Term
| the digestive tract extends from ___ to ___ |
|
Definition
|
|
Term
| the digestive tract aka ___ |
|
Definition
|
|
Term
| accessory organs of the digestive tract |
|
Definition
| teeth, tongue, salivary glands, liver, gallbladder, pancreas |
|
|
Term
| the digestive tract functions to ____ |
|
Definition
|
|
Term
| How do molecules move in the digestive tract? |
|
Definition
|
|
Term
|
Definition
| increased surface area, increased gradient, thin membrane for diffusion |
|
|
Term
| ___ is movement of food through the GI tract |
|
Definition
|
|
Term
| ___ is taking food into the mouth |
|
Definition
|
|
Term
| ___ is chewing the food and mixing it with saliva |
|
Definition
|
|
Term
| ___ is swallowing the food |
|
Definition
|
|
Term
| ___ is the rhythmic wave-like contractions that move food through the GI tract |
|
Definition
|
|
Term
| the muscles through most of the GI tract are ___ |
|
Definition
|
|
Term
| ___ is found only at both ends of the GI tract |
|
Definition
|
|
Term
| skeletal muscle is found in the ___, and ___ |
|
Definition
| tongue,upperesophagus; external anal sphincter |
|
|
Term
|
Definition
| antral-pyloric pumping; segmentation; haustrations; mass movement |
|
|
Term
| ___ is periodic propulsion |
|
Definition
|
|
Term
| ___ are mixing movements; peristalsis |
|
Definition
|
|
Term
| ____ - stomach; retropulsion |
|
Definition
|
|
Term
|
Definition
|
|
Term
| secretions of the GI tract include ___ and ___ secretions |
|
Definition
|
|
Term
| exocrine secretions include ____ |
|
Definition
| HCl, H20, HC03-, bile, lipase, pepsin, amylase, trypsin, elastase, and histamine are secreted into the lumen of the GI tract. |
|
|
Term
| endocrine secretions involve the ___ and ___ to secrete ___ that help regulate the GI system. |
|
Definition
| stomach; small intestine; hormones |
|
|
Term
| ___ is the breakdown of food particles into subunits (is a ___) |
|
Definition
| digestion; chemical structure change |
|
|
Term
| ___ is the process of the passage of digestion (___) into the blood or lymph |
|
Definition
| absorption; chemical subunits |
|
|
Term
| ____: temporary storage and elimination of indigestible food |
|
Definition
|
|
Term
| GI tract is divided into the ___ and ____ |
|
Definition
| alimentary canal; accessory digestive organs |
|
|
Term
| the GI tract is ___ long and extends from ____ |
|
Definition
|
|
Term
|
Definition
| mucosa; submucosa; muscularis externa; and serosa |
|
|
Term
| the mucosa lines the ___ of the GI tract, and consists of ____ |
|
Definition
| lumen; simple columnar epithelium |
|
|
Term
| 3 subsections of the mucosa |
|
Definition
1) lamina propria
2) muscularis mucosae
3) goblet cells |
|
|
Term
| ___: thin layer of connective tissue containing lymph nodules |
|
Definition
|
|
Term
|
Definition
|
|
Term
| ____: thin layer of smooth muscle responsible for the folds. folds increase ____ |
|
Definition
| muscularis mucosae; surface area for absorption |
|
|
Term
| 4 layers of the GI tract from outer to inner |
|
Definition
1) serosa
2) muscularis externa
3) submucosa
4) mucosa |
|
|
Term
| ___: thick, highly vascular layer of connective tissue |
|
Definition
|
|
Term
| in the submucosa, absorbed molecules enter the ___ and ___ |
|
Definition
|
|
Term
| the submucosa contains ___ and ___ |
|
Definition
| submucosal glands; submucosal plexus (Meissner's plexus) |
|
|
Term
| the ___ provides autonomic nerve supply to the muscularis mucosae |
|
Definition
|
|
Term
| the ___ is responsible for segmental contractions and peristaltic movement through the GI tract |
|
Definition
|
|
Term
| 2 layers of the muscularis externa |
|
Definition
1) inner circular layer of smooth muscle
2) outer longitudinal layer of smooth muscle |
|
|
Term
| contractions of the layers of the muscularis externa ____; ______. |
|
Definition
| move food through the tract; pulverize and mix the food |
|
|
Term
| the ___ is located between the 2 muscle layers of the muscularis externa |
|
Definition
|
|
Term
| the myenteric plexus is a ____ |
|
Definition
| major nerve supply to the GI tract |
|
|
Term
| 3 cell structures in the muscularis externa: |
|
Definition
1. interstitial cells of Cajal
2. smooth muscle cells
3. autonomic axon |
|
|
Term
| ___: production of slow waves |
|
Definition
| interstitial cells of Cajal |
|
|
Term
