Term
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Definition
| two types exist cell surface, nuclear receptor. Most hormone receptors are large proteins between 2-100 thousand/cell |
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Term
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Definition
| interacts with receptor, drives effect, also affects receptor |
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Term
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Definition
| change membrane permeability, act on receptor and related proteins to open or close an ion gate |
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Term
| Metabolic/peptide hormone action |
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Definition
| (insulin, GI hormones) activates adenylyl cyclase which carries on a downstream activity which carries out secondary effect specific to response |
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Term
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Definition
| amplify signal. cAMP,cGMP, calcium, calmodulin, membrane phospholipid metabolites. |
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Term
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Definition
| involved in adrenocorticotropin, TSH, LH, FSH, ADH, PTH, glucagon, catecholamines, secretin, and hypothalamic releasing hormones. binds to inactive protein kinase A promoting dissociation. |
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Term
| Calcium/Calmodulin function |
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Definition
| calmodulin saturated with calcium activates myosin kinase (smooth muscle contraction). |
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Term
| Membrane Phospholipid metabolites |
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Definition
| activated phospholipase breaks down phosphatidyl inositol biphosphate into inositol triphophate and diacyl glycerol. ITP3 mobilizes calcium from mitochondria and ER,DAG activates protein kinase C involved in cell division. DAG supplies arachidonic acid precursor molecule |
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Term
| Steroid Hormone mechanism of action |
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Definition
| diffuses/tansported to nucleus=>binds DNA=>initiates transcription=>mRNA diffueses to cytoplasm to promote ribosomes to form protein. |
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Term
| Thyroid Hormone Mechanism |
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Definition
| thyroxine and triiodothyronine secreted by thyroid, enter multiple cell types, can bind hundreds of DNA sites, drive cellular function for days or weeks |
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Term
| G-protein coupled receptors |
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Definition
| guanonsine triphosphate binding proteins. adenylayte cyclase, Ca2+ calmodulin, inositol 1,4,5-triphosphate. 3 subunits a,B,G. bind GTP active form. |
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Term
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Definition
| g proteins regulate activity of effector molecules resulting ultimately in biologic response. Identity of G proetin determined by alpha subunit which is responsible for effector activation. |
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Term
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Definition
| linked to G protein-coupled receptors. activation results in transient increase in intracellular cAMP levels. |
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Term
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Definition
| activation of effectors by G-protein is subject to regulation that prevents overstimulation by an agonist. |
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Term
| Adenylate Cyclase mechanism |
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Definition
| binding-GDP replaced by GTP-G protein activates adenylate cyclase-Adenylat cyclase catalyses conversion of ATP to cAMP-cAMP activates protein kinase A, phosphorylates specific proteins, producing highly specific physiologic actions-cAMP degraded to 5'AMP by phosphodiesterase. |
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Term
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Definition
| could be hormone or synthetic. bind to a receptor and transform into a response. |
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Term
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Definition
| bind receptor but does not transform into response. |
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Term
| Partial Agonist/Partial Antagonist |
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Definition
| partial agonist block binding of full agonist and suppress receptor activity to level of partial agonist |
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Term
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Definition
| act in different ways through same receptor. |
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Term
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Definition
| chronic stimulation of cells with peptide hormone can decrease the amounts of receptor that are expressed on cell surface. |
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Term
| Protein Hormone synthesis |
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Definition
| does not require special machinery. Growth Hormone, Prolactin, PTH produced similarly to other secreted proteins |
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Term
| Peptide Hormones synthesis |
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Definition
| produced by cleavage of a larger protein. |
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Term
| Thyroid Hormone synthesis |
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Definition
| produced by iodination and coupling of tyrosine residues of thymoglobulin |
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Term
| Hormone production regulation |
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Definition
| 1. level of transcription 2. posttranslational mechanisms 3.level of release (hypothalamic-pituitary-target gland system and free-standing endocrince glands) |
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Term
| Hypthalamic-pituitary-gland system |
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Definition
| CNS-Hypothalamus-Pituitary-Peripheral gland which releases feedback control on hypothalamus and pituitary. |
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Term
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Definition
| steroids, thyroid hormones, Vit-D are bound to plasma proteins. Growth Hormone, IGF-I, IGF-2=>IGF binding proteins. Vasopressin Oxytocin bind neurophysisns. |
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Term
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Definition
| plasmas binding protein that binds cortisol and progesterone |
