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INTRODUCTION TO THE ENDOCRINE SYSTEM AND THE PITUITARY- HYPOTHALAMIC AXIS D. C. MIKULECKY PROFESSOR OF PHYSIOLOGY
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COMPARISON OF ENDOCRINE AND NERVOUS SYSTEMS zNERVOUS SYSTEM z“WIRED” zCHEMICAL SIGNAL AT TARGET CELL zRAPID zBRIEF DURATION z ENDOCRINE SYSTEM z “WIRELESS” z CHEMICAL SIGNAL AT TARGET CELL z SLOW z LONG DURATION
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CATEGORIES OF HORMONES zPEPTIDES zAMINES zSTEROIDS
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PEPTIDES zHYDROPHILIC zDISSOLVED IN PLASMA zRECEPTOR ON CELL SURFACE zSECOND MESSENGERS zMAY ACTIVATE SPECIFIC GENES TO REGULATE PROTEIN SYNTHESIS
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PEPTIDE HORMONES zHYPOTHALAMIC zPITUITARY zPANREATIC zPARATHYROID zGI zKIDNEY zLIVER zHEART
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AMINES zTHYROID HORMONE zCATECHOLAMINES zALL DERIVED FROM AMINO ACID TYROSINE zUNIQUE SYNTHETIC AND SECRETORY PATHWAYS
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STEROIDS zDERIVED FROM CHOLESTEROL zLIPOPHILIC zRECEPTOR IN CYTOPLASM zMAY ACTIVATE SPECIFIC GENES TO INITIATE PROTEIN SYNTHESIS zADRENAL CORTICAL zGONADAL zPLACENTAL
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PLASMA CONCENTRATION OF HORMONES zDEPENDS ON RATE OF SECRETION zNEGATIVE FEEDBACK zNEUROENDOCRINE REFLEXES zDIURNAL RHYTHMS
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TYPES OF ENDOCRINE DISORDERS zHORMONE EXCESS zHORMONE DEFICIENCY zDECREASED RESPOSIVENESS OF RECEPTORS
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THE PITUITARY- HYPOTHALAMIC AXIS INTERFACING THE NERVOUS SYSTEM WITH THE ENDOCRINE SYSTEM
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HYPOTHALAMUS AND POSTERIOR PITUITARY HYPOTHALAMUS NEUROSECRETORY NEURONS ANTERIOR PITUITARY POSTERIOR PITUITARY SYSTEMIC ARTERY SYSTEMIC VEIN VASOPRESSIN OXYTOCIN
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HYPOTHALAMUS AND ANTERIOR PITUITARY HYPOTHALAMUS NEUROSECRETORY NEURONS ANTERIOR PITUITARY: TSH ACTH PROLACTIN GROWTH HORMONE LH FSH POSTERIOR PITUITARY
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CLASSIFICATION OF ANTERIOR PITUITARY HORMONES zGLYCOPROTEIN FAMILY: TSH, FSH,LH zGROWTH HORMONE PROLACTIN FAMILY: GH OR STH zPROOPIOMELANOCORIN FAMILY: ACTH, -LIPOTROPIN, -ENDORPHIN
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HYPOTHALAMIC-HYPOPHYSEAL PORTAL SYSTEM zSECRETED BY NERVE CELLS IN HYPOTHALAMUS zVESSELS PASS THROUGH STALK OF PITUITARY FROM HYPOTHALAMUS TO ANTERIOR PITUITARY zCARRY HYPOTHALAMIC REGULATORY HORMONES
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HYPOTHALAMIC REGULATORY HORMONES zHYPOPHYSIOTROPIC HORMONES zCONTROL THE SECRETION OF OTHER HORMONES BY ACTING ON ENDOCRINE TISSUE
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HYPOTHALAMIC RELEASING AND INHIBITING HORMONES (HYPOPHYSIOTROPIC) zCONTROL THE SECRETION OF ANTERIOR PITUITARY TROPIC HORMONES zTRH:THYROTROPIN-RELEASING HORMONE zPRF:PROLACTIN RELEASING FACTOR zPIF:PROLACTIN INHIBITING FACTOR zGHRH:GROWTH HORMONE RELEASING HORMONE zSRIF: SOMATOTROPIN RELEASE-INHIBITING FACTOR zCRH:CORTICOTROPHIN RELEASING HORMONE zGnRH: GONADOTROPIN RELEASING HORMONE
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HIERARCHICAL CONTROL INPUT HORMONE 1 (RELEASING/INHIBITING) HORMONE 2 (TROPIC) HORMONE 3 TARGET CELLS SYSTEMIC CIRCULATION H/H PORTAL SYSTEM HYPOTHALAMUS ANTERIOR PITUITARY ENDOCRINE GLAND
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NEGATIVE FEEDBACK INPUT HORMONE 1 (RELEASING/INHIBITING) HORMONE 2 (TROPIC) HORMONE 3 TARGET CELLS SYSTEMIC CIRCULATION H/H PORTAL SYSTEM HYPOTHALAMUS ANTERIOR PITUITARY ENDOCRINE GLAND
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ANTERIOR PITUITARY HORMONES:TSH zTHYROID GLAND zTHYROID HORMONES (T 3 & T 4 )
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ANTERIOR PITUITARY HORMONES:ACTH zADRENAL CORTEX zCORTISOL
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ANTERIOR PITUITARY HORMONES:PROLACTIN zMAMMARY GLANDS zBREAST GROWTH AND MILK SECRETION
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ANTERIOR PITUITARY HORMONES: GROWTH HORMONE zLIVER zSOMATOMEDINS zBONE zSOFT TISSUE zGROWTH z MANY TISSUES z INTERMEDIARY METABOLISM z INCREASE OR DECREASE
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ANTERIOR PITUITARY HORMONES: LH & FSH: ACT ON GONADS zLH:LUTEINIZING HORMONE zSEX HORMONE SECRETION zF: ESTROGEN AND PROGESTERONE zM: TESTOSTERONE z FSH:FOLLICLE STIMULATING HORMONE z GAMETE PRODUCTION z OVA z SPERM
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