* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download Hypothalamic and Pituitary Hormones
Survey
Document related concepts
Bovine somatotropin wikipedia , lookup
Hormonal contraception wikipedia , lookup
Hormone replacement therapy (menopause) wikipedia , lookup
Xenoestrogen wikipedia , lookup
Triclocarban wikipedia , lookup
Neuroendocrine tumor wikipedia , lookup
Menstrual cycle wikipedia , lookup
Endocrine disruptor wikipedia , lookup
Hormone replacement therapy (male-to-female) wikipedia , lookup
Hyperthyroidism wikipedia , lookup
Hyperandrogenism wikipedia , lookup
Breast development wikipedia , lookup
Mammary gland wikipedia , lookup
Adrenal gland wikipedia , lookup
Transcript
Hypothalamic Pituitary Hormones Lecture NO : 2nd MBBS Dr Muhammad Ramzan Hypothalamic hormones - the definition • These are the hormones/factors produced by the Hypothalamic nuclei/neurons – the Neuro secretary cells • Reach the anterior Pituitary through the portal veins to stimulate/inhibit the release of hormones from it or 1 • Travel along the axons of Neuro secretary cells to the posterior pituitary for storage and released when required 2 Hypothalamic Hormones – 2 types Releasing / Inhibitory and Neuro hormones • Hypothalamic hormones are of 2 types • Hypothalamic Releasing or Inhibitory hormones/factors for 1 the stimulation/inhibition of anterior pituitary gland • Neuro hormones produced by the hypothalamic nuclei to be stored in posterior pituitary for further release 2 Hypothalamic pituitary hormones – 2 types Hypothalamic Releasing (HRH) or Hypothalamic Inhibitory hormones(HIH) • These hormones are secreted by the Hypothalamic nuclei • Transported to the Anterior Pituitary via Portal veins that stimulate/inhibit to produce several hormones • They are named as Releasing / Inhihibitory Hypothalamic hormones for the respective Pituitary Hormones Like : • Hypothalamic Stimulatory /Inhibitory hormone or factor for Growth hormone (GHRH or GHIH) Hypothalamic Releasing / inhibitory hormones/factor Hypothalamic Neuro hormones from PVN and Supraoptic nuclei • • • • • These are synthesized in the hypothalamic nuclei - PVN SOP Travel along the axons of secretary neurons to be stored in posterior pituitary and are released directly into the : Circulation in response to appropriate stimulus These are the hormones of Posterior Pituitary/ Neuro hypophysis Like Anti diuretic hormone/Vasopressin (ADH) and Oxytocin Hypothalamus – the Neuro hormones Neuro hormones – difference from Hypothalamic Releasing/inhibitory hormones (3 points) • Neuro hormones require no Hypothalamic releasing/Inhibitory hormones (Requirement for synthesis) 1 • Travel along the axons of hypothalamic secretary cells to the Posterior Pituitary gland (method of transport ) 2 • Stored there as secretary vesicles and released into the circulation in response to a stimulus (storage) 3 Difference B/W Hypothalamic Stimulatory/Inhibitory hormones and Hypothalamic Neuro hormones Hypothalamic Stimulator/Inhibitory Hormones Hypothalamic NeuroHormones Requirement for stimulation/inhibition Require either of these for their release/inhibition Require no Hypothalamic stimulatory/ inhibitory Hormones Transportation from Hypothalamus to Pituitary Gland Are transported to Pit. Gland Via Portal veins Are transported via axons of Neuro -secretary cells Storage before their release into circulation Not stored in Pituitary Gland, Are released directly into systemic Circulation Stored in Axons of Neuro – secretary cells, Released in response to an approprpriate stimulus Parameters Hypothalamic Releasing Hormones – 5 (the major ones) Hypothalamic Inhibitory Hormone HIH - 5 • • • • • • • Growth Hormone Releasing Hormone - GHRH 1 Thyrotropin Releasing Hormone - TRH 2 Corticotropin Releasing Hormone - CRH 3 Gonadotropin Releasing hormone - GnRH 4 Prolactin Releasing hormones - PRH 5 (Others are Somatostatin and Dopamine , inhibit the Pit. Hor.) Same is true for the existence of HIH with same names Hypothalamic Releasing/Inhibiting Hormones 5 Pituitary Gland – the background • Pituitary gland or Hypophysis is an endocrine gland, situated below the hypothalamus • It is enclosed in a bony cavity at the base of the skull called the Sella Turcica (Turkish saddle) • It is about the size of a pea and weighs 500- 900mg. Turkish Saddle Pituitary Gland – the Master gland Receives messages from CNS • Pituitary is also called as the Master gland, as it regulates the secretions of many glands and influences the : • Body growth, reproductive system and metabolism • Pituitary Is a link B/W the hypothalamus and endocrine system and receives messages (HRH and HIH) from CNS • Thus establishing the science of Neuro endocrinology Pituitary Gland – the divisions • • • Pituitary gland is divided into 2 : Anterior Pituitary gland or Adenohypophysis Posterior Pituitary gland or Neuro hypophysis Pituitary Gland – the division Hormones of Anterior Pituitary Gland 1 6 in no • 1. 2. 3. 4. Are 6 in Number Growth Hormone or GH Thyroid Stimulating Hormone or/ Thyrotropin - TSH Adrenocorticotropic hormone /Corticotrophin – ACTH Prolactin or PRL Hormones of Anterior Pituitary gland – the others the Gonadotropins 5 Luteinizing Hormone or LH 6 Follicular Stimulating Hormone or FSH No 5 and 6 are called collectively as Gonadotropins Melanocyte Stimulating hormone is secreted from the middle part of the Pituitary gland Anterior Pituitary Hormones Types of Anterior Pituitary hormones Tropics and non tropics • Hormones from the Anterior Pituitary gland are divided into 2 on the basis of regulating the : • Growth/nutrition/functions of other endocrine glands in the body • Tropics and • Non Tropics Anterior pituitary hormones - the Tropics - 4 • Four (4) of these ones are called Tropic Hormones as they stimulate the growth, nutrition and function of : • other endocrine glands • TSH : regulates Thyroid gland secretion • ACTH : controls secretion of Adrenal Cortex • FSH : maintains female sex hormones level and follicle growth • LH : regulates Testosterone and secondary sex characters The Tropic hormones – 4 in no Hormones of anterior Pituitary the Non Tropics. 2 in no • Rest 2 of the anterior Pituitary hormones are the ones that do not stimulate the secretion of other endocrine glands • Growth hormone : Promotes protein synthesis and cell division in cartilage; bone, muscles and organs • Prolactin : promotes development of breast and milk production after child birth • Melanocyte Stimulating Hormone : regulates skin colour changes and degree of pigmentation in Melanocytes Hormones of Posterior Pituitary gland - 2 • • • • • The Posterior Pituitary produces 2 hormones : Vasopressin /Ant diuretic hormone (ADH) and Oxytocin. ADH : maintains water; fluid /electrolyte balance. And BP 1 Oxytocin : stimulates the contraction of the smooth muscles of the uterus; Myoepithelial cells of ducts of mammary glands and vas deferens 2 Posterior Pituitary hormones – the actions