I. Endocrine System 1-26-10 The Endocrine System – the 2nd great controlling system of the body A. 1st is the nervous system – built for speed, uses nerve impulses B. 2nd is the endocrine system – slower, uses chemical messengers called II. hormones Hormones – chemical structures secreted by endocrine glands A. Can be Amino acid based or Steroids B. Have target cells or target organs C. Have two mechanisms to trigger changes is cells 1. If steroids, diffuse through plasma membranes and enter nucleus 2. Non-steroids, bind to plasma membrane and for a series of reactions III. Endocrine Stimuli A. Hormonal B. Humoral C. Neural IV. Hypothalamus A. Part of nervous system B. Produces several hormones V. Pituitary Gland A. Connected to hypothalamus 1. Has 2 functional lobes a) Anterior – all hormones are proteins, secondary messenger systems, hormonal stimuli (GH, PRL, FSH, LH, TSH) b) Posterior – Does not make hormones, only stores hormones made by hypothalamus. (Oxycotin, ADH) VI. Thyroid Gland A. Located at base of throat B. Produces thyroid hormone and calcitonin VII. Parathyroid Gland A. Tiny masses of glandular tissue behind thyroids B. Secretes parathyroid hormone 1. Regulates calcium ions in blood VIII.Adrenal Glands – found over kidneys– 2 sections A. Adrenal cortex – 3 groups of steroid hormones 1. Regulate mineral content in blood, promote normal cell metabolism, male and female sex hormones B. Adrenal Medulla 1. Secretes epinephrine (adrenaline) and norepinephrine a) Released when sympathetic NS goes into “fight-or-flight” mode IX. Pancreatic Islets Endocrine System 1-26-10 A. (Also called Islets of Langerhans) B. Produce Insulin and glucagon C. Show More
