The Endocrine System, Second Edition

Disordersofanteriorpituitaryfunction:over-secretion48Disordersofunder-secretionofanteriorpituitaryhormones49Testsforhypopituitarism50Insufficientgrowthhormonesecretion505THEADRENALGLANDSPARTI:THEADRENALMEDULLA53Introduction54Wheretofindtheadrenalglands54Bloodsupply54Nervesupply55Embryologyoftheadrenalgland55Theadrenalmedulla55Disordersoftheadrenalmedulla:phaeochromocytoma59Familialphaeochromocytoma59Pharmacologicalusesofhormonesoftheadrenalmedulla606THEADRENALGLANDSPARTII:THEADRENALCORTEX61Introduction62Structureoftheadrenalcortex62Hormonesproducedbytheadrenalcortex62Regulationofsteroidproduction66Transportofsteroidhormonesinblood68Disordersofadrenalsteroids71Pharmacologicaluseofglucocorticoids737THETHYROIDGLAND75Introduction76Thyroidanatomy77Whatisagoitre?77Bloodsupply77Structureofthethyroid78Synthesisofthyroidhormones78Iodine79ThyroxineandT3:thethyroidhormonesinblood79Controlofthyroidfunction81Cellularactionofthyroidhormones82Effectsofthyroidhormones82Disordersofthyroidhormonesecretion83Causesofthyroidhyposecretion85Effectsofthyroidhormoneinsufficiency:myxoedema851INTRODUCTION1Whatisendocrinology?2Whatdohormonesdo?2Typesofhormone:theirsynthesisandsecretion4Thetransportandmetabolismofhormones7Importantconceptsinendocrineregulation8Endocrinedisorders10Endocrineinvestigations:generalprinciples122RECEPTORSANDHORMONEACTION15Introduction16Generalcharacteristicsofreceptors16Typesofhormonereceptors17Cell-membranereceptors17Hormonalregulationoftranscription23Intracellularreceptors24Disordersofreceptorfunction263THEHYPOTHALAMUSANDPITUITARYPARTI:THEHYPOTHALAMUSANDPOSTERIORPITUITARY27Introduction28WherecanIfindthehypothalamusandpituitary?28Connectionbetweenthehypothalamusandpituitary31Developmentofthehypothalamusandpituitary31Thehormonesofthehypothalamus31Thehormonesoftheposteriorpituitary32Releaseofposteriorpituitaryhormonesispartofaneuroendocrinereflex:oxytocinsecretionandactions32Regulationofvasopressinsecretion33Actionsofargininevasopressin34Disordersofvasopressinsecretionandaction35Thirst36Otherhypothalamichormones374THEHYPOTHALAMUSANDPITUITARYPARTII:THEANTERIORPITUITARY39Introduction40Structureoftheanteriorpituitary40Thehormonesoftheanteriorpituitary41Regulationofhormonesecretionintheanteriorpituitary43Growthhormoneandprolactininblood46Actionsoftheanteriorpituitaryhormonesgrowth:hormoneandprolactin46CONTENTS8HORMONALCONTROLOFREPRODUCTIONPARTI:MALEREPRODUCTIVESYSTEM87Introduction88Wherearethetestes?88Whatarethetestes?89Testicularbloodandnervesupply90Spermatogenesis91Androgenproduction91Hormonalcontroloftesticularfunction91Transportoftestosteroneinblood93Actionsoftestosterone93Hormone-dependentcancerinmen95Disordersofmalereproduction96Therapeuticusesofandrogens97Abuseofanabolicandrogenicsteroids97Decliningspermcounts989HORMONALCONTROLOFREPRODUCTIONPARTII:FEMALEREPRODUCTIVESYSTEM99Introduction100Structureoftheovary100Ovarianhormones100Transportandmetabolismofoestrogenandprogesterone102Oestrogens102Androgensecretionbytheovaries104Hormonalregulationofovarianfunction105Hormone-dependentcancerinwomen105Themenstrualcycle105Disordersofthemenstrualcycle108Theendocrinologyofpregnancy11010HORMONALCONTROLOFREPRODUCTIONPARTIII:DEVELOPMENTANDFERTILITY115Introduction116Genderdeterminationanddifferentiation116Hormonalcontrolofsexualdifferentiation116Abnormalitiesofsexualdifferentiation117Hormonesduringdevelopment:pubertyandmenarche118Disordersofpuberty119Menopauseandtheclimacteric121Prematureovarianfailure122Symptomsofthemenopause122Hormonereplacementtherapy123Alternativetherapies125Hormonalcontroloffertility:contraception125Hormonalcontroloffertility:assistedconception12611INSULINANDTHEREGULATIONOFPLASMAGLUCOSE129Introduction130Glucoseinurine130Insulinandtheresponsetohighbloodglucoselevels131Disordersofbloodglucoseregulation:diabetesmellitus135Gestationaldiabetes143Themetabolicsyndrome—agrowingproblem?14312HORMONALREGULATIONOFPLASMACALCIUMANDCALCIUMMETABOLISM147Introduction148Serumcalcium148Thestructure,functionsandendocrinologyofbone149Hormonesinvolvedintheregulationofserumcalcium151Parathyroidhormone151Calcitriol:sourceandactivationofvitaminD153Effectsofotherhormonesonplasmacalcium156Disordersofhypercalcaemia156Disordersofhypocalcaemia157Diseasesofbone158Abriefmentionofcalcitonin159Regulationofserumphosphate15913MISCELLANEOUSHORMONES161Erythropoietin162Immune–endocrineinteractions:cytokinesandeicosanoids163Age-relatedchangesinhormonesecretion164Melatonin164Guthormones166Thehormonalcontrolofappetite:fatisanendocrinetissue167Multipleorgandisordersinendocrinology168Regulationofbloodpressureandvolume169Thenext100yearsofendocrinology169Glossary171Index173CONTENTSChapterobjectivesAfterstudyingthischapteryoushouldbeableto:1.Explainwhatismeantbyahormoneandnamethemajorendocrineorgans.2.Categorizecommonhormonesbytheirbasicchemicalstructures.3.Understandtheroleofplasmabindingproteinsforsomehormones.4.Understandthedifferentformsofendocrineregulation,includingsetpoint,diurnalvariation,endocrineaxisandnegativefeedback.5.Understandthebasisofend