydrolysis Sucrase is the name given to a number of enzymes that catalyse the Hydrolysis of Sucrose to Fructose and Glucose. Sugar is a class of edible Crystalline substances mainly Sucrose, Lactose, and Fructose. Trypsin ( is a Serine protease found in the Digestive system, where it breaks down Proteins Trypsin predominantly cleaves peptide chains at the carboxyl Chymotrypsin (bovine γ chymotrypsin,) is a digestive enzyme that can perform Proteolysis. As the acid level changes in the small intestines, more enzymes are activated to split apart the molecular structure of the various nutrients so they may be absorbed into the circulatory or lymphatic systems. pH is the measure of the acidity or alkalinity of a Solution. Nutrients pass through the small intestine's wall, which contains small, finger-like structures called villi, each of which is covered with even smaller hair-like structures called microvilli. Villus ( Latin: "shaggy hair" plural villi) can refer to Intestinal villus. Microvilli (singular microvillus) are microscopic cellular membrane protrusions that increase the surface area of cells and are involved in a wide variety of functions including The blood, which has absorbed nutrients, is carried away from the small intestine via the hepatic portal vein and goes to the liver for filtering, removal of toxins, and nutrient processing. Blood is a specialized Bodily fluid that delivers necessary substances to the body's cells such as nutrients and oxygen—and transports Waste products The hepatic portal vein (often portal vein for short is a Portal vein in the human body that drains blood from the Digestive system and its associated The liver is a vital organ in the human body and is present in Vertebrates and some other animals

The small intestine and remainder of the digestive tract undergoes peristalsis to transport food from the stomach to the rectum and allow food to be mixed with the digestive juices and absorbed. In the Esophagus After food is chewed into a bolus it is swallowed to move it into the esophagus The circular muscles and longitudinal muscles are antagonistic muscles, with one contracting as the other relaxes. When the circular muscles contract, the lumen becomes narrower and longer and the food is squeezed and pushed forward. A lumen (Lat lūmen, an opening or light (pl lumina is the inside space or lining of a tubular structure such as an artery or intestine When the longitudinal muscles contract, the circular muscles relax and the gut dilates to become wider and shorter to allow food to enter. In the stomach there is another phase that is called Mucus which promotes easy movement of food by wetting the food. It also nullifies the effect of HCL on the stomach by wetting the walls of the stomach as HCL has the capacity to digest the stomach.

Large intestine

Main article: Large intestine

After the food has been passed through the small intestine, the food enters the large intestine. The large intestine is the last part of the Digestive system: the final stage of the Alimentary canal in Vertebrate Animals Its function is to The large intestine is the last part of the Digestive system: the final stage of the Alimentary canal in Vertebrate Animals Its function is to The large intestine is roughly 1. 5 meters long, with three parts: the cecum at the junction with the small intestine, the colon, and the rectum. The metre or meter is a unit of Length. It is the basic unit of Length in the Metric system and in the International The cecum or caecum (from the Latin caecus meaning Blind) is a pouch connected to the Ascending colon of the Large In Biology the small Intestine is the part of the Gastrointestinal tract (gut between the Stomach and the Large intestine, and comprises The colon is a storage tube for solid wastes The main function of the colon appears to be extraction of Water and salts from Feces. The rectum (from the Latin rectum intestinum, meaning straight intestine) is the final straight portion of the Large intestine in some Mammals The colon itself has four parts: the ascending colon, the transverse colon, the descending colon, and the sigmoid colon. The ascending colon is smaller in caliber than the Cecum, with which it is continuous The transverse colon the longest and most movable part of the colon, passes with a downward convexity from the right Hypochondrium region across the abdomen opposite The descending colon of humans passes downward through the left Hypochondrium and lumbar regions along the lateral border of the left Kidney. The sigmoid colon ( pelvic colon; sigmoid flexure) forms a loop which averages about 40 cm The large intestine absorbs water from the bolus and stores feces until it can be egested. Feces, faeces, or fæces (see spelling differences) is a waste product from an animal's digestive tract expelled through the Anus Defecation is the final act of Digestion by which organisms eliminate solid semisolid or liquid Waste material ( Faeces) from the Digestive tract Food products that cannot go through the villi, such as cellulose (dietary fiber), are mixed with other waste products from the body and become hard and concentrated feces. Villus ( Latin: "shaggy hair" plural villi) can refer to Intestinal villus. Cellulose is an Organic compound with the formula, a Polysaccharide consisting of a linear chain of several hundred to over ten thousand β(1→4 Dietary fibers are the indigestible portion of plant foods that move food through the Digestive system, absorbing water and easing Defecation. Feces, faeces, or fæces (see spelling differences) is a waste product from an animal's digestive tract expelled through the Anus The feces is stored in the rectum for a certain period and then the stored feces is egested due to the contraction and relaxation through the anus. The anus is an opening at the opposite end of an Animal 's Digestive tract from the Mouth. The exit of this waste material is regulated by the anal sphincter. The anus is an opening at the opposite end of an Animal 's Digestive tract from the Mouth.

