Chapter 15 Biology

alimentary canal; aka gastrointestinal tract

tubular portion of the digestive tract that leads from the mouth to the anus

anus

outlet of the alimentary canal

ascending colon

portion of the large intestine that travels superiorly as it extends from the entry of the small intestine to the transverse colon

bicuspids

flat premolar teeth used for grinding food

bile

fat particles, temporarily stored in the gallbladder before being released into the small intestine

body region

central and widest portion of hte stomach

bolus

soft mass of chewed food formed by tongue

cardiac region

most superior portion of the stomach

cecum

blind pouch, such as the one below where the small intestine enters the large intestine

cephalic phase

in gastric secretion, the phase that is stimulated by central nervous system stimuli such as the taste, sight, or smell of food

cholecystokinin

hormone secreted by the small intestine that stimulates the release of pancreatic juice from the pancreas and bile from the gallbladder

chyme

semifluid food mass leaving the stomach

circular folds

permanent transverse folds of the luminal surface of the small intestine, involving the mucosa and the submucosa

colon

the part of the large intestine between the cecum and the rectum, made up of four portions

cuspids

canine teeth

descending colon

portion of the large intestine that travels inferiorly as it extends from the transverse colon to the sigmoid colon

duodenum

first portion of the small intestine into which ducts from the gallbladder and pancreas enter

enteric nervous system

nerve network that is built into the wall of the organs of the digestive tract

esophagus

tube that transports food from the mouth to the stomach

fundic region

pouch that is superior to the body of the stomach

gastric gland

gland within the stomach wall that secretes gastric juice

gastric inhibitory polypeptide

hormone produced by small intestine cells that inhibits stomach movement and acid secretion; also promotes release of insulin in response to glucose consumption; also referred to as glucose-dependent insulinotropic peptide

gastric juice

thin, watery digestive fluid secreted by the gastric glands in the stomach and containing hydrochloric acid and enzymes, such as pepsin

gastric phase

period of gastric juice secretion that is stimulated by gastrin, caused by the presence of food in the stomach and by stomach stretching

gastric pits

openings into gastric glands

gastrin

hormone produced when we eat that regulates acid secretion by the stomach and growth of the gastric mucosal layer - weakly stimulates stomach contraction

gastrointestinal tract

tube that travels from the mouth to the anus; aka alimentary canal

ghrelin

hormone manufactured primarily by stomach cells that causes growth hormone secretion, and stimulates fat storage and food intake

greater omentum

portion of the peritoneum that hangs down in front of the intestines like a large, double-layered apron; insulates abdominal cavity, rids the body of pathogens, and walls off portions of the alimentary walls that are infected

gut

long, continuous tube, composed of 4 layers, through which food moves during the process of digestion

hard palate

anterior portion of the roof of the mouth that contains several bones

haustra

the many pouches or small sacs into which the large intestine is divided

haustrum

singular of haustra

ileum

lower portion of the small intestine

incisors

chisel-shaped teeth for biting

intestinal phase

period of gastric juice secretion that is stimulated by the presence of food in the intestine and by intestinal stretching

intrinsic factor

protein produced by the normal gastrointestinal mucosa that facilitates absorption of vitamin B12

jejunum

middle portion of the small intestine

lacteal

lymph vessel in a billus of the wall of the small intestine

large intestine

portion of the digestive tract that extends from the small intestine to the anus

laryngopharynx

lower portion of the pharynx near the opening to the larynx

leptin

peptide hormone produced by fat cells; plays a role in body weight regulation by acting on the hypothalamus to suppress appetite and burn fat stored in adipose tissue

lesser omentum

portion of peritoneum that is a mesentery that runs between the stomach and the liver

lumen

space within a tubular structure such as a blood vessel or intestine

mesentery

fold of peritoneal membrane that attaches an abdominal organ to the abdominal wall

microvilli

cylindrical process that extends from some epithelial cell membranes and increases the membrane surface area

molar

three posterior pairs of teeth in each human jaw with a rounded or flattened surface adapted for grinding; found behind the incisors and canines

mouth

opening through which food enters

mucosa

membrane rich in mucous glands that lines body passages and cavities that communicate directly or indirectly with the exterior, such as the digestive, respiratory, and genitourinary tracts

muscularis

smooth muscular layer of the wall of contractile organs, such as the digestive organs and the bladder