HUN 2201 BASIC PRINCIPLES OF HUMAN NUTRITION

Digestive tract or gastrointistinal tract (GI tract)

Alimentary canal or gut

Ansomia

Complete inability to detect odors

Salivary amylase

Enzyme in saliva that begins starch digestion

Lingual lipase

Enzyme secreted into saliva that begins fat digestion

doudenum

First segment of the small intestine

epiglottis

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

Lumen

Hollow space through which food and fluids can pass (digestive tract)

Mucosa

Innermost layer of the digestive tract wall

Oral cavity

Mouth

Mechanical digestion

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

Pharynx

Section of the alimentary cana; that connects the nasal cavity with the top of the esophagus

Salivary glands

Structures that produce saliva and secrete the fluid into the oral cavity

Digestion

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

Absorbtion

The uptake and removal of nutrients from the digestive tract

Villi

Tiny, fingerlike projections of the small intestinal mucosa that are involved in digestion and nutrient absorbtion

Saliva

Watery fluid that contains mucus and a few enzymes

Mucus

Watery slippery fluid secreted by special cells

enterocytes

absorptive cells that form the outer later of a villus

gut microbiota

bacterial populations that reside in the human large intestine

digestive system

body system the breaks down food and absorbs nutrients

mucous cells

cells that secrete mucus

Hormones

chemical messengers that convey information to target cells

gastroesophageal reflux disease (GERD)

chronic condition characterized by frequent heartburn that can damage the esophagus

hemorrhoids

clusters of small veins in the anal canal

Gastric juice

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

diverticulitis

condition characterized by inflamed diverticula

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

Lysozyme

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

cecum

first segment of the large intestine

bile

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

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

Chloecystokinin (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

goblet cells

intestine cells that secrete mucus

gut microbiota transplantation (GMT)

introduction of fecal material from one person into another person's colon; "fecal transplant"

rectum

last section of the large intestine

ileum

last segment of the small intestine

probiotics

live microbes that promote good health for their human hosts; products that contain beneficial microbes

jejunum

middle segment of the small intestine

stomach

muscular sac that stores and mixes food

Esophagus

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

gastroesophageal reflux (GER)

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

Enzyme

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

Chemical digestion

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

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

Upper esophageal sphincter (UES)

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

pyloric sphincter

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

Segmentation

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

chyme

semiliquid mass that forms when food mixes with gastric juice

Diverticula

small pouches that form in the wall of the colon

external anal sphincter

sphincter that allows feces to be expelled form the anus and is under voluntary control

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

intrinsic factor

substance necessary for absorbing vitamin B-12

Prebiotics

substances in food that support the growth of probiotics

Sphincters

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

microvilli

tiny hairlike projections that form the brush border of an enterocyte

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

Crohn's 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

peristalsis

waves of muscular contractions that help move material through most of the digestive tract