CHAPTER 30 The Endocrine System © 2011 The McGraw -Hill Com panies, Inc A ll rights reserv e d 30-2 Learning Outcomes 30.1 Define the term endocrine glands 30.2 Describe the general functions of the endocrine system 30.3 Define the term hormone 30.4 Explain the difference in hormone control by positive and negative feedback loops © 2011 The McGraw -Hill Com panies, Inc A ll rights reserv e d 30-3 Learning Outcomes (cont.) 30.5 Describe the locations of the hypothalamus, pituitary gland, pineal body, thyroid gland, parathyroid glands, adrenal glands, pancreas, thymus, and gonads 30.6 List the hormones released by the pituitary gland and give the functions of each 30.7 List the hormones released by the thyroid gland and parathyroid glands and give the functions of each © 2011 The McGraw -Hill Com panies, Inc A ll rights reserv e d 30-4 Learning Outcomes (cont.) 30.8 List the hormones released by the adrenal glands and give the functions of each 30.9 List the names of the endocrine cells of the pancreas, the hormones released by them, and the function of each hormone 30.10 List the hormones released by the pineal body, thymus, and gonads, and give the functions of each © 2011 The McGraw -Hill Com panies, Inc A ll rights reserv e d 30-5 Learning Outcomes (cont.) 30.11 Name the hormones produced by the kidneys and heart, listing which organ produces the hormone, and the hormone’s function 30.12 Describe stressors and their effect on the body 30.13 Describe the causes, signs and symptoms, and treatment of various endocrine disorders © 2011 The McGraw -Hill Com panies, Inc A ll rights reserv e d 30-6 Introduction • The endocrine system includes the organs of the body that secrete hormones directly into body fluids such as blood – Regulates chemical reaction in cells and therefore control functions of the organs, tissues, and other cells to n i Glands bloodstream to secrete hormones target tissues © 2011 The McGraw -Hill Com panies, Inc A ll rights reserv e d 30-7 Hormones • Endocrine glands – Ductless – Release hormones • Directly into target tissues • Into bloodstream to be carried to target tissues • Hormones – chemicals secreted by a cell that affect the functions of other cells © 2011 The McGraw -Hill Com panies, Inc A ll rights reserv e d 30-8 Hormones (cont.) • Many are derived from steroids that easily cross the cell membrane • Examples of steroidal hormones – Estrogen – Progesterone – Testosterone – Cortisol Hormones © 2011 The McGraw -Hill Com panies, Inc A ll rights reserv e d 30-9 Hormones (cont.) • Nonsteroidal hormones – Made of amino acids or proteins and cannot cross the cell membrane easily – Bind to receptors on the surface of the cells – G-protein – activated by the hormone-receptor complex • Activates enzymes inside cell • Prostaglandins – Local, or tissue, hormones – Derived from lipid molecules – Do not travel in the bloodstream – Target tissues are located close by – Produced by organs such as • • • • • Kidneys Heart Stomach Uterus Brain © 2011 The McGraw -Hill Com panies, Inc A ll rights reserv e d 30-10 Feedback Loops • Control hormone levels • Negative feedback loop – Hormone release stops in response to decrease in stimulus • Stimulus (eating) raises blood glucose levels • Pancreas releases insulin in response to elevated blood glucose • Blood glucose decreases as it is used by the body or stored in the liver • Insulin release stops as blood glucose levels normalize © 2011 The McGraw -Hill Com panies, Inc A ll rights reserv e d 30-31 The Stress Response • Stressor – Any stimulus that produces stress – Types • Physical factors • Psychological factors • Positive stimuli © 2011 The McGraw -Hill Com panies, Inc A ll rights reserv e d 30-32 The Stress Response (cont.) • Physiologic response to stress caused by hormone release – General stress syndrome • Increased heart rate, respiratory rate, and BP • Increase in glucose and fatty acids in blood, which leads to weight loss • Increase in cortisol if stress prolonged – Decreased body repair – Susceptibility to illness © 2011 The McGraw -Hill Com panies, Inc A ll rights reserv e d 30-33 Apply Your Knowledge Match the following: ANSWER: A Extreme heat _ A Physical stress B Death of friend _ B Psychological stress A Fractured leg _ C Positive stimulus C Wedding _ B Exam _ B Hearing an explosion nearby _ C “A” on an exam _ A Flu _ B Car stolen _ © 2011 The McGraw -Hill Com panies, Inc A ll rights reserv e d 30-34 Common Diseases and Disorders Disease/Disorder Description Acromegaly Too much growth hormone produced in adults; enlargement of bones and thickened skin Addison’s disease Adrenal gland fails to produce enough corticosteroids Cretinism Extreme form of hypothyroidism present prior to or soon after birth Cushing’s disease