Diabetes intro pathophysiology Flashcards
Pancreas
plays a fundamental role in digestive enzymes and hormones
Exocrine
Digestion break down
Endocrine
Regulates immediate utilization and storage of food energy
Alpha cells
secrete glucagon
effective breakdown of liver glycogen and increase glucose levels in the blood
beta cells
secrete insulin and amylin
increase uptake of glucose into cells and facilitate conversion of glucose to glycogen in the liver
Insulin is a __ hormone
anabolic
insulin is a key regulatory hormone of
glucose disappearance
insulin secretion is regulated by glucose and incretin hormones
Increased during absorptive state and decreased during
post-absorptive state
Insulin effects live, muscle and adipose tissues
-Inhibit hepatic glucose production and glucagon
secretion
-Stimulate glycogenesis in liver
-Stimulates glucose uptake in muscle and fat tissue
Amylin
Co-secreted with insulin in response to nutrient stimuli
- Inhibits postprandial glucose excursions:
- Suppresses digestive secretions
- Slows gastric emptying
Glucagon is a ___hormone
catabolic
Glucagon is a major regulator of
glucose appearance
glucagon works ___ to insulin
antagonistically
glucagon release is inhibited by
increase in glucose levels and the presence of fatty acids and ketones
glucose release is stimulated by
decrease in glucose levels and presence of amino acids
pancreatic hormones
glucagon
insulin
amylin
counter-regulatory hormones
Glucagon
Epinephrine
Growth hormone
Cortisol
Glucagon
promotes gluconeogenesis and glycogenolysis,
increases release of fatty acids from adipose cells
Epinephrine
increases the use of fat for energy, promotes
glycogenolysis, inhibits insulin release
Growth Hormone
decreases the peripheral use of glucose
Cortisol
critical during periods of fasting and starvation;
increase gluconeogenesis
Counter-regulatory hormones (overall)
Counteract the storage functions of insulin in regulating blood glucose levels
during periods of fasting, exercise, stress, and other situations that either limit
glucose intake or deplete glucose stores
Normal Fed State
increase glucose –> pancreatic B cells release insulin –> insulin stimulates glucose uptake by cells –> insulin stimulates glycogenesis in the liver (glucose to glycogen) –> levels return to normal
Normal fasting state
decrease in glucose –> pancreatic a cells release glucagon –> glucagon stimulates gluconeogenesis and glycogenolysis in liver and release of glucose to plasma –> normal levels return
Function of gut
Oral ingestion of food
stimulates release of
incretin hormones from
the small intestine
GLP-1 is released from
L cells of ileum and
colon
GIP released from
k cells of duodenum
GIP
-Acts at β cell
-Enhances glucose-
dependent insulin
secretion
-May act as an insulin
sensitizer in adipocytes
-GIP has no effect on
glucagon secretion, gastric
motility, or satiety
GLP-1
-Acts at α and β cells
-Enhances glucose-
dependent insulin
secretion
-Suppresses glucagon
secretion
-Slows gastric emptying
-Has a satiety effect on the
brain
Active GLP-1 and GIP made inactive by
DPP-4 enzyme
Role of kidney in glucose regulation
glucose filtration in glomerulus
glucose reabsorption in proximal tubule
minimal glucose excretion in collecting duct
