INTRODUCTION TO THE ENDOCRINE SYSTEM AND THE PITUITARY- HYPOTHALAMIC AXIS D. C. MIKULECKY PROFESSOR OF PHYSIOLOGY
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
CATEGORIES OF HORMONES zPEPTIDES zAMINES zSTEROIDS
PEPTIDES zHYDROPHILIC zDISSOLVED IN PLASMA zRECEPTOR ON CELL SURFACE zSECOND MESSENGERS zMAY ACTIVATE SPECIFIC GENES TO REGULATE PROTEIN SYNTHESIS
PEPTIDE HORMONES zHYPOTHALAMIC zPITUITARY zPANREATIC zPARATHYROID zGI zKIDNEY zLIVER zHEART
AMINES zTHYROID HORMONE zCATECHOLAMINES zALL DERIVED FROM AMINO ACID TYROSINE zUNIQUE SYNTHETIC AND SECRETORY PATHWAYS
STEROIDS zDERIVED FROM CHOLESTEROL zLIPOPHILIC zRECEPTOR IN CYTOPLASM zMAY ACTIVATE SPECIFIC GENES TO INITIATE PROTEIN SYNTHESIS zADRENAL CORTICAL zGONADAL zPLACENTAL
PLASMA CONCENTRATION OF HORMONES zDEPENDS ON RATE OF SECRETION zNEGATIVE FEEDBACK zNEUROENDOCRINE REFLEXES zDIURNAL RHYTHMS
TYPES OF ENDOCRINE DISORDERS zHORMONE EXCESS zHORMONE DEFICIENCY zDECREASED RESPOSIVENESS OF RECEPTORS
THE PITUITARY- HYPOTHALAMIC AXIS INTERFACING THE NERVOUS SYSTEM WITH THE ENDOCRINE SYSTEM
HYPOTHALAMUS AND POSTERIOR PITUITARY HYPOTHALAMUS NEUROSECRETORY NEURONS ANTERIOR PITUITARY POSTERIOR PITUITARY SYSTEMIC ARTERY SYSTEMIC VEIN VASOPRESSIN OXYTOCIN
HYPOTHALAMUS AND ANTERIOR PITUITARY HYPOTHALAMUS NEUROSECRETORY NEURONS ANTERIOR PITUITARY: TSH ACTH PROLACTIN GROWTH HORMONE LH FSH POSTERIOR PITUITARY
CLASSIFICATION OF ANTERIOR PITUITARY HORMONES zGLYCOPROTEIN FAMILY: TSH, FSH,LH zGROWTH HORMONE PROLACTIN FAMILY: GH OR STH zPROOPIOMELANOCORIN FAMILY: ACTH, -LIPOTROPIN, -ENDORPHIN
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
HYPOTHALAMIC REGULATORY HORMONES zHYPOPHYSIOTROPIC HORMONES zCONTROL THE SECRETION OF OTHER HORMONES BY ACTING ON ENDOCRINE TISSUE
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
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
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
ANTERIOR PITUITARY HORMONES:TSH zTHYROID GLAND zTHYROID HORMONES (T 3 & T 4 )
ANTERIOR PITUITARY HORMONES:ACTH zADRENAL CORTEX zCORTISOL
ANTERIOR PITUITARY HORMONES:PROLACTIN zMAMMARY GLANDS zBREAST GROWTH AND MILK SECRETION
ANTERIOR PITUITARY HORMONES: GROWTH HORMONE zLIVER zSOMATOMEDINS zBONE zSOFT TISSUE zGROWTH z MANY TISSUES z INTERMEDIARY METABOLISM z INCREASE OR DECREASE
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