- absorption
- passage of digested products from the intestinal lumen through mucosal cells and into the bloodstream or lacteals
- accessory digestive organ
- includes teeth, tongue, salivary glands, gallbladder, liver, and pancreas
- accessory duct
- (also, duct of Santorini) duct that runs from the pancreas into the duodenum
- acinus
- cluster of glandular epithelial cells in the pancreas that secretes pancreatic juice in the pancreas
- alimentary canal
- continuous muscular digestive tube that extends from the mouth to the anus
- aminopeptidase
- brush border enzyme that acts on proteins
- anal canal
- final segment of the large intestine
- anal column
- long fold of mucosa in the anal canal
- anal sinus
- recess between anal columns
- appendix
- (vermiform appendix) coiled tube attached to the cecum
- ascending colon
- first region of the colon
- bacterial flora
- bacteria in the large intestine
- bile
- alkaline solution produced by the liver and important for the emulsification of lipids
- bile canaliculus
- small duct between hepatocytes that collects bile
- bilirubin
- main bile pigment, which is responsible for the brown color of feces
- body
- mid-portion of the stomach
- bolus
- mass of chewed food
- brush border
- fuzzy appearance of the small intestinal mucosa created by microvilli
- cardia
- (also, cardiac region) part of the stomach surrounding the cardiac orifice (esophageal hiatus)
- cecum
- pouch forming the beginning of the large intestine
- cementum
- bone-like tissue covering the root of a tooth
- central vein
- vein that receives blood from hepatic sinusoids
- cephalic phase
- (also, reflex phase) initial phase of gastric secretion that occurs before food enters the stomach
- chemical digestion
- enzymatic breakdown of food
- chief cell
- gastric gland cell that secretes pepsinogen
- chylomicron
- large lipid-transport compound made up of triglycerides, phospholipids, cholesterol, and proteins
- chyme
- soupy liquid created when food is mixed with digestive juices
- circular fold
- (also, plica circulare) deep fold in the mucosa and submucosa of the small intestine
- colon
- part of the large intestine between the cecum and the rectum
- common bile duct
- structure formed by the union of the common hepatic duct and the gallbladder’s cystic duct
- common hepatic duct
- duct formed by the merger of the two hepatic ducts
- crown
- portion of tooth visible superior to the gum line
- cuspid
- (also, canine) pointed tooth used for tearing and shredding food
- cystic duct
- duct through which bile drains and enters the gallbladder
- deciduous tooth
- one of 20 “baby teeth”
- defecation
- elimination of undigested substances from the body in the form of feces
- deglutition
- three-stage process of swallowing
- dens
- tooth
- dentin
- bone-like tissue immediately deep to the enamel of the crown or cementum of the root of a tooth
- dentition
- set of teeth
- deoxyribonuclease
- pancreatic enzyme that digests DNA
- descending colon
- part of the colon between the transverse colon and the sigmoid colon
- dipeptidase
- brush border enzyme that acts on proteins
- duodenal gland
- (also, Brunner’s gland) mucous-secreting gland in the duodenal submucosa
- duodenum
- first part of the small intestine, which starts at the pyloric sphincter and ends at the jejunum
- enamel
- covering of the dentin of the crown of a tooth
- enteroendocrine cell
- gastric gland cell that releases hormones
- enterohepatic circulation
- recycling mechanism that conserves bile salts
- enteropeptidase
- intestinal brush-border enzyme that activates trypsinogen to trypsin
- epiploic appendage
- small sac of fat-filled visceral peritoneum attached to teniae coli
- esophagus
- muscular tube that runs from the pharynx to the stomach
- external anal sphincter
- voluntary skeletal muscle sphincter in the anal canal
- fauces
- opening between the oral cavity and the oropharynx
- feces
- semisolid waste product of digestion
- flatus
- gas in the intestine
- fundus
- dome-shaped region of the stomach above and to the left of the cardia
- G cell
- gastrin-secreting enteroendocrine cell
- gallbladder
- accessory digestive organ that stores and concentrates bile
- gastric emptying
- process by which mixing waves gradually cause the release of chyme into the duodenum
- gastric gland
- gland in the stomach mucosal epithelium that produces gastric juice
- gastric phase
- phase of gastric secretion that begins when food enters the stomach
- gastric pit
- narrow channel formed by the epithelial lining of the stomach mucosa
- gastrin
- peptide hormone that stimulates secretion of hydrochloric acid and gut motility
- gastrocolic reflex
- propulsive movement in the colon activated by the presence of food in the stomach
- gastroileal reflex
- long reflex that increases the strength of segmentation in the ileum
- gingiva
- gum
- haustral contraction
- slow segmentation in the large intestine
- haustrum
- small pouch in the colon created by tonic contractions of teniae coli
