Pituitary and hypothalamus
•Download as PPTX, PDF•
10 likes•5,298 views
Anatomy, Pathology/ disorders and Management / pharmacological
Recommended
More Related Content
What's hot
What's hot (20)
Viewers also liked
Similar to Pituitary and hypothalamus
Similar to Pituitary and hypothalamus (20)
More from Oriba Dan Langoya
More from Oriba Dan Langoya (20)
Recently uploaded
Recently uploaded (20)
Pituitary and hypothalamus
- 1. Pituitary and Hypothalamus Oriba Dan Langoya
- 2. Disorders of the Anterior Pituitary and Hypothalamus • Ant pit often is referred to as the "master gland“ • Produces 6 major hormones: 1. Prolactin (PRL) 2. Growth hormone (GH), 3. Adrenocorticotropic hormone (ACTH) 4. Luteinizing hormone (LH) 5. Follicle-stimulating hormone (FSH) 6. Thyroid-stimulating hormone (TSH)
- 4. Anatomy and Development • Pit gland weighs 600mg located in sellar turcica • Pit dev’t from Rathke's pouch involves a cplx interplay of lineage-specific transcription factors • Transcription factor Prop-1 induces pit dev’t of Pit- 1-specific lineages as well as gonadotropes • Pit-1 determines cell-specific expression of GH, PRL, and TSH in somatotropes, lactotropes, and thyrotropes. • High levels of ER in cells that contain Pit-1 favors PRL expression, whereas thyrotrope embryonic factor (TEF) induces TSH expression
- 5. Hypothalamic & Ant Pit Insufficiency Etiology of Hypopituitarism • Development/structural • Transcription factor • Pituitary dysplasia/aplasia • Congenital CNS mass, encephalocele • Primary empty sella • Congenital hypothalamic disorders (septo-optic dysplasia, • Prader-Willi synd • Kallmann syndrome) • Traumatic • Surgical resection • Radiation damage • Head injuries • Infections • Fungal (histoplasmosis) • Parasitic (toxoplasmosis) • Tuberculosis • Pneumocystis carinii
- 6. Etiology of Hypopituitarism • Neoplastic • Pituitary adenoma • Parasellar mass (germinoma, ependymoma, glioma) • Rathke's cyst • Craniopharyngioma • Pituitary metastases (breast, lung, colon carcinoma) • Lymphoma and leukemia • Meningioma • Infiltrative/inflammatory • Lymphocytic hypophysitis • Hemochromatosis • Sarcoidosis • Histiocytosis X • Granulomatous hypophysitis • Vascular • Pituitary apoplexy • Infarction with diabetes; postpartum necrosis) • Sickle cell disease • Arteritis
- 7. Dev’tal and Genetic Causes of Hypopituitarism Pituitary Dysplasia Result in aplastic, hypoplastic, or ectopic pituitary gland dev’t Septo-Optic Dysplasia Pit dysfunction leads to diabetes insipidus, GH def and short stature, and, TSH def. Mutations in the HESX1 gene Tissue-Specific Factor Mutations Pit-1 mutations cause combined GH, PRL, and TSH deficiencies Prop-1 is appears to be required for Pit-1 function PROP1 mutations result in combined GH, PRL, TSH, and gonadotropin deficiency Over 80% of these patients have growth retardation
- 8. Developmental Hypothalamic Dysfunction Kallmann Syndrome Defective hypothalamic GnRH syn & is assoc with anosmia or hyposmia due to olfactory bulb agenesis Xterized by low LH and FSH levels and low conc of sex steroids (testosterone or estradiol) Repetitive GnRH admin restores normal pit gonadotropin responses, pointing to a hypothalamic defect Bardet-Biedl Syndrome Rare genetical disorder xterized by mental retardation, renal abnormalities, obesity, and polydactle. Central diabetes insipidus may or may not be associated. • GnRH deficiency occurs, Retinal degeneration begins in early childhood, and most patients are blind by age 30
- 9. Developmental Hypothalamic Dysfunction Leptin and Leptin Receptor Mutations Lack causes broad spectrum of hypothalamic abnormalities, • Including hyperphagia, obesity, and central hypogonadism. • Decreased GnRH prodn in these patients results in attenuated pituitary FSH and LH synthesis and release. Prader-Willi Syndrome Deletion of genes on chromosome 15q. • Xterised by hypogonadotropic hypogonadism, hyperphagia-obesity, chronic muscle hypotonia, mental retardation, and adult-onset diabetes mellitus
- 10. Acquired Hypopituitarism Caused by • Accidental or neurosurgical trauma • Vascular events such as apoplexy • Pituitary or hypothalamic neoplasms, • Craniopharyngioma, lymphoma, or metastatic tumors. • Inflammatory disease such as lymphocytic hypophysitis • Infiltrative disorders such as sarcoidosis, hemochromatosis • Tuberculosis; or irradiation.
