1. Chapter 19: Endocrine and Reproductive Systems Essential questions: How do hormones change cell activities? How do humans reproduce?

2. I. Endocrine system: consists of glands that transmit chemical messengers throughout the body II. Hormones: chemical messengers carried through bloodstream and affect many types of cells A. Two types of hormones

3. 1. Amino acid based hormones: can not move through cell membrane a) hormone attaches to cell b) second messenger inside the cell relays the hormone signal c) changes occur within the cell

4. 2.Steroid hormones: can cross the cell membrane and into the nucleus a) can activate certain genes to make certain proteins b) causes cell activity to change Steriod hormone

5. Steroid Hormone Target cell membrane mRNA Cytoplasm Protein synthesis Altered cellular function Receptor Hormone- receptor complex Nucleus DNA Nonsteroid hormone (first messenger) Receptor Target cell membrane cAMP (second messenger) Enzyme activities Altered cellular function Cytoplasm Nucleus Hormone Action Section 39-1

6. B. Glands: organ that consists of cells that secrete materials into other regions of the body 1. Exocrine glands: secrete nonhormonal chemicals into ducts a) sweat glands b) salivary glands 2. Endocrine glands: secrete hormones into bloodstream Comparison

7. Hypothalamus The hypothalamus makes hormones that control the pituitary gland. In addition, it makes hormones that are stored in the pituitary gland. Pituitary gland The pituitary gland produces hormones that regulate many of the other endocrine glands. Parathyroid glands These four glands release parathyroid hormone, which regulate the level of calcium in the blood. Thymus During childhood, the thymus releases thymosin, which stimulates Tcell development. Adrenal glands The adrenal glands release epinephrine and nonepinephrine, which help the body deal with stress. Pineal gland The pineal gland releases melatonin, which is involved in rhythmic activities, such as daily sleep-wake cycles. Thyroid The thyroid produces thyroxine, which regulates metabolism. Pancreas The pancreas produces insulin and glucagon, which regulate the level of glucose in the blood. Ovary The ovaries produce estrogen and progesterone. Estrogen is required for the development of secondary sex characteristics and for the development of eggs. Progesterone prepares the uterus for a fertilized egg. Testis The testes produce testosterone, which is responsible for sperm production and the development of male secondary sex characteristics Section 39-1 Figure 39–2 The Endocrine Glands

8. III. Endocrine glands A. Pituitary gland 1. Located in base of skull (brain) 2. Secretes eight hormones that regulate different parts of the body 3. Important for normal functioning of the body

9. B. Thyroid gland 1. Located in neck near larynx 2. Thyroid hormone helps to maintain normal heart rate, blood pressure, and body temperature 3. Requires small amount of iodine to create hormone Thyroid gland

10. C. Adrenal glands 1. Located above each kidney 2. Produces epinephrine and norepinephrine (known as adrenaline and noradrenaline) 3. Used during stressful and dangerous situations (fight or flight response)

11. D. Gonads 1. Produce sex hormones that regulate body changes at puberty 2. Male: testes which produce testosterone 3. Female: ovaries which produce estrogen and progesterone

12. E. Pancreas 1. Regulates blood sugar level using two hormones 2. Insulin: stimulates cells to absorb glucose from the blood 3. Glucagon: stimulates the release of glucose into the bloodstream by the liver Pancreas

13. NameLocationFunctionHormone PituitaryBase of Skull Normal functioning of body 8 hormones, growth hormones ThyroidNeck Normal heart rate, blood pressure, temperature Thyroxine AdrenalAbove Kidney Stressfull conditions, fight or flight Adrenaline GonadsLower Abdomen Regulates changes at puberty Testosterone, estrogen PancreasAbdomen Regulate blood sugar levels Insulin, Glucagon

14. Endocrine System Concept Map 1.Follow the directions on the handout 2.Use the large white paper to make the map 3.You may work with a partner, but your maps shouldn’t be identical 4.Turn in your map at the end of class 5.Use your notes and additional information from your textbook

15. IV. Male Reproductive System A. Formation of Sperm 1. Testes: sperm producing organ of male reproductive system 2. Males begin to produce sperm during puberty when testosterone is released 3. Sperm cells undergo meiosis to turn 46 chromosomes into 23 chromosomes

16. 4. Mature sperm has three regions a) head: contains enzymes and 23 chromosomes b) midpiece: mitochondria for energy c) tail: flagellum that propels the sperm

18. B. Male reproductive structures 1. Testes: reproductive gland 2. Seminiferous tubules: coiled tubules in testes that produce sperm 3. Scrotum: external sac that holds testes and has a lower temperature for normal sperm production 4. Epididymis: long coiled tubule attached to testes that stores sperm until they are mature

20. 5. Vas deferens: tube from epididymis that enters abdominal cavity and merges with the urethra 6. Urethra: tube that urine and sperm use to exit the body 7. Glands release fluids that mix with sperm a) seminal vesicles b) bulbourethral gland c) prostate gland

21. 8. Semen: sperm and fluids from glands 9. Penis: urethra passes through it to deposit sperm in the female reproductive system 10. Ejaculation: process in which sperm is expelled by contractions of smooth muscles 11. 300 – 400 million sperm leave the male’s body Summary