| ___: Depolarization and opening of calcium channels, production of action potentials |
|
Definition
|
|
Term
| ___: neural input to ICC and smooth muscle |
|
Definition
|
|
Term
| the smooth muscle of the GI tract contains small cells interconnected by gap junctions or "nexus" called ____ |
|
Definition
|
|
Term
| the smooth muscle is ____; they generate their own cyclic depolarization - "slow wave" |
|
Definition
|
|
Term
| the depolarization caused by the smooth muscle can ____; so all the cells ____ |
|
Definition
| spread to adjacent cells through the gap junctions; depolarize and contract at the same time. |
|
|
Term
| ___ occur automatically in response to endogenous pacemaker activity |
|
Definition
| contractions of intestinal smooth muscles |
|
|
Term
| rhythm of contractions of intestinal smooth muscles is paced by ____ |
|
Definition
| graded depolarizations called slow waves |
|
|
Term
| slow waves produced by ___ |
|
Definition
| interstitial cells of Cajal |
|
|
Term
| slow waves spread from 1 smooth muscle cell to another through ___ |
|
Definition
|
|
Term
| the neural properties of visceral smooth muscle are ___; while the neural properties of striated muscle are ___ |
|
Definition
|
|
Term
| the neurotransmitters in visceral smooth muscle are ___ |
|
Definition
| both excitatory and inhibitory |
|
|
Term
| the neurotransmitters in striated muscle are ___ |
|
Definition
|
|
Term
| EC coupling dependent on ___ in visceral smooth muscle; and ___ in striated muscle |
|
Definition
| extracellular calcium; intracellular calcium |
|
|
Term
| visceral smooth muscle contains ___, while the striated muscle contains ___ |
|
Definition
|
|
Term
| where is smooth muscle located in the GI tract |
|
Definition
| muscularis mucosa; muscularis externa: circular and longitudinal |
|
|
Term
| smooth muscle is described as a ____ |
|
Definition
| syncytium "unitary muscle" |
|
|
Term
smooth muscle
electrical = ____
mechanical = ____
longitudinal layer = ___
circular layer = ____ |
|
Definition
gap junction - nexus
intermediate junction
interstitial cells of Cajal
most tightly coupled |
|
|
Term
| the structure of smooth muscle cells is ___; _____ |
|
Definition
| dense bodies; intracellular skeleton "cytoskeleton" |
|
|
Term
| the structure of smooth muscle cells contain ___ such as ___ and ___ |
|
Definition
| intermediate filaments; desmin; vimentin |
|
|
Term
| the ___ is a binding and protective outer layer |
|
Definition
|
|
Term
| the serosa consists of ___ covered with ____ |
|
Definition
| connective tissue; simple squamos epithelium |
|
|
Term
| extrinsic innervation of the GI tract can come from the ___ or the ___. |
|
Definition
| parasympathetic nervous system; sympathetic nervous system |
|
|
Term
| extrinsic innervation from the parasympathetic nervous system is due to the ___ and stimulates ___ |
|
Definition
| vagus and sacral spinal nerves; motility and GI secretions |
|
|
Term
| extrinsic innervation from the sympathetic nervous system is due to ____ and they ____ |
|
Definition
| postganglionic sympathetic fibers that pass through submucosal and myenteric plexuses and innervate GI tract; reduce peristalsis and secretory activity |
|
|
Term
| intrinsic regulation is regulated by 4 groups: |
|
Definition
| enteric nervous system; submucosal and myenteric plexuses; paracrine secretion; and hormonal secretion |
|
|
Term
| ___: secreted by the mucosa |
|
Definition
|
|
Term
| ___: molecules acting locally |
|
Definition
|
|
Term
| ____: local regulation of the GI tract |
|
Definition
| submucosal and myenteric plexuses |
|
|
Term
| intinsic regulation by the enteric nervous system is due to ____ |
|
Definition
| sites where parasympathetic fibers synapse with postganglionic neurons that innervate smooth muscle |
|
|
Term
| submucosal and myenteric plexuses in the enteric nervous system contain ___ neurons |
|
Definition
|
|
Term
| In the enteric nervous system; __ and ___ stimulate smooth muscle contraction (peristalsis) above the bolus |
|
Definition
|
|
Term
| in the enteric nervous system; __,___, and ___ stimulate smooth muscle (peristalsis) relaxation below the bolus |
|
Definition
|
|
Term
| Intrinsic and extrinsic regulation is controlled by ___ and ___ regulators |
|
Definition
|
|
Term
| 3 types of intestinal reflexes |
|
Definition
| gastroileal reflex; ileogastric reflex; intestino-intestinal reflex |
|
|
Term
