Abeka Biology Chapter 9 - Digestion

Colon cancer

cancer of the colon; of which diet is a significant factor

Gastric ulcers

an ulcer that occurs in the stomach

Duodenal ulcers

an ulcer that occurs where the duodenum is exposed to gastric juice as the stomach contents enter the small intestine

Digestive enzyme

any of the enzymes involved in digestion

Incisor

any of the four front cutting teeth on each jaw

Bicuspid

any of the four light-grinding teeth next to the cuspids (one pair on each side) on each jaw; also called premolar

Molar

any of the six heavy grinding teeth (three to a side) at the back of each jaw

Duodenum

first and shortest section of the small intestine

Jejunum

middle section of the small intestine

Enamel

mineral substance that covers the crown of a tooth

Cardiac sphincter

the area of thickened circular muscles where the esophagus joins the stomach

Clostridium botulinum

the bacterium that causes botulism

Pepsin

the most important gastric enzyme

Pharynx (throat)

throat

Dentin

bone-like layer that surrounds the pulp of a tooth

Cementum

bone-like structure that fastens the root of a tooth to the jaw

Salmonellosis

common food infection caused by bacteria of the genus Salmonella

Vermiform appendix

a small, finger-like structure in the cecum; the appendix that sometimes becomes infected and caused appendicitis

Papillae

taste-bud-containing projections on the tongue

Chyme

thick liquid formed in the stomach, consisting of digestive juices and partially digested food

Ileum

third and longest section of the small intestine

Villus

tiny, hair-like projection of the small intestine that absorbs digested food; plural villi

Eustachian tube

tube connecting the throat to the middle ear

Large intestine

tube-like organ that prepares undigested food for expulsion from the body

Intestinal glands

digestive glands in the small intestine that produce intestinal juice

Common bile duct

duct through which bile enters the small intestine from the gallbladder

Cuspid

either of two tearing teeth flanking the incisors on each jaw; also called canine

Dyspepsia (gastric indigestion)

gastric indigestion

Bile salts

group of substances in bile that emulsify fats

Capillary

microscopic blood vessel, linking an artery and vein, in which the exchanges between body cells and blood take place

Absorption

movement of water, digested food, and other dissolved substances from the small intestine into the bloodstream

Pyloric sphincter

muscle structure that opens and closes to control the movement of food from the stomach to the small intestine

Stomach

muscular digestive organ that thoroughly mixes food with digestive juices

Tongue

muscular organ that pushes food between the teeth, mixes it with mucus and saliva, and prepares chewed food for swallowing

Ulcer

open sore in the mucous membrane of the digestive tract

Cecum

pouch in the large intestine at the junction with the small intestine; similar structure in horses and rabbits where fermentation of cellulose occurs

Peristalsis

rhythmic wave of muscular contractions that moves food through the digestive tract

Gallbladder

sac-like organ that stores bile

Digestive gland

secreting body that produces digestive enzymes and digestive juices

Typhoid fever

serious illness acquired from food or water contaminated with the bacteria Salmonella Typhi

Saliva

sticky digestive juice produced by the salivary glands

Elimination

the last step of digestion, or the process of releasing waste

Tooth

structure in the mouth that cuts, breaks, or crushes food into smaller pieces

Catalyst

substance that speeds up a chemical change but is not consumed in the process

Pancreatic duct

the tube which carries the pancreatic juice from the pancreas into the small intestine

Peptic ulcer

ulcer caused by the digestive action of pepsin; includes both gastric and duodenal ulcers

Feces

undigested waste materials from the digestive process

Anus

valve that closes the rectum and serves as the digestive tract's second opening to the exterior

Microvilli

fine extensions of the cell membrane on epithelial cells of the small intestine

Esophagus

foot-long muscular tube connecting the pharynx to the stomach

Pulp

inner part of a tooth consisting mainly of blood vessels and nerves

Oral cavity (mouth)

inside of the mouth

Liver

large abdominal organ that functions as the body's chemical factory; produces bile; filters blood; and stores glycogen, vitamins, minerals, and reserve blood

Dysentery

painful infection of the colon that causes severe diarrhea and cramps accompanied by blood in the feces

Insulin

pancreatic hormone that signals the liver and muscles to remove glucose from the blood and store it as glycogen

Neck of the tooth

part of a tooth at the gum line

Botulism

severe food poisoning caused by the bacterium Clostridium botulinum

Mucus

slimy substance that lubricates the mucous membrane of the oral cavity

Bolus

small ball into which food is formed by the tongue

Epiglottis

small flap of cartilage in the pharynx that closes the top of the trachea during swallowing

Pancreatic amylase

the enzyme in pancreatic juice that digests carbohydrates

Pancreatic lipase

the enzyme in pancreatic juice that digests fats

Calorie

unit used to measure the energy content of food; equal to the amount of energy needed to raise the temperature of on kilogram (or one liter) of water by one degree Celsius

Heartburn

a burning sensation that occurs when the cardiac sphincter malfunctions, allowing gastric juice to enter the esophagus

Intestinal juice

a digestive juice produced by the intestinal glands of the small intestine which contains several enzymes

Digestive juices

a liquid made of a small amount of digestive enzymes and mostly water that helps digest food; secreted by the digestive glands

Bile

greenish substance secreted from the liver that helps in the digestion of fats

Gastric lipase

an enzyme in the stomach which aids in the digestion of certain fats

Gastric amylase

an enzyme in the stomach which aids in the digestion of starch

Lipase

an enzyme that breaks down the fats into individual fatty acids

Salivary gland

any of the six saliva-secreting digestive glands of the mouth

Sodium bicarbonate

chemical produced by the pancreas to neutralize stomach acid in chyme that enters the small intestine

Mastication

chewing

Hydrochloric acid

component of gastric juice that softens foods, kills bacteria, reacts with certain minerals to make them soluble, and provides the acid medium required for the enzyme pepsin

Appendicitis

condition caused by infection of the vermiform appendix

Constipation

condition that occurs when feces are so dry that defecation is difficult

Diarrhea

condition that occurs when insufficient water is removed from feces, resulting in soft and watery feces and frequent defecation

Salivary amylase

digestive enzyme produced by the salivary glands that begins the digestion of starch

Gastric juice

digestive juice formed by the secretions of the stomach

Pancreatic juice

digestive juice, produced by the pancreas, that contains digestive enzymes needed in the small intestine

Dental caries (cavities)

disease in which acid attacks the teeth, penetrating the enamel and dentin; also called tooth decay and cavities

Food poisoning

gastrointestinal disease caused by consumption of food contaminated with bacteria or bacterial toxins

Metabolism

general term for the chemical processes of life

Small intestine

long, tubular organ that is the primary organ of digestion and absorption

Colon

long, tubular section of the large intestine that absorbs water from undigested food

Taste bud

organ of taste, consisting of chemoreceptors for different types of taste

Pancreas

organ that produces pancreatic juice and contains the islets of Langerhans

Glucagon

pancreatic hormone that signals the liver to convert glycogen to glucose and release the glucose into the blood stream

Root of the tooth

part of a tooth that anchors it below the gum

Crown

part of a tooth that is exposed above the gums

Emulsification

process of breaking large droplets into smaller droplets

Digestion

process that changes food substances with large, complex chemical molecules into substances with smaller, less complex molecules

Rectum

section of the large intestine that stores feces until they are expelled from the body

Glycogen

stored glucose in the liver and muscles

Palate

structure that forms the roof of the mouth

Alimentary canal

tube leading from the mouth to the anus that forms the main portion of the digestive system

Urea

waste substance made from excess amino acids