The Endocrine System

1. The Endocrine System

2. Learning Objectives • Distinguish between endocrine and exocrine glands and define the terms hormone and prostaglandins • Identify and locate the primary endocrine glands and list the major hormones produced by each gland • Describe the mechanisms of steroid and nonsteroid hormone action

3. Learning Objectives • Distinguish between endocrine and exocrine glands and define the terms hormone and prostaglandins • Identify and locate the primary endocrine glands and list the major hormones produced by each gland • Describe the mechanisms of steroid and nonsteroid hormone action

4. Made up of glands that produce and secrete hormones (chemical messengers) • Regulation of growth, metabolism, sexual development • Responses to stress and injury • Internal balance of body systems (homeostasis) What is the system?

5. HORMONES are chemical MESSENGERS that act on target cells (or organs) Endocrine – secretions inside the body Exocrine – secretions outside the body (sweat) BIG IDEA

6. TWO MAJOR CLASSES • Non steroidal

7. Mechanism of Steroid Hormone Action

8. Major Structures

9. REGULATION OF HORMONE • Hormone secretion is controlled by homeostatic feedback • Negative feedback: Mechanisms that reverse the direction of a change in a physiologic system • Positive feedback: (Uncommon) mechanisms that amplify physiologic changes

11. Steroids  - water soluble • Non steroid hormones • Prostoglandins - act locally, on nearby organs Hormone Action

12. The pituitary is often called the “master gland” Its actions are controlled by the hypothalamus in the brain. Hormone Control

13. 22 = Thalamus 24 = Hypothalamus Pituitary Gland

14.   Control of Hormones Negative feedback system When the hormone levels rise, the organ that secretes the hormone is switched off

15. Anterior pituitary gland (adenohypophysis) • Major hormones • Thyroid-stimulating hormone (TSH) • Adrenocorticotropic hormone (ACTH) • Follicle-stimulating hormone (FSH) • Luteinizing hormone (LH) • Growth hormone (GH) • Prolactin hormone (PH

16. Prolactin or PRL - PRL stimulates milk production from a woman's breasts after childbirth and can affect sex hormone levels from the ovaries in women and the testes in men. Anterior Pituitary Hormones

17. Growth hormone or GH - GH stimulates growth in childhood and is important for maintaining a healthy body composition. In adults it is also important for maintaining muscle mass and bone mass. It can affect fat distribution in the body.

18. Problems with the pituitary gland can result in Dwarfism

19. Sites • http://www.youtube.com/watch?v=4TKSjaWQWSs • http://www.youtube.com/watch?v=gEWSAOqple0&feature=related • http://www.youtube.com/watch?v=Q_fjrtxih2o

21. http://www.youtube.com/watch?v=Kn0_zJ4Aiuo

22. Or a person can grow too much. These are pictures of the man known as “The Alton Giant”, Robert Wadlow.

23. Adrenocorticotropin or ACTH - ACTH stimulates production of cortisol by the adrenal glands. Cortisol, a so-called "stress hormone," is vital to survival. It helps maintain blood pressure and blood glucose levels. Many diet aids claim that they block cortisol levels. Cortisol from stress may lead to fat deposits in the belly.

24. Thyroid-stimulating hormone or TSH - TSH stimulates the thyroid gland to make thyroid hormones, which, in turn, control (regulate) the body's metabolism, energy, growth and development, and nervous system activity.

