Help
Options
Didn't know it?
click below
click below
Knew it?
click below
click below
Don't Know
Remaining cards (0)
Know
retry
shuffle
restart
0:00
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.
Normal Size Small Size show me how
Normal Size Small Size show me how
chapter 16
the digestive system--vocab
| Term | Definition |
|---|---|
| digestive system | the organ system that changes food into simpler organic and inorganic molecules that can be absorbed by the blood and lymph and used by cells; consists of the alimentary tube and accessory organs. |
| alimentary tube | the series of digestive organs that extends from the mouth to the anus; consists of the oral cavity, pharynx, esophagus, stomach, small intestine, and large intestine. |
| accessory organs | the digestive organs that contribute to the process of digestion, although digestion does not take place within them; consist of the teeth, tongue, salivary glands, liver, gallbladder, and pancreas. |
| mechanical digestion | the physical breaking up of food into smaller pieces. (ex: chewing) |
| chemical digestion | the breakdown of food accomplished by digestive enzymes; complex organic molecules are broken down to simpler organic molecules. |
| oral cavity | (or buccal cavity)the cavity in the skull bounded by the hard palate, cheeks, and tongue. |
| teeth | bony projections in the upper and lower jaws that function in chewing. |
| periodontal membrane | lines the socket and produces a bone-like cement that anchors the tooth. |
| enamel | outermost layer of the crown; made by cells called ameloblasts. |
| dentin | within the enamel; very similar to bone and is produced by cells called odontoblasts. also forms the roots of a tooth. |
| pulp cavity | innermost portion of a tooth; contains blood vessels and nerve endings of the trigeminal nerve(5th cranial). |
| gingiva | the gums; the tissue that covers the upper and lower jaws around the necks of the teeth. |
| tongue | made of skeletal muscle that is innervated by the hypoglossal nerves(12th cranial). |
| papillae | small projections on the upper surface of the tongue, many of which contain taste buds. |
| saliva | the secretion of the salivary glands; mostly water and containing the enzyme amylase. |
| salivary glands | the three pairs of exocrine glands that secrete saliva into the oral cavity; parotid, submandibular, and sublingual pairs. |
| parotid glands | the pair of salivary glands located just below and in front of the ears. |
| submandibular glands | the pair of salivary glands located at the posterior corners of the mandible. |
| sublingual glands | the pair of salivary glands located below the floor of the mouth. |
| esophagus | muscular tube that takes food from the pharynx to the stomach; no digestion takes place here. |
| lower esophageal sphincter | the circular smooth muscle at the lower end of the esophagus; prevents backup of stomach contents. |
| mucosa | lining, of the alimentary tube, made of epithelial tissue, areolar connective tissue, and two thin layers of smooth muscle. |
| submucosa | made of areolar connective tissue with many blood vessels and lymphatic vessels. |
| enteric nervous system | the nerve fibers and plexuses of the alimentary tube; regulates secretions and contractions; is able to function independently of the CNS. |
| Meissner's plexus | the nerve networks in the submucosa. they innervate the mucosa to regulate secretions. |
| peristalsis | one-way contractions, move the food toward the anus. |
| Auerbach's plexus | the enteric nerve plexus in the external muscle layer of the organs of the alimentary tube; regulates the contractions of the external muscle layer. |
| stomach | the sac-like organ of the alimentary tube between the esophagus and the small intestine; is a reservoir for food and secretes gastric juice to begin protein digestion. |
| pyloric sphincter | the circular smooth muscle at the junction of the stomach and the duodenum; prevents backup of intestinal contents into the stomach. |
| rugae | folds of the mucosa of organs such as the stomach, urinary bladder, and vagina; permit expansion of these organs. |
| gastric pits | the glands of the stomach and consist of several types of cells; their collective secretions are called gastric juice. |
| mucous cells | secrete mucus, coats the stomach lining and helps prevent erosion by the gastric juice. |
| chief cells | the cells of the gastric pits of the stomach that secrete pepsinogen, the inactive form of the digestive enzyme pepsin. |
| pepsin | the enzyme found in the gastric juice that begins protein digestion; secreted by chief cells. |
| parietal cells | the cells of the gastric pits of the stomach that secrete hydrochloric acid and the intrinsic factor. |
| proton pumps | an enzyme of the parietal cells of the stomach lining; secretes a hydrogen ion(in exchange for potassium), which unites with a chloride ion to form HCI in gastric juice. |
| small intestine | the organ of the alimentary tube between the stomach and the large intestine; secretes enzymes that complete the digestive process and absorbs the end products of digestion. |
| duodenum | the first 10 inches of the small intestine; the common bile duct enters it. |
| jejunum | the second portion of the small intestine, about 8 feet long. |
| ileum | the third and last portion of the small intestine, about 11 feet long. |
| liver | the organ in the upper right and center of the abdominal cavity; secretes bile for the emulsification of fats in digestion; has many other functions related to the metabolism of nutrients and the composition of blood. |
| liver lobule | the structural unit of the liver; a columnar hexagon of liver cells and sinusoids surrounding a central vein; includes the smallest bile ducts. |
