Regulation of Blood Glucose Levels: Insulin, Glucagon, and Diabetes - Prof. Douglas N. Ish, Study notes of Biology

Download Regulation of Blood Glucose Levels: Insulin, Glucagon, and Diabetes - Prof. Douglas N. Ish and more Study notes Biology in PDF only on Docsity! 26 March Figure 16.7 – Main responses of target cells to insulin Figure 16.8 Regulation of blood glucose levels Hypo (low) and hyper (high) glucemia (glucose levels) Figure 16.9 – Control of insulin secretion Figure 16.10 Blood plasma glucose and glucagon Negative regulators of blood glucose levels → oppose actions of insulin Glucagon (liver) Epinephrine Sympathetic nerves Cortisol Growth hormone Post-absorptive state ↓ [insulin] ↑ [glucagon] Figure 16.11 – Sympathetic nervous system and blood glucose levels Flgure 16.4 – Glucose counter regulatory controls (anti-insulin) Cortisol/growth hormone not coupled to absorptive/post-absorptive state; permissive facilitatory Cortisol – permissive, reduces sensitivity to insulin GH – differential, stimulates protein anabolism, effects on carbohydrate and lipid metabolism are minor Diabetes – “to pass through” Diabetes mellitus – high blood sugars (glucose) levels (hyperglycemia) Type 1 → loss of insulin producing beta cells (immune disease) Delivery of insulin to prevent diabetic ketoacidosis Type 2 → reduced insulin sensitivity (early stage) or insulin resistance (leads to increased insulin levels) Improve insulin sensitivity or reduce glucose production by liver Exercise, diet (decrease carbohydrate intake) Diabetes insipidus – excretion of large amounts of dilute urine due to vasopressin (ADH) deficiency Figure 16.20 Ketoacidosis Severe insulin deficiency (diabetes mellitus) Figure 16.14 – Hunger regulation Feeding center in hypothalamus Arcuate nucleus – secretes neuropeptide Y (NPY) Stimulates eating (creates hunger sensation) Leptin Secreted by adipose tissue