Chapter3 The Hypothalamus and Pituitary Part IThe Hypothalamus and Posterior PituitaryReference - Textbook Reference Course Website3ContentIntroductionOxytocinVasopressinINTRODUCTIONAnatomical and Functional Connection Between the Hypothalamus and Pituitary6hypophyseal portal system Hypothalamo hypophyseal tractCase: Mr. Jones, a 30-year-old man6 weeks earlierbegan passing a lot of urineOnce or twice per hourFull bladder four or five times during the nightUnusually thirstyConstantly drinking waterUrine was very palein recent weeksHeadaches at night or wakingForgetfulErection dysfunction Case: Mr. Jones, a 30-year-old manTest at GP (General Physician)Urine testNo protein, no glucoseBlood testGlucose and calcium level normalTest at endocrine clinicLooked uncomfortableDehydrated with a dry mouth and tongueBody Temperature normalResting pulse rate: 100 b.p.m.Blood pressure: 105/65 mmHgFundoscopy: optic nerve to be swollen in both eyesVisual field test: loss of vision in both temporal (outer) halves of the fieldMemory problem: Confuse and could not remember how he had got to the hospital or what he eaten that dayKnew the name of his girlfriend and could remember distant eventsVisual Field DefectOxytocin and VasopressinThe Hormone of the Posterior PituitarySmall peptides nine amino peptideSeven of them are commonSynthesized in the hypothalamus by magnocellular neuronsAction potential initial release in the nerve11Synthesis and Release of Vasopressin and OxytocinOXYTOCINRole of Oxytocin (OXT)Effect on mammary glands. Cause the contraction of the myoepithelial cells - milk ejectionUnconditioned and conditioned reflex Effect on uterusstimulate the smooth muscle contraction, especially that towards the end of gestation. at least partially responsible for causing birth of the baby1314OXYTOCINOxytocin Release: Neuroendocrine Reflex15Clinical UseOxytocinInduce laborIncrease uterine contractions during laborReduce postpartum bleeding after laborAtosiban: the antagonist of oxytocin receptorTreatment of the preterm labor 17Recent Work about OxytocinOxytocinBehavior HormoneCardiovascular HormoneGastrointestinal Hormone?VASOPRESSIN (ADH)Roles of ADHAntidiuretic effect Pressure effectconstricting the arterioles everywhereNeurotransmitter1920Vasopressin ReceptorslV2-receptor: lcollecting ductlVascular endothelial cellslV1(a)-receptor: lvascular smooth musclelV3(1b) receptor: lneurons (in CNS and ENS)lCorticotropin cells (in pituitary gland)Disorders of VasopressinDeficiencyCaused by a tumour or trauma of the brainDiabetes inspidus (hypothalamic or cranial)Polyuria large volumes of very dilute urinePolydipsia (烦渴）- excessive thirstTreatment: Desmopressin a synthetic analogue of vasopressinDisorders of VasopressinExcessCauses: Neoplasm-Lung cancerNeurological disease meningitis (脑膜炎）Lung disease pneumonia and tuberculosisPrescribed drug carbamazepine （立痛定）Syndrome of inappropriate ADH (SIADH)Urine more concentrated Hyponatraemia Headache, nausea, vomiting, confusion, comaClinical Use of VasopressinTo teat the diabetes insipidusReduce bleeding during gastrointestinal surgeryBoost factor VIII concentration in mild haemophiliaExplanation of Mr. Jones Syndromes and Signs6 weeks earlierbegan passing a lot of urineUnusually thirstyin recent weeksHeadaches at night or wakingForgetfulErection dysfunction Explanation of Mr. Jones Syndromes and SignsTest at endocrine clinicLooked uncomfortableDehydrated with a dry mouth and tongueBody Temperature normalResting pulse rate: 100 b.p.m.Blood pressure: 105/65 mmHgFundoscopy: optic nerve to be swollen in both eyesVisual field test: loss of vision in both temporal (outer) halves of the fieldMemory problem