Human Reproduction and Development: Reproductive Systems, Development Before Birth, and Birth

1. Human Reproduction and Development Section 1: Reproductive Systems Section2: Human Development Before Birth Section 3: Birth

2. Human Reproduction and Development Section 1 Reproductive Systems Human Male Reproductive System • Reproductive glands are called the testes and are located outside the body cavity in a pouch called the scrotum. • A temperature lower than 37°C is required for the development of sperm.

3. Human Reproduction and Development Section 1 Reproductive Systems Sperm Cells • Sperm cells develop in the seminiferous tubules located in the testes. • Each is a single cell that carries DNA. The midpiece contains many mitochondria that provide energy for the flagella

4. Human Reproduction and Development Section 1 Sperm Pathway from Seminiferous tubules • Travel to the epididymis and are stored • Travel through the vas deferens. • The two vas deferens join together and enter the urethra. The seminal vesicle, holds the liquid that mixes with sperm to form semen. Semen contains fluid from the epididymis, seminal vesicle, prostate gland, and vas deferens.

5. Human Reproduction and Development Section 1 Reproductive Systems Male Hormones • Testosterone is a steroid hormone that is necessary for the production of sperm. • Three hormones influence testosterone production. • Gonadotropin-releasing hormone (GnRH) • Follicle-stimulating hormone (FSH) • Luteinizing hormone (LH)

6. Human Reproduction and Development Section 1 Reproductive Systems Human Female Reproductive System • Egg cells are produced in the ovaries. • Inside each ovary are oocytes, which are immature eggs. • The egg travels through an oviduct, a tube that connects to the uterus. • The cervix at the lower end of the uterus has a narrow opening into the vagina, which leads to the outside of the female’s body.

7. Human Reproduction and Development Section 1 Reproductive Systems • Estrogen and progesterone are steroid hormones made by cells in the ovaries. • The anterior pituitary gland also produces LH and FSH.

8. Human Reproduction and Development Section 1 Reproductive Systems The Menstrual Cycle • The length of the menstrual cycle can vary from 23 to 35 days. • The cycle can be divided into three phases: the flow phase, the follicular phase, and the luteal phase.

9. Human Reproduction and Development Section 1 Reproductive Systems

10. Release of Egg • Ovulation – egg travels from the ovary through the fallopian tube/oviduct (4 days) • The ova is fertilized by sperm in the fallopian tube/oviduct.

11. Production of Eggs/Sperm by Meiosis • Eggs and sperm have 23 chromosomes, half the number found in somatic (body) cells. • The nuclei of the sperm and female egg fuse to have 46 chromosomes. • After puberty, males make sperm 24/7, 20-150 million sperm per ml. for most of their lives. • All female ova are formed before birth and matures during ovulation, 1 million follicles (contain ova) in each ovary

12. Human Reproduction and Development Section 2 Fertilization Fertilization • Process of a sperm joining with an egg • Sperm and eggs each are haploid, and each normally has 23 chromosomes. • Fertilization restores the diploid number of 46 chromosomes.

13. Human Reproduction and Development Section 2 Fertilization • The tip of each sperm cell is a specialized lysosome called an acrosome that weakens the plasma membrane surrounding the egg. • Eventually the plasma membrane becomes weak enough that one sperm can penetrate the egg. • Immediately following this penetration, the egg forms a barrier to prevent other sperm from entering the now-fertilized egg.

14. Fertilization • Only one sperm can penetrate the surface of the egg-a chemical reaction changes the exterior of the cell: the Zonapellucida • A fertilized egg is a zygoteand will begin mitosis • Fertilization occurs in the fallopian tube

16. Human Reproduction and Development Section 3 Summary • Hank explains Sexual Reproduction. • .

17. Human Reproduction and Development Section 2 Human Development Before Birth Early Development • The fertilized egg is called a zygote. • Around 30 hours after fertilization, the zygote undergoes its first mitosis and cell division • By the third day, the embryo, called a morula, leaves the oviduct and enters the uterus.

19. Human Reproduction and Development Section 2 Human Development Before Birth • By the fifth day, the morula has developed into a blastocyst. • The blastocyst attaches to the endometrium around the sixth day and is fully implanted by Day 10. • In lab fertilized eggs the inner cell mass are called embryonic stem cells.

20. Human Reproduction and Development Section 2 Human Development Before Birth Extraembryonic Membranes • Four extraembryonic membranes form. • These membranes are the amnion, the chorion, the yolk sac, and the allantois.

