Type 1 Diabetes Flashcards
diabetes
Group of metabolic disorders that are characterized by higher than normal blood sugar (dysglycemia) with disturbances in CHO, PRO, and FAT metabolism due to:
- impaired insulin secreation (beta cell dtysfunctioning)
- impaired insulin action/ glucose utilization (insulin resistance)
- both
- or absolute insulin deficiency
- therefore cannot maintain glucose homeostasis
type 1 diabetes
- results from the pancreas’s failure to produce enough insulin
- cause is unknown
what are the 3 main storage areas in the body for glucose (this may mean they being converted first)
1) liver
2) adipose tissue
3) muscle tissue
glycogenolysis
- biochemical breakdown of glycogen to glucose whereas glycogenesis is the opposite, the formation of glycogen from glucose.
- Glycogenolysis takes place in the cells of muscle and liver tissues in response to hormonal and neural signals
gluconeogenesis
metabolic pathway that results in the generation of glucose from certain non-carbohydrate carbon substrates
actions of glucagon and insulin on fats
INSULIN:
-uptake of fat into adipose tissues, uptake of CHO into adipose tissue, promotes chemical reactions that convert fa and glc to TGA, inhibits lipolysis (therefore decrease in blood fa and increase is TGA storage)
GLUCAGON:
-promotes fat breakdown, inhibits TGA synthesis, enhances ketogenesis (fa to ketones)
actions of glucagon and insulin on proteins
INSULIN:
-AT of aa into muscle and tissue, increase rate of incorporation into muscle, inhibit protein degradation (therefore blood aa decrease and increase in protein synthesis)
GLUCAGON:
-inhibits hepatic protein synthesis, promotes degradation of hepatic protein, stimulated gluconeogenesis
metabolism of carbs
-sum of anabolic (building) and catabolic (breakdown) process of starches into smaller units, GLUCOSE, fructose, galactose in the body that are in it’s main sources of immediate energy (fuel)
what CHO form is glucose stored as?
glycogen
which CHO is an exception to the metabolism process?
fibre
what is the easiest form of energy for the body to use for fuel?
glucose»» fatty acids
what are carbs a compound of
carbon, hydrogen, and oxygen- (CH2O)n
Do proteins and fats raise blood sugar level?
no (they can later be converted to glucose)
calorie content of macronutrients
1g CHO- 4 calories
1g PRO- 4 calories
1g FAT- 9 calories
Islets of langerhans
- regions of the pancreas that contain its endocrine (i.e., hormone-producing) cells
- alpha-> glucagon (25%)
- beta-> insulin and amylin (60%)
- delta-> somatostatin (10%)
glucagon
- secreted by alpha cells
- catabolic
- release of glucose
- glycogenolysis, gluconeogenesis, lipolysis
insulin
-secreted by beta cells
anabolic
-glucose uptake into cells
-glycogen synthesis, lipid synthesis, protein synthesis (by increasing aa uptake)
somatostatin
- (-) feedback to slow rate of digestion and nutrients
-In the pancreas, somatostatin is produced by the delta cells of the islets of Langerhans, where it serves to block the secretion of both insulin and glucagon from adjacent cells
(-also released by hypothalamus-> affects growth hormone)
what do glucagon and insulin have in common?
- both produced in pancreas
- boh involved in the regulation of metabolites
- however they end up doing the opposite function
what happens when the pancreas senses high blood sugar?
- secretes insulin (anabolic)
- insulin unlocks “doors” on tissue cells on the 3 storage sites
- glucose then moves from circulation into these storage sites
- blood sugar is thus lowered
what happens when the pancreas senses low blood sugar?
- it secretes glucagon (catabolic)
- binds to liver and then converts glycogen to glucose which is released into the blood
physiologic fasting blood sugar
3.9-5.7mmol/L
normal post prandial blood sugar
aka after eating
-7.8mmol
Physiological pattern of insulin secretion
- insulin levels peaks and dips throughout the day depending on your meals through the say
- 3 to 6 minutes after blood sugar is raised, insulin will start to be secreted-> it follows the path of the blood glucose
Which hormone dominates during the “fed state”
insulin
Which hormone dominates during the “fasted state”
glucagon
what occurs with an increase in insulin
-increase in glucose oxidation
-increase in glycogen synthesis-glycogenesis (therefore glucose uptake)
(inhibits glycogenogensis and gluconeogenesis)
-increase in fat synthesis
-increase in protein synthesis