25. Luteinizing hormone or LH - LH regulates testosterone in men and estrogen in women. (gonadotropin) • Follicle-stimulating hormone or FSH - FSH promotes sperm production in men and stimulates the ovaries to release eggs (ovulate) in women. LH and FSH work together to allow normal function of the ovaries or testes. (gonadotropin)

27. Oxytocin - Oxytocin causes milk letdown in nursing mothers and contractions during childbirth. Posterior Pituitary Hormones

28. Antidiuretic hormone or ADH - ADH, also called vasopressin, is stored in the back part of the pituitary gland and regulates water balance. If this hormone is not secreted properly, this can lead to problems of sodium (salt) and water balance, and could also affect the kidneys so that they do not work as well. Posterior Pituitary Hormones

29. Diuretics – increase urine production • Many common foods and drinks contain chemicals that are diuretics (alcohol) Midol relieves symptoms of bloating because it contains a diuretic that will make you urinate more Active Ingredients: (in each caplet): Acetaminophen (500 mg) (Pain Reliever), Caffeine (60mg) (Diuretic, Stimulant), Pyrilamine Maleate (15 mg) (Diuretic)Inactive Ingredients: Carnauba Wax, Croscarmellose Sodium, FD&C Blue 2, Hypromellose, Magnesium Stearate, Microcrystalline Cellulose, Pregelatinized Starch, Propylene Glycol, Shellac, Titanium Dioxide, Triacetin

30. Hypothalamus • Actual production of ADH and oxytocin occurs in the hypothalamus • After production in the hypothalamus, hormones pass along axons into the pituitary gland • The secretion and release of posterior pituitary hormones are controlled by nervous stimulation

32. The thyroid hormones control your metabolism, which is the body's ability to break down food and store it as energy and release of energy THYROID GLAND

33. THYROID HORMONES • Thyroxin (T4) & Tri-iodothyronine(T3) - both increase the rate at which cells release energy from carbohydrates • Calcitonin – regulates the blood concentration of calcium • • BMR – basal metabolic rate : how many calories the body must consume to maintain life

34. Thyroid hormone is partly made of iodine. Iodine is essential for the formation of thyroxin. If a person doesn’t eat enough iodine, they can’t make thyroid hormone. • so it the size of the follicle grows • gland grows • GOITER. • Iodine is only found in seafood, so if salt wasn’t iodized, a lot of people wouldn’t get enough iodine, and there would be a lot of goiters. Problems with the Thyroid

35. Goiter

36. HypothyroidismBefore and After Treatment

37. Hypothyroidism

38. Cretinism (hypothyroidism in infants)

40. Hyperthyroidism (Grave’s Disease)

41. Located behind the thyroid, four tiny glands Parathyroid Hormone (PTH) - takes calcium from the bones to make it available in the blood Parathyroid Glands

42. Signs of low calcium • http://www.youtube.com/watch?feature=endscreen&v=e4IPBRIsCc0&NR=1

43. Located at the top of the kidneys Adrenal Cortex - outer area Adrenal Medulla  - inner area Adrenal Glands = Adrenaline Adrenal Glands

44. Epinephrine & Norepinephrine – increased heart rate, breathing rate, elevated blood pressure (fight or flight, response to stress) Adrenal Medulla People with severe life threatening allergies often carry injectors

45. Aldosterone – a mineralcorticoid, helps kidneys conserve sodium and excrete potassium, maintaining blood pressure • Cortisol – glucocortoid, keeps blood glucose levels stable • Adrenal Sex Hormones - androgens (male) and estrogens (female) Adrenal Cortex

46. Female Sex Glands • The ovaries contain two structures that • secrete hormones • The ovarian follicles • Little pockets in which egg cells, or ova, develop • Secrete estrogen, the “feminizing hormone” • The corpus luteum

47. Female Sex Glands (cont’d) • Effects of estrogen • Development and maturation of breasts and external genitals • Development of adult female body contours • Initiation of menstrual cycle

48. Male Sex Glands • The interstitial cells of the testes secrete the male hormone testosterone • Effects of testosterone • Maturation of external genitals • Beard growth • Voice changes at puberty • Development of musculature and body contours typical of the male

49. Cushing’s syndrome • hypersecretion of cortisol • Round “moon” face and “buffalo hump” Adrenal Gland Disorders

50. Addison’s disease • Hyposecretion of cortisol • Low blood pressure results • Increased pigmentation