21. Human Reproduction and Development Section 2 Human Development Before Birth The Placenta • Provides food and oxygen and removes wastes • The placenta has two surfaces • A fetal side that forms from the chorion and faces the fetus • A maternal side that forms from uterine tissue

22. Human Reproduction and Development Section 2 Human Development Before Birth • As an embryo develops, the chorionic villi begin to grow into the uterine wall. • Nutrients, oxygen, and wastes diffuse across maternal and fetal blood vessels, and are carried to and from the fetus through the umbilical cord. • The placenta contains tissue from both mother and fetus. • Blood cells and plasma cannotpass through the placenta between the mother and fetus

25. Human Reproduction and Development Section 2 Human Development Before Birth Diagnosis in the Fetus • Ultrasound • Procedure in which sound waves are bounced off the fetus • Determines if the fetus is growing properly • Determines the position of the fetus in the uterus • Determines the gender of the fetus

27. Human Reproduction and Development Section 2 Human Development Before Birth Amniocentesis • Amniocentesis is performed in the second trimester. • Fluid from the amniotic sac is removed and analyzed.

28. Human Reproduction and Development Section 2 Human Development Before Birth Three Trimesters of Development • Human development takes around 266 days from fertilization to birth. • The time span is divided into three trimesters

29. Human Reproduction and Development Section 2 Human Development Before Birth The First Trimester Months 1-3 Weeks 1-13 • All tissues, organs, and organ systems begin to develop. • At the end of eight weeks, the embryo is called a fetus.

30. Do Now:A. Convert the three trimesters to weeks B. Estimate the cost in dollars of having a baby? Include prenatal care

31. Prenatal care and delivery costs can range from about $9,000 to over $250,000. With insurance coverage (including ACA) the deductible must be met first for the Mom and the newborn. Deductibles are $2,500.00 for MCPS employees, so $5,000 is the initial cost.

32. Fetal Development • Weeks 1-9

33. Week 10-14 • http://www.youtube.com/watch?v=sivegxcp2Bk

34. Human Reproduction and Development Section 2 Human Development Before Birth The Second Trimester Months 4-6 Weeks 14-26 • Period of growth . • The fetal heartbeat might be heard.

35. Week 15-20 • http://www.youtube.com/watch?v=VsjcqkOjp0U

36. Boy or Girl? • http://www.youtube.com/watch?v=SuWoXFIcgCg

37. Week 21-27 • http://www.youtube.com/watch?v=lw0M-HTlMoo

38. Human Reproduction and Development Section 2 Human Development Before Birth The Third Trimester Months 7-9 Weeks 27-40 . • The fetus continues to grow at a rapid rate. • Fat accumulates under the skin to provide insulation for the fetus once it is born.

39. Week 28-37 • http://www.youtube.com/watch?v=BIzb-IqF4i8

40. Human Reproduction and Development Section 3 Birth Birth • Birth occurs in three stages: dilation, expulsion, and the placental stage. • The beginning of the birthing process is called labor.

41. Labor and Birth • http://www.youtube.com/watch?v=BgZ5z6RB06c

42. Vaginal Birth • http://www.youtube.com/watch?v=zRXpnNYLbmo Stage 1: Contractions until cervix is dilated to 10 cm Stage 2: Pushing begins Stage 3: Placenta is delivered Stage 4: Recovery, body adjusts to the abrupt physical change

43. Baby grasps surgeon’s hand during cesarean birth

44. A B C D Human Reproduction and Development Chapter FQ 1 Section 1 Formative Questions What condition is necessary in order for the seminiferous tubules in the testes to produce sperm cells? a slightly acidic environment a temperature lower than 37° C nutritive fluids from the seminal vesicles the release of gonadotropin- releasing hormone (GnRH)

45. A B C D Human Reproduction and Development Chapter FQ 2 Section 1 Formative Questions Which hormone influences the development of male secondary sex characteristics at puberty? follicle-stimulating hormone (FSH) gonadotropin-releasing hormone (GnRH) luteinizing hormone (LH) testosterone

46. A B C D Human Reproduction and Development Chapter FQ 3 Section 1 Formative Questions Which hormones secreted by the anterior pituitary gland regulate the levels of testosterone in males and estrogen in females? follicle-stimulating hormone (FSH) gonadotropin-releasing hormone (GnRH) luteinizing hormone (LH) Both A and C

47. A B C D Human Reproduction and Development Chapter FQ 4 Section 1 Formative Questions What prevents the menstrual cycle from continuing once an egg has been fertilized? Progesterone levels remain high. Estrogen levels decrease. The corpus luteum degenerates. Blood supply to the endometrium decreases.

48. A B C D Human Reproduction and Development Chapter FQ 6 Section 2 Formative Questions Why are several hundred sperm cells needed for the fertilization of an egg? They carry hormones to the egg. They contribute DNA to the egg. They help each other swim to the egg. They weaken the egg’s plasma membrane.

49. A B C D Human Reproduction and Development Chapter FQ 7 Section 2 Formative Questions What is the hollow ball of cells that attaches to the wall of the uterus around the sixth day after fertilization? the amniote the blastocyst the morula the zygote

50. A B C D Human Reproduction and Development Chapter FQ 8 Section 2 Formative Questions What is the thin tissue layer that forms a fluid-filled sac around the developing embryo? amnion allantois chorion yolk sac