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