Term
| ENS is made up of ___ and ___ plexi. |
|
Definition
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Term
| Myenteric plexus controls __ ___ and submucosal plexus receives sensory from chemoreceptors and mechanoreceptos in GI and controls _____, _____, _____. |
|
Definition
| GI motility; secretions, epithelial cell fxn, villus blood flow |
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Term
| PSNS regulation is by ___ and ___ nerves and is usally inhibitory/excitatory for GI motility. Both nn contain sensory afferents and motor efferents. |
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Definition
| vagus, pelvic; excitatory |
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Term
| SNS is usually inhibitory/exicitatory for GI motility and its projections synapse in the ___ and ___ plexuses and directly innervate ___ and some ___. |
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Definition
| inhibitory; myenteric, submocosal; blood vessels, smooth mm |
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Term
| Classic endocrine hormones (5) are ... |
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Definition
| gastrin, CCK, secretin, GIP, motilin |
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Term
| Paracrine and juxtacrne regulation affects neighboring cell(s) and they include (7)... |
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Definition
| somatostatin, serotonin, histamine, adenosine, prostaglandins, cytokines, guanylin |
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Term
| Neurocrine regulation is released by neurons at synapses and they include (6)... |
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Definition
| acetylcholine, VIP, GRP, NO, serotonin, epi |
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Term
| GI peptides: Gastrin-related are ___ and ___. Secretin-related are ___, ___, ___, ___. Others are ___, ___, ___, ___. |
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Definition
| gastrin, CCK; Secretin, GIP, VIP, Glucagon; Motilin, substance P, GRP, guanylin |
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Term
| Gastrin stimulates:___, ___, ___, ___, ___, ___. Triggered by ___ . |
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Definition
| HCL secretion by parietal cells, histamine secretion by ECL, emptying, mucosal growth, pepsinogen secretion, GI blood flow; low pH |
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Term
| CCK stimulates ___, ___, ___, ___, ___, ___, and inhibits ___. |
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Definition
| pancreatic bicarb secretion, pancreatic enzyme secretion, gallbladder contraction, pancreatic growth, pepsinogen secretion, GI blood flow; emptying |
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Term
| Secretin stimulates ___, ___, ___, ___, and inhibits ___, ___, ___. |
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Definition
| pancreatic bicarb secretion, biliary bicarb secretion, pancreatic growth, pepsinogen secretion; gastric acid secretion, emptying, mucosal growth |
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Term
| GIP stimulates ___, and inhibits ___. |
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Definition
| insulin release, gastric acid secretion |
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Term
| Motilin stimulates ___, ___. |
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Definition
| gastric motility, intestinal motility |
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|
Term
| Gastrin stimulates release of (3)... |
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Definition
|
|
Term
| Fat stimulates release of (4)... |
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Definition
| CCK, GIP Secretin, Motilin |
|
|
Term
| Carbs stimulate release of (1)... |
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Definition
|
|
Term
| Acid stiumulates release of (3) and inhibits release of (1)... |
|
Definition
| Secretin, CCK, Motilin; Gastrin |
|
|
Term
| Distention stimulates release of (1)... |
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Definition
|
|
Term
| Nerve stimulates release of (2)... |
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Definition
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|
Term
| Paracrine: Somatostatin is released in response to ___ and it inhibits ___ secretion. |
|
Definition
|
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Term
| paracrine: Guanylin stimulates ___ and ___ secretion and may be involved in __ and ___ homeostasis. |
|
Definition
| intestinal Cl, fluid; salt, water |
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Term
| Paracrine: Histamine increases ___ and ___ secretion. |
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Definition
| gastric acid, intestinal fluid |
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Term
| GI sm mm contrxn: excitatory agents that increase [Ca]i (4)... |
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Definition
| Acetylcholine, serotonin, opiod peptides, substance P? |
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|
Term
| GI sm mm contrxn: excitatory agents which increase release of acetylcholine and substance P (2)... |
