Chapter 7a Introduction to the Endocrine System 2013 Pearson Education Inc About This Chapter Hormones The classification of hormones Control of hormone release Hormone interactions Endocrine pathologies Hormone evolution 2013 Pearson Education Inc Hormones Function Control Rates of enzymatic reactions Transport of ions or molecules across cell membranes Gene expression and protein synthesis 2013 Pearson Education Inc Figure 7 1 An endocrine disorder in ancient art Figure 7 2 2 ANATOMY SUMMARY Hormones Location Hormone Primary Target s Main Effect s Pineal gland Melatonin A Brain other tissues Circadian rhythms immune function antioxidant Hypothalamus N Trophic hormones P see Fig 7 8 Anterior pituitary Release or inhibit pituitary hormones Posterior pituitary N Oxytocin P Vasopressin ADH P Anterior pituitary G Prolactin P Growth hormone somatotropin P Corticotropin ACTH P Thyrotropin TSH P Follicle stimulating hormone P Luteinizing hormone P Breast and uterus Kidney Breast Liver Many tissues Adrenal cortex Thyroid gland Gonads Gonads Milk ejection labor and delivery behavior Water reabsorption Milk production Growth factor secretion Growth and metabolism Cortisol release Thyroid hormone synthesis Egg or sperm production sex hormone production Sex hormone production egg or sperm production KEY G gland C endocrine cells N neurons P peptide S steroid A amino acid derived Figure 7 2 3 ANATOMY SUMMARY Hormones Location Hormone Primary Target s Main Effect s Thyroid gland Triiodothyronine and thyroxine A Calcitonin P Many tissues Bone Metabolism growth and development Plasma calcium levels minimal effect in humans Parathyroid gland Parathyroid hormone P Thymus gland Thymosin thymopoietin P Bone kidney Lymphocytes Regulates plasma Ca2 and phosphate levels Lymphocyte development Heart C Liver C Stomach and small intestine C Pancreas G Atrial natriuretic peptide P Angiotensinogen P Insulin like growth factors P Gastrin cholecystokinin secretin and others P Insulin glucagon somatostatin pancreatic polypeptide P Kidneys Adrenal cortex blood vessels Many tissues GI tract and pancreas Increases Na excretion Aldosterone secretion increases blood pressure Growth Assist digestion and absorption of nutrients Many tissues Metabolism of glucose and other nutrients KEY G gland C endocrine cells N neurons P peptide S steroid A amino acid derived Figure 7 2 4 ANATOMY SUMMARY Hormones Location Hormone Primary Target s Main Effect s Adrenal medulla N Epinephrine norepinephrine A Many tissues Adrenal cortex G Aldosterone S Cortisol S Androgens S Kidney C Skin C Erythropoietin P 1 25 Dihydroxy vitamin D3 calciferol S Vitamin D3 S Kidney Many tissues Many tissues Bone marrow Intestine Na and K homeostasis Stress response Sex drive in females Fight or flight response Red blood cell production Increases calcium absorption Intermediate form of hormone Precursor of 1 25 dihydroxy vitamin D3 KEY G gland C endocrine cells N neurons P peptide S steroid A amino acid derived Figure 7 2 5 ANATOMY SUMMARY Hormones Location Hormone Primary Target s Main Effect s Testes male G Androgens S Inhibin P Ovaries female G Estrogen progesterone S Inhibin P Relaxin pregnancy P Many tissues Anterior pituitary Many tissues Anterior pituitary Uterine muscle Sperm production secondary sex characteristics Inhibits FSH secretion Egg production secondary sex characteristics Inhibits FSH secretion Relaxes muscle Adipose tissue C Placenta pregnant females only C Leptin adiponectin resistin Estrogen progesterone S Chorionic somatomammotropin P Chorionic gonadotropin P Hypothalamus other tissues Many tissues Many tissues Corpus luteum Food intake metabolism reproduction Fetal maternal development Metabolism Hormone secretion KEY G gland C endocrine cells N neurons P peptide S steroid A amino acid derived Figure 7 2 1 ANATOMY SUMMARY Hormones Hormones Cell to cell communication molecules Chemical signals Secreted by a cell or group of cells Transported by blood Distant target tissue receptors Activates physiological response at low concentrations Pheromones elicit physiological or behavioral response on other organisms of the same species 2013 Pearson Education Inc Hormones Cellular mechanism of action Depends on binding to target cell receptors Initiates biochemical responses Half life indicates length of activity 2013 Pearson Education Inc Hormones Classification by Chemical Class Peptide or protein hormones Steroid hormones Amino acid derived or amine hormones 2013 Pearson Education Inc Table 7 1 Comparison of Peptide Steroid and Amino Acid Derived Hormones Hormones Peptides or Proteins Preprohormone Large inactive precursor Prohormone Smaller inactive Proteolytic post translational modification Peptide protein hormones Bind surface membrane receptors Cellular response through signal transduction system 2013 Pearson Education Inc Figure 7 3 ESSENTIALS Peptide Hormone Synthesis and Processing Figure 7 3 ESSENTIALS Peptide Hormone Synthesis and Processing Slide 1 mRNA Preprohormone Ribosome Endoplasmic reticulum ER Messenger RNA on the ribosomes binds amino acids into a peptide chain called a preprohormone The chain is directed into the ER lumen by a signal sequence of amino acids Cytoplasm ECF Plasma Capillary endothelium 2013 Pearson Education Inc Figure 7 3 ESSENTIALS Peptide Hormone Synthesis and Processing Slide 2 mRNA Preprohormone Ribosome Endoplasmic reticulum ER Signal sequence Prohormone Messenger RNA on the ribosomes binds amino acids into a peptide chain called a preprohormone The chain is directed into the ER lumen by a signal sequence of amino acids Enzymes in the ER chop off the signal sequence creating an inactive prohormone Cytoplasm ECF Plasma Capillary endothelium 2013 Pearson Education Inc Figure 7 3 ESSENTIALS Peptide Hormone Synthesis and Processing Slide 3 mRNA Preprohormone Ribosome Endoplasmic reticulum ER Signal sequence Prohormone Transport vesicle Messenger RNA on the ribosomes binds amino acids into a peptide chain called a preprohormone The chain is directed into the ER lumen by a signal sequence of amino acids Enzymes in the ER chop off the signal sequence creating an inactive prohormone The prohormone passes from the ER through the Golgi complex Golgi complex Cytoplasm ECF Plasma Capillary endothelium 2013 Pearson Education Inc Figure 7 3 ESSENTIALS Peptide Hormone Synthesis and Processing Slide 4 mRNA Preprohormone Ribosome Endoplasmic reticulum ER Signal sequence Prohormone Transport vesicle Golgi