1. REGULATION CHEMICAL REGULATION –CHAPTER 16

2. Chemical vs Nervous Regulation Body systems never rest – make constant adjustments to maintain homeostasis Nervous system and endocrine system Endocrine system releases chemicals into the blood stream and regulates metabolism, growth, reproduction Chemical regulation is slower than impulse regulation Chemical regulation results lasts longer than nervous regulation

3. Glands Glands are made of epithelial cells that secrete substances needed by the body Exocrine glands have ducts that carry secretions to where they are needed Endocrine glands (ductless glands) secrete directly into the blood stream Make up the endocrine system Secrete hormones that travel in the blood stream Controls homeostasis, metabolism, growth, reproduction

4. Exocrine glands have ducts that carry secretions to where they are needed

5. Endocrine glands (ductless glands) secrete directly into the blood stream

6. Hormones Chemical messengers – where secreted is not where it is used Target tissue is the specific tissue that recognizes a specific hormone Hormone stimulates target tissue to increase, decrease, stop or start activities Hormones do not act directly on the target tissue but change a cellular process that affects the target tissue

7. Target tissue is the specific tissue that recognizes a specific hormone Hormone stimulates target tissue to increase, decrease, stop or start activities

8. Hormones Two types of hormones Protein type (made of amino acids) cannot pass through the cell membrane (ex: insulin) Steroid type (lipid-like) can pass through the cell membrane (ie: estrogen)

9. Hormones Protein type (made of amino acids) cannot pass through the cell membrane (ex: insulin)

10. Hormones Steroid type (lipid-like) can pass through the cell membrane (ie: estrogen)

11. The Regulation of Hormones The rate of secretion varies with the needs of the body Chemical stimulation regulates secretions and overlaps with the nervous system Chemical regulation is accomplished by feedback Positive feedback – reinforces the original change Negative feedback – opposes the original change Negative feedback usually maintains homeostasis

12. Mechanisms of Hormone Action Hormones are in the blood and enter all organs but are only recognized by the target tissues HOW?

13. One-messenger Model Steroid hormones Enters all cells of the body but only the target tissue has receptor proteins that react with the hormone and form an active factor. The active factor produces the hormone effect.

14. Two-messenger Model Protein-type hormones Cannot pass through the cell membrane – specific receptors on the outer surface of the target cell membranes that react and activate enzymes in the membranes that act as a second messenger.

15. Add the following table to the bottom of page 20 in your packet

16. Compare Chemical Regulation vs Nervous Regulation Chemical RegulationNervous Regulation Both systems work together to maintain homeostasis Reacts more slowly Reacts more quickly Effects last longer Effects are short term Chemical messengers Electrochemical messengers Messengers (hormones) travel all over the body in the blood (circulation) Messengers are directed to a specific area (nerve pathways)

17. Turn to the diagram on page 26 in your packet

18. HUMAN ENDOCRINE Pineal Testes Pancreas Adrenals Thymus Parathyroids Thyroid Pituitary Hypothalamus Ovary

19. Turn to page 28 in your packet Follow along with the notes

20. Pituitary Gland Known as the Master Gland Controls the release of hormones from many other endocrine glands Connected to the hypothalamus which Controls the release of hormones from the pituitary Receives information from the nervous system Stimulates the pituitary to release hormones

21. ANTERIOR PITUITARY 1. Thyroid-stimulating hormone (TSH)  Stimulates the production and release of thyroxin from the thyroid 2. Adrenocorticotropic hormone (ACTH)  Stimulates the production and release of hormones from the adrenal glands 3. Growth hormone (GH)  Indirectly affects bone and cartilage growth  Directly affects cellular metabolism 4. Follicle-stimulating hormone (FSH)  Stimulates development of eggs (female – ovaries)  Stimulates production of sperm (males – testes) 5. Luteinizing hormone (LH)  Stimulates the release of eggs from the ovaries  Controls production of sex hormones in males and females 6. Prolactin  Stimulates secretion of milk after child birth

22. POSTERIOR PITUITARY 1. Connected to the hypothalamus 2. Oxytocis Stimulates contraction of the uterus during child birth 3. Vasopressin Controls reabsorption of water by the nephrons in the kidneys

23. THYROID Located under the larynx – in front of the trachea Thyroxin Regulates the rate of metabolism Calcitonin Regulates the blood’s calcium level

24. PARATHYROID GLANDS Four tiny glands in the back of the thyroid 1. Parathyroid hormone Regulates calcium and phosphate metabolism hypersecretion – removes Ca from the bones – osteoporosis hyposecretion – lowers the blood’s Ca level – tetany

25. THE ADRENAL GLANDS Located on the kidneys Helps the body deal with stress (fight or flight response)

26. THE ADRENAL GLANDS Adrenal medulla (inner layer of the adrenal gland) Epinephrine or adrenalin (80%) Norepinepherine or noradrenalin (20%) Regulates the fight or flight response Responds to fear, anger, pain, exertion Causes increased rate of metabolism and increased release of glucose (increases heart rate, blood pressure, breathing rate, blood clotting, and sweating)

27. THE ADRENAL GLANDS Adrenal cortex (outer layer of the adrenal gland) 1. Cortisol Controls metabolism of carbohydrates, proteins, and fats 2. Cortisone Counteracts allergies 3. Aldosterone Regulates mineral balance in the blood

