Nutrition Flashcards
Chronic disease
Progresses slowly or with little change and lasts a long time.
Acute disease
Develops quickly, produces sharp symptoms, and runs a short course.
acute = sharp
Digestion
The process by which food is broken down into absorbable units (nutrients).
Digestion = take apart
Absorption
The uptake of nutrients by the cells of the small intestine for transport into either the blood or the lymph.
absorb = suck in
Mastication
Chewing
Gastrointestinal (GI) tract
The digestive tract. The principle organs are the stomach and the intestines.
gastro = stomach intestinalis = intestine
Digestive system
All the organs and glands associated with the ingestion and digestion of food.
The four basic taste sensations:
Sweet, sour, bitter, salty
sometimes savory/umami is included
Lumen
The space within a vessel, such as the intestine.
Pharynx
The passageway leading from the nose and mouth to the larynx and esophagus, respectively.
Epiglottis
Cartilage in the throat that guards the entrance to the trachea and prevents food from entering it when a person swallows. Closes off the airway so that choking doesn’t occur when swallowing.
epi = upon (over) glottis = back of tounge
Esophagus
The food pipe; the conduit from the mouth to the stomach.
Sphincter
A circular muscle surrounding, and able to close, a body opening. Found at specific points along the GI tract and regulate the flow of food particles.
Band/binder
Esophageal sphincter
A sphincter muscle at the upper or lower end of the esophagus. The lower esophageal sphincter is also called the cardiac sphincter.
Stomach
A muscular, elastic, saclike portion of the digestive tract that grinds and churns swallowed food, mixing it with acid and enzymes to form chyme.
Pyloric sphincter
The circular muscle that separates the stomach from the small intestine and regulates the flow of partially digested food into the small intestine; also called the pylorus or pyloric valve.
pylorus = gatekeeper
Small intestine
A 10ft length of small-diameter intestine that is the major site of digestion of food and absorption of nutrients. Its segments are the duodenum, jejunum, and ileum.
Gallbladder
The organ that stores and concentrates bile. When it receives the signal that fat is present in the duodenum, the gallbladder concentrates and squirts bile through the bile duct into the duodenum.
Pancreas
A gland that secretes digestive enzymes and juices into the duodenum. (The pancreas also secretes hormones into the blood that help to maintain glucose homeostasis.)
Duodenum
The top portion of the small intestine (about “12 fingers’ breadth” long in ancient terminology)/
duodecim = 12
Jejunurn
The first 2/5 of the small intestine beyond the duodenum.
Ileum
The last segment of the small intestine.
Ileocecal valve
The sphincter separating the small and large intestines.
Large intestine or colon
The lower portion intestine that completes the digestive process. Its segments are the ascending colon, the transverse colon, the descending colon, and the sigmoid colon.
sigmoid = shaped like the letter S (Sigma in Greek)
Appendix
A narrow blind sac extending from the beginning of the colon that stores lymph cells.
Rectum
The muscular terminal part of the intestine, extending from the sigmoid colon to the anus.
Bolus
A portion; with respect to food, the amount swallowed at one time.
bolos = lump
Motility
The ability of the GI tract muscles to move.
Chyme
The semisolid mass of partly digested food expelled by the stomach into the duodenum.
chymos = juice
Peristalsis
Wavelike muscular contradictions of the GI tract that push its contents along.
peri = around stellein = wrap
Segmentation
A periodic squeezing or partitioning of the intestine at intervals along its length by its circular muscles.
Reflux
A backward flow.
re = back flux = flow
Enzymes
Facilitate the making and breaking of bonds in chemical reactions. The enzyme itself is a catalyst that remains unchanged.
Hormones
Act as chemical messengers, sometimes regulating enzyme action.
-ase
A word ending denoting an enzyme. The word beginning often identifies the compounds the enzyme works on.
Carbohydrase
An enzyme that hydrolyzes carbohydrates.
Lipase
An enzyme the hydrolyzes lipids (fats).
Protease
An enzyme that hydrolyzes proteins.
Digestive enzymes
Proteins found in digestive juices that act on food substances, causing them to break down into simpler compounds.
The enzymes involved in digestion facilitate a chemical reaction known as hydrolysis.
Hydrolysis
A chemical reaction in which a major reactant is split into two products, with the addition of a hydrogen atom (H) to one and a hydroxyl group (OH) to the other (from water, H2O). (The noun is hydrolysis, the verb is hydrolyze.)
The addition of water to break a molecule into smaller pieces. Breaks a disaccharide in two, with H added to one and OH to the other. Commonly occurs during digestion.
hydro = water lysis = breaking
The breakdown of food into nutrients requires secretions from five different organs:
- The salivary glands
- The stomach
- The pancreas
- The liver (via the gallbladder)
- The small intestine
Catalyst
A compound that facilitates chemical reactions without itself being changed in the process.
pH
The unit of measure expressing a substance’s acidity or alkalinity.
Glands
Cells or groups of cells that secrete materials for special uses in the body.
Exocrine glands
Secrete their materials “out” (into the digestive tract or onto the surface of the skin).
exo = outside krine = to separate
Endocrine glands
Secrete their materials “in” (into the blood).
endo = inside krine = to separate
Salivary glands
Exocrine glands that secrete saliva into the mouth.
Saliva
The secretion of the salivary glands. Its principal enzyme begins carbohydrate digestion.
Gastric glands
Exocrine glands in the stomach wall that secrete gastric juice into the stomach.
gastro = stomach
Gastric juice
The digestive secretion of the gastric glands of the stomach.
Hydrochloric acid
A acid composed of hydrogen and chloride atoms (HCI) that is normally produced by the gastric glands.
Mucus
A slippery substance secreted by the cells of the GI lining (and other body linings) that protects the cells from exposure to digestive juices )and other destructive agents). The lining of the GI tract with its coat of mucus is a mucous membrane.
Liver
The organ that manufactures bile. It is the first to receive the nutrients absorbed from the GI tract and prepares them for use by the body. It is the body’s major metabolic organ. Detoxifies substances that might cause harm and prepares waste products for excretion.
Stores about 1/3 of the body’s glycogen and releases glucose into the bloodstream as needed.
Bile
An emulsifier that prepares fats and oils for digestion; an exocrine secretion made by the liver, stored in the gallbladder, and released into the small intestine when needed.
It brings fats into suspension in water so that the enzymes can break them down into their component parts.
Emulsifier
A substance with both water-soluble and fat-soluble portions that promotes the mixing of oils and fats in a watery solution.
Pancreatic juice
The exocrine secretion of the pancreas, containing enzymes for the digestion of carbohydrate, fat, and protein as well as bicarbonate, a neutralizing agent. The juice flows from the pancreas into the small intestine through the pancreatic duct. (The pancreas also has an endocrine function, the secretion of insulin and other hormones.)