Transcript Pancreas - Schoolwires.net

Mrs. Ashley
Medical Assistant Science
PANCREAS ANATOMY
esophagus
stomach
ductus choledocus
pancreas
duodenum
duct of
Santorini
duct of
Wirsung
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Exocrine and endocrine cells
90% of pancreas related to exocrine (digestive
function)
10% endocrine (homeostasis for glucose
levels in the body)
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◦ Both an exocrine and endocrine organ
◦ Cells with exocrine function release
an alkaline fluid containing sodium
bicarbonate and enzymes →
 pancreatic duct → small intestine
◦ Pancreatic “juice” aids in breakdown
and digestion of food in the small
intestine
◦ Pancreatic exocrine cells = acinar
cells
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Acinar cells - exocrine cells of the pancreas
that produce and transport digestive enzymes
Amylase, lipase, phospholipase, proteases
(trypsinogen, chymotrypsinogen)
PANCREATIC SECRETIONS
1. PROTEASES (70%)
Endopeptidases (trypsin, chymotrypsin, elastases)
Exopeptidases (carboxypeptidases)
trypsinogen
trypsin
activates all other precursors
enterokinase
(duct walls)
2. NUCLEASES (DNAase, RNAase)
3. PANCREATIC AMYLASE (hydrolyse starch and gl;ycogen)
4. PANCREATIC LIPASE (triglycerides
fatty acids and glycerol)
PANCREAS (PANORAMIC)
islet of
Langerhans
pancreatic acini
islet of
Langerhans
pancreatic lobe
BV
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Islets of Langerhans - endocrine cells of the
pancreas that produce and secrete
hormones into the bloodstream
Glucagon - Alpha cells (A cells) - raises the
level of glucose (sugar) in the blood by
causing liver to break down stored glycogen
Insulin - Beta cells (B cells) - stimulates
cells to use glucose and reduce glucose
levels in blood
Antagonistic Hormones
Endocrine Function :
Cells of the Islet of Langerhans synthesize
and release hormones into the circulation.
Hormones travel through the bloodstream to
target tissues (especially liver and muscle)
At the target cells, hormones bind specific
receptors and cause cell changes that control
metabolism
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Chemically – high levels of glucose and amino
acids in the blood
Hormonally – beta cells are sensitive to
several hormones that may inhibit or cause
insulin secretion
Neurally – stimulation of the parasympathetic
nervous system causes insulin to be secreted.
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Transported through the blood to target tissues
where it binds to specific receptors
The binding of insulin to target cells:
◦ Acts as a biochemical signal to the inside of the cell
 Overall, cell metabolism is stimulated
 There is increased glucose uptake into the cell
 Regulation of glucose breakdown within the
cell
 Regulation of protein and lipid breakdown
within the cell
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Blood glucose is decreased because insulin
causes glucose to leave the bloodstream and
enter the metabolizing cells.
With the exception of brain, liver and
erythrocytes, tissues require membrane
glucose carriers.
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Inflammation of the pancreas
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Pancreas suddenly becomes inflamed
Causes: Gallstones
Ethanol
Trauma
Steroids
Mumps
Autoimmune
Scorpion venom
Hyperlipidaemia, hypothermia ↑Ca2+
Drugs
Symptoms
 epigastric and central abdominal pain
 vomiting and nausea
 swollen and tender abdomen
 fever
 dehydration and low blood pressure
Diagnosis
 medical history and physical exam
 blood test: ↑ amylase, lipase
 abdominal ultrasound, Endoscopic
Ultrasound, CT scan
Treatment
 nothing to eat or drink
 intravenous fluids
 analgesia
 ERCP and gallstone removal
Complications
 shock, Acute respiratory distress syndrome,
renal failure, Disseminated intravascular
coagulation, sepsis, ↓Ca2+
 pancreatic necrosis, pseudocyst, abscesses,
bleeding, thrombosis
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inflammation of the pancreas - gets worse
over time and leads to permanent damage
Causes: many years of alcohol use
hereditary disorders of the
pancreas
cystic fibrosis
haemochromatosis
autoimmune conditions
Symptoms
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nausea and vomiting
weight loss
diarrhea
steatorrhea
Treatment
 drugs - analgesia, lipase, fat-soluble
vitamins
 diet
 surgery – pancreatectomy
pancreaticojejunostomy
Complications
 pseudocyst, diabetes, biliary obstruction,
local arterial aneurysm, splenic vein
thrombosis
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The single most common endocrine disorder
– group of glucose intolerance disorders
Incidence is estimated at 8.3% of the North
American population
35% are pre-diabetic
Many of these cases are undiagnosed
Historically - distinguished by weight loss,
excessive urination, thirst, hunger
Excessive urination = polyuria
Excessive thirst = polydipsia
Excessive hunger = polyphagia
Modern characterization is by hyperglycemia
and other metabolic disorders
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increased level of glucose in the blood
(normal blood glucose level 3.5-6.0 mmol/l)
90 mg/100ml
Type 1 ( insulin-dependent DM, IDDM)
 destruction of insulin-secreting pancreatic β
cells (autoimmune response)
 juvenile diabetes-tends to begin in early
childhood
 patient always needs insulin
Type 2 (non-insulin dependent DM, NIDDM)
 insulin resistance
 Β cell dysfunction, ↓insulin secretion
Causes of insulin resistance:
 metabolic syndrome (central obesity, hyperglycaemia,
hypertension, ↓HDL cholesterol, ↑triglycerides)
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renal failure
pregnancy
cystic fibrosis
polycystic ovarian syndrome
Glucose in urine- Because when insulin is not
present, glucose is not taken up out of the
blood at the target cells.
So blood glucose is very highly increased →
increased glucose filtered and excreted in the
urine (exceeds transport maximum)
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Mechanisms of insulin
resistance:
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post-receptor defects
in insulin action
gene mutation
circulating
autoantibodies
Diagnosis
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blood glucose level
urine sample
HbA1c test
Treatment:
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diet
oral
hypoglycaemics
Control diet
Carbohydrates should make up about
55-60% of patient’s total calories
Fats should make up <30% of patient’s
total calories
Proteins should make up about 15-20%
of patient’s total calories
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Monitor exercise
Remember: muscles are a target tissue of
insulin, and metabolize much glucose for
energy
Sometimes exercise →irregular blood glucose
levels So diabetic patients should be
monitored when they are exercising
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insulin injections (long-acting, shortacting, rapid-acting)
insulin pen
insulin pump therapy
Complications
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diabetec ketoacidosis
hypoglycaemia
diabetic retinopathy
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atherosclerosis (heart disease and stroke)
neuropathy (diabetic foot care)
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Age over 40 years
Diabetes during a previous pregnancy
Excess body weight
Family history of diabetes
Dyslipidaemia (large amount of lipids in
body)
Hypertension
Low activity level
Metabolic syndrome
Polycystic ovarian syndrome
Acanthosis nigricans- darkening and
thickening of skin