Study BIOL 472 Topic 17 Flash Cards
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Pile Management Card
BIOL 472 Topic 17
BIOL 472 Topic 17
| colorectal caner |
| occult blood test |
| hemmeroids |
|
-varicose veins in anal canal -itching, throbbing, bleeding -detroy by burning, cutting, or rubber banding |
| Hirschsprung's disease |
|
constriction of LI wall (aganglionic megacolon) -feces back up |
| diverticulitis |
| diet lacks bulk cusing outward herniation of Haustra wall, can become infected |
| appendix |
| -off cecum (pain in right Iliac region) |
| mesocolon mesentary |
| anchors LI to posterior wall |
| LI |
|
-6ft -larger diameter than SI -anchored by mesocolon mesentary to posterior wall -absorbs WATER and ELECTRLYTES -production of Vit. K, B complex by bacteria -expulsion of feces by mass peristalsis mvts -3 parts: 1. cecum 2. colon (ascending, transverse, descending, sigmoid) 3. rectum -tunica mucosa: mostly simple columnar but stratefied squamous at rectum -tunica muscularis: taenia coli (thickening of longitudinal muscles) -Haustra: "puckered" pouches that form distension of 1 haustra causes propulsion of contents into next haustra |
| when the common bile duct meets the pancreatic duct... |
|
...forms ampulla of vater -sphincter of Oddi controls release into SI |
| enzymes of pancreas |
| amalyase, trypsin, lipase |
| pancreas |
|
-exocrine and endocrine functions -exocrine: secretion of product into duct, digestive enzymes, alkaline juice -acinar cells produce pancreatic juice, secreted into pancreatic duct, enters SI -alkaline juice pH (same CA rxn; HCO3 secreted in lumen (active), active H+ exchange w/ Na+, Na+ secretion into lumen) -enzymes amalyase, trypsin, lipase endocrine: regulates blood sugar w/ insuin and glucagon hormones |
| 3 pairs of salivary glands |
|
1. sublingual (under the tongue) 2. submandibular (under the jawbone) 3. parotid (near the hinge of the jawbone) |
| Auerbach's plexus |
| -controls SI mvt |
| SI mvt |
|
-controlled by Auerbach's plexus of ANS 1. segmentation (back and forth mixing of chyme and enzymes; brings digested nutrients into contact w/ villi and microvilli) 2. peristalsis (forward propulsion of chyme along SI) -also, pumping of villi by muscularis mucosa (meissner's plexus) |
| VIP |
|
decreases smooth muscle motility -dilation of peripheral vessels -inhibition of acid secretion |
| motilin |
|
-responsible for MMC (migrating motor complex) -peristaltic wave from esophagus to large intestines during interdigestive period -empties stomach |
| secretin |
|
-release due to acid in duodenum -stimulates bicarbonate release from pancreas to neutralize -makes intestines basic to shut down its secretion |
| CCK-PZ |
|
-release due to duodenal filling, acid -esp. protein and fats -inhibits GI motility -stimulates gall bladder contraction or bile deivery -stimulates pancreatic secretion (release of digestive enzymes) |
| GIP |
|
-gastrin inhibitory peptide -release due to duodenal filling, acid -inhibits GI motililty, acid production gives SI time for absorption |
| SI hormone production |
|
GIP CCKPZ secretin motilin VIP note: gastrin, CCK, GIP, secretin most important -some GI hormones also neurotransmitters |
| intestinal glands |
|
-crypts of Leiberkuhn -intestinal juice (basic pH) -lysozyme (antibacterial to keep GI flora at bay) |
| tunica mucosa |
|
-specialized for absorption in SI -3 modifications increase surface area: 1. simple columnar epithelium w/ microvilli 2. arranged in villi 3. plica circularis |
| largest portion of alimentary canal |
| SI (also does most digestion) |
| SI |
|
-largest portion of alimentary canal -6ft -receives most enzymes from pancreas -emulsification of fats via bile from liver -absorption of nutrients (capillaries and lacteals -secrete hormones basic pH (stomach was acidic) -3 parts: 1. Duodenum 2. Jejunum 3. Ileum |
| vomiting |
