PHIS 206 1st Edition Lecture 31 Outline of Last Lecture I Endocrine System II Hormones III Endocrine System IV Hormones controlling secretions of other hormones V Complexities VI Hormones Chemical Structures VII Peptides and Steroids VIII Peptides IX Steroids X Amines XI Common Characteristics of All Hormones XII Circulating Levels of Hormones XIII Endocrine Disorders XIV Hypersecretion XV Down Regulation Outline of Current Lecture I Location Anatomy of Pituitary II Blood Supply in Anterior Pituitary Gland III Mammals except humans IV 2 Kinds of Hormones of Posterior Pituitary V Anterior Lobe VI Secretions of Anterior Pituitary VII Hormones of Anterior Lobe VIII Growth Hormone Current Lecture I II III Location Anatomy of Pituitary line going through your head and intersection is pituitary adeno hypophysis arises from connective tissue anterior gland neuro hypophysis posterior pituitary with cell bodies in the hypothalamus neurohormones of neurocells Blood Supply in Anterior Pituitary Gland consists of blood already in arteries and capillaries in hypothalamus hypothalamus secretes a lot of tropic hormones affecting pituitary gland Mammals except humans These notes represent a detailed interpretation of the professor s lecture GradeBuddy is best used as a supplement to your own notes not as a substitute IV V VI VII intermediate secretes hormones non functional in humans modifies darkening of skin 2 Kinds of Hormones of Posterior Pituitary Vasopressin ADH cells that secret it are osmoreceptors increase rate of water plasma osmolarity increases classic negative feedback released in bloodstream Oxytocin promotes uterine contraction promotes lactation entirely neural stimulation Anterior Lobe site of synthesis secretion 6 hormones Peptide Hormones Prolactin Growth Hormone Thyroid Stimulating Hormone Adrenocorticotropin Follicle Stimulating Hormone Luteinizing Hormone Interstitial Cell Stimulating Hormone Tropic hormones that stimulate activities of other hormones ThyroidStimulating Hormone Adrenocorticotropin Follicle Stimulating Hormone Luteinizing Hormone Interstitial Cell Stimulating Hormone Gonado tropic Follicle Stimulating Hormone Secretions of Anterior Pituitary direct feedback from target cells 2 Levels of Secretion control by secretions from hypothalamus since circulation in anterior has blood which has already been in the capillaries of the hypothalamus the hypothalamus secretes directly into the bloodstream Advantages o Hypothalamic Hormones don t get diluted when it is on its way to the anterior 5L Hypothalamo Hypophyseal Portal System o arteriole capillary arteriole capillary venule Hormones of Anterior Lobe Thyrotropin Releasing Hormone TRH Corticotropin Releasing Hormone CRH Prolactin Releasing Hormone PRH Prolactin Inhibiting Hormone PIH ONLY ONE THAT IS NOT A PEPTIDE NOT TROPIC Growth Hormone Releasing GRH NOT TROPIC Growth Hormone Inhibiting GHI Gonadotropin Releasing Hormone GnRH The ones without inhibitors have inhibitors but they are not released by the hypothalamus VIII Growth Hormone Major effect it has promotion of growth extension of long bones Additional Effects stimulation of protein synthesis Essential to the growth of all tissues inhibition of protein breakdown Has a general metabolic effect fat mobilizing effect decreases glucose intake by muscles Muscles metabolize faster as fuel when increases plasma glucose levels Growth Hormone increases Also stimulates tissue growth increases rate of amino acids and protein synthesis Effect on Bone growth cartilaginous plate thickens and bones ossifies behind it long bones synthesize more at the end can only happen until the cartilaginous plates are totally ossified Chemical Situations of Growth Hormone Deficiency Causes defective anterior pituitary synthesizes too much or too less Growth Hormone Adults results in reduced muscle and strength reduced bone density In Children results in dwarfism poor muscle development large amount of accumulation of subcutaneous fat Clinical Situations of Growth Hormone Excess Cause pituitary tumor increase in height normal proportions and of adolescence long bones cannot grow anymore but short bones can thicken jaw bone can be prominent brows thicken large hands acromegaly adult pituitary giant whose hypersecretion of Growth Hormone continued onto adulthood growth hormone is secreted throughout life
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