Term
| Note- because so much of this lecture was learned in biochemistry, I am leaving out a lot of Dr. Garret's notes |
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Definition
| Sorry for any inconvenience :) |
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Term
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Definition
Ingested nutrients are entering the blood from the GI tract
(approx. 4 hr after a meal) |
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Term
| Define postabsorptive state |
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Definition
| GI tract is empty and energy is supplied by body stores. Late morning and late afternoon and entire night |
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Term
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Definition
| More than 24 hours without eating |
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Term
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Definition
| In liver (25%) and skeletal muscle (75%) |
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Term
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Definition
| In the liver, glucose is transformed into α-glycerol phosphate and fatty acid and complexed with protein |
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Term
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Definition
| VLDL is broken down into fatty acids and glycerol by lipoprotein lipase in the membranes of capillaries in adipose tissue. The fatty acids diffuse into the adipocytes where they are used to synthesize triglycerides. |
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Term
| What are the three sources of fatty acids in adipose tissue? |
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Definition
a. glucose which has been converted to α-phosphoglycerol and fatty acids
b. ingested triglycerides via chylomicrons
c. VLDL synthesized in the liver |
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Term
| What are the two mechanisms for maintaining plasma glucose? |
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Definition
1) producing glucose
2) shift fuel source from glucose to fat (glucose sparing) |
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Term
| How many kcal does the body typically require? How much can gluconeogenesis and glycolosis produce? |
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Definition
| Body requires 1500-3000 kcals/day, however, gluconeogenesis and glycolysis provide only 750 kcal/day. |
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Term
| What are normal fasting glucose levels? |
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Definition
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Term
| What are the minimal glucose levels required by brain? |
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Definition
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Term
| What is the Tm of renal proximal tubules for glucose? |
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Definition
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Term
| What do each type of cell in the Islets of Langerhans produce? |
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Definition
α cells (glucagon), β cells (insulin), δ cells (somatostatin)
β Cells make up 60-80% of cells in Islets. |
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Term
| What is the insulin C-chain? |
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Definition
| C-peptide, connecting peptide is released with insulin and slowly metabolized (half-life is 30 min.). Since C-chain has a longer half-life than insulin, C-chain is measured in the blood as an indicator of insulin secretion. |
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Term
| How do β cells sense energy levels? |
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Definition
β-Cells contain an ATP-dependent K channel which is opened by ADP and closed by ATP.
Closure of K channels causes cell to depolarize, activating voltage-gated Ca++ channels. Influx of Ca++ causes secretion of insulin from secretory vesicles. |
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Term
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Definition
| Hormones that enhance insulin release and help buffer changes in plasma glucose concentrations |
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Term
| What factors in addition to glucose regulate the release of insulin during a meal? |
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Definition
| Two peptides, glucose-dependent insulinotropic polypeptide (GIP) and glucoagon-like-peptide-1 (GLP-1) |
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Term
| Define Glucose-dependent insulinotropic peptide (GIP) |
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Definition
| GIP is secreted from K cells in the duodenum. GIP secretion is stimulated by food intake, particularly carbohydrates and fats, and occurs within minutes of food intake (feed forward regulation). |
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Term
| What are the effects of Glucose-dependent insulinotropic peptide (GIP)? |
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Definition
Stimulates glucose-dependent insulin secretion in normal individuals.
DOES NOT affect gastric emptying or food intake |
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Term
| Define Glucagon-like-peptide-1 (GLP-1) |
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Definition
| GLP-1 is released from L-cells in distal small intestine and colon. GLP-1 is contained in the proglucagon peptide. |
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Term
| What are the effects of Glucagon-like-peptide-1 (GLP-1)? |
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Definition
Stimulate glucose-dependent insulin secretion, increased proinsulin gene expression
Decreases glucagon secretion
Enhance β-cell proliferation. This effect is not dependent on glucose
Decreases gastric emptying and GI motility
Promotes satiety, decreases food intake |
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Term
| Do people with type 2 diabetes, is GLP-1 active? |
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Definition
| In Type 2 diabetes, GLP-1 is active, but secretion is decreased. |
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Term
| List symptoms of hypoglycemia |
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Definition
a. headaches
b. confusion
c. dizziness
d. incoordination
e. slurred speech
f. convulsions
g. coma
a. tachycardia
b. trembling
c. nervousness
d. sweating
e. anxiety |
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Term
| What is the criteria for diabetes? |
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Definition
| Criteria for diabetes is fasting plasma glucose > 140 mg/dl or plasma glucose > 200 mg/dl 2 hrs after a oral glucose load. |
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Term
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Definition
9% of diabetic patients
2 peaks of incidence: first peak at puberty, second peak around 40 years of age
lack of insulin due to destruction of pancreatic islet cells autoimmune disease – cause of disease is unknown |
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Term
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Definition
| excessive thirst due to increased urine flow and loss of water. Untreated patients are thirsty and consume large quantities of water. |
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Term
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Definition
| osmotic diuresis and loss of electrolytes and nutrients causing dehydration. |
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Term
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Definition
| excessive food consumption, probably due to loss of glucose in urine |
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Term
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Definition
90% of diabetic patients, usually in overweight adults, starting at middle age
80% of T2DM patients are obese
not enough glucose is excreted in urine to produce weight loss
ketosis seldom occurs spontaneously, and usually is associated with stress from trauma or infections |
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Term
| Define insulin resistance |
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Definition
| target tissues are unresponsive to insulin. Cells have decreased glucose uptake and decreased glycogen synthesis. Insulin resistance is thought to be related to obesity. |
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Term
| What do biguaninides (metformin, glucophage) do? |
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Definition
| inhibit hepatic gluconeogenesis |
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Term
| What do sulfonylureas (tolbutamide, ORIMIDE; glyburide, MICRONASE) do? |
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Definition
Stimulate secretion of insulin from
pancreas |
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Term
| What do GLP-1 agonists (exenatide, BYETTA)do? |
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Definition
enhances glucosestimulated
insulin release, decreases release of nutrients from stomach, decreases food intake |
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Term
| Which diabetes has poluphagia with weight gain? |
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Definition
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Term
| Which diabetes is often asymptomatic? |
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Definition
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Term
| List Chronic abnormalities of Type I and Type II Diabetes |
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Definition
1. atherosclerosis
2. peripheral vascular disease – leads to amputations
3. kidney failure
4. neuropathies
5. ulcerations and infections
6. retinopathy leading to blindness |
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Term
| Define the glucose tolerance test |
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Definition
| 75 gm glucose given to individual then blood glucose is measured for several hours. |
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