1 / 39

Endocrine System

Endocrine System. Chapter 16 Human Anatomy & Physiology 8/e , Marieb & Hoehn. (Pearson 2010). Today’s class. Endocrine glands and hormones Mechanisms of hormone action Hypothalamus and pituitary gland Adrenal gland Thyroid and parathyroid glands Pancreas. Nervous and endocrine systems.

aristotle-russell
Download Presentation

Endocrine System

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Endocrine System Chapter 16 Human Anatomy & Physiology 8/e, Marieb & Hoehn. (Pearson 2010)

  2. Today’s class • Endocrine glands and hormones • Mechanisms of hormone action • Hypothalamus and pituitary gland • Adrenal gland • Thyroid and parathyroid glands • Pancreas

  3. Nervous and endocrine systems • Two systems of internal communication and regulation • act individually or together • Nervous system • high-speed electrical signals via neurons • Endocrine system • endocrine glands secrete hormones • slower, longer-acting responses

  4. Endocrine glands • Ductless • Secrete hormones into bloodstream • hormones affect target with receptor • some prehormones and prohormones fig 16.1

  5. Types of chemical signals pheromones endocrine paracrine Human Reproductive Biology, 3/e. by S. Mader. McGraw Hill publishers. 2005. fig 5A

  6. Hormones trigger cell signalling Three stages: • reception • signal transduction • response

  7. Structural categories of hormones • Polypeptides and proteins • Amino acid derivatives (amines) • Steroids • (Eicosanoids)

  8. Examples (autocrine regulator) (Anatomy and Physiology, 8/e, Seeley, Stephens and Tate, 2008, McGraw Hill, fig 17.3)

  9. General hormone effects • Interactions • Synergistic (effect of 2 combine better than one) • Permissive • Antagonistic • Concentration • half-life (how long in the blood stream) • Target cell specificity • receptor type, number and affinity • upregulation, desensitization/downregulation

  10. Importance of receptorse.g. complete androgen insensitivity syndrome (AIS) • XY individual • testes present • no ovaries or uterus • testosterone synthesized but no functional receptor Human Reproductive Biology, 3/e. by S. Mader. McGraw Hill publishers. 2005. fig 3.14

  11. Mechanisms of hormone action • Peptide/protein/amines: receptors in Plasma membrane (cuz the molecules are too big) • different mechanisms, between from getting point A to B e.g. • cAMP – second message. 1st message in hormone • DAG/IP3 (phospholipase C) – cut the phosphol • tyrosine kinase • Activate “premade” proteins • Lipids: intracellular receptors • reach target via carrier proteins in plasma • why the need for carrier? Need a carrier cuz there hydrphobic and direct to the right tissue • nuclear hormone receptors as transcription factors • They create protein with transcription, translation, termination.

  12. Recall cAMP as second messenger fig 16.2

  13. phospholipase C PIP2 IP3 + DAG Phospholipase C system Human Physiology, 10e, by Fox, McGraw Hill publishers, 2008, fig 11.9

  14. Insulin and its tyrosine kinase receptor no second messenger required Human Physiology, 10e, by Fox, McGraw Hill publishers, 2008, fig 11.11

  15. Lipid-soluble hormones fig 16.3

  16. Control of hormone release • Endocrine gland stimuli • Humoral • Neural • Hormonal • Nervous system modulation

  17. Control of hormone release fig 16.4

  18. Hypothalamus and pituitary • Control much of endocrine system • Integrate nervous and endocrine systems • receives nerve signals from body • initiates appropriate responses • Neurosecretory cells • Posterior pituitary – not true (keeper and releaser of hyperthalmus) • stores and releases hormones made by hypothalamus • Anterior pituitary • Hypthalmus when to make/ nt make the hormones • true endocrine gland makes 6 trophic hormones

  19. Hypothalamus and posterior pituitary What are functions of oxytocin and ADH? fig 16.5a

  20. Hypothalamus and anterior pituitary fig 16.5b

  21. Targets of anterior pituitary hormones Human Physiology, 10e, by Fox, McGraw Hill publishers, 2008, fig 11.15

  22. Hypothalamus and anterior pituitary • Hypothalamic-releasing hormones stimulate anterior pituitary • gonadotropin-releasing hormone (GnRH) • prolactin-releasing hormone (PRH) • growth hormone-releasing hormone (GHRH) • corticotropin-releasing hormone (CRH) • thyrotropin-releasing hormone (TRH)

  23. Hypothalamus-pituitary-target axis Hypothalamusanterior pituitary target • GnRH FSH, LH  gonads  sex hormones • PRH prolactin  mammary glands • GHRH growth hormone  various • CRH ACTH  adrenal cortex  corticosteroids (stress response) • TRH  TSH thyroid  metabolism hormones

  24. hypothalmus-pituitary-gonad axis Feedback examples hypothalmus-pituitary-thyroid axis Human Physiology, 10e, by Fox, McGraw Hill publishers, 2008, figs 11.17, 11.18

  25. Thyroid gland • Located just inferior to larynx • Follicles • follicular cells • thyroxine • colloid fluid • Parafollicular cells • calcitonin fig 16.8

  26. Thyroid hormones • T3 and T4 (thyroxine) • elevate basal metabolic rate • stimulate protein synthesis, increase respiration, etc • Calcitonin • lowers blood calcium concentrations • inhibits dissolution of calcium phosphate in bone • stimulates excretion of calcium in urine

  27. Synthesis of thyroid hormone fig 16.9

  28. Diseases of thyroid: hypothroidism • Hypothyroidism:  thyroid function • slower than normal metabolism • myxedama (fluid/mucoprotein accumulation in subcutaneous tissue) • Causes • Gland defect (e.g. by Hashimoto’s thyroiditis) • Too little TRH and/or TSH for trophic effects • Endemic goiter: by iodine deficiency • Hyperthyroidism:  thyroid function • more rapid than normal metabolism • e.g. by Grave’s disease (autoimmune) • autoantibodies are TSH receptor agonists fig 16.10

  29. Parathyroid glands • 4 glands embedded in lateral lobes of thyroid gland • Secrete parathyroid hormone (PTH) • control of blood Ca2+ levels fig 16.11

  30. Recall fig 16.12

  31. Adrenal gland • Outer cortex • no neural innervation • steroid hormones • corticosteroids (corticoids) • aldosterone effects will be covered in more detail with urinary system • Medulla • preganglionic sympathetic neurons • catecholamines • epinephrine (mainly) • norepinephrine

  32. Adrenal gland fig 16.13

  33. Cushing’s syndrome: excess glucocorticoid fig 16.15

  34. Stress and adrenal gland fig 16.16

  35. Aldosterone release from adrenal cortex * Aldosterone targets kidneys fig 16.4

  36. Pancreas • Exocrine and endocrine • Islets • alpha cells: glucagon • in response to  blood glucose • stimulates liver: glycogen  glucose, fat hydrolysis • beta cells: insulin • in response to blood glucose • promotes entry of glucose into tissue • glucose  glycogen, fat • feeding versus fasting?

  37. Pancreas and blood glucose homeostasis Human Physiology, 10e, by Fox, McGraw Hill publishers, 2008, fig 11.31 fig 16.18

  38. Other hormones • Pineal gland: melatonin • Gonads (testes and ovaries): sex hormones • will be covered with reproductive system • Other organs (non-endocrine glands) secrete hormones • heart, GI tract, kidneys, skin, adipose tissue, skeleton, thymus

  39. Up next • December office hours • Monday, December 6: 10-12, 2-4 • Monday, December 13, 2-5 • Exam (cumulative) • Tuesday, December 14, 9-11

More Related