Hormonal Regulation of Carbohydrates

Hormones What are hormones?

Islet of Langerhans As blood goes through the pancreas, insulin or glucagon is released into the blood stream based on the b.g.l http://www.britannica.com/EBchecked/media/101913/The-islets-of-Langerhans-are-responsible-for-the-endocrine-function

Blood Glucose Level When B.G.L is high When B.G.L is low Insulin is released (β) Muscles and liver takes in glucose (why?) Excess glucose is turned into fat (why?) When B.G.L is low Glucagon is released (α) Epinephrine and cortisol are released Hydrolysis of glycogen The release of insulin and glucagon is not an all-or-nothing situation. The relative concentrations of these two hormones in the blood determine the shift between energy storage and mobilization Impared glucose regulation: hyperglycemia and hypoglycemia

Hypoglycemia Feel nauseated, dizzy, irritable, sleepy, etc Too much insulin Prolonged exercise Reactive hypoglycemia Fasting hypoglycemia

Insulin-Responsive Glucose Transporter Glucose transporter – ATP & protein pump Insulin responsive glucose transporters – muscles and adipose tissue Brain and liver cells have glucose transporters that do not require insulin for the uptake of glucose http://www.lifesci.utexas.edu/faculty/sjasper/bio301L/digestion.html http://www.40daydetox.com/blood-sugar-insulin-and-diabetes-day-29/insulin-cell-receptors/

a lot more complex… http://flipper.diff.org/app/items/info/3459

Insulin Promotes Energy Storage Uptake of glucose into some cells Glycogenesis: glucose  glycogen Glucose  fatty acids (irreversible) Stimulate protein synthesis

Glucagon Promotes Mobilization of Stored Energy Glycogenolysis: glycogen  glucose Gluconeogenesis: amino acids  glucose Ketogenesis: fatty acids  glucose Liver glycogenolysis is stimulated by glucagon Muscle glycogenolysis is stimulated by epinephrine Gluconeogenesis is stimulated by both glucagon and epinephrine

Immediate Energy Source Cortisol released in response to a “fight or flight” situation Decrease glucose uptake (exept for the brain) Stimulate gluconeogenesis

Ketogenesis Fatty acids  ketones Occurs in the liver Stimulated by glucagon Energy usable by the brain, heart, muscles, and kidney Accumulation of ketones  ketosis Gluconeogenesis results in muscle loss and has its consequences (cardiac muscles).

Concept Map again… but yay~!! Groups of 3 Blood glucose level Chemical reactions in b.g.l. regulation Hormones involved in b.g.l. regulation Body tissues involved in b.g.l regulation