Page 22 Complete Your CE Test Online - Click Here Disclaimer The information provided at this activity is for continuing education purposes only and is not meant to substitute for the independent medical judgment of a healthcare provider relative to diagnostic and treatment options of a specific patient’s medical condition. ©2018: All Rights Reserved. Materials may not be reproduced without the expressed written permission or consent of Elite Professional Education, LLC. The materials presented in this course are meant to provide the consumer with general information on the topics covered. The information provided was prepared by professionals with practical knowledge of the areas covered. It is not meant to provide medical, legal, or professional advice. Elite Professional Education, LLC recommends that you consult a medical, legal, or professional services expert licensed in your state. Elite Professional Education, LLC has made all reasonable efforts to ensure that all content provided in this course is accurate and up to date at the time of printing, but does not represent or warrant that it will apply to your situation nor circumstances and assumes no liability from reliance on these materials. Quotes are collected from customer feedback surveys. The models are intended to be representative and not actual customers. Introduction The endocrine system is quite complex and works in conjunction with the nervous system to maintain the delicate balance that ensures homeostasis. It is imperative for nurses to understand how the endocrine system functions and how alterations in functioning can lead to a number of pathologies. This education program provides information on the anatomy and physiology of the endocrine system, disorders of the endocrine system, treatment options for endocrine pathologies, and nursing considerations related to care of patients suffering from such pathologies. ANATOMY AND PHYSIOLOGY OF THE ENDOCRINE SYSTEM Components of the endocrine system The endocrine system, in conjunction with the nervous system, is responsible for regulating and integrating the metabolic activities of the body. It consists of endocrine glands, hormones, and receptors [1,2] . The endocrine glands secrete specific hormones produced by the body to regulate cell and organ activity[3] . The primary glands of the endocrine system are the[1] : ● ● Pituitary gland. ● ● Thyroid gland. ● ● Parathyroid gland. ● ● Adrenal glands. ● ● Pancreas. ● ● Thymus. ● ● Pineal gland. ● ● Gonads (ovaries and testes). The hormones that are secreted by the glands of the endocrine system are chemical messengers that transfer information from one set of cells to another to coordinate bodily functions[3] . Hormones cause changes in the metabolic activities in specific cells while nerve impulses cause gland secretion and muscle contraction. Hormonal action is rather slow, but of prolonged duration. The action of nerve impulses, on the other hand, is rapid but of short duration[2] . Anatomy and physiology alert! There are two types of hormones. Group 1 hormones are those that bind to intracellular receptors and are lipophilic (have a strong affinity for lipids) such as the steroid hormones. Group II hormones are those that bind to cell surfaces and are hydrophilic (readily absorbing or dissolving in water) such as polypeptides, glycoproteins, and catecholamines[3] . Receptors, the third component of the endocrine system, are protein molecules. Receptors bind with other molecules (such as hormones) to cause specific physiologic changes in target cells[1] . Negative and positive feedback The endocrine system depends on both negative and positive feedback for its regulation. Negative feedback takes place when the rate of production of a particular product decreases as the concentration of that product increases. Negative feedback manages the rate of production to avoid accumulation of a particular product. For example, as the amount of some hormones reach the desired level, the body stops or reduces the rate of their production to avoid excessive accumulation[1,3] . Positive feedback occurs when the rate of production of a particular product increases as the concentration of that product increases. Positive feedback is less common in the body than negative feedback. An example of positive feedback is the secretion of oxytocin that stimulates uterine muscle contraction during labor. As labor progresses, pressure on the cervix continues to stimulate oxytocin release, which continues to stimulate uterine muscle contraction[3] . GLANDS OF THE ENDOCRINE SYSTEM AND THEIR SECRETIONS Pituitary gland The pituitary gland (also referred to as the hypophysis) is generally considered to be the most important gland of the endocrine system. It is responsible for the production of the hormones that control many functions of other endocrine glands[1,2] . Because of its importance, the pituitary gland is often called the master gland[1] . The pituitary gland is quite small, only about the size of a pea. It is located on the inferior side of the brain in the sella turcica of the sphenoid bone and is attached to the hypothalamus of the brain by the pituitary stalk[3] . The pituitary gland is divided into two primary regions: the anterior lobe (adenohypophysis) and the posterior lobe (neurohypophysis) [1,3] . The anterior pituitary is the larger of the two regions and produces six hormones that are regulated by the hypothalamus[1,2,3] : ● ● Growth hormone (GH): GH, also referred to as somatotropin, stimulates growth of bone and tissue. It accelerates the rate of body growth by stimulating the uptake of amino acid by the cells of the body, increasing tRNA synthesis, and promoting protein synthesis [3]. Deficiency of GH in children causes growth failure. In adults, GH deficiency leads to difficulty maintaining adequate amounts of body fat, muscle, and bone mass. This hormone is also linked to emotional well-being[2] . ● ● Thyroid-stimulating hormone (TSH): TSH, or thyrotropin, stimulates the synthesis and release of thyroid hormones from the thyroid gland[1,3] . A lack of thyroid hormones because of a defect in the pituitary gland or in the thyroid itself is called hypothyroidism[2] . ● ● Adrenocorticotropic hormone (ACTH): ACTH stimulates the adrenal cortex to produce and secrete various steroid hormones [2,3] . ● ● Follicle-stimulating hormone (FSH): FSH stimulates the ovaries in women and the testes in men. In women, this hormone stimulates the growth of ovarian follicles, and in men, it stimulates the spermatogenesis[1,3] . ● ● Luteinizing hormone (LH): In females, LH stimulates maturation of ovarian follicles, ovulation, and stimulation of the corpus luteum to secrete estrogens and progesterone. In males, LH stimulates interstitial cells to secrete testosterone[3] . ● ● Prolactin (PRL): PRL targets the mammary glands. This hormone promotes mammary gland development and stimulates milk production in females. PRL is regulated by the production of