| ___: distension of ileum, decreases gastric motility |
|
Definition
|
|
Term
| ___: overdistention in 1 segment, causes relaxation throughout the rest of the intestine |
|
Definition
| intestino-intestinal reflex |
|
|
Term
| ____: increases gastric activity causes increased motility of ileum and movement of chyme through ileocecal sphincter |
|
Definition
|
|
Term
| 2 endocrine and paracrine regulators of the gut |
|
Definition
|
|
Term
| ___ stimulates ___, which send impulses into the intrinsic nervous system; and activates motor neurons |
|
Definition
| serotonin; intrinsic afferents |
|
|
Term
| ____ stimulates contraction of the ______ |
|
Definition
| motilin; duodenum and stomach antrum |
|
|
Term
| ____ increases surface area and speeds digestion |
|
Definition
|
|
Term
| mastication mixes ___ with ___ which contains ____ |
|
Definition
| food; saliva; salivary amylase |
|
|
Term
| ___ is an enzyme that can catalyze the partial digestion of starch |
|
Definition
|
|
Term
|
Definition
| parotid, submandibular, sublingual, oral |
|
|
Term
| ___ contains enzymes, fluoride, water, and mucus |
|
Definition
|
|
Term
| ____ begins the digestion of starch |
|
Definition
|
|
Term
| ___ begins as a voluntary activity |
|
Definition
|
|
Term
| deglutition requires about ___ muscles, ___ cranial nerves, and ___ control |
|
Definition
|
|
Term
|
Definition
| oral, pharyngeal, and esophageal |
|
|
Term
| In the phases of deglutition; ___ is voluntary; ___ phases are involuntary and cannot be stopped |
|
Definition
| oral; pharyngeal and esophageal |
|
|
Term
| during deglutition; the ___ is raised, and the ___ covers the entrance to the respiratory tract |
|
Definition
|
|
Term
| from the mouth to the stomach; involuntary contractions and relaxations in the mouth, pharynx, larynx, and esophagus are coordinated by the swallowing center in the ____ |
|
Definition
|
|
Term
| the ___ connects the pharynx to the stomach |
|
Definition
|
|
Term
| in the esophagus; the upper third contains ___; middle third contains ____; the terminal portion contains ____. |
|
Definition
| skeletal muscle; a mixture of skeletal and smooth muscle; only smooth muscle |
|
|
Term
| in the esophagus; ___ is produced by a series of localized reflexes in response to distension of wall by the bolus |
|
Definition
|
|
Term
| wave like muscular contractions in the esophagus; ___ contracts behind yet relaxes in front of the bolus; followed by ____; after food passes into stomach the ____. |
|
Definition
| circular smooth muscle; longitudinal contraction (shortening) of smooth muscle; LES constricts |
|
|
Term
| ___ is controlled by the brainstem takes about 5 sec to go from pharynx to les |
|
Definition
|
|
Term
| primary peristalsis requires ___ |
|
Definition
|
|
Term
| if food does not move through esophagus, it initiates a local reflex called ____ |
|
Definition
|
|
Term
| ____ is slower, weaker, and not as well coordinated |
|
Definition
|
|
Term
| ___ is a burning sensation caused by the reflux of acid from the stomach into the esophagus |
|
Definition
|
|
Term
| the ___ is the most distensible part of the GI tract. |
|
Definition
|
|
Term
| the stomach empties into the ___ |
|
Definition
|
|
Term
| 4 functions of the stomach |
|
Definition
1. stores food
2. initiates digestion of proteins
3. kills bacteria
4. moves food (chyme) into intestine |
|
|
Term
| contractions of the stomach churn ___; mix ___; and push food into ___ |
|
Definition
| chyme; chyme with gastric secretions; the intestine |
|
|
Term
| in the stomach, the gastric mucosa has ____ |
|
Definition
| gastric pits in the folds |
|
|
Term
| in the stomach, ____ secrete mucus and alkaline fluid |
|
Definition
| columnar epithelial cells |
|
|
Term
| in the stomach, cells that line the folds deeper in the mucosa are ___ |
|
Definition
|
|
Term
| cell types in the gastric glands |
|
Definition
| goblet cells, parietal cells, chief cells, enterochromaffin-like cells (ECL), G cells, D cells |
|
|
Term
gastric glands secrete gastric juice
goblet cells:
parietal cells:
chief cells:
ECL cells:
G cells:
D cells: |
|
Definition
Goblet: mucus
Parietal: HCL and intrinsic factor
Chief: pepsinogen
ECL: histamine, serotonin, ghrelin
G: gastrin
D: somatostatin |
|
|
Term
| parietal cells secrete __ into gastric lumen by primary active transport through the ___ |
|
Definition
|
|
Term
