Nutrition Test 1

choking

A person chokes when a piece of food slips into the trachea and becomes lodged so securely that it cuts off breathing (see Figure H3-1). Without oxygen, the person may suffer brain damage or die.

bolus

After a mouthful of food has been chewed and swallowed

Taste

Fluids also help dissolve the food so that the tongue can taste it; only particles in solution can react with taste buds. When stimulated, the taste buds detect one, or a combination, of the four basic taste sensations: sweet, sour, bitter, and salty.

stomach Ph

The lower the pH, the higher the H + ion concentration and the stronger the acid. A pH above 7 is alkaline, or base (a solution in which OH-ions predominate). The stomach enzymes work most efficiently in the stomach's strong acid,

lacteals

The lymphatic vessels of the intestine that take up nutrients and pass them to the lymph circulation

gas

The most common offenders are foods rich in the carbohydrates—sugars, starches, and fibers. When partially digested carbohydrates reach the large intestine, bacteria digest them, giving off gas as a by-product.

small intestine:

a 10-foot 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.

reflux:

a backward flow.

sphincter

a circular muscle surrounding, and able to close, a body opening. Sphincters are found at specific points along the GI tract and regulate the flow of food particles.

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.)

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.

appendix:

a narrow blind sac extending from the beginning of the colon that stores lymph cells.

mucus

a slippery substance secreted by 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. (The noun is mucus; the adjective is mucous.)

esophageal sphincter:/ cardiac sphincter

a sphincter muscle at the upper or lower end of the esophagus. The lower esophageal sphincter is also called the cardiac sphincter.

(HIME-lick) maneuver (abdominal thrust maneuver):

a technique for dislodging an object from the trachea of a choking person (see Figure H3-2); named for the physician who developed it.

bicarbonate:

an alkaline compound with the formula HCO3 that is secreted from the pancreas as part of the pancreatic juice. (Bicarbonate is also produced in all cell fluids from the dissociation of carbonic acid to help maintain the body's acid-base balance.)

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.

villi

fingerlike projections from the folds of the small intestine; singular villus.

jejunum

first two-fifths of the small intestine beyond the duodenum

epiglottis

food pipe; the conduit from the mouth to the stomach.

GI tract anatomy

mouth, pharynx, esophagus, esophageal sphincter, diaphragm, stomach, pyloric sphincter, liver, gallbladder, bile duct, appendix, small intestine, ileocecal valve, pancreas, pancreatic duct, large intestine, rectum, anus

vomiting:

of the contents of the stomach up through the esophagus to the mouth.

anus

terminal outlet of the GI tract.

pyloric (pie-LORE-ic) 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 pylorus or pyloric valve.

esophagus

the food pipe; the conduit from the mouth to the stomach.

diarrhea:

the frequent passage of watery bowel movements.

ileum

the last segment of the small intestine.

intestine or colon

the lower portion of intestine that completes the digestive process. Its segments are the ascending colon, the transverse colon, the descending colon, and the sigmoid colon

homeostasis

the maintenance of constant internal conditions (such as blood chemistry, temperature, and blood pressure) by the body's control systems. A homeostatic system is constantly reacting to external forces to maintain limits set by the body's needs.

rectum:

the muscular terminal part of the intestine, extending from the sigmoid colon to the anus.

small intestine bacterial production

the neutral pH and slow peristalsis of the lower small intestine and the large intestine permit the growth of a diverse and abundant bacterial population.1 Bacteria in the intestines are sometimes referred to as flora.

gallbladder:

the organ that stores and concentrates bile. When it receives the signal that fat is present in the duodenum, the gallbladder contracts and squirts bile through the bile duct into the duodenum.

pharynx

the passageway leading from the nose and mouth to the larynx and esophagus, respectively.

lumen (LOO-men)

the space within a vessel, such :as the intestine.

ileocecal valve

the sphincter separating the small and large intestines

microvilli

tiny, hairlike projections on each cell of every villus that can trap nutrient particles and transport them into the cells;

duodenum (doo-oh-DEEN-um, doo-ODD-num):

top portion of the small intestine (about "12 fingers' breadth" long in ancient terminology).