Chemical Classification Of Hormones

Chemical Clas Sificati
 
Created Dec 11, 2009
by dockdance14
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Endocrine System
-Endocrine glands (ductless) secrete hormones  
Hormones
intercellular chemical messengers that are secreted into the blood and each target cells thru...
Chemical classes of hormones
1. Amines   2. Proteins and Peptides   3. Steroids
Amines
-derivative of tyrosine   * Thyroid Hormones -T3 and T4 (secretes more T4, but T3 has...
Thyroid Gland
-anterior neck -circular arrangement of epithelial cells surround thyroid follicle; no blood...
Synthesis of T3 and T4 in Thyroid Gland
-Uptake of I- from blood and transport thru epithelial cells of thyroid follicles into follicular...
Storage of T3 and T4 in Thyroid Gland
-Thyroglobulin is the colloid in follicular lumen -Thyrogloblin = storage form of T3 and T4
Release of T3 and T4 from Thyroid Gland
-Endocytosis of thyroglobulin by thyroid follicular cells -Intracellular hydrolysis of thyroglobulin,...
Transport of T4 and T3 in Blood
-Binding to thyroxine-binding globulin (TBG) -Most T3 and T4 in blood are in bound form -Only...
Intracellular Actions of T4 and T3 in Target Cells
-Carrier-mediated uptake of T3 and T4 into target cells -T4 converted to T3 by intracellular...
Actions of Thyroid Hormone on Target Tissues
-Target tissues = all tissues in body, except RBCs (no nucleus)   Actions: - stimulation...
Symptoms of Hypothyroidism
-Low BMR -Cold intolerance -Weight gain -Lethargy -Slow reflexes
Symptoms of Hyperthyroidism
-High BMR -Heat intolerance -Weight loss -Hyperactivity -Rapid reflexes
Catecholamines
Sources: Adrenal medulla- norepinephrine (20%) and epinephrine (80%) Hypothalamus- dopamine   -Transported...
Catecholamine Receptors
Types: -Adrenergic- NE and Epi -Dopaminergic- Dop   Location: plasma membrane   Receptors:...
Actions of NE and Epi
Heart: stim HR and force of contraction (CO, BP)   Vascular smooth muscle: stimulates...
Actions of Dopamine
Ant Pit Gland: inhibits prolaction secretion
Snthesis of proteins
Preprohormone Prohormone Hormone Hormone
Protein/Peptide hormones
-Most hormones -Hypothalamus: most -Post and Ant Pit: all -GI system: all -Pancreas: important...
Protein/Peptide Receptors
-Many types -Location: plasma membranes (polar) -Receptors: act as ion channels, enzymes,...
Steroid Hormones
-derived from cholesterol -highly nonpolar --> not stored
Adrenal Gland
Medulla = inner Cortex = outer   1. Zona Glomerulosa- aldosterone 2. Zona Fasiculata-...
Major Steroid Hormones of Adrenal Cortex
1. Corticosterone 2. Aldosterone 3. Cholesterol 4. Cortisol 5. Androgens = Dehydroepiandrosterone...
Types of Adrenocortical Steroids
1. Mineralcorticoids -Actions on renal handling of minerals (Na and K) -Aldosterone and Corticosterone   2....
Transport of Adrenal Corticosteroids in Blood
-Binding to corticosteroid binding globulin (CBG) -Most in blood are bound -Only free form...
Intracellular Actions of Adrenal Corticosteroids in Target Cells
-Diffuse into target cells -Receptors for corticosteroids are intracellular -Hormone-receptor...
Actions of Normal Basal Concentrations of Cortisol on Target Tissues
-Permissive for catecholamine actions on vascular smooth muscle (bp) -Permissive for enzyme...
Actions of Stress Levels (Inc conc) of Cortisol on Target Tissues
-Enhanced vascular reactivity to catecholamines (bp) -Enhanced actions on metabolism to provide...
Gonadal Steroid Hormones
Males: Androgens    Testosterone   Females: Estrogens    Estradiol Progesterone   *estrogen...
Males
Testes = testosterone
Female
Ovaries = predominant steroid varies w/ phase of menstrual cycle Follicular phase (1st 2 wks)...
Transport of Gondal Steroids in Blood
-Binding to sex hormone binding globulin (SHBG) -Most are bound form -Free form is active
Intracellular Actions of Gonadal Steroids on Target Tissues
-Diffuse into target cells -Location = intracellular -Hormone-receptor complexes act as transcription...
Conversion of Gonadal Steroids to Active Forms in Some Target Cells in Male
Testosterone -> 5-alpha-Dihydrotestosterone   Testosterone -> Estradiol
Mechanism of Action of Hormones with Intracelullular Receptors
-Free hormone diffuses through cell (nonpolar) -Receptors in nucleus -Function as transcription...
Mechanism of Action of Hormones with Plasma Membrane Receptors
-Polar -Receptors on plasma membranes
Regulation of Hormone Receptors
-By natural hormonal ligands: up and down reg -By other hormones: permissive effects, whereby...
Permissive Action of Thyroid Hormone on Epinephrine-Induced Lipolysis
Thyroid hormone = little effect   Epinephrine = min effect   TH and Epi = large...


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