22. Section 39-3

23. V. Female Reproductive System A. Formation of eggs 1. Ovaries: gamete-producing organ in females and contains 400,000 eggs when female is born 2. Eggs mature over her lifetime and 300-400 are released from puberty to about age 50 3. Egg is formed by meiosis 4. Ovum: mature egg that is 75,000 times larger than a sperm cell

24. B. Female reproductive structures 1. Ovary: almond-shaped and located in lower abdomen 2. Fallopian tube: tube that carries egg from ovary to uterus 3. Uterus: hollow, muscular organ the size of a fist 4. Cervix: lower entrance of uterus

25. 5. Vagina: muscular tube from cervix to the outside of the body 6. Vulva: folds of skin that cover and protect the opening to the system Summary

26. Section 39-3

28. C. Preparation for pregnancy 1. Menstrual cycle: series of changes that occur about every 28 days to prepare for a possible pregnancy 2. Follicular phase: immature egg starts to mature a) follicle: layer of cells that surround the egg and supply nutrients to the egg

29. b) FSH: follicle stimulating hormone stimulates the follicle c) Estrogen level increases causing the lining of the uterus to thicken d) Lasts about 14 days 3. Ovulation: release of an egg from ruptured follicle a) LH: luteinizing hormone increases and causes the rupture of the follicle b) Egg is swept into the fallopian tube by cilia

30. 4. Luteal phase: egg travels through the fallopian tube and it is the best time for fertilization a) corpus luteum: ruptured follicle begins to secrete progesterone and estrogen to thicken uterus 5. Menstruation: lining of the uterus and blood are discharged through vagina a) If egg is not fertilized, levels of hormones drop and menstruation occurs

31. b) If egg is fertilized, hormones will continue to maintain lining of uterus and menstruation will not occur c) Menopause: menstruation ceases when ovaries cannot secrete enough estrogen and progesterone (around age 50)

32. Section 39-3

33. VI.Gestation: nine month period in which changes transforms a single cell into a human A. Fertilization: sperm and egg fuse and form a zygote 1. Zygote: fertilized egg with 46 chromosomes 2. Sperm travels through vagina, cervix, uterus, and into the fallopian to encounter an egg

34. 3. Sperm attaches to the protective layer around the egg 4. Head of the sperm contains enzymes that break down layer and allow one sperm to enter the egg 5. Chemical changes in the egg’s cell membrane after a sperm enters will stop any other sperm from entering

35. B. Cleavage and Implantation 1. Cleavage: zygote begins dividing but does not increase in size 2. Morula: ball of cells 3. Blastocyst: ball of cells with a large, fluid-filled cavity 4. In the uterus, blastocyst attaches to uterine lining

36. Section 39-4

37. 5. Implantation: process in which blastocyst burrows and embeds itself into the lining SummarySummary C. Pregnancy: nine-month period of development once the blastocyst has implanted 1. First Trimester: most dramatic changes in human development a) Embryo: develops from mass of cells that form three distinct types of cells

38. b) Germ layers: ectoderm, mesoderm, and endoderm will form different body parts c) Amniotic sac: fluid filled sac that surrounds the embryo and acts as a cushion d) Yolk sac: first blood cells and reproductive cells will come from this sac e) Placenta: organ that connects embryo to mother and pass nutrients, gases, drugs, and other substances f) Umbilical cord: attaches embryo to placenta

40. Amniotic sac Placenta Umbilical cord Uterus Amnion Fetal portion of placenta Maternal portion of placenta Maternal artery Maternal vein Umbilical arteries Umbilical vein Villus in chorion Amnion Umbilical cord The Placenta Section 39-4

41. g) Blood of embryo and mother never mix h) Fetus: 8 weeks until birth i) All organ systems will begin forming by the end of the first trimester

42. 2. Second trimester: uterus begins to enlarge a) fetus’s heartbeat can be heard b) skeleton begins to form c) fetus begins to wake and sleep and mother can feel movements

43. Ultrasound picture at 23 weeks

44. 3. Third trimester: fetus grows quickly a) changes that will enable it to survive outside the mother b) react to sound and see light and darkness c) develops fat deposits

45. D. Birth: occurs 270 days after fertilization 1. Hormones initiate childbirth by causing the muscles of the uterus to contract 2. Labor: muscles contractions and other events that lead up to childbirth 3. Amniotic sac breaks 4. Muscles in the cervix and vagina relax and enlarge

46. 5. Strong contractions push a fetus through the cervix, vagina and from the body 6. Placenta and uterine lining are expelled from the mother after the baby 7. Newborn breathes immediately 8. Umbilical cord is clamped and cut Summary

47. 5 Minutes after birth

48. 10 Minutes after birth

49. 6 months old 6 Months18 Months

50. 2 ½ Years old 4 ½ Years old 7 Years Old

51. More Than One Fertilization is the fusion of a sperm and an egg to form a zygote, the single cell from which all cells of the human body are derived. When an egg is fertilized, the remarkable process of human development begins. 1.If two eggs are released during ovulation, each can be fertilized by a sperm. What do you think would be the result? Explain your answer.

52. 2.If one zygote splits into two, each can continue development on its own. What do you think would be the result? Explain your answer. 3.Triplets are three babies born at the same time. Describe three ways that triplets could develop.