Pancreas I Flashcards
The exocrine pancreas is composed of ?
What does it secrete?
Where do these secretions head to ?
These digestive enzyme need to be activated
The endocrine pancreas is composed of what type of cells?
What do these cells secrete?
Composed of the islets of Langerhans that
secrete:
- insulin by β cells
- glucagon by α cells
- somatostatin by δ cells
- PP cells secrete pancreatic polypeptide
Excrine pancreas diagrams
Diabetes Mellitus can be defined as a group of metabolic disorders sharing the commone feature of hyperglycemia…Hypergycemia in diabetes is caused by?
- defects in insulin secretion
- insulin action
- or, most commonly, both
Chronic hypergycemia and associated metabolic dysregulation might cause?
secondary damage in multiple organ systems, especially the kidneys, eyes,
nerves and blood vessels
After a meal, Insulin in normal subjects does what two things in normal people?
- It decreases liver glucose production by decreasing both glycogenolysis and gluconeogenesis
-
It increases glucose uptake by skeletal muscle and adipose tissue by
translocating glucose transporters
What counter-regulatory hormones increases within the earliest stages of hypoglycemia ?
What type of natual behaviors occur during a hypoglycemic state?
What happens to the plasma glucose concetration levels?
Relation between insulin and glucagon:
- In the earliest stages (within minutes):
- decreased insulin increased glucagon
Behavior defenses:
- The initial symptoms of sweating, anxiety, palpitations, hunger and tremor
- plasma glucose concentration falls below 55 mg/dL
There is a direct relationship between overnight blood glucose and the cause of the following morning hyperglycemia glucose level… What are they?
the cause of morning hyper glycemia is …nocturnal growth hormone secretion and hypoinsulinemia
How can exercise affect someone with insulin-deficient diabetes?
increases glucose utilization
by muscle can cause
hypoglycemia in patients with
insulin-deficient diabetes
Hypoglycemia-Associated Autonomic Failure (HAAF) in Diabetes is defined as ?
What is the Hypoglycemia-Associated Autonomic Failure (HAAF) mechanism?
- the clinical syndromes of defective glucose counter-regulation and hypoglycemia unawareness
- hypoglycemia, even if asymptomatic, causes a vicious cycle of recurrent hypoglycemia
HAAF mechanism:
-reducing the sympathoadrenal response to subsequent hypoglycemia due to:
- changes in hypothalamic functions
- increase in cortisol
What is the most important stimulus for insulin synthesis and release?
glucose itself
How does glucose get inside the cells?
- Glucose enters beta cells via the glucose transporter, GLUT2, which causes the release of insulin into the blood stream to bind to insulin receptors
- Insulin stimulates glucose uptake by skeletal muscle and fat by GLUT-4
- GLUT-2 acts on?
- GLUT-3 acts on?
- GLUT-4 acts on?
- GLUT-2 acts on– Beta cells, liver cells
- GLUT-3 acts on– All tissues, central nervous system
- GLUT-4 acts on?– Skeletal muscle, fat cells
Effect of insulin on metabolism of:
- Glucose?
- Fat: ?
- Protein: ?
- Glucose
- Prevens liver from forming new glucose - inhibits gluconeogenesis
- Increases uptake by skeletal/fat cells
- Prevens liver from forming new glucose - inhibits gluconeogenesis
- Fat: decrease lipolysis
- Causes storage of triglycerides in fat cells
- decrease lipolysis means less fatty acids go to liver leads to decrease production of glucose
- Causes storage of triglycerides in fat cells
- Protein: inhibits breakdown
- decreases catabolism
Effects of insulin on:
- Adipose tissue
- Straited muscle
- Liver
Where does glycated hemoglobin come from?
What is the Clinical test to estimate blood glucose control?
What does this test reflect ?
- measurement of glycated hemoglobin (also called A1C, hemoglobin A1C, glycohemoglobin, or HbA1C)
- Goal is less than or equal to 7% blood glucose
- A1C reflects mean blood glucose over
the entire 120-day lifespan of the red blood cell, but it correlates best with mean blood glucose over the previous 8 to 12 weeks