Nutrition Chapter 4

Diverticulitis

Condition characterized by inflamed diverticula

Mechanical digestion

Refers to physical treatments that food undergoes while it is in the intestinal tract

Chemical Digestion

Refers to the breakdown of large nutrient molecules in food into smaller components, primarily by the action of enzymes

Hemorrhoids

Swollen veins in the anal cavity

Pepsin

active enzyme that begins the enzymatic digestion of proteins

Digestive Tract or Gastrointestinal Tract (GI tract)

alimentary canal or gut

Digestive system

body system that breaks down food into its components , absorbs nutrients, and eliminates the waste

Mucous cells

cells that secrete mucus

Hormones

chemical messengers secreted by organs of the endocrine system that convey information to target cells

Gastroesophageal reflux disease (GERD)

chronic condition characterized by frequent heartburn that can damage the esophagus

Gasstric juice

collection of stomach secretions that includes mucus, hydrochloric acid, intrinsic factor, and digestive enzymes

Anosmia

complete inability to dtect odors

Diverticulosis

condition characterized by the presence of diverticula

Inflammatory bowel disease (IBD

condition that is characterized by chronic inflammation of the GI tract

Hypogeusia

diminished ability to taste substances

Dumping syndrome

disorder that occurs when chyme flows too rapidly into the small intestine

Salivary amylase

enzyme in saliva that begins trarch digestioin

Lysozyme

enzyme in saliva that can destroy some bacteria that are in food or the mouth

Lingual lipase

enzyme secreted into saliva that begins fat digestion

Cecum

first segment of the large intestine

Duodenum

first segment of the small intestine

Epiglottis

flap of tough tissue that prevents the food from entering the larynx and trachea

Bile

fluid that is produced in the liver and stored in the gallbladder until it is needed for that digestion and absorption

Prebiotics

food components that beneficial bacteria in the large intestine use for fuel

lumen

hollow pass through which food and fluids can pass (digestive tract)

Secretin

hormone secreted by the duodenum and first part of the jejunum that stimulates the pancreas and liver to release a bicarbonate-rich solution into the small intestine

Cholecystokinin (CCK)

hormone secreted by the mucosa of the small intestine that stimulates the gallbladder to contract and the pancreas to release pancreatic juice into the small intestine

Gastrin

hormone that stimulates stomach motility and gastric gland secretions

Constipation

infrequent bowel movements and feces that are difficult to eliminate

Mucosa

innermost layer of the digestive tract wall

Goblet cells

intestinal cells that secrete mucus

Rectum

last section of the large intestine

Ileum

last segment of the small intestine

Probiotics

live microorganisms that promote good health for their human hosts

Bolus

mass of food that has been chewed, moistened, mixed with saliva, and swallowed

Jejunum

middle segment of the small intestine

Oral cavity

mouth

Stomach

muscular sac that stores and mixes food

Esophagus

muscular tube that extends about 10 inches from the pharynx to the upper portion of the stomach

Heartburn

pain generally felt in the upper chest that results from the passage of acidic contents from the stomach into the esophagus

Micorflora

population of several kinds of bacteria

Digestion

process of breaking down large food molecules into nutrients that the body can use

Absorption

process of removing nutrients from the intestinal tract and enabling them to enter the circulatory or lymphatic system

Enzyme

protein that speeds up the rate of a chemical reaction without being altered in the process

Ileocecal sphincter

region of ileum that controls the rate of emptying undigested material into the large intestine

Lower esophageal sphincter (LES)

region of the lower part of the esophagus that controls flow of material into the upper part of the stomach; also known as the gastroesophageal sphincter

Pyloric sphincter

region of the stomach that regulates the flow of chyme into the small intestine

Upper esophageal sphincter (UES)

region of the upper part of the esophagus that opens to allow a mass of food to enter the esophagus

Segmentation

regular contractions of circular intestinal muscles followed by muscular relaxations that mix chyme within a short portion of the small intestine

Pharanx

section of the alimentary canal that connects the nasal cavity with the tope of the esophagus

chyme

semiliquid mass that forms when food mixes with gastric juice

Alkaline

solutions with pH values higher than 7

Acidic

solutions with pH values lower than 7

G cells

stomach cells that secrete gastrin

Parietal cells

stomach cells that secrete intrinsic factor and the components of hydrochloric acid into the lumen of the stomach

Chief cells

stomach cells that secrete some chemically inactive digestive enzymes

Salivary glands

structures that produce saliva and secret the fluid into the oral cavity

Intrinsic factor

substance necessary for absorbing vitamin B-12

Sphincters

thinckened regions of circular muscle that control the flow of contents at various points in the GI tract

Diverticula

tiny pouches that form in the wall of the colon

Ageusia

total loss of the ability to taste substances

Ulcerative colitis (UC)

type of IBD that causes ulcers to form in the mucosa of the colon and rectum

Crohns disease

type of IBD; the body's immune system cells attack normal intestinal cells, damaging parts of the intestines

Hepatic portal vein

vein that transports absorbed nutrients to the liver

Lacteal

vessel of the lymphatic system

Mucus

water slippery fluid secreted by special cells

Saliva

watery fluid that contains mucus and a few enzymes