Lecture 38: Homeostasis in Action Flashcards
1
Q
Increasing glucose level, ______ responds to high glucose by secreting _____. This causes _____, skeletal muscle, and ___ ____ to ….
A
- Pancreas
- Insulin
- Liver
- Other tissues
- Take up more glucose
2
Q
Control of blood glucose is mainly by _____ _____.
A
- Negative feedback
3
Q
Insulin can be thought of as…
A
- Signalling that the body has been fed
- i.e promotes uptake and storage of nutrients
4
Q
If there’s no insulin around then the body is going to act as if…
A
- It’s “starved”
- Breaking down stores of glycogen and releasing that glucose to other tissues in the body
- Gluconeogenesis = liver is taking non carbohydrate sources (break down of amino acids) to make new glucose
- Breaking down fat stores to increase lipid levels in blood
- Increase ketone production which can be ‘glucose sparing’.
5
Q
Diabetes derived from Greek….
Mellitus derived from Latin…
A
- “Passing through”
- “Honey” or “Sweet”
6
Q
Diabetes is historically referred to a disease state characterized by…
A
- Polyuria (passing large volumes of urine)
- Polydipsia (excessive thirst)
- Polyphagia (excessive hunger)
7
Q
Type 1 Diabetes Mellitus:
A
- Little or NO INSULIN
- Typically younger onset (children or teenagers)
- May be associated with prior viral illness and subsequent autoimmune response that destroys pancreatic Beta Cells
Environmental agent + genetic predisposition ^^^ - Treatment = Insulin
- HYPO only occurs if they’ve been overtreated with insulin
8
Q
Type II Diabetes Mellitus:
A
- Insulin Resistance
- Cells aren’t responding to the insulin
- May have higher than normal levels of insulin, because glucose ends up staying in blood, which means lots and lots of insulin
- Eventually insulin level may drop off because pancreas has had enough
- May be related to:
Ageing
Obesity
» Reduced numbers or function of insulin receptors
» Altered intracellular signalling in target cells - Other conditions (eg Cushing’s disease, PCOS)
- Hyperglycemia but diff to Type I, insulin levels may still be adequate to suppress lipolysis and ketogenesis but not sufficient to control BGL
- Treatment: Exercise, Weight Loss, Oral Drugs, Insulin if needed
9
Q
Oral Hypoglycemic Drug Classes are used for ____ ____ Diabetes people. These include:
A
- Type II
- Sulphonylureas : increase insulin secretion by beta cells, can cause hypoglycemia if not eating or overdose
- Metformin : reduces glucose output from liver by inhibiting gluconeogenesis
- Thiazolidinediones : increase insulin sensitivity of cells
10
Q
Diabetes Insipidus:
A
- Lots of dilute urine but no glucose in it!!!
- Due to altered secretion of ADH or decreased responsiveness to it
- Often associated with brain injury or tumour in region of pituitary gland
11
Q
Gestational Diabetes (important):
A
- Can affect women during pregnancy
- May resolve after pregnancy or not
- Large baby increased risk of birth injuries, neonatal hypoglycemia, congenital malformations, child/adult obesity?
12
Q
Hyperglycemia is due to:
A
- Inability of most cells (not brain) to absorb glucose
» glucose stays in blood, can’t enter cells, decreased production - Increased output of glucose by liver
» Glycogenolysis and gluconeogenesis
13
Q
Glycosuria is when…
A
- Renal tubes can’t reabsorb the excessive glucose being filtered
14
Q
Polyuria…
A
- Excessive thirst
15
Q
Acute Consequences…
A
- Breakdown of protein and fat
- (Diabetic) Ketoacidosis (DKA) : ketones are acidic and cause acidosis when produced in excess
- Acetone-like smell on breath and can also be detected in urine
- Acidosis causes hyperventilation
- Acidosis can cause hyperkalemia
