w4 diabetes type 1 PAT202

Question 1

what is diabetes?

Answer 1

a disease caused by genetic and environmental factors that impairs the cellular use of glucose

Question 2

alpha cells secrets_?

Answer 2

glucagon-in response to low blood glucose to activiate the sympathetic nervous system
(secreted by pancreas-endocrine function)

Question 3

beta cells secrete_

Answer 3

insulin in response to high blood glucose and to activity of parasympathetic nervous system
(secreted by pancreas-endocrine function)

Question 4

what is glucagon?

Answer 4

pancreatic hormone that acts to increase blood glucose levels- it is secreted when BG is low

• and maintains stable blood glucose levels between meals and during periods of fasting
• it removes glucose from its storage in the liver and send it to the blood (glycogenolysis) raising serum glucose w/in minutes
• increase glycogenolysis- breaks down glycogen to glucose
• increase glyconeogenesis- turns non carbs (fats & proteins) into glucose

Question 5

what is insulin?

Answer 5

pancreatic hormone that acts to decrease blood glucose levels
-has a hypoglycaemic effect b/c its presence causes glucose to leave the blood and serum glucose to fall
w/out insulin glucose is not able to enter cells of the body. these cells may be surrounded by high amounts of glucose but they are unable to use it until insulin arrives
-secretions are increased during fed state
glucose transport: ↑uptake by GLUT-4 receptors into skeletal muscle & adipose tissue
-↓glycogenolysis: inhibits breakdown of glycogen to glucose
↓gluconeogenesis: inhibits making of glucose from non-carbs
↑glycogenesis: turns glucose into glycogen (promotes glycogen storage)

Question 6

what happens when levels of glucose are low?

Answer 6

glucagon is secreted, and its primary function is to maintain adequate blood glucose levels between meals
-glucagon has a hyperglycemic effect b/c it causes blood glucose to rise

Question 7

what are the hormones associated w/ hyperglycaemia

Answer 7

• epinephrine
• thyroid hormones
• growth hormone
• corticosteroids

Question 8

what is the normal range of serum glucose during fasting?

Answer 8

4-7 mmol/L

Question 9

what is the normal glucose range after meals

Answer 9

5-10mmol/L (or 5-8 if tightly controlled)

Question 10

what happens after a meal?

Answer 10

glucose is rapidly absorbed from the GI tract, and serum levels rise
-some of the glucose is taken up by the cells and used for immediate energy needs, but above two-thirds is stored in the liver and muscle cells as glycogen, the storage form of glucose

Question 11

what is glycogenolysis?

Answer 11

when glucose levels fall between meals, glycogen is broken down in a process called glycogenolysis-(the process of glycogen breaking down) and glucose is released into the blood stream

Question 12

insulin is secreted by which organ?

Answer 12

pancreas - it will recognize the rising serum glucose levels and release insulin

Question 13

what are the physiological actions of insulin?

Answer 13

• promotes the entry of glucose into cells
• provides for the storage of glucose, as glycogen
• inhibits the breakdown of fats and glycogen
• increases protein synthesis and inhibits gluconegenesis- which is the production of new glucose from non-carhohydrate molecules

Question 14

a hypoglycaemic state (low serum glucose stimulates the release of _

Answer 14

glucagon and inhibits the release of insulin

Question 15

a hyperglycemic state (high serum glucose) stimulates_

Answer 15

the release of insulin and inhibits the release of glucagon

Question 16

what are factors that decrease blood glucose levels?

Answer 16

fasting
exercise
alchohol

Question 17

what are factors that increase blood glucose levels

Answer 17

stress from infection

• injury
• surgery =triggers release of epinephrine and nonrepinephrine
• large meals/over consumption of carbohydrates
• growth hormone
• corticosteroids

Question 18

what is type 1 DM?

Answer 18

results from autoimmune destruction of pancreatic beta cells, causing an absolute lack of insulin secretions
-thought to be caused by an interaction of genetic, immunological, and environmental factors

Question 19

what are the S/S of type 1 DM?

Answer 19

• hyperglycemia (most diagnostic sign)
• polyuria- excessive urination
• polyphagia- increased hunger
• polydipsia-increased thirst
• glucosuria-high levels of glucose in the urine
• weight loss
• fatigue
• bedwetting in children who previously didn’t wet the bed during the night
• irritability and other mood changed
• blurred vision

Question 20

what happens if DM goes untreated?

Answer 20

produces long-term damage to arteries, which leads to heart disease, stroke, kidney disease, and blindness

• lack of adequate circulation to the feet may cause gangrene of the toes, which may require amputation
• nerve degeneration is common and produces symptoms ranging from tingling in the fingers/toes to a complete loss of sensation of a limb

Question 21

if glucose is unable to enter the cell, how does the body get energy?

Answer 21

-uses lipids as energy source and keto acids- (a acidic waste product of lipid metabolism that lowers the pH of the blood) causing diabetic ketoacidosis (DKA)

Question 22

what is diabetic ketoacidosis? DKA

Answer 22

type of metabolic acidosis d/t an excess of ketone bodies-can progress to coma and death if untreated

Question 23

what is type 2 diabetes?

Answer 23

chronic metabolic disease caused by insufficient secretions of insulin by the pancreas and a lack of sensitivity of insulin receptors

Question 24

what is the function of pancreas (the exocrine function)

Answer 24

• secretes enzymes into duodenum to support digestion of macromolecules
• secretes bicarbonate into duodenum to raise pH of chyme

Question 25

what is the function of the pancreas- endocrine function

Answer 25

islets of Langerhans includes two types of cells that secrete hormones
alpha and beta cells

Question 26

how does insulin work?

Answer 26

Insulin binds with plasma membrane receptors found on cells throughout the body
-receptor binding sends cascade of signals to activate glucose transporters (GLUT) for entry of glucose into the cell
The primary GLUT is called GLUT4
-stored in cellular vesicles until activated by the insulin receptor
-is then translocated to cell surface where it facilitates the diffusion of glucose into the cell
Translocation of GLUT4 to the cell surface is associated with a 10- to 21-fold increase in glucose diffusion into the cell
-skeletal, cardiac muscle, liver, adipose cells

Question 27

what is a glucose transporters? (GLUT)

Answer 27

insulin promotes formation of glucose transports (GLUT4) that bring glucose from blood into the cells

Question 28

why is infection, illness, injury/trauma, surgery, physical, and emotional stress an issue w/ DM?

Answer 28

causes hyperglycaemia (counter regulatory hormone response)

• increase of epinephrine, growth hormone and cortisol
• inhibits glucose uptake into cells and increase blood glucose through glycogenolysis and gluconeogenesis: inhibits insulin release
• causes increase blood glucose =hyperglycaemia and ketoacidosis can occur

Question 29

genetic susceptibility for type 1 DM

Answer 29

• first degree relative (parent or sibling) w/ type 1 diabetes
• strongest association w/ major histocompatibility complex (MHC)

Question 30

environmental factors of type 1 DM?

Answer 30

• viral infection
• helicobacter pylori
• exposures to cow’s milk proteins
• relative lack of vitamin D (also implicated)

Question 31

what is the goal of treatment for type 1 DM?

Answer 31

• restoration of near normal BG levels and correct of repeated metabolic disorders
• treatment include: insulin, meal planning, exercise, and self-monitoring of BG
• transplant -islet cells and the whole pancreas