| parietal cell's basolateral membrane takes in __ against its electrochemical gradient by coupling its transport with___ |
|
Definition
|
|
Term
| ____ is stimulated by changing conformation of parietal cells |
|
Definition
|
|
Term
| this change is stimulated by ___, ___, and ___ |
|
Definition
| Gastrin from G cells, Ach from PNS activation, and histamine from H2 receptors |
|
|
Term
| ___ because histamine potentiates Ach and Gastrin effects, blocking it has great effect |
|
Definition
|
|
Term
| ___ makes gastric juice very acidic |
|
Definition
|
|
Term
| HCL ___ so they become more digestible |
|
Definition
| denatures ingested proteins |
|
|
Term
| HCl activates ___ to ___, because it is more active at a pH of 2.0 |
|
Definition
|
|
Term
| digestion and absorption in the stomach; ___ are partially digested by pepsin (about 15-25%) |
|
Definition
|
|
Term
| digestion and absorption in the stomach; ___ digestion by salivary amylase is soon inactivated by ___ |
|
Definition
|
|
Term
| digestion and absorption in the stomach; ___ and ___ are the only commonly ingested substances absorbed - but important for rapidly absorbed drug formulations |
|
Definition
|
|
Term
| ____: Erosions of the mucosa of the stomach or duodenum extending into the muscularis externa, produced by action of HCl, refluxed bile salts, or ingested substances. |
|
Definition
|
|
Term
| ___ are normal; ___ are not |
|
Definition
|
|
Term
| ____: a natural protective mechanism for lining of stomach – aided by rapid turnover of cells, tight junctions between cells, secretion of alkaline mucus, prostaglandins, high blood flow (to dilute and “wash out”) |
|
Definition
|
|
Term
| _____: Erosions of the mucous membranes of the stomach or duodenum produced by action of HCl. |
|
Definition
|
|
Term
| ____: ulcers of the duodenum are produced by excessive gastric acid secretions |
|
Definition
| zollinger - ellison syndrome |
|
|
Term
| ____: bacterium that resides in the GI tract may produce ulcers |
|
Definition
|
|
Term
| ___: histamine released by tissue damage and inflammation stimulate further acid secretion |
|
Definition
|
|
Term
| protective mechanisms of the stomach; ___ and ___ are impermeable to HCl |
|
Definition
|
|
Term
| protective mechanisms of the stomach; ___ contains HCO3- |
|
Definition
|
|
Term
| protective mechanisms of the stomach; ___ between adjacent epithelial cells |
|
Definition
|
|
Term
| protective mechanisms of the stomach; rapid rate of ___ (___) |
|
Definition
| cell division (entire epithelium replaced in 3 days) |
|
|
Term
| protective mechanisms of the stomach; ____ inhibit gastric secretions |
|
Definition
|
|
Term
| in the small intestine; each villus is a ____ |
|
Definition
|
|
Term
| the small intestine villus is covered with ___ interspersed with ___ |
|
Definition
| columnar epithelial cells; goblet cells |
|
|
Term
| in the small intestine; epithelial cells at the tips of villi are exfoliated and replaced by _____. |
|
Definition
| mitosis in crypt of lieberkuhn |
|
|
Term
| in the small intestine; lamina propria contain ___, ___, and ___ |
|
Definition
| lymphocytes, capillaries, and central lacteal |
|
|
Term
| what are the two major types of contractions that occur in the small intestine? |
|
Definition
| peristalsis and segmentation |
|
|
Term
| ___ is the major contractile activity of the small intestine. |
|
Definition
|
|
Term
| Segmentation in the small intestine involves the contraction of ___; and mixes ___ |
|
Definition
| circular smooth muscle; chyme |
|
|
Term
| ___ in the small intestine is a slow movement |
|
Definition
|
|
Term
| during peristalsis in the small intestine; the pressure at ____ is greater than ___ |
|
Definition
| the pyloric end of the small intestine; at the distal end |
|
|
Term
| in the intestine; ___ contain brush border enzymes that are not secreted into the lumen |
|
Definition
|
|
Term
| in the intestine; brush border enzymes remain attached to the ___, with their active sites exposed to the ___. |
|
Definition
|
|
Term
| in the intestine; absorption requires both ___ and ___ |
|
Definition
| brush border enzymes; pancreatic enzymes |
|
|
Term
| most common defect in the intestine is the loss of ___, which leads to ____ |
|
Definition
| lactase; lactose intolerance |
|
|
Term
| absorption in the small intestine; ____: carbs, amino acids, lipids, iron, water, and Calcium |