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Definition
|
|
Term
| GI sm mm contrxn: excitatory agents which inhibit adenylyl cyclase: (1)... |
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Definition
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|
Term
| GI sm mm contrxn: inhibitory agents which increase cAMP or cGMP: (4)... |
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Definition
| VIP, Beta-adrenergics, glucagon, NO |
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|
Term
| GI sm mm contrxn: inhibitory agents which inhibit release of ACH and substance P: (3)... |
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Definition
| somatostatin, neuropeptide Y, alpha-adrenergics |
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Term
| Primary innervation of the esophagus is from the ___ nerve |
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Definition
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Term
| LES is innervated by both ___ and ___. And relaxation of LES is increased frequ of firing in ___ and decreased firing in ___. |
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Definition
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Term
| Receptive relaxation is mediated by a ___ reflex that is elicited by stretching of the stomach. ___ may be neurotransmitter for receptive relaxation. ___ makes the orad area more distensible. |
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Definition
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Term
| Gastric peristaltic contrxns after a meal last __-__ sec w/ __ contractions per min and this leads to ___. Contractions are initiated by the intrinsic electrical activity of sm mm cells at the pacmaker region. |
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Definition
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|
Term
| Regulation of gastric emptying: stimulates emptying: ____ by local enteric reflex and ___ by gastrin mediation |
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Definition
| stomach filling, peptides and aa in stomach |
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Term
| Regulation of gastric emptying: inihibts emptying: ___ by vagovagal reflex and secretin mediation; ___ by CCK; ___; ___ . |
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Definition
| acid in duodenum; fats in duodenum; hyperosmolarity; peptides and aa in duodenum |
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|
Term
| Slow waves or the Basic Electrical Rhythm (BER) originates in the |
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Definition
| ICC or Interstitial Cells of Cajal |
|
|
Term
| Frequ is lowest/highest in stomach and lowest/highest in duodenum |
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Definition
| lowest(3/min); highest(12/min) |
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Term
| Segmental contxns move material ___ while peristaltic contrxns move material ___. Motility is stimulated by ___, inihibited by ___ and has a strong ___ component. |
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Definition
| back and forth; down the small intestine; PSNS; SNS; myogenic |
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|
Term
| Ileocecal sphincter is controlled by ___ and __. |
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Definition
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|
Term
| Gastroileal reflex is mediated by ___. Food in stomach increases ileal peristalsis which relaxies ileocecal sphincter. |
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Definition
| extrinsic, autonomic nervous system |
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Term
| Large Intestine-most contrnxs are ___ and produce ___. Peristaltic activity is called ___. |
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Definition
| segmental, haustra; mass movement |
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|
Term
| Gastrocolic reflex-food in stomach increases frequ of mass mvmts...has a ___ reflex and ___ component as well. |
|
Definition
| vagovagal; hormonal (CCK) |
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Term
| Megacolon/Hirschsprung's Disease is congenital absence of ___ ___ in the distal colon which causes a strongly contracted and ___ distal colon. |
|
Definition
| intramural ganglion; nonpropulsive |
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Term
| Vomiting center is in ___ and it receives inputs from chemical trigger zone, touch receptors in throat, and mechano/chemo-receptors in stomach and duodenum and it also communicates w/ the ___ center. |
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Definition
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Term
| Digestive enzymes: ___ fxns on starch and ___ degrades triglycerides. |
|
Definition
| alpha-amylase; lingual lipase |
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Term
| Secretory rate for saliva can be __ ml/gram/min |
|
Definition
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Term
| Saliva is always ___ to plasma |
|
Definition
|
|
Term
| Gastric secretion is composed of ___ and ___ from parietal cells, ___ from chief cells and ___ from surface epithelial cells. |