|
-irritation triggers vomiting center in brain -saliva stimulation -squeeze stomach b/w diaphragm and abs -muscles cause pressure -open spincters -can cause metabolic alkalosis |
| vagotomy |
|
Vagotomy is the surgical cutting of the vagus nerve to reduce acid secretion in the stomach -if ulcer is very bad |
| ulcers |
|
-hypersecretion of acid or lack of mucous protection (acid, alcohol) -lesser curvature, pyloris, duodenum most vulnerable -bacteria causes 90% -used to be treated w/ H2 bockers omeprazole vagotomy |
| acidity of stomach |
|
high acidity increases gastrin release high protein meal buffers acidity tends to stimulate acid production empty stomach is highly acidic inhibits gastrin and acid production |
| omeprazole |
| blocks H+K+ATPase pump by internally affecting cell |
| acid production inhibited by... |
|
ACh antagonists (atropine) histamine (H2) blockers gastrin blockers (weaker) |
| pyloric sphincter |
| -controls emptying of stomach into duodenum |
| tunica muscularis |
|
3 layers: 1. outer longitudinal 2. middle circular 3. inner oblique |
| D cells |
|
-somatostatin production (also pancreatic D cells) -acid secretion inhibitor |
| enterochromaffin cells |
|
-histamine production -acid secretion stimulator |
| mucous neck cells |
|
-produces mucous -protects stomach |
| G cells or APUD |
|
-(amine precursor uptake decarboxylase) -gastrin production -activated by food in stomach -released in blood -increased acid secretion by parietal cells -increased GI motility |
| chief cells |
|
-pepsinogen (w/ acid activated to) pepsin -pepsin carries our initial protein digestion -could autolyse cell |
| pernicious anemia |
|
-lack of intrinsic factor -lack of Vit B12 absorption for RBC production -can't make RBCs |
| parietal cells |
|
-HCl production -secrete intrinsic factor (Vit. B12 absorption for RBC production) -pernicious anemia |
| gastric pits |
|
-stomach glands -contain specialized cells -makes chyme -mucous -parietal -chief -G cells or "APUD" enterochromaffin D cells |
| mucosa |
|
secretion: mucous, acid, digestive enzymes absorption: drugs, water, alcohol, aspirin folds called rugae in the stomach simple columnar epithelium gastric pits |
| heart burn |
| -reflux of acid at the cardiac spincter |
| stomach parts |
|
cardiac: upper portion w/ sphincter fundus: upper portion body: greater vs lesser curvature pyloris: controls emptying into SI |
| stomach |
|
-widest part of alimentary canal -produces enzymes/acids -distensible/contractable |
| swallowing |
| deglutition |
| pharnyx/esophagus |
|
-swallowing center in medulla -trigeminal, glossopharyngeal, vagus, hypoglossal -mouth must be closed -tongue pushes food back -initially involuntary contraction of pharynx -inhibition of respiration -larnyx rises, epiglottis closes glottis -upper esophaguseal spincter relaxes -peristalic wave initiated -lower esophageal sphincters relax -(liquids via gravity) -second, painful wave if unsuccessful |
| parotid gland |
| Either of the pair of salivary glands situated below and in front of each ear |
| mumps virus |
|
-inflammation of parotid glands -Either of the pair of salivary glands situated below and in front of each ear |
| buccal glands |
| Any of the mucous glands in the membrane lining the cheeks of mammals, except aquatic forms |
| salivary glands |
| -exocrine glands |
| acinar gland |
|
-secretory epithelium -in salivary glands |
| salivary glands |
|
-accessory digestive organs -produce saliva -acinar gland -amalyase -lipase -buccal glands -parotid, submandibular, submaxillary, sublingual |
| short reflex innervation |
|
-integrated only in enteric nervous system -local reflexes begin, integrate, and end entirely in GI tract -stimuli such as hormones, chemicals, distention -activate exocrine glands along tract -activates smooth muscle in tract |
| long reflex innervation |
|
