Endocrine system

1. Endocrine system Unit 9

2. What are the 8 glands of the endocrine system? • Think back a few chapters, what is translation and transcription? Activator: 2.9.2016

3. Regulates reproduction, growth and development, defenses, balance of nutrients in the blood, metabolism, and energy use • 0.5 pounds of endocrine tissue Role of endocrine system

4. Chemical messengers • Hormone means “to arouse” by altering cellular activity What are hormones?

5. Start by circulating in the blood • Hormones bind to certain cells or organs Mechanisms of hormones action

6. Target Cell/Organ- The cell or organ a hormone attaches to • In order for the target to respond to the hormone, a protein receptor must be present on the plasma membrane or in the cell Hormone attachment

7. Activation means the hormone causes a change in the target cell 2 types of hormone activation: • Steroids(cholesterol and sex hormones) are lipid soluble • Amino-acid based (proteins, peptides, and amines) are non-lipid soluble Hormone activation

9. Lipid-soluble, so they can move through the plasma membrane 1. Steroidal hormone activation

10. Hormone diffuses through plasma membrane Step 1

11. Hormone binds to specific receptor protein • Becomes a hormone-receptor complex (HRC) • HRC enters the nucleus • Hormone (H) + Receptor Complex (RC) = HRC Step 2

12. The HRC binds to DNA Step 3

13. Certain genes in the DNA are altered, new mRNA is transcribed • Think back to translation and transcription Step 4

14. mRNA is translated, new protein is created • This protein will cause the desired effect to the cell Step 5

16. Non lipid soluble, so the hormones must attach to the plasma membrane directly Amino-acid hormone activation:

17. Hormone binds to membrane receptor attached to membrane Step 1

18. Binding sets off a series of reactions that activates enzymes w/in the cell Step 2

19. The enzyme then catalyzes (speeds up) a reaction that produces a messenger molecule Step 3

20. Messenger molecule creates the change desired within the cell Step 4

22. Diffuse thru PM • H + R = HRC, enters nucleus • Bind to DNA • Alter genes of DNA & makes new mRNA • Make a new protein STEROIDAL

23. Attach to receptor in PM • Enzymes are released • Speed up the production of a messenger molecule • Messenger molecule creates the desired effect on cell NON- STERIODAL

24. How do glands know when to release hormones?

25. Use negative feedback mechanisms to maintain hormone levels in the blood How do glands know when to release hormones?

26. Too much of a hormone, the glands stop producing • Too little, and the glands produce more What are negative feedback mechanisms?

27. 3 main categories of stimuli: • Hormonal • Humoral • Neural What kinds of stimuli activate endocrine glands?

28. Endocrine organs are prodded by other hormonesto create their own hormones • rhythmic/always working Hormonal stimuli

29. Step 1: Hypothalamus secretes hormones that activate pituitary gland to release hormones. Example of hormonal stimuli

30. Step 2: Pituitary gland releases hormones that activates adrenal glands AS WELL AS cut off the hormones of the hypothalamus

31. Step 3: New hormones are released by the adrenal glands into the body AS WELL AS cutting off the hormone production in the pituitary glands • This allows the hypothalamus to start producing hormones again

32. Initiated by low levels of ions or nutrients monitored by endocrine organs • Works in short bursts/ Used only when needed Humoral stimuli

33. Hormones respond to neural activity • Ex) responding to stress • Sympathetic nervous system produces norepinephrine which when stressed, which causes increased heart rate, blood pressure, etc. Neural stimuli

34. Endocrine organs

35. “Master gland” • Hangs by a stalk under the hypothalamus 2 parts: • Anterior • Posterior Pituitary Gland

36. 6 total hormones produced here. • 2 work on non-endocrine targets • 4 work on other endocrine glands, these are called trophic hormones Anterior pituitary

37. Growth hormone (GH)- division of cells, growth of bones and muscle • Prolactin (PRL) - Milk production of the breasts 2 Non-endocrine targets

38. The 4 tropic hormones stimulate: • Follicle-stimulating (FSH)- Helps regulates menstrual cycle and egg production in women, sperm production in men • Luteinizing (LH)- • Thyroid-stimulating (TSH)- stimulates the thyroid to release its hormones • Adrenocorticotrophic (ACTH)- stimulates the adrenal glands to release their hormones 4 endocrine gland targets

39. Works directly with the hypothalamus to secrete the hormones produced by the hypothalamus Posterior pituitary

40. 1. Oxytocin (OT) :common in women, stimulates contractions during labor, sex, and also causes milk ejection • 2. Antidiuretic hormone (ADH) Kidneys reduce water excretion (inhibits urine production) 2 hormones from posterior pituitary

41. Large gland made up of two bulbs on each side of the trachea • Thyroid hormone • Calcitonin Thyroid gland

42. Major metabolic hormone- Controls the rate at which glucose is converted into energy and heat • Also controls normal tissue growth and development Thyroid Hormone

43. Decreases calcium levels in the blood by depositing calcium in the bones • Only secreted when calcium levels are high Calcitonin

44. Tiny masses of tissue found on the posterior surface of the thyroid gland Parathyroid glands (4)

45. Releases osteoclasts • Opposite role of calcitonin Effect of PTH

46. Curve over the top of the kidneys • Adrenal cortex • Adrenal medulla Adrenal glands

47. 3 types: • Mineralocorticoids • Glucocorticoids • Sex hormones Hormones of the adrenal cortex

48. Regulate mineral (or salt) & water balance in the blood Mineralocorticoids

49. Increase blood glucose levels • Inhibit some pain-causing molecules (anti-inflammatory) Glucocorticoids

50. Both produced in small amounts throughout life regardless of gender • Androgens (male sex hormone) • Estrogens (female sex hormone) Sex hormones