Exam 4 Endocrine Function Endocrine Function Control and regulate organ systems and organ functions diffuse communication blood borne chemicals transmitters Hormones Wide spread and long lasting Endocrine Glands ductless glands with very rich vascular network hormones enter circulatory system Distinct Functions Regulation homeostasis ion water nutrient thermoregulation cellular metabolism Growth and development Reproductive function Given this diffuse mechanism of communication how do hormones target specific cells Requires specificity of RECEPTORS specific to different hormone chemical messengers G protein linked Secondary Messenger pathways adenyl cyclase cAMP catalyzing activating protein kinase change cell function specific intracellular function and mechanisms Regulation of Stomach Cephalic Phase sight taste or smell of food trigger autonomic control sympathetic NS fight or flight Gastric Phase stretch of stomach muscles activates receptors enteric stretch receptors Stomach contractions and secretions Intestinal Phase digestion of SI duodenum enteric reflex pathways fatty acids and acidic gastric juices Hormones secretin gastric inhibitory peptide cholecystokinin Negative Positive Food chemicals change pH release of Gastrin Feedback Mechanism if pH is too LOW decrease of Gastrin secretion Regulation of Small Intestine Activity Enteric Reflexes change stretch change pH Peristalsis and Segmentation Stomach Juices Foodstuff chyme secretin gastric inhibitory peptide GIP cholecystokinin CCK Secretin activity gastric acid inhibits gastric acid production and stimulate HCO3 in SI to neutralize CCK presence of fats fats take time to digest slow gastric activity GIP released in presence of carbohydrates accompanied by glucagon like peptide 1 GLP1 Act hormonally on pancreas to promote release of insulin ready for carb absorption Hormonal parathyroid hormone active VD kidney activated decrease promotes absorption of Ca2 absorption at SI Aldosterone promoted H2O and Na absorption Pituitary Gland Master Gland Anterior lobe is glandular meaning producing hormones posterior lobe is NOT glandular it is an extension of the hypothalamus hormones produced by hypothalamus are transported and controlled by hypothalamus Anterior Lobe Hormones Follicle Stimulating Hormone FSH tropic hormone regulates gamete production regulates activity of gamete Luteinizing Hormone LH tropic hormone regulates gamete production regulates activity of gamete Adrenocorticotropic Hormone ACTH regulates Growth Hormone regulates growth of muscle and adrenal cortex long bones Prolactin stimulate development promotes lactation stimulates production of testosterone Thyroid Stimulating Hormone TSH controlling activity of thyroid gland Posterior Lobe Hormone Oxytocin regulates uterine contraction triggers lactation Antidiuretic Hormone ADH regulates absorption at the nephron Hormone Interactions Permissiveness require the binding of 2 or more hormones to alter cell function Synergism interaction of 2 or more hormones which enhance the effect of each individual hormone Antagonism interaction of 2 or more hormones which interrupt to effect of each individual hormones Mechanism of Control Humoral Control endocrine gland detect change in physiological state and responds to correct it ex parathyroid gland sensor controller effector via hormones Neural Control endocrine gland responds to neural stimulation brain is the controller ex adrenal gland endocrine gland is the effector Hormonal Control endocrine gland is controlled by hormones released by a different endocrine gland 2nd endocrine gland controller releases tropic hormones Tropic Hormones produced by one endocrine gland to control another endocrine gland Follicle Stimulating Hormone ovaries and gonads Adrenocorticotropic Hormone ACTH adrenal gland affects the hormones it produces Thyroid Stimulating Hormone TSH stimulates Thyroid Hormone Atrial Natriuretic Peptide ANP responds as result of high blood pressure effects kidney and adrenal gland Insulin Resistance excessive insulin leads to decrease in GLUT4 glucose receptors metabolic acidosis high triglycerides and free fatty acid levels supra acide dismutase mitochondrial antioxidant mechanism cortisol stress hormone decreases GLUT4 in blood receptors Diabetes Mellitus Greek siphon latin sweet like honey Symptoms Hunger Thirst Frequent and excessive urination fatigue glucose is in the blood and urine NOT in the tissues cells yelling to brain we are hungry Chronically High Blood sugar damages the vasculature thickening of basement membrane and Damage endothelial hyperplasia reduced blood flow poor glucose control reduced diffusion of oxygen the nerves blood vessels less elastic retina kidney Hypovolemia Reduced blood flow impaired healing low flow high tissue glucose O2 rapid aggressive infection amputation to contain infection