Carbohydrate digestion

Carbohydrates are formed in growing plants and are found in grains, leafy vegetables, and other edible plant foods. Carbohydrates (from ' Hydrates of Carbon ' or saccharides ( Greek σάκχαρον meaning " Sugar " are the most The molecular structure of these plants is complex, or a polysaccharide; poly is a prefix meaning many. Polysaccharides are relatively complex Carbohydrates They are Polymers made up of many Monosaccharides joined together by Glycosidic bonds Plants form carbohydrate chains during growth by trapping carbon from the atmosphere, initially carbon dioxide (CO2). Carbon dioxide ( Chemical formula:) is a Chemical compound composed of two Oxygen Atoms covalently bonded to a single Carbon is stored within the plant along with water (H2O) to form a complex starch containing a combination of carbon-hydrogen-oxygen in a fixed ratio of 1:2:1 respectively.

Plants with a high sugar content and table sugar represent a less complex structure and are called disaccharides, or two sugar molecules bonded. A disaccharide is a Sugar (a Carbohydrate) composed of two Monosaccharides 'Disaccharide' is one of the four chemical groupings of carbohydrates ( Once digestion of either of these forms of carbohydrates are complete, the result is a single sugar structure, a monosaccharide. Monosaccharides (from Greek monos: single sacchar: sugar are the most basic unit of Carbohydrates They consist of one sugar and These monosaccharides can be absorbed into the blood and used by individual cells to produce the energy compound adenosine triphosphate (ATP). Adenosine-5'-triphosphate ( ATP) is a multifunctional Nucleotide that is most important as a " molecular currency" of intracellular Energy

The digestive system starts the process of breaking down polysaccharides in the mouth through the introduction of amylase, a digestive enzyme in saliva. Amylase is an Enzyme that breaks Starch down into Sugar. Amylase is present in human Saliva, where it begins the chemical process For the band see Saliva (band; for the village in Azerbaijan see Səliva. The high acid content of the stomach inhibits the enzyme activity, so carbohydrate digestion is suspended in the stomach. Upon emptying into the small intestines, potential hydrogen (pH) changes dramatically from a strong acid to an alkaline content. In Chemistry, an alkali (from Arabic: Al-Qaly القلي القالي) is a basic, ionic salt of an Alkali metal The pancreas secretes bicarbonate to neutralize the acid from the stomach, and the mucus secreted in the tissue lining the intestines is alkaline which promotes digestive enzyme activity. In Inorganic chemistry, bicarbonate ( IUPAC -recommended nomenclature hydrogencarbonate) is an intermediate form in the Deprotonation Amylase is secreted by the pancreas into the small intestines and works with other enzymes to complete the breakdown of carbohydrate into a monosaccharide which is absorbed into the surrounding capillaries of the villi. Villus ( Latin: "shaggy hair" plural villi) can refer to Intestinal villus.

Nutrients in the blood are transported to the liver via the hepatic portal circuit, or loop, where final carbohydrate digestion is accomplished in the liver. The liver is a vital organ in the human body and is present in Vertebrates and some other animals The liver accomplishes carbohydrate digestion in response to the hormones insulin and glucagon. Insulin is a Hormone with intensive effects on both metabolism and several other body systems (eg vascular compliance Glucagon is an important Hormone involved in Carbohydrate metabolism. As blood glucose levels increase following digestion of a meal, the pancreas secretes insulin causing the liver to transform glucose to glycogen, which is stored in the liver, adipose tissue, and in muscle cells, preventing hyperglycemia. Glycogen is a Polysaccharide of Glucose (Glc which functions as the secondary short term energy storage in Animal cells "Adipose" redirects here For the Doctor Who monster see " Partners in Crime " Hyperglycemia, hyperglycaemia, or high blood sugar is a condition in which an excessive amount of Glucose circulates in the Blood plasma A few hours following a meal, blood glucose will drop due to muscle activity, and the pancreas will now secrete glucagon which causes glycogen to be converted into glucose to prevent hypoglycemia. Hypoglycemia or hypoglycaemia is the medical term for a pathologic state produced by a lower than normal level of Glucose ( sugar) in the blood