-connects diff regions of the GI tract -also connects system w/ CNS -vagus nerve (ACh) is major stimulator in parasympathetic portion of ANS -serotonin stimulates activation of Meissners/Auerbachs plexus -splanchnic nerves (sympathetic fibers are inhibitory; use NE, E -digestive reflexes integrated in the CNS are called long reflexes -ex: sight/smell of food |
| neural control of digestion |
|
-sight/smell of food stimulates salivary and gastric secretions -chemoreceptors in stomach (HCl) -mechanoreceptors (distention in stomach) -long reflex innervation -short reflex innervation |
| diahhrea |
|
-intestinal secretion of fluid is not balances by absorption, resulting in a watery stool -normal intestinal water absorption is disrupted |
| MgSO4 |
|
-body can handle Na+ salts -stimulates diarrhea -water loss -Epsin salts |
| kidney max urine [] |
| 1200mosmol/L |
| body must excrete |
|
600mosmol/L in 1 day ----------------------------- 1200 mosmol/L = 0.5 L urine/day ex: seawater is 2400 mosmol/L 2400/1200= 2L urine excreted for every 1L seawater ingested |
| max urine flow |
|
16mL/min -if water absorbed above this, water intoxication -swelling of brain, convulsions, coma, death -also happens if too much ADH administered |
| water absorption |
| -absorbed until isoosmotic w/ plasma |
| daily water balance |
|
-lots fo volume flux thru GI -important for BP, kidney function -inputs: 1200 drinking/food 1500 saliva 2000 stomach 500 bile 1500 pancreas 1500 SI reabsorption: 8500 SI 350 LI 150 feces |
| ezetimible |
|
-binds to NPC1L1 protein on enterocytes and hepatocytes -this receptor is mediator of dietary absorption -lower absoprtion rate from diet enhances uptake of serum cholesterol (LDL) by peripheral cells |
| statins |
|
-binds to HMG CoA reductase -reduce cholesterol synthesis by liver -decreases LDL -increases HDL |
| cholestyramine |
|
-binding resin -forms insoluble bile/fat complexes that are excreted |
| treatments for high cholesterol |
|
-low fat diet w/ moderate alcohol -cholestyramine -statins -ezetimible -vytorin |
| at risk cholesterol |
|
240 and above LDL > 160 HDL <35 |
| HDL |
|
-good -tends to promote storage of cholesterol, esp in liver |
| LDL |
|
-bad -tends to remain in circulation -promotes plaque formation |
| normal cholesterol |
|
200 mg/dl and below ideal: LDL<130 HDL>45 |
| fat/cholesterol absorption |
|
-emulsified (H2O soluble) via bile -broken down into free fatty acids, monoglycerides w/ lipases (pancreas) -lipids absorpbed as FFA's and monogycerides in SI -conjugated w/ apoproteins by mucousal cell to form chylomicron -exocytosis via mucosal cells releases chylomicrons into lacteals of lymphatic system for transport eventually into venous system, stored as peripheral fat |
| protein absorption |
|
-broken down by stomach acid, pepsin (stomach), trypsin (pancreas) -absorbed as AAs and small peptides -absorption coupled w/ Na+ down [] gradient -secondary active transport -transport to liver via hepatic portal system |
| carb absorption |
|
-broken down by amylase from pancreas -absorbed in mono and di form into capillaries -absorption coupled w/ Na+ down [] gradient -secondary active transport -transport to liver via hepatic portal system |
| bile salts |
|
-actively reabsorbed in ileum -portal blood leads back to liver |
| jaundice |
| -bile tract blockage, liver failure, hemolysis can cause it |
| hepatic sinusoids |
|
-kupffer cells break down RBCs -Hb broken into Fe and bilirubin -bilirubin binds to albumin -absorbed by liver cells -processed into bile salts -stored by gall bladder -released by common bile duct -bile salts recirculated many times per day in GI tract |
| HNG CoA reductase |
| -mediates cholesterol synthesis in hepatocytes |
| liver functions |
|