Hypercortisolism; over-production of cortisol Diabetes insipidus Kidneys fail to reabsorb water, resulting in excessive urination; hyposecretion of ADH © 2011 The McGraw -Hill Com panies, Inc A ll rights reserv e d 30-35 Common Diseases and Disorders (cont.) Disease/Disorder Description Diabetes mellitus Chronic disease characterized by elevated blood glucose levels Type I Insulin-dependent diabetes mellitus; usually develops in childhood Noninsulin-dependent diabetes mellitus; primarily in adults but increased incidence in teens Occurs during pregnancy; usually temporary Type II Gestational Dwarfism Too little growth hormone (somatotropin) produced during childhood © 2011 The McGraw -Hill Com panies, Inc A ll rights reserv e d 30-36 Common Diseases and Disorders (cont.) Disease/Disorder Description Gigantism Too much growth hormone produced during childhood Goiter Enlargement of thyroid gland, causing swelling in neck; deficiency of iodine in diet Graves’ disease Hyperthyroidism; antibodies attach to thyroid gland, causing it to produce too much thyroid hormone Myxedema Thyroid gland produces inadequate amounts of thyroid hormone; common in females over 50 © 2011 The McGraw -Hill Com panies, Inc A ll rights reserv e d 30-37 Correct ! Apply Your Knowledge True or False: ANSWER: F Acromegaly develops as a result of too much growth hormone in a _ child in an adult T In diabetes insipidus, the kidneys fail to reabsorb water _ T Too little growth hormone in childhood results in dwarfism _ F Myxedema is the result of hyperthyroidism _ hypothyroidism T Addison’s disease is the result of too little corticosteroid _ F Cushing’s disease is the result of too little ACTH _ too much ACTH F Cretinism is an extreme form of hyperthyroidism present at birth _ hypothyroidism © 2011 The McGraw -Hill Com panies, Inc A ll rights reserv e d 30-38 In Summary 30.1 Endocrine glands are ductless glands, releasing hormones directly into the bloodstream and tissues 30.2 The organs of the endocrine system produce hormones that regulate the chemical reactions within cells, controlling the functions of organs, tissues, and other cells 30.3 Hormones are chemicals released by cells that affect the functioning of other cells © 2011 The McGraw -Hill Com panies, Inc A ll rights reserv e d 30-39 In Summary (cont.) 30.4 In a negative feedback loop, a stimulus causes a body reaction, which is detected by another area of the body, which stops the reaction The rise in blood sugar causing the pancreas to release insulin to lower blood sugar is an example In a positive feedback loop, a stimulus begins a process which will continue as long as the stimulus continues; as happens with a nursing infant, where the suckling releases milk from the mother’s breast until the suckling stops © 2011 The McGraw -Hill Com panies, Inc A ll rights reserv e d 30-40 In Summary (cont.) 30.5 The hypothalamus, pituitary, and pineal glands are located within the brain The thyroid and parathyroid glands are located in the neck The thymus is found in the mediastinum The adrenal glands are located above each kidney, and the pancreas is located behind the stomach In females, the gonads (ovaries) are in the abdominal cavity and in males, the gonads (testes) are found within the scrotal sac © 2011 The McGraw -Hill Com panies, Inc A ll rights reserv e d 30-41 In Summary (cont.) 30.6 The pituitary gland releases the following hormones: GH, MSH, ACTH, TSH, FSH, LH, PRL, ADH and OT Each hormone’s specific function may be found in Table 30-1 30.7 The thyroid gland releases calcitonin, T3, and T4 which are important in growth and protein synthesis The parathyroid releases PTH which balances the action of calcitonin © 2011 The McGraw -Hill Com panies, Inc A ll rights reserv e d 30-42 In Summary (cont.) 30.8 The adrenal medulla secretes epinephrine and norepinephrine, which work with the sympathetic nervous system The adrenal cortex produces many hormones, but the two major ones are aldosterone for BP maintenance and cortisol, which decreases inflammation 30.9 The endocrine cells of the pancreas are known as the Islets of Langerhans The two types of cells are Alpha cells, which release glucagon, and Beta cells, which release insulin © 2011 The McGraw -Hill Com panies, Inc A ll rights reserv e d 30-43 In Summary (cont.) 30.10The pineal body releases melatonin to regulate circadian rhythms, the thymus releases thymosin and thymopoietin to promote T cell production, ovaries release estrogen and progesterone (females), and the testes (males) release testosterone 30.11The kidneys produce erythropoietin, affecting the bone marrow, and the heart produces atrial natriuretic peptide, affecting BP © 2011 The McGraw -Hill Com panies, Inc A ll rights reserv e d 30-44 In Summary (cont.) 30.12Stressors are defined as stimuli that produce a stress response, a physiologic response to the stimulus that changes the body’s functioning in some way 30.13 The diseases and disorders of the endocrine system are as varied as the organs and hormone dysfunctions that cause them An overview of these conditions is in Table 30-2, and more detail on the most common of these conditions is found in the Pathophysiology section at the end of this chapter © 2011 The McGraw -Hill Com panies, Inc A ll rights reserv e d 30-45 End of Chapter 30 I t s not s t re ss t hat kills us, it is our re act ion t o it ~ Hans S e lye © 2011 The McGraw -Hill Com panies, Inc A ll rights reserv e d [...]