- 11. Acquired Hypopituitarism • Inflammatory Lesions commonly infections by • Tuberculosis • Opportunistic Fungal infection assoc with HIV • Tertiary syphilis • Other inflammatory processes, such as granulomas and sarcoidosis • Lymphocytic Hypophysitis • Often in postpartum women; it usually presents with hyperprolactinemia, • Mildly elevated PRL levels. • patients manifest syms of progressive mass effects with headache and visual disturbance. ESR often is elevated
- 12. Pituitary Apoplexy • Acute intrapituitary hemorrhagic vascular events • May occur spontaneously in a preexisting • Adenoma; • Postpartum (sheehan's syndrome); or in assoc with diabetes • Hypertension, sickle cell anemia, or acute shock • Apoplexy is an endocrine emergency • May result in severe hypoglycemia, hypotension and shock, central nervous system (CNS) hemorrhage, and death. • Acute symps include severe headache with signs of meningeal irritation, bilateral visual changes, ophthalmoplegia, and, in severe cases. • Cardiovascular collapse and loss of consciousness
- 13. Presentation and Diagnosis • Clinical manifestations of depend on which hormones and the extent of hormone deficiency • GH def causes growth disorders in children & abnormal body composit in adults • Gonadotropin def causes menstrual disorders and infertility and decreased sexual function, infertility, and loss of secondary sexual Xteristics in men. • TSH def causes growth retardation in children and features of hypothyroidism in children and adults. • ACTH def leads to hypocortisolism • PRL def causes failure of lactation. • When lesions involve the posterior pituitary, polyuria and polydipsia reflect loss of vasopressin secretion
- 14. Laboratory Investigation • Biochemical diagnosis of pituitary insufficiency is made by demonstrating low levels of trophic hormones in the setting of low levels of target hormones • Test for • ACTH • TSH • FSH/LH • GH • Vasopressin
- 15. Treatment: Hypopituitarism ACTH, Hormone Replacement • Hydrocortisone (10–20 mg A.M.; 5–10 mg P.M.) • Cortisone acetate (25 mg A.M.; 12.5 mg P.M.) • Prednisone (5 mg A.M.) FSH/LH • Males • Testosterone enanthate (200 mg IM every 2 weeks) • Testosterone skin patch (5 mg/d) • Females • Conjugated estrogen (0.65–1.25 mg qd for 25 days) • Progesterone (5–10 mg qd) on days 16–25 • Estradiol skin patch (0.5 mg, every other day) • For fertility: Menopausal gonadotropins, human chorionic gonadotropins
- 16. Treatment: Hypopituitarism TSH L-Thyroxine (0.075–0.15 mg daily) • Generally hormone replacement therapy, including glucocorticoids, thyroid hormone, sex steroids, growth hormone, and vasopressin GH • Adults: Somatotropin (0.1– 1.25 mg SC qd) • Children: Somatotropin [0.02–0.05 (mg/kg per day)] • Vasopressin • Intranasal desmopressin (5–20 g twice daily) • Oral 300–600 g qd