28. PANCREAS Is both an exocrine and endocrine gland!!

29. PANCREAS Exocrine Secretes digestive juices through the pancreatic duct to the small intestines

30. PANCREAS Endocrine –secretions from the islets of Langerhans 1. Alpha cells Secretes glucagon Raises the blood sugar (glucose) levels 2. Beta cells Secretes insulin Lowers blood sugar (glucose) levels When the islets of Langerhans fail to produce insulin – diabetes mellitus results

31. THE GONADS (sex glands) Ovaries (female) 1. Estrogen Stimulates the development of female reproduction system Stimulates the development of secondary female sex characteristics 2. Progesterone Regulates female menstrual cycle

32. THE GONADS (sex glands) Testes (male) 1. Testosterone Stimulates the development of male reproduction system Stimulates the development of secondary male sex characteristics

33. Turn to page 22 in your packet

34. What is Regulation? All the activities that help maintain an organism’s homeostasis

35. Compare Nervous System vs Endocrine System The nervous system: Responds quickly Short lasting The endocrine system: Responds more slowly Longer lasting

36. Compare Endocrine Glands vs Exocrine System Endocrine glands (ductless glands) secrete hormones which travel to target tissues through the blood examples = ovaries, thyroid Exocrine glands have ducts or tubes that carry secretions to the target organ example = digestive glands (pancreas)

37. Compare Two Types of Hormones Steroid small and lipid-like can pass through the cell membrane example = estrogen one messenger model enters many cells effects only cells with specific receptor proteins

38. Compare Two Types of Hormones Protein-type made of amino acids – large molecules cannot pass through the cell membrane example = insulin two messenger model target cells have receptor proteins on the cell membrane surface hormone and receptor combine – release enzyme into the cell that acts as a second messenger

39. Check out the diagrams on page 23B in your packet (one and two messenger models)

40. Check out the diagram on page 23A in your packet (positive and negative feedback)

41. Regulation of Hormone Secretion Feedback = the level of one hormone inhibits or stimulates the production of another hormone 1. Positive feedback = reinforces the original change 2. Negative feedback = opposes the original change

42. Turn to page 27 in your packet

43. Turn to page 29 in your packet

44. RECEIVES SENSORY INPUT HYPOTHALAMUS Part of the brain Receives sensory input Controls the release of hormones in the pituitary (releasing factors) PITUTARY GLAND “Master Gland” secretes secretes TSH ACTH (thyrotrophic stimulating hormone)(adrenocorticotrophic hormone) secretes cortisol (controls the metabolism of carbohydrates, proteins, and fats) ADRENAL CORTEX An increased rate of metabolism will inhibit the hypothalamus An decreased rate of metabolism will stimulate the hypothalamus THYROID secretes thyroxin (controls the rate of metabolism)

45. Endocrine Disorders and Diseases

46. Anterior Pituitary Growth Hormone HYPERSECRETIONHYPOSECRETION Gigantism (child onset) Body proportional Dwarfism (body proportional) Acromegaly (adult onset) Enlarged hands, feet and facial features

47. Gigantism (child onset) Body proportional Anterior Pituitary - Growth Hormone HYPERSECRETION

48. Acromegaly (adult onset) Enlarged hands, feet and facial features Anterior Pituitary - Growth Hormone HYPERSECRETION

49. Dwarfism (body proportional) Anterior Pituitary - Growth Hormone HYPOSECRETION

50. Adrenal Cortex cortisol (controls metabolism) HYPERSECRETIONHYPOSECRETION Cushing’s Disease Fat deposits upper body, puffy face, excess facial hair Addison’s Disease Sluggish, weight loss, weakness John F. Kennedy had Addison‘s Disease

51. Thyroid thyroxin (rate of metabolism) HYPERSECRETIONHYPOSECRETION Hyperthyroidism Nervous, irritable, eyes may protrude Hypothyroidism ADULT onset: Sluggish, tired, weight gain CHILD onset: cretinism – dwarfism (body not proportional) and mental retardation

52. Thyroid Thyroxin contains iodine Deficiency of iodine causes a goiter

53. Pancreas secretes insulin for glucose metabolism HYPERSECRETIONHYPOSECRETION Diabetic Shock Cold sweat, confusion, In extreme cases: unconsciousness, coma, death Uncontrolled diabetes Dehydration, weight loss, thirst, irritability Remember: the pancreas is both an exocrine gland (digestive juices) and an endocrine gland (insulin and glucagon for controlling blood sugar levels.

54. Review the answers to the worksheets on pages 24-25 in your packet

55. Please turn to page 21 in your packet Did you know that plants have hormones, too?

56. Plant Hormones Chemical messengers Produced in tips of roots and stems (meristem region) Three kinds 1. Auxins = hormones that affect growth Stimulate or slow growth Cause cells to lengthen and differentiate Affects abscission (dropping off of leaves, fruit, flowers) 2. Gibberellins Distributed evenly through out the plant tissue Affects stem growth and fruit size 3. Cytokinins stimulate cell division and growth during seed germination

57. Auxins and Tropism Tropism = growth of a plant in a specific direction in response to a stimulus Toward the stimulus – positive tropism Away from the stimulus – negative tropism Kinds of tropism phototropism = light geotropism = gravity thigmotropism = touch hydrotropism = water

58. Nastic Movements Plant movement in response to a stimulus, but independent of the direction of the stimulus Prayer plant – leaves collapse due to loss of turgor (water pressure) Venus fly trap

59. Photoperiodism  Response of a plant in response to changes in the length of a day  Not time of light that determines flowering, but the number of dark hours 1) Short-day (long night) plants bloom in spring, late summer 2) Long-day (short night) plants bloom in summer 3) Day-neutral plants are not affected by light hours  Affected by pigment phytochrome