NUR 0013 1st Edition Lecture 1Outline of Current Lecture: 1. Principles of the Endocrine system a. Anatomical location2. General Characteristics of the Endocrine Glanda. Roles3. Chemical Structure of Hormones. (3)a. Amino acids ( most common)b. Lipid solublec. Eicosanoids – considered not real hormones by some Current Lecture: Chapter 16. Endocrine systemI. Principles of the Endocrine System A. anatomical locations of Glands of the Endocrine System1. Located in the Head Hypothalamus (a neuroendocrine gland)- has neuro and endocrine effects  Pituitary (a.k.a. hypophysis)  Pineal2. Located in the Neck Thyroid Parathyroid - posterior of thyroid3. Located in the Thorax Thymus 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. Heart4. Located in the Abdomen Pancreas Adrenals Gonads - ovaries and testes Intestines and Stomach lining - often overlooked Placenta - during pregnancyB. General Characteristics of the Endocrine System The other great controlling system of the body. Unlike the nervous system, the endocrine system works slowly over, minutes, hours, weeks, years etc. The nervous system and endocrine are interdependent on one another for the regulation of bodily functions (e.g. neurohormones, adrenal gland, pituitary, etc.) Its messenger is not an electrical signal, but rather a chemical messenger known as ahormone (from Greek: to set in motion ). Hormone defined1. It is produced in minute amounts by a collection of specialized epithelial cells.2. It is secreted directly into the blood or extracellular fluid.3. It acts on specific tissues called target cells.Note: this definition is constantly changing and there are hormones that do not fulfillthis definition C. Chemical Structure of Hormones. (3 derivities)1. Amino acid derivatives  From simple amino acids to complex proteins (i.e. AA, peptides, glycoproteins, proteins) Thyroid hormone, epinephrine, and norepinephrine, adrenal medulla are examples of small amino acid hormones. Insulin and glucagon are examples of more complex protein hormones.2. Steroid derivatives Synthesized from lipid cholesterol. Sex hormones (gonads) and adrenal cortex hormones are the primary steroid hormones. 3. Eicosanoids Leukotrienes and prostaglandins Not “true hormones” - because the effects are local and not long distance Also called autocrine or paracrine substances.o Autocrine- effects the same gland that secrets ito Paracrine- close or near it. Effects are not the same glad that secretes it Synthesized from cell membrane phospholipids (arachidonic acid)o This is from the break down of cell membraneD. Mechanisms of Hormone Action1. Hormones bind with receptors in target tissues and cause certain specific activities to occur.2. They DO NOT make the cells do new things, but only alter the conditions so that the cells will start performing or increase processes that they already do such as protein synthesis or enzyme activity3. Hormones have different effects on different target cells.4. Cell response to hormonal stimulus Membrane potential and membrane permeability by opening or closing ion channels in the cell membrane- Stimulates the synthesis of enzymes within the cell. Activates or deactivates enzymes in the cell. Induces the cell to secrete some product. Can cause phosphorylation of enzymes (add a phosphate