|
Definition
|
|
Term
| absorption in the small intestine; ___: Bile salts, vitamin B12, electrolytes, and H20 |
|
Definition
|
|
Term
| in the large intestine, the outer surface bulges outward to form ___ |
|
Definition
|
|
Term
| the large intestine has little ___ |
|
Definition
|
|
Term
| the maximum water transport in the large intestine is about ___, but does work against ___ |
|
Definition
|
|
Term
| the large intestine absorbs: |
|
Definition
| water, electrolytes, several vitman B complexes, vitamin K, and folic acid |
|
|
Term
| in the large intestine, ___ produce significant amounts of folic acid and vitamin K |
|
Definition
|
|
Term
| in the large intestine; ___ ferment indigestible molecules to produce short-chain fatty acids |
|
Definition
|
|
Term
| the large intestine secretes ___, via active transport of ___ into intestinal lumen |
|
Definition
|
|
Term
| the membrane of the large intestine contains _____ |
|
Definition
|
|
Term
| Most of the fluid and electrolytes are absorbed by the ___; absorbs about 90% of remaining volume |
|
Definition
|
|
Term
| in the small intestine; absorption of H2O occurs __ as a result of the ___ created by ____. |
|
Definition
| passively; osmotic gradient; active transport |
|
|
Term
| in the small intestine; aldosterone stimulates NaCl and H2O absorption in the ___ |
|
Definition
|
|
Term
| ___: waste material passes to the rectum |
|
Definition
|
|
Term
| defecation occurs when ___ rises and ___ relaxes |
|
Definition
| rectal pressure; external anal sphincter |
|
|
Term
| the defecation reflex is due to the contraction of ___ muscles to increase rectal pressure and relax internal anal sphincter |
|
Definition
| longitudinal rectal muscles |
|
|
Term
| excretion is aided by contractions of ____; pushes feces from the rectum |
|
Definition
| abdominal and pelvic skeletal muscles |
|
|
Term
| ___: to much water reabsorbed leading to very hard feces and difficulty in defacation. |
|
Definition
|
|
Term
| constipation can lead to ___ |
|
Definition
|
|
Term
| ___: to little water absorped leading to fluid loss along with feces |
|
Definition
|
|
Term
| the ___ is the largest internal organ |
|
Definition
|
|
Term
| the ___ is the major functional cell in the liver. |
|
Definition
|
|
Term
| hepatocytes form ___ that are 1-2 cells thick |
|
Definition
|
|
Term
| hepatocytes are arranged into functional units called ___ |
|
Definition
|
|
Term
| in the liver, plates are separated by ___, and are more permeable than other ___ |
|
Definition
|
|
Term
| the liver contains phagocytic ___ |
|
Definition
|
|
Term
| the liver secretes bile into ___, which are drained by ___ |
|
Definition
| bile canaliculi, bile ducts |
|
|
Term
| the hepatic portal system has ___ in series |
|
Definition
|
|
Term
| products of ___ that are absorbed are delivered to the liver. |
|
Definition
|
|
Term
| ____ drain into the ___, which carries blood to the liver |
|
Definition
| intestinal capillaries; hepatic portal vein |
|
|
Term
| in the hepatic portal system; 3/4 of blood is ____; 1/4 of blood is ____; the ___ drains the liver |
|
Definition
| deoxygenated (from intestine); oxygenated (hepatic artery); hepatic vein |
|
|
Term
| ___ involves compounds that recirculate between the liver and intestine. |
|
Definition
| enterohepatic circulation |
|
|
Term
| many compounds involved in enterohepatic circulation can be absorbed through the ___ and enter ____. |
|
Definition
| small intestine; hepatic portal blood |
|
|
Term
| a variety of ___ are secreted by the liver into the bile ducts |
|
Definition
|
|
Term
| these compounds can be excreted into the ___ with ___. |
|
Definition
|
|
Term
| the liver produces and secretes ____ a day |
|
Definition
|
|
Term
| ___ is produced in spleen, bone marrow, and liver. |
|
Definition
|
|
Term
| free bilirubin combines with ___ and forms conjugated bilirubin, and is secreted into the bile |
|
Definition
|
|
Term
| bilirubin is converted by __ in intestine to ___ |
|
Definition
|
|
Term
| urobilinogen is absorbed by the ___ and enters the ____. |
|
Definition
|
|
Term
| urobillinogen is recycled or filtered by ___ and excreted in ___ |
|
Definition
|
|
Term
| bile acids are derivatives of ___ |
|
Definition
|
|
Term
| the bile pathway is a major pathway of ___ in the body |
|
Definition
|
|
Term