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Definition
| HCl, intrinsic factor; pepsinogen; mucins |
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Term
| Salivary glands produce a fluid that is ___, high in __ and __; low in __ and __. |
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Definition
| high volume; K+, HCO3-; Na+, Cl- |
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Term
| Acinar cells secrete the ___ enzymes, ___, and a fluid that is similar to plasma in electrolyte composition and osmolarity |
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Definition
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Term
| Duct epithelial cells reabsorb __ and __; secrete __ and __; are perm/imperm to water. |
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Definition
| Na, Cl; K, HCO3; impermeable |
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Term
| Major regulator of salivation is ___ ___. |
|
Definition
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|
Term
| Pyloric gland mucosa- contains G cells which produce GI hormone ___ and it also contains ___ cells important for the gastric mucosal barrier. |
|
Definition
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|
Term
| Stimulation of parietal cell acid secretion is accompanied by increase in lumenal mb w/ its __ ATPase and __ channel that catalyze H+ and Cl- secretion. The ___ ATPase enzyme is irreversibly inhibited by ___ (___) and this drug is being used to block gas |
|
Definition
| H/K; Cl-; H/K; omeprazole (Prilosec) |
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|
Term
| Stimulators of gastric acid secretion are: ___ from PSNS and enteric nn, ___ from gastric mast cells, and ___ from antral G cells |
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Definition
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|
Term
| ___ occurs when the response to simultaneous administration of two stimulants is greater than the sum of responses to either agent alone. |
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Definition
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|
Term
| ___ potentiates the stimulating effects of gastrin and ACh thus ___ is used in treating gastric acid hypersecretion. |
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Definition
|
|
Term
| ___ blocks ACh secretion, which potentiates effects of histamine and gastrin |
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Definition
|
|
Term
| H+ and Na+ in gastric juice: as flow rate incr, H+ rises/falls and Na+ rises/falls |
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Definition
|
|
Term
| pepsinogen, activated to pepsin by ___, is stimulated strongest by ___ and ___. |
|
Definition
|
|
Term
| The only indispensable product of gastric secretion, ___, is secreted by ___ cells. pernicious anemia destroys |
|
Definition
| intrinsic factor; parietal |
|
|
Term
| ___ syndrome is caused by a pancreatic tumor that is hypersecretory for ___. Results in ___ ulcers. |
|
Definition
| Zollinger-Ellison; gastrin; duodenal |
|
|
Term
| Fxn of pancreas is secretion of ___ and ___. |
|
Definition
|
|
Term
| Enzymes are produced by ___ cells; Bicarb is produced by ___ cells. |
|
Definition
|
|
Term
| Major stimuli for enzyme secretion are ___ and ___ from vagal and enteric nn. |
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Definition
|
|
Term
| Major stimulus for bicarb secretion is ___. |
|
Definition
|
|
Term
| ___ and ___ potentiate the effect of secretin on ductal cells. (secretin does not potentiate the effect of these above on acinar cells. |
|
Definition
|
|
Term
| Like gastric secretions, pancreatic fluid is ___ to plasma at all rates of secretion. |
|
Definition
|
|
Term
| Due to action of Cl/HCO3 exchanger on lumenal mb of ductal cells, at high rates of secretion, ___ is high and ___ is low. |
|
Definition
|
|
Term
| Three phases of pancreatic secretion: Cephalic: ___ vol, ___ enzyme and stimuli mediated by vagal release of ___. |
|
Definition
|
|
Term
| Three phases of pancreatic secretion: Gastric: ___ vol, ___ enzyme and the ___ reflex is a response to gastric distention |
|
Definition
|
|
Term
| Three phases of pancreatic secretion: Intestinal phase: ___ vol, ___ enzyme that makes up ___ % of maximal response which is mediated by GI peptide hormones ___ and ___ released from EC cells in duodenum, and ___ released from vagus and enteric nn. |
|
Definition
| high; high; 70-80; secretin, CCK; ACh |
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|
Term
| Vagotomy can block up to __ % of total pancreatic response to a meal. |
|
Definition
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|
Term
| The intracellular 2nd messenger for secretin is ___ and the 2nd messenger for CCK and ACh is ___ released in response to increase IP3 production. |
|
Definition
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|
Term
| Fxn of bile is to promote the ___ and ___ of ingested lipids and to ___ such as bilirubin, cholesterol, drugs, heavy metals, toxins, etc. |
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Definition
| digestion, absorption; expel waste products and toxins |
