Food and Nutrition 4.5-4.9 Vocab

Duodenum

first segment of the small intestine (≈ 10 inches) (shortest), where bile is put in, pancreas is connected, breaks down food

Jejunum

middle segment of the small intestine (≈ 3-5.5 feet long) (middle length)

Ileum

last segment of the small intestine (≈ 5-9 feet long) (longest)

Ileocecal Sphincter

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

Bile

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

Gallbladder

stores bile

Pancreas

produces digestive enzymes, dumps in the enzymes, secretes bicarbonate ions (HCO3-), raises pH

Segmentation

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

Villi

tiny, fingerlike projections of the small intestinal mucosa that are involved in digestion and nutrient absorption, increase surface area

Enterocytes

absorptive cells that form the outer layer of a villus

Microvilli

tiny hairlike projections that form the brush border of an enterocyte

Simple Diffusion

high concentration to low concentration, small things, through membrane

Facilitated Diffusion

sugars, larger molecules, need bigger hole, protein channel, opening doesn't need any assistance to get through, diffuse through protein channel

Active Transport

uses protein channel, but goes from low concentration to high concentration, needs to be let in, goes against gradient

Osmosis

diffusion of water

Endocytosis

membrane will surround a large chunk of something and pull in, not common

Lacteal

vessel of the lymphatic system

Hepatic Portal Vein

vein that transports absorbed nutrients to the liver

Cecum

first segment of the large intestine

Rectum

last section of the large intestine, stores fecal matter

External Anal Sphincter

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

Goblet Cells

intestinal cells that secrete mucus

Microflora

population of several kinds of bacteria

Probiotics

live microorganisms that promote good health for their human hosts

Prebiotics

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

Secretin

hormone that stimulates the pancreas and liver to release a bicarbonate-rich solution into the small intestine (raises pH level of chyme)

Cholecystokinin

hormone that stimulates the gallbladder to contract and the pancreas to release pancreatic juice into the small intestine

Constipation

infrequent bowel movements and feces that are difficult to eliminate

Diverticula

tiny pouches that form in the wall of the colon

Diverticulosis

condition characterized by the presence of diverticula

Diverticulitis

disorder characterized by inflamed diverticula

Hemorrhoids

swollen veins in the anal canal

Heartburn

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

Gastroesophageal Reflux Disease (GERD)

chronic condition characterized by frequent heartburn that can damage the esophagus

Ulcer

sore on the lining of the stomach

Irritable Bowel Syndrome (IBS)

characterized by intestinal cramps and abnormal bowel function, particularly diarrhea, constipation, or alternating episodes of both

Inflammatory Bowel Disease (IBD)

condition that is characterized by chronic inflammation of the GI tract

Ulcerative Colitis

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

Chron's Disease

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