| principle bile acids are ___ and ___; which combine with glycine or taurine to form ___; and these aggregate as ___ |
|
Definition
| cholic acid; chenodeoxycholic acid; bile salts; micelles |
|
|
Term
| 95% of bile acids are absorbed by the ___ |
|
Definition
|
|
Term
| the ___ can remove hormones, drugs, and other biologically active molecules from the blood |
|
Definition
|
|
Term
| the inactivation of steroid hormones and drugs is by excretion into the ___, phagocytosis by ___, liver converts into ___, excreted in ___ |
|
Definition
| bile; kupffer cells; urea; urine |
|
|
Term
| the liver helps regulate ___ concentration by: ____=fed state; ___=fasted |
|
Definition
| blood glucose; glycogenesis and lipogenesis; glycogenolysis and gluconeogenesis. |
|
|
Term
| the liver contains enzymes required to convert free fatty acids into ____. |
|
Definition
|
|
Term
| ___ and most of the ____ are produced by the liver |
|
Definition
| albumin; plasma globulins (except immunoglobulins) |
|
|
Term
| ___ constitutes 70% of the total plasma protein |
|
Definition
|
|
Term
| ___ transport cholesterol and hormones |
|
Definition
|
|
Term
| ___ produce blood clotting factors 1,2,3,5,7,9, and 11 |
|
Definition
|
|
Term
| ___ contributes most to the colloid osmotic pressure in the blood. Edema!! |
|
Definition
|
|
Term
| ___: sac-like organ attached to the inferior surface of the liver. function:___ |
|
Definition
| gallbladder; stores and concentrates bile |
|
|
Term
| when gallbladder fills with bile, it ___ |
|
Definition
|
|
Term
| contraction of the muscularis layer of the gallbladder ____ into the ___ into ___ |
|
Definition
| ejects bile; common bile duct; duodenum |
|
|
Term
| when the small intestine is empty, ____ closes, and bile is forced up to the _____. |
|
Definition
| sphincter of oddi closes; cystic duct to the gallbladder. |
|
|
Term
| gallstones can be ___ or ___ |
|
Definition
| cholesterol stones or calcium stone |
|
|
Term
| cholesterol stones result from ___ |
|
Definition
| to much cholesterol in bile |
|
|
Term
| Complete digestion of food requires action of both ___ and ___ enzymes |
|
Definition
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Term
| most pancreatic enzymes are produced as ___ |
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Definition
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Term
| ____ triggers the activation of other pancreatic enzymes |
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Definition
| trypsin (when activated by enteropeptidase) |
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Term
| ____ inhibitor attaches to trypsin and inhibits its activity in the pancreas |
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Definition
| pancreatic trypsin inhibitor |
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Term
| ___ and ___ modify the activity of the GI system. |
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Definition
| neural; endocrine mechanisms |
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Term
| GI tract is both ____, and a ____ |
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Definition
| an endocrine gland; and a target for the action of hormones |
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Term
| gastric ___ and ___ are automatic |
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Definition
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Term
| waves of contraction are initiated spontaneously by ____ |
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Definition
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Term
| extrinsic control of gastric function (and all GI function) can be divided into 3 phases: |
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Definition
| cephalic phase, gastric phase, and intestinal phase |
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Term
| the cephalic phase is stimulated by the sight, smell, and taste of ___ |
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Definition
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Term
| in the cephalic phase, the activation of the vagus stimulates _____, and directly stimulates ___ and ___; and indirectly stimulates ____ |
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Definition
| chief cells to secrete pepsinogen; G cells to secrete gastrin; ECL cells to secrete histamine; parietal cells to secrete HCL |
