Pancreas Flashcards
Head of pancreas has more of a ___ function, near which organ
Tail of pancreas has more __ function, near what
What is present throughout
Exocrine, duodenum
Endocrine, spleen
Endo and exo function
Pancreas is anatomically ___ in abdomen
Retroperitoneal
Islets of langerhands
____ cells
3 types, which most prevalent, what they produce
Endocrine
Alpha, glucagon
Beta, insulin, 75%
Delta, somatostatin
Insulin secretion stimulated by what
Glucagon secretion inhibited by what
Glucose
Insulin
Glucagon producing cells have high conc of what if beta cells secreting insulin
Insulin
Glucose does not control what
Alpha cells that make glucagon
Beta cells respond to changes in what
Bg to release insulin
Overall effect of insulin is ___
Promotes synthesis of what
Anabolic
Carb, fat, protein
____ is cleave to form insulin
C peptide
Synthesis of insulin:
____ to ___ to __ and __
Preproinsulin
Proinsulin
Insulin and c peptide
Insulin leads to __ hormone composed of __ and ___, linked by ___
Peptide
A and b chains
Disulfide (strong)
__ and __ __ are stored and released together
Insulin and c peptide
Insulin circulates in __ form, half life of what, degraded by what
Free
3-8 min
Liver and kidney
What is measured as an index of endocrine capacity of pancreas
C peptide
Physiologic effect of c peptide
Decreases gfr to uptake more glucose by body
Glucose uptake is by ___ transporter which leads to cell depolarization, ca influx, and release of insulin from storage
Glut 2
What happens if drug blocks atp sensitive k channel
Cell stays depolarized (no k leaving), more insulin release
If drug makes atp sensitive k channel more sensitive to being blocked what happens
Quicker insulin release when bg rises
What happens if born w less sensitive k channel
Need more atp to block channel, need more glucose before insulin will be realeased. Higher bg set point, 150-170
What happens to bg after bolus dose of insulin
Bg rises, stored insulin was used and body has to make more
Limiting factor for glycolysis, in which cells
Glucose, beta
Not in cardiac cells or neurons
Glucagon increases what 3 things in blood
Glucose, FA, ketoacids
Glucagon
Structure
Synthesized as what, then what happens to it
Straight chain polypeptide
Preproglucagon, cleaved to glucagon and stored in secretory vesicles
Glucagon release increased when
Main target organ of glucagon
Fasting, when insulin levels low
Liver
Receptor of glucagon, stimulated what, increases what, __ to phosphorylate target proteins
GPCR (Gs)
Adenylyl cyclase, cAMP
PKA
Liver functions to increase BG 3
Glycogenolysis (breakdown glycogen)
Gluconeogenesis (glucose synthesis)
Synthesis of ketoacids from fatty acids
Cant convert __ into glucose but can convert fat into __ __
Fat
Ketone bodies
What two things are antagonists
Glucagon and insulin
Transporter that moves to cell surface, always open, when glucose high on outside
Glut 4
What enhances glucose response and does what
AA plus glucose, enhances protein synthesis and muscle growth
Glut 1
Distribution
Does what
Widely distributed
Supplies many cells w glucose. High affinity, low capacity, passive
Glut 2
Where they are 4
About
B cells, kidney, intestines, liver
Low affinity, high capacity, passive
Glut 3
Where they are
Supplies neurons w glucose
Passive
Glut 4
Where they are
Dependent on what
Muscle and fat
Insulin dependent
Glut 5
Where
Transports what
Intestines
Fructose transporter, passive
Sglt 1 and 2
Where
__-__ ___ transporters
Intestines and kidney
Na glucose co transporters. Active
Insulin
Decreases 2
Increases 6
Appetite and glucagon
Increases glucose uptake by tissue, glycolysis, glycogen syth, tg synth, aa uptake, protein synth
Lack of insulin/glucagon
Increases 8
Decreases 2
Inc appetite, glucagon, bg, gluconeogenesis, lipolysis, protein breakdown, glycogenolysis, Ketone body production (ketoacidosis)
Decreases glucose uptake by tissues and protein synthesis
Just ate: __ and __ high, __ low. __ lowers then __ lowers. __ starts to increase
Bg and insulin. Glucagon
Bg then insulin, glucagon
After meal when glucagon goes up stim ___, __ and __ release
Liver converts __ to __ bodies.
Glycolysis,
Ffa and tg
Ffa to ketone
Right after we eat liver __ is high when bg high. Use more __ when bg lowers.
Glycogen
Glycogen
Type 1 dm
Prevalence
What happens
10%
Autoimmune destruction of b cells
Type 2 dm
Prevalence
What happens
90%
Insulin resistance
MODY
What happens
Prevalent in who
Genetic defect in insulin production or release
2% of less than 15 year old diabetics
Endocrine disorders that cause diabetes
Cushing, acromegaly, pheocromocytoma
Hormones that raise bg
Mainly cortisol and glucagon
Gh and epi do as well
__ transporter sees chronic hyperglycemia in cell, leads to __ cell loss, __ production decreases
Glut 2
Beta
Insulin
Type 1 dm is a type __ hypersensitivity
4
Type 2 dm is progressive loss of what
Insulin sensitivity of muscle and fat cells
Type 1 onset What age Weight Insulin Anti islet cell bodies Ketoacidosis
<20 Normal Decreased Present Common
Type 2 onset Age Weight Insulin Anti islet cell antibodies Ketoacidosis
>30 Obese Increase None Rare
Genetics type 1 vs type 2
Type 1, <50% accordance in twins, HLA D linked
> 90% accordance in twins, no HLA assoc
Pathogenesis type 1
Autoimmunity, immunopathic. Insulin deficiency severe
Pathogenesis type 2
Insulin resistance and relative insulin deficiency
Islet cells type 1
Insulitis early
Atrophy and fibrosis
B cell depletion
Islet cells type 2
No insulitis
Atrophy and amyloid deposits
Mild b cell depletion
Gestational dm
- what it is
- increased risk of what after pregnancy
- caused by what
Undiagnosed dm that presents in pregnancy
Subsequent gestational dm and type 2 dm
Chorionic somatomammotropin