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|
Term
| Organic compostion of bile includes: (5)... |
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Definition
| Bile acids, Bile salts, lecithin, cholesterol, bile pigments(bilirubin) |
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|
Term
| Bile has a ___ fluid like plasma and the ducts modify bile to produce a ___-rich fluid. |
|
Definition
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|
Term
| Bile acids/salts are ___, they have both hydrophilic and hydrophobic domains\. Together with ___ and ___, they emulsify lipids to enhance digestion by lipases and form ___ ___ which are important for fatty acid absorption in the intestine. |
|
Definition
| amphipaths; cholesterol, lecithin; mixed micelles |
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Term
| Bile is ___ absorbed in all small intestine and ___ reabsorbed in the ileum. |
|
Definition
| passively; actively(Na-dependent) |
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Term
| ___ stimulates gallbladder contraction and relaxation of sphincter of oddi. ___ also stimulates gallbladder contraction. ___ stimulates fluid secretion by bile duct cells. |
|
Definition
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|
Term
| Gallbladder stores and concentrates bile ___ fold through the active reabsorption of ___, ___, and ___. Water follows passively. |
|
Definition
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|
Term
| ___ results from bile that is supersaturated w/ cholesterol or has low phospholipid or bile acid content. |
|
Definition
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|
Term
| Pigment stones form when ___ ___ is deconjugated |
|
Definition
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|
Term
| Most ___ and all ___ occurs in the small intestine. |
|
Definition
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|
Term
| Carbs: only the monosaccharides ___, __, and ___ are abosrbed by the small intestine |
|
Definition
| glucose, galactose, and fructose |
|
|
Term
| Carbs: Gluc and Gal are transported across the enterocyte lumenal mb by a ___ (___). Fructose is transported into cells on the facilitative transporter ___. Gluc and Gal and Fruct exit the enterocyte across the serosal mb by the facilitative transporter |
|
Definition
| Na/Gluc Coporter (SGLT1); GLUT5; GLUT2 |
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|
Term
| Carbs: The major clinical disorder of carb absorption is ___ ___. |
|
Definition
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|
Term
| Proteins: Can be absorbed as ___, ___, or ___. |
|
Definition
| aa, dipeptides, tripeptides |
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|
Term
| Proteins: Pepsin is secreted as ___ by ___ cells and activated to pepsin by ___. It's active at pH ___ and inactive at pH > ___. And it is/is not required for protein digestion. |
|
Definition
| pepsinogen; chief; gastric acid; 1-3; 5; is not |
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|
Term
| Trypsinogen is activated to trypsin (which activates ___) by the brush border enzyme ___. |
|
Definition
| other proteases; enterokinase |
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|
Term
| Brush border peptidases are important for digestion of ___ and absorption of ___ and ___ is faster than free amino acids, which, are absorbed into ___ by a ___. |
|
Definition
| oligopeptides; dipeptides, tripeptides; enterocytes; Na-coupled transporter |
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Term
| There are several rare genetic diseases of protein absorption associated with defective transporters in enterocyte lumenal membranes. These include ___ (neutral aa), ___ (cystine), and ___ (proline). |
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Definition
| Hartnup's; Cystine; Prolinuria |
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Term
| Lipids: are abosorbed as ___, ___, and ___. Mixing action of stomach serves to increase surface area of lipid available to ___, the major digestive enzymes of lipids. |
|
Definition
| fatty acids, monoglycerides, and cholesterol; pancreatic lipases |
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|
Term
| Major pancreatic enzymes responsible for lipid digestion are: ___ -activity enhanced by colipase, ___, and ___. |
|
Definition
| pancreatic lipase, cholesterol ester hydrolase, pancreatic phospholipase A2 |
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Term
| ___ formation is critical for lipid absorption. Within enterocytes, ___ and ___ are resterified to ___ and ___. Together with cholesterol and apoproteins, they are assembled into ___ in the enterocyte. |
|
Definition
| Micelle; FA, Monoglycerides; Triglycerides, Phospholipids; chylomicrons |
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Term
| Chylomicrons are released from ___ and travel to the ___ for transport throughout the body. Failure of enterocytes to synthesize apoprotein B results in inability to export chylomicrons and causes ___. |
|
Definition
| enterocyte; lymph vessel; Beta-lipoproteinemia |
|
|
Term
