The document summarizes key points about the endocrine system from Chapter 13 of Hole's Human Anatomy and Physiology. It defines the endocrine system and describes the general characteristics and functions of hormones. It discusses the major endocrine glands including the pituitary, thyroid, parathyroid, adrenal, pancreas and others. It explains how hormones are classified, their mechanisms of action, and how their secretions are controlled through feedback loops and the nervous system. Stress responses mediated by the endocrine system are also summarized.

1. Hole’s Human Anatomy and Physiology Twelfth Edition Shier  Butler  Lewis Chapter 13 Endocrine System Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

3. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Hormone secretion (a) (b) Blood flow Skin Duct Thyroid gland Endocrine gland Endocrine cell Exocrine gland (sweat gland) Exocrine cells

5. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. (a) (b) Nerve impulse Bloodstream Neuron transmits nerve impulse Glandular cells secrete hormone into bloodstream Neurotransmitter released into synapse Post- synaptic cell responds Target cells (cells with hormone receptors) respond to hormone Hormones have no effect on other cells

9. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. O H 3 C (a) Cortisol (d) Oxytocin OH HO C HO (b) Norepinephrine H H OH H C NH 2 C H H C C H H C H H C H H H H H H C C C C C (e) Prostaglandin PGE 2 H OH H H H OH C H H H H C H C C H H C C H H C O OH H H H H C HO H 3 C C O C O C Ala Val Asp His Ser Arg Gly Arg Arg Asp Ser Glu Pro Arg Asp Ala Ser Glu Glu Phe Ile Gly Asp His His Ser Leu Leu Met Ala Pro Pro Ala Ala Glu Glu Leu Asp Ser Gly Glu Glu Glu Arg Gly Cys Cys Asp Glu Ile Pro Leu Gly His Ileu Met Glu Ser Phe Ala Leu Glu Ser Asp Ile Leu Leu Leu Asp Glu Leu Gly Glu S S CH 2 OH Val Lys Lys Lys Lys Val Lys Lys Lys Val Lys Tyr Val Val Lys Lys Lys Try Val Tyr (c) Parathyroid ho rm one (PTH)

14. 13.1 Clinical Application Using Hormones to Improve Athletic Performance

17. Control Sources Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. too high too low Control center Endocrine gland inhibited. Receptors Hormone control mechanism senses change. Effectors Hormone secretion decreased. Stimulus Hormone levels rise or controlled process increases. Response Hormone levels return toward normal. Normal hormone levels Stimulus Hormone levels drop or controlled process decreases. Response Hormone levels return toward normal. Receptors Hormone control mechanism senses change. Effectors Hormone secretion increased. Control center Endocrine gland stimulated.

18. Control Sources Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Nervous system (a) (b) (c) Target cells Action Target cells Action – – – – Anterior pituitary gland Action Hypothalamus Peripheral endocrine gland Target cells Endocrine gland Changing level of substance in plasma Endocrine gland

20. Optic nerve Sphenoid bone Hypothalamus Optic chiasma Sella turcica Third ventricle Trochlear nerve Basilar artery Anterior cerebral artery Pituitary stalk (Infundibulum) Anterior lobe of pituitary gland Sphenoidal sinus Posterior lobe of pituitary gland Oculomotor nerve Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

22. Anterior pituitary Peripheral endocrine gland Hypothalamus Target cells (Hormone 3) + – – – + + Inhibition Stimulation Releasing hormone (Hormone 1) Anterior pituitary hormone (Hormone 2) Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. © Michael Ross/Photo Researchers, Inc. Secretory cells

23. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Thyroid Mammary gland Ovary Testis Bone Muscle Hormones from Anterior Pituitary Hormones from Hypothalamus GHRH Growth hormone- releasing hormone SS Somatostatin PRF Prolactin- releasing factor PIH Prolactin- release inhibiting hormone TRH Thyrotropin- releasing hormone CRH Corticotropin- releasing hormone GnRH Gonadotropin- releasing hormone GH Growth hormone PRL Prolactin TSH Thyroid- stimulating hormone ACTH Adrenocorticotropic hormone LH Luteinizing hormone FSH Follicle- stimulating hormone Adipose tissue Adrenal cortex