| bile | the secretion of the liver that is stored in the gallbladder and passes to the duodenum; contains bile salts to emulsify fats; is the fluid in which bilirubin and excess cholesterol are excreted. |
| hepatic duct | the duct that takes bile out of the liver; joins the cystic duct of the gallbladder to form the common bile duct. |
| common bile duct | the duct formed by the union of the hepatic duct from the liver and the cystic duct from the gallbladder, and joined by the main pancreatic duct; carries bile and pancreatic juice to the duodenum. |
| bile salts | the active component of bile that emulsifies fats in the digestive process. |
| emulsify | to physically break up fats into smaller fat globules; the function of bile salts in bile. |
| secretin | a hormone secreted by the duodenum when food enters; stimulates secretion of bile by the liver and secretion of bicarbonate pancreatic juice. |
| gallbladder | an accessory organ of digestion; a sac located on the undersurface of the liver; stores and concentrates bile. |
| cystic duct | the duct that takes bile into and out of the gallbladder; unites with hepatic duct of the liver to form the common bile duct. |
| cholecystokinin | a hormone secreted by the duodenum when food enters; stimulates contraction of the gallbladder and secretion of enzyme pancreatic juice. |
| pancreas | located in the upper left abdominal quadrant between the curve of the duodenum and the spleen, and is about 6 inches in length. |
| amylase | a digestive enzyme that breaks down starch to maltose; secreted by the salivary glands and the pancreas. |
| lipase | a digestive enzyme that breaks down emulsified fats to fatty acids and glycerol; secreted by the pancreas. |
| trypsin | a digestive enzyme that breaks down proteins into polypeptides; secreted by the pancreas. |
| pancreatic duct | the duct that takes pancreatic juices to the common bile duct. |
| peptidases | digestive enzymes that break down polypeptides to amino acids; secreted by the small intestine. |
| sucrase | a digestive enzyme that breaks down sucrose to glucose and fructose; secreted by the small intestine. |
| maltase | a digestive enzyme that breaks down maltose to glucose; secreted by the small intestine. |
| lactase | a digestive enzyme that breaks down lactose to glucose and galactose; secreted by the small intestine. |
| plica circulares | the circular folds of the mucosa and submucosa of the small intestine; increase the surface area for absorption. |
| villi | folds of the mucosa of the small intestine that increase the surface area for absorption; each villus contains a capillary network and a lacteal. |
| microvilli | microscopic folds of the cell membrane, and are collectively called the brush border. |
| lacteal | a dead-end lymph capillary. |
| chylomicrons | a small fat globule formed by the small intestine from absorbed fatty acids and glycerol. |
| large intestine | the organ of the alimentary tube that extends from the small intestine to the anus; absorbs water, minerals, and vitamins and eliminates undigested materials. |
| colon | the large intestine. |
| cecum | the first part of the large intestine, the dead-end portion adjacent to the ileum. |
| ileocecal valve | a fold of the intestinal mucosa that surrounds the opening from ileum to cecum. |
| appendix | a small tubular organ that extends from the cecum; has no known function for people and is considered a vestigial organ. |
| vestigial organ | an organ that is reduced in size and function when compared with that of evolutionary ancestors; includes the appendix, ear muscles that move the auricle, and wisdom teeth. |
| appendicitis | inflammation of the appendix. |
| appendectomy | the surgical removal of the appendix. |
| taeniae coli | the longitudinal muscle layer of the colon; three bands of smooth muscle fibers that extend from the cecum to the sigmoid colon. |
| haustra | the pouches of the colon. |
| normal flora | in the colon, the bacteria that produce vitamins and inhibit the growth of the pathogens. |
| defecation reflex | the spinal cord reflex that eliminates feces from the colon. |
| internal anal sphincter | the circular smooth muscle that surrounds the anus; relaxes as part of the defecation reflex to permit defecation. |
| external anal sphincter | the circular skeletal muscle that surrounds the internal anal sphincter and provides voluntary control of defecation. |
| non-essential amino acids | the amino acids that can be synthesized by the liver. |
| transamination | the transfer of an amino(NH2) group from an amino acid to a carbon chain to form a non-essential amino acid; takes place in the liver. |
| essential amino acids | the amino acids that cannot be synthesized by the liver and must be obtained from proteins in the diet. |
| deamination | the removal of an amino(NH2) group from an amino acid; takes place in the liver when excess amino acids are used for energy production; the amino groups are converted to urea. |
| beta-oxidation | the process by which the long carbon chain of a fatty acid molecule is broken down into two-carbon acetyl groups to be used in cell respiration; takes place in the liver. |
| albumin | most abundant plasma protein, helps maintain blood volume by pulling tissue fluid into capillaries. |
| clotting factors | produced by the liver; includes prothrombin, fibrinogen, and Factor 8, which circulate in the blood until needed in the chemical clotting mechanism. |
| globulins | proteins that serve as carriers for other molecules, such as fats, in the blood. |
| kupffer cells | the macrophages of the liver; phagocytize pathogens and old red blood cells. |
| bolus | mass of swallowed food. |
| chyme | food changed into liquid-like material by mechanical digestion. |
Created by:
cramacher
Popular Medical sets