Note: In the discussion of digestion of carbohydrates; nouns ending in the suffix -ose usually indicate a sugar, such as lactose. Lactose (also referred to as milk sugar) is a Sugar which is found most notably in Milk. Nouns ending in the suffix -ase indicates the enzyme that will break down the sugar, such as lactase. Lactase (LCT a part of the β-galactosidase family of Enzymes is a Glycoside hydrolase involved in the Hydrolysis Enzymes usually begin with the substrate (substance) they are breaking down. For example: maltose, a disaccharide, is broken down by the enzyme maltase (by the process of hydrolysis), resulting in a two glucose molecules, a monosaccharide. A disaccharide is a Sugar (a Carbohydrate) composed of two Monosaccharides 'Disaccharide' is one of the four chemical groupings of carbohydrates ( Hydrolysis is a Chemical reaction during which one or more water molecules are split into hydrogen and hydroxide ions which may go on to participate in further reactions Glucose (Glc a Monosaccharide (or simple Sugar) also known as grape sugar, is an important Carbohydrate in Biology. Monosaccharides (from Greek monos: single sacchar: sugar are the most basic unit of Carbohydrates They consist of one sugar and

Fat digestion

The presence of fat in the small intestine produces hormones which stimulate the release of lipase from the pancreas and bile from the gallbladder. A lipase is a Water-soluble Enzyme that Catalyzes the Hydrolysis of Ester bonds in water–insoluble Lipid The gallbladder (or cholecyst sometimes gall bladder is a small organ whose function in the body is to store Bile and aid in the digestive process The lipase (activated by acid) breaks down the fat into monoglycerides and fatty acids. A monoglyceride, more correctly known as a monoacylglycerol, is a Glyceride consisting of one Fatty acid chain Covalently bonded to a Glycerol In Chemistry, especially Biochemistry, a fatty acid is a Carboxylic acid often with a long unbranched Aliphatic tail ( chain) which The bile emulsifies the fatty acids so they may be easily absorbed. An emulsion ( IPA: /ɪˈmʌlʃən/ is a mixture of two Immiscible (unblendable liquids

Short- and medium chain fatty acids are absorbed directly into the blood via intestine capillaries and travel through the portal vein just as other absorbed nutrients do. Short chain fatty acids are a sub-group of Fatty acids with Aliphatic tails of less than eight carbons In Chemistry, especially Biochemistry, a fatty acid is a Carboxylic acid often with a long unbranched Aliphatic tail ( chain) which However, long chain fatty acids are too large to be directly released into the tiny intestinal capillaries. In Chemistry, especially Biochemistry, a fatty acid is a Carboxylic acid often with a long unbranched Aliphatic tail ( chain) which Instead they are absorbed into the fatty walls of the intestine villi and reassembled again into triglycerides. (more properly known as, TAG or triacylglyceride) is Glyceride in which the Glycerol is Esterified with three Fatty acids It is the The triglycerides are coated with cholesterol and protein (protein coat) into a compound called a chylomicron. Cholesterol is a Lipid found in the Cell membranes and transported in the Blood plasma of all Animals It is an essential component of mammalian Chylomicrons are large lipoprotein particles that transport dietary lipids from the intestines to other locations in the body

Within the villi, the chylomicron enters a lymphatic capillary called a lacteal, which merges into larger lymphatic vessels. The lymphatic system in Vertebrates is a network of conduits that carry a clear fluid called Lymph. A lacteal is a lymphatic capillary that absorbs dietary fats in the villi of the Small intestine. It is transported via the lymphatic system and the thoracic duct up to a location near the heart (where the arteries and veins are larger). In human Anatomy, the thoracic duct (aka left lymphatic duct is an important part of the Lymphatic system &mdashit is the largest lymphatic vessel in the body The thoracic duct empties the chylomicrons into the bloodstream via the left subclavian vein. In Human anatomy, the subclavian veins are two large Veins one on either side of the body At this point the chylomicrons can transport the triglycerides to where they are needed.