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Term
| the cephalic phase continues into the ____ |
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Definition
| first 30 minutes of a meal |
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Term
| the ___ stimulates the gastric phase |
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Definition
| arrival of food in stomach |
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Term
| gastric secretion is stimulated by: |
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Definition
| distension, chemical nature of chyme (amino acids and short polypeptides), positive feedback effect, negative feedback |
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Term
| chemical nature of chyme: |
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Definition
stimulates G cells to secrete gastrin
stimulates chief cells to secrete pepsinogen, stimulates ECL cells to secrete histamine, and histamine stimulates the secretion of HCL |
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Term
| Positive feedback effect: as more ___ and ___ are secreted, more ___ and ___ are released |
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Definition
| HCl, pepsinogen, polypeptides, amino acids |
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Term
| Negative feedback: as ___ decreases, inhibits ____ |
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Definition
| pH, G cell release of gastrin |
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Term
| HCl secretion decreases if ____ |
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Definition
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Term
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Definition
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Term
| the ___ inhibits gastric activity when chyme enters the small intestine |
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Definition
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Term
| in the intestinal phase, the arrival of chyme increases ___ and ___ |
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Definition
| osmolality and distension |
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Term
| the arrival of chyme activates ____ and produces an ____ |
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Definition
| sensory neurons of vagus; inhibitory neural reflex |
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Term
| the inhibitory neural reflex; inhibits ___ and ___; and in the presence of fat the enterogasterone inhibits ____ and ___ |
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Definition
| gastric motility; secretion; gastric motility; secretion |
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Term
| in the intestinal phase, hormone secretion inhibits ____ |
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Definition
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Term
| secretion of pancreatic juice and bile stimulated by ___ and ___ |
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Definition
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Term
| secretin occurs in response to ____, stimulates production of ___ by ___, stimulates the liver to secrete ___ into the ____ |
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Definition
| duodenal pH < 4.5; HCO3-; pancreas; HCO3-; bile |
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Term
| CCK occurs in response to ____ of chyme in ___. Stimulates the production of ___. Ehances ___, and stimulates the contraction of ____ |
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Definition
| fat and protein content; the duodenum; pancreatic enzymes; secretin; sphincter of Oddi |
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Term
| ___ begins starch digestion |
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Definition
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Term
| ___ digests starch to oligosaccharides |
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Definition
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Term
| oligosaccharies are hydrolyzed by ____ |
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Definition
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Term
| Glucose is transported by ___ with __ into the capillaries |