| Malabsorption of lipids (___) can result from: reduction in ___ (pancreatitis, cystic fibrosis), hypersecretion of ___ (Zollinger-Ellison) leading to increased gastric acid production, reduced duodenal pH and inactivation of pancreatic lipase. Deficiency |
|
Definition
| steatorrhea; pancreatic enzymes; gastrin; bile acids; intestinal; apoprotein B |
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|
Term
| ___ vitamins are included in micelles and absorbed along with other lipids. |
|
Definition
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|
Term
| Water-soluble vitamins are absorbed by ___ . |
|
Definition
|
|
Term
| ___ is absorbed in the ileum and requires intrinsic factor (the only indispensible product of the stomach) |
|
Definition
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|
Term
| Ca absorption depends upon adequate levels of the active form of ___ |
|
Definition
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|
Term
| Iron is absorbed as ___ or ___. Inside the enterocytes Fe 2+ binds to a ___ that transports iron to the basolateral mb where it is transferred to ___ for transport in the blood. Transport of Fe2+ across the ___ mb is the rate-limiting step in absorption |
|
Definition
| heme, Fe2+; carrier protein; transferrin; serosal |
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|
Term
| Water and electrolytes can be absorbed by ___ (passing through cells) or ___ (passing around cells and across tight jxns) mechanisms. Small intestine is more/less permeable to water and electolytes and the fluid it absorbs is close to ___. Colon is more |
|
Definition
| transcellular; paracellular; more; isotonic; less; hypertonic |
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Term
| There are 4 mechanisms for Na absorption and all are expressed in the ___ of enterocytes and they include 1.___, 2.___, 3.___, and 4.___. #__ are important in the small intestine while #___ are important in the colon. |
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Definition
| lumenal mb; Na/nutrient(gluc, aa) transporters; Na/Cl transporters; Na/H transporters; Na channels (expression stimulated by aldosterone); 1-3; 4 |
|
|
Term
| Cl absorption follows ___ absorption throughout the GI tract |
|
Definition
|
|
Term
| K is absorbed in the small intestines by ___ along the ___ pathway(across tight jxns). K secretion in the lumenal mb by channels is stimulated by ___ and in ___, which can lead to hypokalemia. |
|
Definition
| passive diffusion; paracellular; aldosterone; diarrhea |
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|
Term
| Efficient digestion and absorption depends on a balance between ___ and ___. |
|
Definition
|
|
Term
| ___ ,the primary ion secreted by the intestine, is secreted through ___ channels that are regulated by ___. In humans, this channel is the ___. Na follows ___ by passive diffusion along paracellular pathway. ___ follows NaCL secretion. |
|
Definition
| Cl; Cl; cAMP; sytic fibrosis Cl channel (CFTR); Cl; Water |
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|
Term
| Four major causes of diarrhea: ___ results from deranged activation of Cl secretion and it persists with ___. Examples include ___ and ___ infections. Also included are ___ syndrome, ___, and ___. |
|
Definition
| secretory diarrhea; fasting; E.Coli, Cholera; Zollinger-Ellison; VIP-Secreting Adenomas (VIPomas); cholerrheic diarrhea |
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|
Term
| Four major causes of diarrhea: ___ is due to accumulation of nonabsorbed osmolytes in the intestines. Examples include ___, ___, ___, ___, ___. |
|
Definition
| Osmotic diarrhea; lactose intolerance, chronic pancreatitis, bile duct intolerance, pancreatic insufficiency, bacterial overgrowth |
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|
Term
| Four major causes of diarrhea: ___ is due to inflammatory diseases such as ___, ___ in which tight epithelia become leaky. Also there is impaired ___ and excessive ___. |
|
Definition
| Mucosal destruction; ulcerative colitis, Crohn's disease; absorption; fluid secretion |
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|
Term
| Four major causes of diarrhea: ___ causes incr propulsive mm contractions which reduce time available for fluid absorption in the large intestine. Example is ___. |
|
Definition
| altered intestinal motility; IBS |
|
|
Term
| Four major causes of diarrhea: ___ is term given to laxative abuse. It can be part ___ and part ___ diarrhea. |
|
Definition
| Factitious diarrhea; secretory; osmotic |
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|
Term
| If you need more Ca, turn up passove/active Ca uptake in ___. Ca binds calbindin and delivers it toeither Ca pump or exchanger. ___ turns on Ca absoprtion. Passive Ca absorption occurs in ___ and ___. |
|
Definition
| active; duodenum; Vitamin D; jejunum, ileum |
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|
Term
| Fe binds first to ___. Heme is endo cytosed into cell and the Fe is removed by ___. Fe absorption is __ % of that ingested. |
|
Definition
| transferrin; heme oxygenase; 10-20%; |
|
|
Term
| Intrinsic factor, as only indispensable substance b/c it binds to __ and allows it to be absorbed in ___. |
|
Definition
| Vit B12(cobalamin); ileum |
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