- hepatic artery
- artery that supplies oxygenated blood to the liver
- hepatic lobule
- hexagonal-shaped structure composed of hepatocytes that radiate outward from a central vein
- hepatic portal vein
- vein that supplies deoxygenated nutrient-rich blood to the liver
- hepatic sinusoid
- blood capillaries between rows of hepatocytes that receive blood from the hepatic portal vein and the branches of the hepatic artery
- hepatic vein
- vein that drains into the inferior vena cava
- hepatocytes
- major functional cells of the liver
- hepatopancreatic ampulla
- (also, ampulla of Vater) bulb-like point in the wall of the duodenum where the bile duct and main pancreatic duct unite
- hepatopancreatic sphincter
- (also, sphincter of Oddi) sphincter regulating the flow of bile and pancreatic juice into the duodenum
- hydrochloric acid (HCl)
- digestive acid secreted by parietal cells in the stomach
- ileocecal sphincter
- sphincter located where the small intestine joins with the large intestine
- ileum
- end of the small intestine between the jejunum and the large intestine
- incisor
- midline, chisel-shaped tooth used for cutting into food
- ingestion
- taking food into the GI tract through the mouth
- internal anal sphincter
- involuntary smooth muscle sphincter in the anal canal
- intestinal gland
- (also, crypt of Lieberkühn) gland in the small intestinal mucosa that secretes intestinal juice
- intestinal juice
- mixture of water and mucus that helps absorb nutrients from chyme
- intestinal phase
- phase of gastric secretion that begins when chyme enters the intestine
- intrinsic factor
- glycoprotein required for vitamin B12 absorption in the small intestine
- jejunum
- middle part of the small intestine between the duodenum and the ileum
- labial frenulum
- midline mucous membrane fold that attaches the inner surface of the lips to the gums
- labium
- lip
- lactase
- brush border enzyme that breaks down lactose into glucose and galactose
- lacteal
- lymphatic capillary in the villi
- large intestine
- terminal portion of the alimentary canal
- laryngopharynx
- part of the pharynx that functions in respiration and digestion
- left colic flexure
- (also, splenic flexure) point where the transverse colon curves below the inferior end of the spleen
- lingual frenulum
- mucous membrane fold that attaches the bottom of the tongue to the floor of the mouth
- lingual lipase
- digestive enzyme from glands in the tongue that acts on triglycerides
- lipoprotein lipase
- enzyme that breaks down triglycerides in chylomicrons into fatty acids and monoglycerides
- liver
- largest gland in the body whose main digestive function is the production of bile
- lower esophageal sphincter
- smooth muscle sphincter that regulates food movement from the esophagus to the stomach
- main pancreatic duct
- (also, duct of Wirsung) duct through which pancreatic juice drains from the pancreas
- major duodenal papilla
- point at which the hepatopancreatic ampulla opens into the duodenum
- maltase
- brush border enzyme that breaks down maltose and maltotriose into two and three molecules of glucose, respectively
- mass movement
- long, slow, peristaltic wave in the large intestine
- mastication
- chewing
- mechanical digestion
- chewing, mixing, and segmentation that prepares food for chemical digestion
- mesoappendix
- mesentery of the appendix
- micelle
- tiny lipid-transport compound composed of bile salts and phospholipids with a fatty acid and monoacylglyceride core
- microvillus
- small projection of the plasma membrane of the absorptive cells of the small intestinal mucosa
- migrating motility complex
- form of peristalsis in the small intestine
- mixing wave
- unique type of peristalsis that occurs in the stomach
- molar
- tooth used for crushing and grinding food
- motilin
- hormone that initiates migrating motility complexes
- motility
- movement of food through the GI tract
- mucosa
- innermost lining of the alimentary canal
- mucosal barrier
- protective barrier that prevents gastric juice from destroying the stomach itself
- mucous neck cell
- gastric gland cell that secretes a uniquely acidic mucus
- muscularis
- muscle (skeletal or smooth) layer of the alimentary canal wall
- myenteric plexus
- (plexus of Auerbach) major nerve supply to alimentary canal wall; controls motility
- nucleosidase
- brush border enzyme that digests nucleotides
- oral cavity
- (also, buccal cavity) mouth
- oral vestibule
- part of the mouth bounded externally by the cheeks and lips, and internally by the gums and teeth
- oropharynx
- part of the pharynx continuous with the oral cavity that functions in respiration and digestion
- palatoglossal arch
- muscular fold that extends from the lateral side of the soft palate to the base of the tongue
- palatopharyngeal arch
- muscular fold that extends from the lateral side of the soft palate to the side of the pharynx
- pancreas
- accessory digestive organ that secretes pancreatic juice
- pancreatic amylase