24. 13.2 Clinical Application Growth Hormone Ups and Downs

28. Structure of the Gland Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Follicular cells Colloid Extrafollicular cells © Fred Hossler/Visuals Unlimited Larynx Colloid Isthmus (a) (b) Thyroid gland Follicular cell Extrafollicular cell Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

29. Thyroid Hormones Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. OH O I I CH 2 I I OH O I CH 2 I I NH 2 CHCOOH NH 2 CHCOOH Thyroxine (T 4 ) Triiodothyronine (T 3 )

30. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. © Mediscan/Visuals Unlimited © Mediscan/Visuals Unlimited © Mediscan/Visuals Unlimited

32. Structure of the Glands Posterior view Esophagus Pharynx Thyroid gland Parathyroid glands Trachea Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Secretory cells Capillaries Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. © R. Calentine/Visuals Unlimited

33. Parathyroid Hormone Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Liver Intestinal enzymes Ultraviolet light in skin Kidney Stimulated by PTH Hydroxycholecalciferol Foods Ca +2 Ca +2 Ca +2 Cholesterol Provitamin D Vitamin D (Cholecalciferol) Also obtained directly from foods Dihydroxycholecalciferol (active form of vitamin D) Controls absorption of calcium in intestine

34. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. PTH Ca +2 + PTH PTH Ca +2 + Ca +2 Bloodstream – Stimulation Inhibition Release into bloodstream Parathyroid glands (on posterior of thyroid gland) Decreased blood calcium stimulates parathyroid hormone secretion Increased blood calcium inhibits PTH secretion Kidneys conserve Ca +2 and activate Vitamin D Bone releases Ca +2 Intestine absorbs Ca +2 Active Vitamin D

37. Structure of the Glands Cortex Medulla Capsule Zona glomerulosa Zona fasciculata Zona reticularis Chromaffin cells Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. © Ed Reschke Adrenal gland Kidney Adrenal cortex (a) Zona lomerulosa Connective tissue capsule (b) Zona fasciculata Zona reticularis Adrenal medulla Adrenal cortex Adrenal medulla Surface of adrenal gland Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

38. Hormones of the Adrenal Medulla

39. Hormones of the Adrenal Cortex

40. 13.3 Clinical Application Disorders of the Adrenal Cortex

41. 13.1 From Science to Technology Treating Diabetes

43. Structure of the Gland Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Pancreatic islet (Islet of Langerhans) From Kent M. Van De Graaff and Stuart Ira Fox, Concepts of Human Anatomy and Physiology, 2nd ed. ©1989 Wm. C. Brown Publishers, Dubuque, Iowa. All Rights Reserved. Reprinted with permission Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Gallbladder Common bile duct Pancreatic duct Pancreas Duct Capillary Small intestine Digestive enzyme- secreting cells Pancreatic islet (Islet of Langerhans) Hormone-secreting islet cells Know

44. Hormones of the Pancreatic Islets

45. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. too high too low Control center Beta cells secrete insulin Receptors Beta cells detect a rise in blood glucose Effectors Insulin • Promotes movement of glucose into certain cells • Stimulates formation of glycogen from glucose Stimulus Rise in blood glucose Response Blood glucose drops toward normal (and inhibits insulin secretion) Normal blood glucose concentration Stimulus Drop in blood glucose Response Blood glucose rises toward normal (and inhibits glucagon secretion) Receptors Alpha cells detect a drop in blood glucose Effectors Glucagon • Stimulates cells to break down glycogen into glucose • Stimulates cells to convert noncarbohydrates into glucose Control center Alpha cells secrete glucagon

46. 13.4 Clinical Application Diabetes Mellitus

50. Responses to Stress Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Sympathetic impulses CRH released ACTH released Cortisol released Long-term adjustment or resistance stage • Increase in blood concentration of amino acids. • Increased release of fatty acids. • Blood glucose increases. • Blood glycerol and fatty acids increase. • Heart rate increases. • Blood pressure rises. • Breathing rate increases. • Air passages dilate. • Pupils dilate. Anterior pituitary Hypothalamus Adrenal cortex Adrenal medulla Neural signals Hormonal signals Stress results from changes in the external environment Signals from sensory receptors Epinephrine and norepinephrine released Norepinephrine released Short-term “fight or flight” or alarm stage. • Blood flow redistributes. • Increased glucose formed from noncarbohydrates—amino acids (from proteins) and glycerol (from fats).