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Term
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Definition
| plasma binding protein that binds testosterone and estradiol |
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Term
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Definition
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Term
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Definition
| binds to hormones that need transport non-covalently and increases hormone half-life in circulation |
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Term
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Definition
| not bound. available for receptor binding, dictates feedback inhibition of hormone release, cleared from circulation, correlates best with clinical states of hormone excess and deficiency. |
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Term
| Role of plasma binding protein |
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Definition
| plasma protein prevents immediate uptake allowing it to travel to a distal tissue for uptake. Free hormone will be consumed in proximal tissue. |
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Term
| Transport of hormones across membrane |
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Definition
| many nuclear receptor ligands can enter and exit cells by transversing lipd bilayer. influx and efflux varies in different tissues and cell types. ex.) tyroid hormone |
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Term
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Definition
| some proteins are glycosylated glycoproteins have half-lives of hours and need degradation. peptide hormones usually have shorter half-lives(minutes) |
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Term
| Mechanism of Hormone Degradation |
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Definition
| cell surface receptors and nonreceptor hormone-binding sites. Lysosome degrades hormones enzymatically. |
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Term
| Thyroid Hormone degradation |
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Definition
| degraded to inactive forms by deiodinases. Deaminations and decarboxylations of alanine side chains aid as well. |
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Term
| Catecholamine degradation |
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Definition
| very short half-life of 2 minutes. degraded by: catechol-O-methyltransferase(COMT) and Monoamine Oxidase (MAO). |
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Term
| Prostaglandin degradation |
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Definition
| are metabolized within seconds by enzymes as oxidation of teh 15-hydroxyl group that inactivates the prostaglandin. |
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Term
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Definition
| this technology allows us to synthesize growth hormone, insulin, and polypeptide hormones. |
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Term
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Definition
| neurons that secrete hormones into circulation. Hypothalamus does this. |
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Term
| Direct Autonomic innervation of Endocrine |
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Definition
| couples CNS system signals to hormone release, innervations of adrenal medulla, parathyroid, pancreatic islets. |
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Term
| Anterior Pituitary secretion control |
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Definition
| hypthalamic, arcuate, periventricular, medial preoptic, paraventricular from median emmience. Hypophysial portal system. |
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Term
| Anterior Pituitary Hormones |
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Definition
| adrenocorticotropic, growth, prolactin, thyroid-stimulating, LH, FSH |
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Term
| Posterior Pituitary Hormone |
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Definition
| oxytocin, vasopressin(antidiuretic) |
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Term
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Definition
| posterior pituitary vasopressin and oxytocin into general circulation |
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Term
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Definition
| of hypothalamus release hormones into hypothalamic-pituitary blood vessels, which deliver hormones to anterior pituitary. |
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Term
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Definition
| TRH, GnRH, GHRH, Prolactin-releasing factors |
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Term
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Definition
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Term
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Definition
| bioactive amines, peptides, amino acids |
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Term
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Definition
| stimulates prolactin and inhibits CRH-stimulated ACTH release. |
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Term
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Definition
| stimulates the release of several pituitary hormones, including prolactin, growth hormone, and ACTH |
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Term
| Regulation of Anterior Pituitary |
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Definition
| anterior pituitary release is usually regulated by vascular delivery of hypothalamic and peripheral hormones. |
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Term
| 3 patterns of anterior pituitary hormone release |
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Definition
| spontaneous brain rhythms release LH and FSH, peripheral hormones regulate through feedback (corisol, thyroid, ACTH,TSH,LH), "Intervening factors", stress, nutritional influences, illness. |
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Term
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Definition
| releases ACTH, GH, prolactin |
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Term
| Systematic illness effects |
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Definition
| suppress hypothalamic-pituitary-thyroid axis and release gonadotropins |
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Term
| Hormones that stimulate ACTH release |
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Definition
| Angiotensin II, Interleukin-2, cholecystokinin, oxytocin. |
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Term
| Causes of CRH and ACTH release |
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Definition
| interleukin-1, interleukin-2, and epinephrine. |
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