Homeostasis

• Glycogenesis: the formation of glycogen from glucose.
• Glycogenolysis is the breakdown of glycogen
• Glucogeneogenesis Is synthesis of glucose molecules from non-carbohydrates molecules
• The islets of Langerhans has 2 type of cells: a-cells and b-cells.
• a-cells release glucagon, which increases blood glucose levels by stimulating glycogenolysis and gluconeogenesis.
• Beta cells (beta) release insulin, which decreases blood glucose levels by promoting glycolysis and storage of excess glucose as glycogen or fat.
• Pancreas: a large gland behind the stomach which secretes digestive enzymes into the duodenum. Embedded in the pancreas are the islets of Langerhans, which secrete into the blood the hormones insulin and glucagon.
• Type 1 diabetes occurs when beta cells are destroyed by the immune system, leading to little or no insulin being produced.
• If there’s a high glucose concentration, Glycogenesis occurs.
• Gluconeogenesis is the production of new glucose from non-carbohydrate sources such as amino acids.
• Glycogenesis is the process whereby glucose molecules are converted into glycogen and stored in liver and muscle cells.
• Glycogenolysis is the breakdown of stored glycogen into glucose molecules.
• Insulin is released by the pancreas when blood glucose concentrations rise above normal levels.
• The main function of insulin is to lower blood glucose levels by increasing cellular uptake of glucose.
• Insulin is secreted by the Beta cells of the Islets of Langerhans in response to an increase in blood glucose levels.
• The main function of insulin is to lower blood glucose concentrations.
• Adrenaline inhibits glycogenesis
• Insulin increases the permeability of muscle-cells membranes to glucose, so cells can take up glucose.
• Adrenaline is secreted in the adrenal glands
• Adrenaline activates glycogenolysis
• Adrenaline increases the Glucose concentration
• The receptors for adrenaline and glucagon have tertiary structure that makes the complementary in shape to their hormones.
• Glucagon and Adrenaline activate enzyme Adenyl Cyclase.
• Activated Adenyl Cyclase converts ATP into chemical called cyclic AMP (cAMP), which is a second messenger.
• cAMP activates enzyme called Protein Kinase A. This activates a chain reaction that causes glycogenolysis.
• Type 2 diabetes is when the body can't produce enough insulin or the body cells don't respond to insulin. Blood Glucose concentration is higher than normal.
• Type 1 diabetes is when the pancreas stops producing insulin.
• The kidneys main function is to filter out waste products and reabsorb useful solutes.
• Ultrafiltration is when substances are filtered out of the blood and into nephrons (long tubules) that surround the capillaries.
• Selective re-absorption is when useful substances, such as glucose and the right amount of water , are then reabsorbed back into the blood.
• The Nephrons are long tubules with bundles of capillaries where the blood is filtered.
• Bowman's capsule is where ultrafiltration takes place.
• kidney is involved with different capillaries : Afferent Arteriole, Glomerulus, Efferent Arteriole and Blood capillaries.
• Kidney is made of fibrous capsule, which is the protective outer layer, and the cortex and the Medulla.
• Afferent arteriole in kidney, supplies the nephron with blood , arises from renal artery and joins the renal capsule into the glomerulus.
• Efferant arterioles in kidney, carries blood away from the renal capsule. It has a smaller diameter than Afferent arteriole.
• Diabetes Mellitus is an uncontrolled blood glucose concentration.