module 13 pancreas Flashcards
duct cells
secrete aqueous NaHCO3 solution
acinar cells
secrete digestive enzymes
exocrine pancreas
acinar and duct cells
endocrine pancreas
islets of langerhorn
pancreas exocrine enzymes for carb digestion
salivary amylase: mouth
pancreatic amylase: SI
dextrinase, glucoamylase, lactase, maltase, sucrase: SI endothelium
pancreas exocrine enzymes for protein digestion
pepsin: stomach
trypsin, chymotrypsin, carboxypeptidase: SI
aminopeptidase, carboxypeptidase, dipeptidase: SI endothelium
pancreas exocrine enzymes for fat digestion
lingual lipase: mouth
gastric lipase: stomach
pancreatic lipases: SI
Bile Salts from liver: SI
pancreas exocrine enzymes for nucleic acid digestion
pancreatic ribonuclease and deoxyribonuclease: SI
nucleosidases and phosphatases: SI endothelium
Endocrine pancreas cells
Islet of langerhans alpha cell: glucagon beta cell: insulin delta cell: somatostatin - inhibits A & B cells
common problems in geriatric patients r/t GI
constipation fecal incontinence diarrhea reflux disease swallowing disorders
age related changes in GI
dec motility dec. visceral sensitivity liver sensitivity to stress dec. immunity dec. colonic function hormone responsiveness drug metabolism changes pancreas structure and function - change in glucose insensitivity, degradation dec. chief and parietal cells -> dec. acid and pepsin -> inc. pH (alkaline) dec. absorption dec. smooth muscle -> delayed emptying time, dec. anal sphincter tone, dec. peristalsis
geriatric and dec. food intake
mobility imparment ability to obtain food loss of taste/olfaction poor dentition dec. appetite anorexia of aging depression
pediatric changes in GI
hydrochloric acid: low acidity, high pH
-> impaired bacteria destruction, impaired protein digestion
-> inc. risk infection
Dec. amylase/lipase
-> unable to break down complex carbs and fats
Inc. lactase in SI
immature LES
-> dec. sphincter pressure/ inappropriate relaxation -> regurgitation
Short esophagus
-> regurgitation
immature muscles of intestine
-> rapid peristaltic and nonperistaltic wave
-> delayed gastric emptying
-> inc. intragastric pressure
-> regurgitation
dysphagia
difficulty swallowing 3 categories - problem delivering bolus d/t neuromuscular incoordination - altered peristaltic activity - LES dysfunction/obstruction Mechanical/functional obstructions
achalasia
denervation of smooth muscle in esophagus and LES
GERD
relux of chyme from stomach to esophagus
role of the lower esophageal sphincter
hiatal hernia
sliding hernia
paraesophageal hernia
pyloric obstruction
blocking or narrowing of the opening between the stomach and the duodenum
Intestinal obstruction and ileus
chyme flow prevented through the intestinal lumen or failure of normal intestinal motility in the absence of an obstruction lesion
gastric motility and control
swallowing gastrin cholecystokinin motilin secretin gastric emptying
chyme
ingested food that has been crushed, ground, and mixed
gastric emptying
chyme forced through the pyloric canal into SI
GI motility and preg
hormonal effects
- gallbladder enlarges and slows emptying in response to meals
- small bowel transit slowed
- resting pressure of lower esophageal sphincter reduced
Motility reverts toward normal postpartum
pancreatits
inflammation of pancreas
- injury to pancreatic cells and ducts -> leakage of enzymes into pancreatic tissue
- > auto-digestion of pancreatic tissue and leak into blood stream -> injury to blood vessels and other organs
acute pancreatitis causes
duct obstruction acinar cell injury defective intracelluar transport - acinar cell apoptosis/necrosis - leukocyte infiltration
acute pancreatitis s/s
steady pain: epigastric/LUQ - gradually inc., radiates to back N/V tender on palitation dec. bowel sounds abd. distention fever
risk factors acute pancreatitis
galstones ampullary obstruction alcohol hypertriclyceridemia hypercalcemia drugs infection and toxins trauma vascular diseas preg sphincter of oddi dysfunction main pancreatic duct abnormal
chronic pancreatitis
presence of chronic inflammatory lesions in pancreas
key element: necrosis of exocrine parenchyma followed by fibrosis
-> calcification- obstructed flow of pancreatic juices
associated with:
- alcohol
- idopathic
- hereditary
- inc. PTH/Ca
- trauma
chronic pancreatitis s/s
bouts of acute pancreatitis pain radiates to back sequelae - DM - malabsorption - wt loss
complcations of chronic pancreatitis
pseudocyst pancreatic ascities obstruction of common bile duct -> inc. LFT peptic ulcer
insulin secretion
glucose uptake by GLUT2 trasporter in pancreatic cell
-> ATP production -> blocks K+ channel, keeping K+ in
-> depolarization and voltage gated Ca+ channels: influx
-> exocytotic release of insulin from storage granule
PERIPHERAL:
- GLUT4 receptor binds insulin, facilitated diffusion of glucose
-
effects of hyperglycemia (inc. insulin)
dec. appetite
dec. glucagon
inc. glucose uptake into cells
inc. glycolysis
inc. glycogen synthesis
inc. triglyceride synthesis
inc. amino acid uptake
inc. protein synthesis
effects of lack of insulin
inc. appetite
inc. glucagon
dec. glucose uptake by cells
inc. blood glucose
inc. gluconeogenesis
inc. lipolysis
inc. protein breakdown
inc. glycogenlysis
inc. ketone body production -> ketoacidosis
dec. protein synthesis
