6. Carbohydrates
Terms
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- Glucose is derived from what 3 sources?
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1. Dietary carbs
2. Body carb stores
3. Synthesis from protein/triglycerides -
Give examples of:
-Monosacch's
-Oligosacc's
-Polysacc's -
Mono = glucose
Oligo = maltose/lactose
Poly = Starch - Outline the absorption of carbs:
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1. Eat complex carbs
2. Salivary amylase breaks down
3. From stomach to sm intestine
4. Small intestine to portal vein, pancreatic amylase
5. To liver - Key hormones that regulate blood glucose:
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1. Insulin
2. Counter-regulatory hormones - Where is insulin produced?
- pancreatic beta cells of islets of langerhans
- What does insulin do?
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-Promotes glycogenesis - storage of glucose as glycogen;
-Promotes lipogenesis - What are the counter-regulatory hormones?
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SCHAGGET
Somatostatin, Cortisol, HPL, ACTH, GH, Glucagon, Epinephrine, Thyroxine. - What 2 hormones specifically coutneract insulin?
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1. Somatostatin
2. Gastric inhibitory peptide - How do counter-regulatory hormones function? (3 roles)
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1. Stimulate glycogenolysis
2. Stimulate glucose conversion to glycerol
3. Stimulate gluconeogenesis to make glucose from protein - Where is Glucagon secreted from?
- Alpha cells of pancreatic islets of langerhans
- When glucose increases in the body, how do insulin/glucagon respond?
-
Insulin - released
Glucagon - inhibited.
... Want to store it away. - What is a normal blood sugar level?
- 80-120 mg/dl
- What is considered hypoglycemic blood sugar level?
- <70-104 mg/dl
- What is considered hyperglycemic blood sugar level?
- >200 mg/dl
- Waht is considered a hyperglycemic FASTING bl sugar?
- >126 mg/dl
- what is the renal threshold for glucose?
- 160-180 mg/dl
- How is hypoglycemia diagnosed?
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-Physical symptoms
-Insulin levels
-Glucose levels - How would you tell if hypoglycemia is result of administered insulin (treatment) or not?
- Measure C-peptide; commercial insulin lacks this.
- What would clue you in to adult hypoglycemia?
- Hypoglycemic fasting levels - below 50 is uncommon; investigate!
- List 6 disorders of hypo and hyper-glycemia:
-
1. Cushing's
2. Addison's
3. Pheochromocytoma
4. Islet cell tumor
5. Acromegaly
6. Alcoholism - State the defintition of Diabetes Mellitus
- An absolute or relative deficiency of insulin, often progressing to hyperglycemia and associated w/ micro/macro-vascular complications and altered immune response.
- What are the 2 types of D. mellitus?
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1 - insulin dependent
2 - noninsulin dependent - Which type is more common?
- 2
- Which type is ketosis more common in?
- 1
- Which type is obesity common in?
- 2
- Which type has islet cell antibodies?
- 1
- Which one shows insulin resistance more often?
- 2
- How is diabetes diagnosed?
- By testing fasting glucose levels, and 2-hr post prandial glucose levels
- How is the diagnosis confirmed?
- By repeating the test on a different day.
- What are 3 other types of diabetes, other than mellitus?
-
1. Pre-diabetes
2. Gestational
3. Other-condition-associated - How is Gestational diabetes tested for?
- By doing a glucose tolerance test
- How is a glucose tolerance test done?
-
-Draw fasting blood sugar
-Give 50 g Glucose
-Draw at 3 additional hours, on the hour. - What is the structure of insulin like?
-
-2 components: A + B
-Disulfide bond holds A/B tite
-C peptide also bonded to both - How is Pro-insulin in the beta cells activated?
- by enzymes from the Beta cells
- What happens when Proinsulin is cleaved?
- C-peptide is released
- What is the specific action of insulin?
- Increased cell permeability to glucose
- The basic problem in Diabetes type 1 is:
- decreased insulin production; antibodies to the islet cells
- The basic problem in Diabetes type 2 is:
- decreased insulin RESPONSE; further problems differentiate type IIA and IIB
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What is the problem in Diabetes type IIA?
type IIB? -
IIA: decreased insulin receptors
IIB: antibodies to insulin - The 3 targets of Insulin:
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1. Muscle
2. Adipose tissue
3. Liver - What 5 factors can decrease insulin receptors?
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1. Caloric intake (high)
2. Age
3. Weight
4. Antagonsit hormones
5. Chronic high insulin - What 3 factors can increase insulin receptors?
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1. Anorexia
2. Low insulin levels
3. GH/glucocorticoid deficiency - What are 4 factors that affect Insulin's effectiveness?
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1. Concentration reaching target
2. Insulin receptors on target
3. Insulin receptor affinity
4. Cell response to insulin - Which type of diabetes has a more genetic disposition?
- Type I
- What are metabolic complications of diabetes?
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1. Ketoacidosis - type 1
2. Hyperglycemic coma (type 2) - What etiologic factors are associated with Type I? (4)
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1. Viral
2. Autoimmune
3. Genetics
4. HLA type - What etiologic factors are associated with Type II? (4)
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1. Diet
2. Obesity
3. Genetics
4. Post receptor effect - What are the 3 poly's in the pathogenesis of diabetes?
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1. Polyuria
2. Polydipsia
3. Polyphagia - List the 3 chronic complications of diabetes:
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1. Poor wound healing/infections
2. Microangiopathy
3. Macroangiopathy