-carb metabolism: stores glycogen, releases glucose -lipid metabolism (manufactures cholesterol (HMG CoA reductase) -protein synthesis: albumins, fibrinogens, prothrombin -breaks old RBCs into bilirubin -bile production: emulsification of fats -detoxification: chemically alters alcohol, drugs, etc. into kidney excretable compounds such as urea, ammonia, uric acid |
| hepatic portal vein |
|
-blood from GI goes directly into liver via this route -nutrient processing -detoxifies foreign substances -process material before released into body |
| blood flow |
|
-25% of C.O. -arterial flow for metabolically active organs (GI, liver) -venous flow (shunted thru liver for metabolic processing of nutrients that are absorbed in capillaries) -hepatic portal vein receives this flow |
| Adventitia layer |
|
-muscularis externa is bounded by adventitia -outermost connective tissue covering of any organ, vessel, or other structure |
| tunica serosa |
|
-outermost layer in GI tract -serous membrane -simple squamous epithelium that produces fluid -adventitia layer (no cavity) in esophagus |
| Auerbach's (myenteric) plexus |
|
-ANS -lies b/w circular and longitudinal layers -controls and coordinates the motor activity of muscularis -controls GI |
| tunica muscularis |
|
-usually smooth muscle (except: esophagus) -usually 2 layers (inner circular, outer longitudinal, except stomach, 3rd oblique muscle layer) -mechanical digestion -propulsion -Auerbach's (myenteric) plexus |
| Meissner's plexus |
|
-tells glands to secrete, tells muscularis to contract -in tunica submucosa -major nerve network -ennervates cells in the epithelial layer as well as the smooth muscle of the muscularis mucosae |
| tunica submucosa |
|
-dense, irregular connective tissue -larger blood and lymph vessels -binds tunica mucosa to tunica muscularis -highly vascularized -ennervated by ANS -Meissner's plexus: tells glands to secrete, tells muscularis to contract |
| muscularis mucosa |
|
-2 thin layers of smooth muscle (longitudinal and circular) -local mvt of GI epithelium -folding helps increase surface area -contraction of this smooth muscle affects surface area for absorption by moving villi of epithelium |
| lamina propria of tunica mucosa |
|
-loose connective tissue -binds epithelium to muscularis -capillaries and lmphatics -immune protection -contains nerve fibers and small blood vessels into which absorbed nutrients pass -wandering immune cells to patrol for invaders |
| mitotic turnover |
|
-chemo, radiation -affects epithelium lining -rapid turnover of epithelium lining and cell division rate makes organs susceptible to developing cancers |
| epithelium lining of tunica mucosa |
|
-lumen "brush" border -stratified squamous or simple columnar -absorption/protection/secretion -mucous production -secretory function (digestive enzymes from glands) -mitotic turnover (chemo) -most variable in GI tract; change from section to section -cell/cell junctions vary (tight in stomach and colon, leaky in intestines) |
| tunica mucosa |
|
-innermost layer of ailmentary canal -ELM: epithelium lining lamina propria muscularis mucosa |
| accessory digestive organs |
|
-contribute to breakdown of food -teeth, tongue -digestive glands (salvary glands, pancreas, gall bladder) |
| alimentary canal (GI tract proper) |
|
-mouth -pharynx -esophagus -stomach -SI -LI -rectum -one long tube |
| defecation |
| -elimination of indigestible substances |
| absorption |
| -passage of nutrients into circulatory and lymphatic systems for distribution thru the body |
| digestion |
| chemical and mechanical breakdown of foods into smaller units to be absorbed |
| propulsion of food |
|
-waves of peristaltic contraction -push bolus into stomach -gravity not required |
| ingestion |
|
Mastication: chewing to create bolus to swallow deglutition: swallowing; pushes bolus into esophagus |
| Digestion processes |
|
1. ingestion 2. propulsion 3. digestion 4. absorption 5. defecation |
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