... 30- 24 Pancreas • Located behind the stomach • Both exocrine gland and endocrine gland – Exocrine – secretes digestive enzymes into a duct leading to the small intestine – Endocrine – secretes hormones into bloodstream Glands © 2011 The McGraw -Hill Com panies, Inc A ll rights reserv e d 30- 25 Pancreas (cont.) • Islets of Langerhans secrete hormones into bloodstream – Alpha cells secrete glucagon –. .. reserv e d 30- 22 Adrenal Glands (cont.) • Adrenal cortex – Outermost portion – Secretes many hormones, but main ones are • Aldosterone – Stimulates body to retain sodium and water – Important in maintaining BP • Cortisol – Released when stressed – Decreases protein synthesis, resulting in slowed tissue repair – Decreases inflammation © 2011 The McGraw -Hill Com panies, Inc A ll rights reserv e d 30- 23... hemispheres – Melatonin • Regulates circadian rhythms • May play a role in onset of puberty • Thymus gland – Located between lungs – Thymosin • Promotes production of T lymphocytes Glands © 2011 The McGraw -Hill Com panies, Inc A ll rights reserv e d 30- 28 Other Hormone-Producing Organs (cont.) • The gonads – Ovaries • Estrogen • Progesterone – Testes • Testosterone • Stomach – Gastrin • Small intestine – Secretin... pituitary gland • Carries visual information to the brain for interpretation • Two lobes – Anterior lobe – Posterior lobe Pituitary Gland Glands © 2011 The McGraw -Hill Com panies, Inc A ll rights reserv e d 30- 15 Pituitary Gland (cont.) Prolactin Stimulates milk Growth hormone Stimulates increase in size of muscles and bones Luteinizing production Anterior Lobe Females: stimulates ovulation and estrogen... Testosterone • Stomach – Gastrin • Small intestine – Secretin – Cholecystokinin • Heart – Atrial natriuretic peptide – regulates BP • Kidneys – Erythropoietin – stimulates blood cell production Glands © 2011 The McGraw -Hill Com panies, Inc A ll rights reserv e d 30- 29 Back © 2011 The McGraw -Hill Com panies, Inc A ll rights reserv e d 30- 30 Apply Your Knowledge Match the following: ANSWER: D Between... reserv e d 30- 26 Apply Your Knowledge What are the effects of insulin and glucagon? ANSWER: Insulin decreases blood glucose concentration and increases protein synthesis Glucagon does just the opposite It increases blood glucose and decreases protein synthesis Yippee ! © 2011 The McGraw -Hill Com panies, Inc A ll rights reserv e d 30- 27 Other Hormone-Producing Organs • Pineal body – Small gland – Located... 30- 13 Hypothalamus • Hormones – Oxytocin – Antidiuretic hormone (ADH) • Hormones transported to the posterior pituitary for storage • Directs posterior pituitary to release hormones Glands © 2011 The McGraw -Hill Com panies, Inc A ll rights reserv e d 30- 14 Pituitary Gland • Controlled by the hypothalamus • Located at the base of the brain – Protected by a bony structure called the sella turcica –. .. parathyroid glands are located on the thyroid gland T Calcitonin lowers blood calcium levels © 2011 The McGraw -Hill Com panies, Inc A ll rights reserv e d 30- 21 Adrenal Glands • Located on top of each kidney • Divided into the adrenal medulla and adrenal cortex • Adrenal medulla – Central portion – Hormones • Epinephrine • Norepinephrine • Same effects as sympathetic nervous system Glands © 2011... rights reserv e d 30- 18 Thyroid Gland Located below the larynx Divided into follicles that store some of the hormones Major hormones T3 T4 Stimulate protein synthesis and increase cellular energy production Lowers blood calcium levels by activating osteoblasts that build new bone tissue Glands © 2011 The McGraw -Hill Com panies, Inc A ll rights reserv e d 30- 19 Parathyroid Glands • Four located... -Hill Com panies, Inc A ll rights reserv e d 30- 32 The Stress Response (cont.) • Physiologic response to stress caused by hormone release – General stress syndrome • Increased heart rate, respiratory rate, and BP • Increase in glucose and fatty acids in blood, which leads to weight loss • Increase in cortisol if stress prolonged – Decreased body repair – Susceptibility to illness © 2011 The McGraw