2324 MD137 Lecture 1 PDF - Introduction to Endocrinology

Introduction to Endocrinology Study Structure & Function of Endocrine Glands Diagnose and Treat Endocrine Disorders Universit y ofGalway....

Introduction to Endocrinology Study Structure & Function of Endocrine Glands Diagnose and Treat Endocrine Disorders Universit y ofGalway. ie Universit y ofGalway. ie Endocrine Disorders Universit y ofGalway. ie  Evidence Based Historical Observational Evidence: Egyptians The role of gonads Fertility and contraception Removal of ovaries - No pregnancy Removal of testis – No Pregnancy Eunuchs serving in Pharaoh’s harem Detection of Diabetes Excessive Thirst AKHENATEN (1353 BC) -ancient Egyptian ruler, Acromegalic? Carvings of patients with o Acromegaly o Goitre o Achondroplasia  Discovery of the first hormone Starling and Bayliss - 1902 o Interaction between duodenum and pancreas o Discovery of secretin Hormone o Greek “I excite” or “I arouse” o Transported by blood from one organ, which secretes the substance, to the organ where the effect is exerted  Treatments 1889 - Brown-Séquard, a French physician Injected himself with: Blood from testicular veins, semen, and extracts of the dog, guinea pig, or rabbit testicles Reported significant improvement strength, stamina, and concentration First endocrine replacement therapy? Hormone of the 20th Century ? Insulin o 1926- One of the first proteins to be crystallized in pure form. o 1955 - First protein to be fully sequenced o 1958 - First protein to be chemically synthesized o 1979 – First human protein to be manufactured by way of Biotechnology Effect of Insulin Young girl aged 13 years suffering from diabetes She weighed just 45lbs and her chances of surviving for much longer were very poor She was one of the first patients to be treated with insulin In this case Insulin extracted from the pancreases of slaughtered cattle Asprosin - 2013 Synthesized and released by white adipose tissue during fasting Complex role in the central nervous system (CNS), peripheral tissues, and organs Involved in appetite, glucose metabolism, insulin resistance (IR), cell apoptosis, etc. Marfanoid–Progeroid– Lipodystrophy syndrome that prevents accumulation body fat and gaining weight Lipid-dystrophy due to loss of asprosin Layout of Endocrinology Teaching MD137 o Introduction to Endocrinology o Hormone Classification and Cell communication o Hypothalamus-Pituitary o Control of Growth – GH, IGFs, IFGS, Sex steroids o Calcium Metabolism – PTH, Vit D, Calcitonin MD124 o Control of Metabolism - Pancreas, Thyroid, Glucocorticoids MD123 o Fluid Balance – Dr Quinlan MD121 o Blood Pressure – Prof. Wheatley MD210 o Reproduction Types of Glands  What is a Gland  Organs consisting of specialized secretory cells Secreted material is usually a liquid Unicellular or Multicellular Simple of Complex Exocrine or Endocrine  Exocrine Glands Secrete product onto an epithelial surface, directly or through ducts Endocrine Glands Ductless Glands - Secrete Hormones One Organ More Than One Type of Gland What is a Hormone? About 1,630,000,000 results Classical Definition A chemical substance produced by one type of cells and carried in the bloodstream to act on specific target cells at very low concentrations Modern Definition Includes factors that are produced and exert their effects locally Enter ISF not Blood Hypothalamus and Pituitary glands Universit y ofGalway. ie The Pituitary Gland Pituitary - Master Gland o Controls Thyroid, Adrenal Cortex, Ovary, Testes Hypothalamus Control of “The Master” o Hypothalamic-Pituitary Axis Hypothalamus Acts as Relay Station o Input From CNS o Output To Pituitary NS Integration with Endocrine Response  Pituitary Embryological Derivation Anterior Pituitary - Upward Growth from Roof of mouth Rathke’s Pouch - Ectodermal Tissue Posterior Pituitary -Down growth from Floor of 3rd Ventricle Nervous Tissue  Hypothalamic and Posterior Pituitary Connection Neural Connection Cell Bodies lie in SON and PVN in Hypothalmus Produce Hormones Stored in vesicles with Neurophysins Neurophysin 1 - Oxytocin Neurophysin 2 - ADH Directional transport Carried via Axon Released in Posterior Pituitary Hypothalamic Anterior Pituitary Connection Hypothalamic Anterior Pituitary: Vascular Connection Blood Entry to Hypothalamus Superior Hypophysial Artery Primary Capillary Plexus in Median Eminence Fenestrations in blood vessels Blood Exit From Primary Plexus Hypothalamo-Hypophyseal Portal System Descend via Infundibulum Second Capillary Plexus in Pars Distallis Fenestrations in blood vessels Blood Exit From Ant. Pituitary Efferent Veins A patient is diagnosed with Cushing's disease due to a pituitary adenoma producing excess adrenocorticotropic hormone (ACTH). Which hypothalamic hormone stimulates the secretion of ACTH from the anterior pituitary? A) Somatostatin B) Gonadotropin-releasing hormone (GnRH) C) Corticotropin-releasing hormone (CRH) D) Thyrotropin-releasing hormone (TRH) E) Growth hormone-releasing hormone (GHRH) A patient with a history of head trauma is experiencing diabetes insipidus due to damage to the hypothalamus. Which hormone, normally produced in the hypothalamus and released by the posterior pituitary, is deficient in this condition? A) Oxytocin B) Vasopressin (Antidiuretic hormone, ADH) C) Cortisol D) Thyroxine E) Growth hormone A 25-year-old female is evaluated for infertility. Tests reveal low levels of luteinizing hormone (LH) and follicle-stimulating hormone (FSH). Which hypothalamic hormone's deficiency could be contributing to her low LH and FSH levels? A) Prolactin-inhibiting hormone (Dopamine) B) Corticotropin-releasing hormone (CRH) C) Gonadotropin-releasing hormone (GnRH)