Endocrine Principles IV 4 Complex inputs and the central nervous system A B C CNS endocrine anatomy Posterior pituitary Anterior pituitary 1 2 3 D Hypothalamic inputs Hormones Feedback You now know everything Input Types of input Simple Examples H H H Hormones regulating other hormones CNS integrated regulation H H Glucose regulation by insulin Calcium regulation by parathyroid hormone Complex Hormone H Regulated by response Sensed by endocrine tissue directly H H H H H H H Hormones Complex stimuli Combination Response 2 The 4th path to target response neuroendocrine H Specialized nerve cells Many peptide hormones are neurotransmitters Can go both ways H H signal H Response H 3 Most neuronal control occurs through the hypothalamus and the pituitary gland Diencephalon Corpus callosum Thalamus Hypothalamus Pineal gland Pituitary gland 4 The pituitary is really two glands Anterior pituitary hypothalamus Hypothalamicpituitary axis HPA Infindibulum Anterior pituitary Anterior front Posterior back Hypothalamu s Sphenoid bone Posterior pituitary 5 The posterior pituitary Two 9 amino acid peptide hormones Antidiuretic hormone ADH Vasopressin Oxytocin Prohormones travel down long axons Processed to mature hormones Released into capillary beds Hypothalamus Prohormones made in large neural soma Blood flow in To general circulation 6 The anterior pituitary Hypothalamic regulating hormones made in small neural soma Blood flow in Regulate trophic hormone synthesis and release from specific endocrine epithelial cells Small compared to posterior pituitary neurons Regulating hormones released into portal circulation Travel down capillary beds Trophic hormones to general circulation 7 Anterior posterior pituitaries do NOT share circulation Do not interact directly 8 HPA axis allows endocrine system to respond to complex stimuli Sensory neurons Time Senses Energy in out Hypothalamic integrating center Six hypothalamic regulatory hormones Physical stress Temperature Six anterior pituitary tropic hormones Emotional stress Osmotic Autonomic inputs Regulate Metabolism Stress response Development 9 GHIH PIH dopamine GnRH CRH Adrenal cortex FSH LH Prolactin TSH GHRH GH Anterior Pituitary ACTH TRH Hypothalamus Hormones of the hypothalamic anterior pituitary axis Thyroid gland Gonads Breast Cortisol Aldosterone Epinephrine Androgens estrogens Thyroid hormone Many tissues 10 Anterior pituitary secretes hormones from specialized cell types Proportion of each cell type This is where the idea of a master gland comes from Mammotroph Growth hormone Thyroid Stimulating H Corticotroph Somatotroph Luteinizing H Follicle Stimulating H Adrenocorticotropin Prolactin Gonadotroph Thyrotroph 11 Terminology applies only to the HPA axis Pituitary control loops Hypothalamus Ultra short Loop RH Target Organ H H Short Loop H hormone T tropic R releasing Long Loops TH Pituitary 12 Note that Releasing hormones or inhibiting hormones are always secreted by the hypothalamus Anterior pituitary hormones are usually given some sort of regulatory designation Thyroxine stimulating hormone Adrenocorticotrophic hormone Follicle stimulating hormone No circulating steroid hormones are made in the brain or pituitary Hypothalamus all peptides except dopamine Anterior pituitary glycoproteins peptides 13 Remember this We will cover 40 hormones 70 recognized hormones 100 s meet the technical definition 14 You now know EVERYTHING about them Don t panic BUT you do need to get to work you really need to grasp these topics soon The rest of the time will be spent Covering hormone function Unique responses Compare contrast steroid protein hormone properties 15 Review questions 1 Identify which of the following hormones are proteins or steroids and if their origin is from the anterior pituitary the hypothalamus or neither Hormone Type Endocrine tissue Androstenedione Follicle stimulating hormone Growth hormone inhibiting hormone Thyroid stimulating hormone Insulin Cortisol Corticotropin releasing hormone 2 Draw and label a hypothalamus with a posterior and anterior pituitary Add a short and long feedback loop 3 A hormone is released from the posterior pituitary and inhibits the release of something releasing hormone Would this be considered long loop short loop or ultrashort loop negative feedback 4 Define the following a Portal Circulation b The suffixes tropic or trophic statin and medin 16 Hints Tips From slide 7 Portal Circulation a part of the circulatory system where a vein drains into a capillary bed then back into the venous system as opposed to normal circulation where the blood goes from arterial capillary venous circulation From Slide 10 We will discuss all of this later remember there is no need to memorize abbreviations all will be supplied on the test For reference purposes RH Releasing hormone SH Stimulating hormone ACTH Adrenocorticotropic hormone CRH Corticotrophin RH FSH Follicle SH GH Growth hormone GHRH Growth Hormone RH GHIH Growth hormone inhibiting hormone also somatotrophin GnRH Gonadotropin RH IGF1 Insulin like growth factor 1 LH Luteinizing hormone PIH Prolactin inhibiting hormone also dopamine TRH Thyrotropin RH TSH Thyroid SH 17 Hints Tips From slide 33 The brain actually does make steroid hormones However they all appear to be used locally within the brain So that if one tested venous blood from the one s arm none of the steroids found there would be from the brain It is important to note that circulating steroids often affect the function of the CNS tropic or trophic affecting or regulating statin inhibit medin intermediary 18
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