BIOLOGY 225 Lecture Notes - Lecture 23: Anterior Pituitary, Insulin Resistance, Blood Sugar
Document Summary
Set point: the value of the variable that the body is trying to maintain. Output of effector amplifies variable away from the set point. Output of effect brings variable back to set point. Type 1: loss of beta cells of the pancreas, little or no insulin being produces, no cure but there is treatment. Type 2: caused by insulin resistance. Insensitive to endogenous insulin: deficiency in response of pancreatic beta cells to glucose, non-insulin-dependent diabetes mellitus, inflated fat cells and over-nourished liver/muscle cells, hyperplasia of pancreatic beta cells. Hypothalamic-pituitary axis stimulates the adrenal cortex: hypothalamus. Secretes corticotropin-releasing hormone (crh: anterior pituitary. Secretes adrenocorticotropic hormone (acth: adrenal cortex. Stimulates target cells to increase blood glucose level. Medulla produces catecholamines (epinephrine and norepinephrine) Effects of glucocorticoids: proteins and fats break down and convert to glucose leading to increase in blood glucose, possible suppression of immune system. Stress corticosteroids alarm and resistance: drug-cortizone, insect bite.