Digestive hormones

There are at least four hormones that aid and regulate the digestive system:

Significance of pH in digestion

Digestion is a complex process which is controlled by several factors. pH plays a crucial role in a normally functioning digestive tract. pH is the measure of the acidity or alkalinity of a Solution. In the mouth, pharynx, and esophagus, pH is typically about 6. 8, very weakly acidic. Saliva controls pH in this region of the digestive tract. For the band see Saliva (band; for the village in Azerbaijan see Səliva. Salivary amylase is contained in saliva and starts the breakdown of carbohydrates into monosaccharides. Amylase is an Enzyme that breaks Starch down into Sugar. Amylase is present in human Saliva, where it begins the chemical process Monosaccharides (from Greek monos: single sacchar: sugar are the most basic unit of Carbohydrates They consist of one sugar and Most digestive enzymes are sensitive to pH and will not function in a low-pH environment like the stomach. Low pH (below 5) indicates a strong acid, while a high pH (above 8) indicates a strong base; the concentration of the acid or base, however, does also play a role. In Chemistry, a base is most commonly thought of as an aqueous substance that can accept Protons This refers to the Brønsted-Lowry theory of acids and

pH in the stomach is very acidic and inhibits the breakdown of carbohydrates while there. Carbohydrates (from ' Hydrates of Carbon ' or saccharides ( Greek σάκχαρον meaning " Sugar " are the most The strong acid content of the stomach provides two benefits, both serving to denature proteins for further digestion in the small intestines, as well as providing non-specific immunity, retarding or eliminating various pathogens. Denaturation is a process in which Proteins or Nucleic acids lose their structure (tertiary structure by application of some external stress or compound for Immune system|Adaptive immune systemThe innate immune system comprises the cells and mechanisms that defend the host from infection by other organisms in a non-specific manner A pathogen (from Greek πάθος pathos "suffering passion" and γἰγνομαι (γεν- gignomai (gen- "I give birth to" infectious

In the small intestines, the duodenum provides critical pH balancing to activate digestive enzymes. The liver secretes bile into the duodenum to neutralise the acidic conditions from the stomach. Also the pancreatic duct empties into the duodenum, adding bicarbonate to neutralize the acidic chyme, thus creating a neutral environment. The pancreatic duct, or duct of Wirsung, is a duct joining the Pancreas to the Common bile duct to supply pancreatic juices which aid in Digestion In Inorganic chemistry, bicarbonate ( IUPAC -recommended nomenclature hydrogencarbonate) is an intermediate form in the Deprotonation Chyme is the semifluid mass of partly digested food expelled by the stomach into the duodenum The mucosal tissue of the small intestines is alkaline, creating a pH of about 8. 5, thus enabling absorption in a mild alkaline in the environment.

Specialized organs in non-human animals

Organisms have evolved specialized organs to aid in the digestion of their food, modifying tongues, teeth, and other organs to assist in digestion. eVolution is the third Album by eLDee, it was due to be released in 2008 The tongue is the large bundle of Skeletal muscles on the floor of the Mouth that manipulates Food for chewing and swallowing (deglutition Certain insects may have a crop or enlarged esophagus, while birds and cockroaches have developed gizzards to assist in the digestion of tough materials. A crop (or croup) is a thin-walled expanded portion of the Alimentary tract used for the storage of food prior to Digestion that is found in many animals The esophagus or oesophagus (see American and British English spelling differences) sometimes known as the gullet, is an organ in The gizzard, also referred to as the ventriculus, gastric mill, and gigerium, is an organ in the digestive tract found in Birds Reptiles Herbivores have evolved cecums (or an abomasum in the case of ruminants) to break down cellulose in plants. Herbivory is a form of Predation in which an Organism, known as a herbivore, consumes principally Autotrophs ref name=Campbell>Campbell The cecum or caecum (from the Latin caecus meaning Blind) is a pouch connected to the Ascending colon of the Large The abomasum, also known as the maw, and the rennet-bag Physiologically a ruminant is a Mammal of the order Artiodactyla that digests plant-based food by initially softening it within the animal's first stomach known Cellulose is an Organic compound with the formula, a Polysaccharide consisting of a linear chain of several hundred to over ten thousand β(1→4

See also

References

Other references

  1. ^ Maton, Anthea; Jean Hopkins, Charles William McLaughlin, Susan Johnson, Maryanna Quon Warner, David LaHart, Jill D. Nutrition (also called nourishment or aliment) is the provision to cells and Organisms of the materials necessary (in the form of food to support Wright (1993). Human Biology and Health. Englewood Cliffs, New Jersey, USA: Prentice Hall. ISBN 0-13-981176-1.  

External links

Dictionary

digestion

-noun

  1. The process, in the gastrointestinal tract, by which food is converted into substances that can be utilized by the body.
  2. The result of this process.
  3. The ability to use this process.
  4. The processing of decay in organic matter assisted by microorganisms.
  5. The assimilation and understanding of ideas.
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