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Definition
| secondary active transport; Na+ |
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Term
| digestion begins in the stomach when pepsin digests ___ to form ___ |
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Definition
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Term
| in the duodenum and jejunum, ___ cleave peptide bond in the interior of the polypeptide |
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Definition
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Term
| ___ cleave peptide bonds from the ends of the polypeptide |
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Definition
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Term
| free amino acids are absorbed by ____ |
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Definition
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Term
| dipeptides and tripeptides are transported by secondary active transport using a ____ to transport them into the ___ |
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Definition
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Term
| they are then ___ into free amino acids and then secreted into the ___ |
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Definition
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Term
| the arrival of lipids in the ___ serves as a stimulus for secretion of ___ which releases ___ |
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Definition
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Term
| ____: bile salts are secreted into duodenum to break up fat droplets |
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Definition
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Term
| ____ and ___ hydrolyze triglycerides to free fatty acids and monglycerides |
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Definition
| pancreatic lipase; colipase |
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Term
| ___ coats the emulsification droplets and anchors the ___ enzyme to burn them |
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Definition
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Term
| this forms ___ and moves to ____ |
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Definition
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Term
| free fatty acids, monoglycerides, and lysolecithin leave ___ and enter into ___ |
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Definition
| micelles; epithelial cells |
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Term
| inside ___, they resynthesize triglycerides and phospholipids within chell. combine with a protein to form ___ |
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Definition
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Term
| fats are then secreted into ___ |
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Definition
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Term
| in ___, lipoprotein lipase hydrolyzes triglycerides to free fatty acids and glycerol for use in cells |
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Definition
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Term
| remnants containing ___ are taken to the liver. there they form ___ which take triglycerides to cells. Once triglycerides are removes, ___ are converted to ____ |
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Definition
| cholesterol; VLDLs; VLDLs; LDLs |
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Term
| LDLs transport ___ to ___ and ___ |
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Definition
| cholesterol; organs; blood vessels |
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Term
| ___ transport excess cholesterol back to liver |
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Definition
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Term
| the absorption of fat soluble vitamins requires ____ |
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Definition
| the same mechanisms as fat absorption |
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Term
| the absorption of water soluble vitamins is mostly by ___, some use ___ |
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Definition
| diffusion; active transport mechanisms |
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