- enzyme secreted by the pancreas that completes the chemical digestion of carbohydrates in the small intestine
- pancreatic juice
- secretion of the pancreas containing digestive enzymes and bicarbonate
- pancreatic lipase
- enzyme secreted by the pancreas that participates in lipid digestion
- pancreatic nuclease
- enzyme secreted by the pancreas that participates in nucleic acid digestion
- parietal cell
- gastric gland cell that secretes hydrochloric acid and intrinsic factor
- parotid gland
- one of a pair of major salivary glands located inferior and anterior to the ears
- pectinate line
- horizontal line that runs like a ring, perpendicular to the inferior margins of the anal sinuses
- pepsinogen
- inactive form of pepsin
- peristalsis
- muscular contractions and relaxations that propel food through the GI tract
- permanent tooth
- one of 32 adult teeth
- pharynx
- throat
- phosphatase
- brush border enzyme that digests nucleotides
- porta hepatis
- “gateway to the liver” where the hepatic artery and hepatic portal vein enter the liver
- portal triad
- bile duct, hepatic artery branch, and hepatic portal vein branch
- premolar
- (also, bicuspid) transitional tooth used for mastication, crushing, and grinding food
- propulsion
- voluntary process of swallowing and the involuntary process of peristalsis that moves food through the digestive tract
- pulp cavity
- deepest portion of a tooth, containing nerve endings and blood vessels
- pyloric antrum
- wider, more superior part of the pylorus
- pyloric canal
- narrow, more inferior part of the pylorus
- pyloric sphincter
- sphincter that controls stomach emptying
- pylorus
- lower, funnel-shaped part of the stomach that is continuous with the duodenum
- rectal valve
- one of three transverse folds in the rectum where feces is separated from flatus
- rectum
- part of the large intestine between the sigmoid colon and anal canal
- reticuloendothelial cell
- (also, Kupffer cell) phagocyte in hepatic sinusoids that filters out material from venous blood from the alimentary canal
- retroperitoneal
- located posterior to the peritoneum
- ribonuclease
- pancreatic enzyme that digests RNA
- right colic flexure
- (also, hepatic flexure) point, at the inferior surface of the liver, where the ascending colon turns abruptly to the left
- root
- portion of a tooth embedded in the alveolar processes beneath the gum line
- ruga
- fold of alimentary canal mucosa and submucosa in the empty stomach and other organs
- saccharolytic fermentation
- anaerobic decomposition of carbohydrates
- saliva
- aqueous solution of proteins and ions secreted into the mouth by the salivary glands
- salivary amylase
- digestive enzyme in saliva that acts on starch
- salivary gland
- an exocrine gland that secretes a digestive fluid called saliva
- salivation
- secretion of saliva
- segmentation
- alternating contractions and relaxations of non-adjacent segments of the intestine that move food forward and backward, breaking it apart and mixing it with digestive juices
- serosa
- outermost layer of the alimentary canal wall present in regions within the abdominal cavity
- sigmoid colon
- end portion of the colon, which terminates at the rectum
- small intestine
- section of the alimentary canal where most digestion and absorption occurs
- soft palate
- posterior region of the bottom portion of the nasal cavity that consists of skeletal muscle
- stomach
- alimentary canal organ that contributes to chemical and mechanical digestion of food from the esophagus before releasing it, as chyme, to the small intestine
- sublingual gland
- one of a pair of major salivary glands located beneath the tongue
- submandibular gland
- one of a pair of major salivary glands located in the floor of the mouth
- submucosa
- layer of dense connective tissue in the alimentary canal wall that binds the overlying mucosa to the underlying muscularis
- submucosal plexus
- (plexus of Meissner) nerve supply that regulates activity of glands and smooth muscle
- sucrase
- brush border enzyme that breaks down sucrose into glucose and fructose
- tenia coli
- one of three smooth muscle bands that make up the longitudinal muscle layer of the muscularis in all of the large intestine except the terminal end
- tongue
- accessory digestive organ of the mouth, the bulk of which is composed of skeletal muscle
- transverse colon
- part of the colon between the ascending colon and the descending colon
- upper esophageal sphincter
- skeletal muscle sphincter that regulates food movement from the pharynx to the esophagus
- Valsalva’s maneuver
- voluntary contraction of the diaphragm and abdominal wall muscles and closing of the glottis, which increases intra-abdominal pressure and facilitates defecation
- villus
- projection of the mucosa of the small intestine
- voluntary phase
- initial phase of deglutition, in which the bolus moves from the mouth to the oropharynx
- α-dextrin
- breakdown product of starch
- α-dextrinase
- brush border enzyme that acts on α-dextrins