1. Reproduction and Development
Chapter 27

2. Multiple Births Becoming more common Increased use of fertility drugs
High order multiple births are risky
Increased risk of miscarriage
Premature delivery
Low birth weights

3. p.461b

4. Impacts, Issues Video
Mind-boggling births

5. Methods of Reproduction
Sexual reproduction
Meiosis, gamete formation, and fertilization
Offspring show genetic variation
Asexual reproduction
Single parent produces offspring
Offspring are genetically identical

6. Asexual Reproduction

7. Cost of Sexual Reproduction
Specialized cells and structures must be formed
Special courtship and parental behaviors can be costly
Nurturing developing offspring, either in egg or body, requires resources (usually from mother)

8. Early Development
Where embryos develop

9. Male Reproductive System
bladder
seminal vesicle
vas deferens
prostate gland
bulbourethral gland
urethra
epididymis
scrotum
testis
penis

10. A Sperm’s Journey Testes Epididymis Vas deferens Ejaculatory ducts
Produces immature sperm
Epididymis
Matures and stores sperm
Vas deferens
Ejaculatory ducts
Urethra

11. Sperm Travel Route
Route sperm travel

12. Male Components and Accessory Glands
PROSTATE GLAND
EJECULATORY DUCT
SEMINAL VESICLE
urinary bladder
URETHRA
urethra
anus
anterior
posterior
BULBOURETHRAL GLAND
VAS DEFERENS
PENIS
erectile tissue
EPIDIDYMIS
TESTIS
Fig. 27-7, p.467

13. Male Reproductive System

14. Glandular Secretions Secretions from epididymis aid sperm maturation
Seminal vesicles secrete fructose and prostaglandins
Prostate-gland secretions buffer pH in acidic vagina
Bulbourethral gland secretes mucus

15. Sperm Production vas deferens seminal vesicle prostate gland
bulbourethral gland
urethra
penis
epididymis
seminiferous tubule
testis
Fig. 27-9a, p.468

16. secondary spermatocyte immature sperm (haploid)
Sperm Production
MITOSIS
MEIOSIS I
MEIOSIS II
lumen
Sertoli cell
spermato-gonium (diploid)
secondary spermatocyte
late spermatid
immature sperm (haploid)
early spermatids
primary spermatocyte
Fig. 27-9b, p.468

17. Spermatogensis
Spermatogenesis

18. A Mature Sperm Spermatids mature to become sperm
Head
Midpiece
Tail
Glandular products + sperm = semen

19. Hormonal Control Testosterone Follicle-stimulating hormone (FSH)
Produced by Leydig cells in testes
Controlled by luteinizing hormone (LH)
Follicle-stimulating hormone (FSH)
Starts sperm production
LH and FSH
produced by pituitary, controlled by hypothalamus

20. Female Reproductive Organs
ovary
ovary
oviduct
uterus
uterus
oviduct
vagina
clitoris
vagina

21. Female Reproductive Organs
Female reproductive system

22. The Uterus Myometrium Endometrium Cervix
Thick layer of smooth muscle in walls
Endometrium
Uterine lining
Cervix
Connects uterus and vagina

23. Menstrual Cycle
The fertile period for a human female occurs on a cyclic basis
Menstrual cycle lasts about 28 days on average

24. Menstrual Cycle Follicular phase Ovulation Luteal phase Menstruation
Uterine lining regenerates
Oocyte matures
Ovulation
Oocyte released from ovary
Luteal phase
Hormones thicken endometrium

25. The Ovarian Cycle Girl is born with primary oocytes already in ovaries
Oocytes are suspended in meiosis 1
Meiosis resumes, one oocyte at a time, with the first menstrual cycle

26. Ovarian Cycle
Ovarian function

27. Ovulation

28. Female Hormonal Control
Hypothalamus
GnRH
Rising estrogen stimulates surge in LH
Anterior pituitary
Progesterone,
estrogens LH
FSH
Ovary
follicle growth,
oocyte maturation
Estrogen
Corpus luteum
forms

29. Cycle Overview
hypothalamus
GnRH
anterior pituitary
FSH LH
FSH LH
GnRH secretion affects LH and FSH secretion by pituitary
LH and FSH affect follicle maturation
Estrogens and progesterone from ovary affect uterus
FSH LH LH
ovulation
estrogens
estrogens
progesterone
estrogens
menstruation
FOLLICULAR PHASE
LUTEAL PHASE

30. Menstrual cycle summary
Cycle Overview
Menstrual cycle summary

31. Female Hormones
Follicular Phase

32. Ovulation and luteal phase
Female Hormones
Ovulation and luteal phase

33. Fertilization Sperm penetrates egg cytoplasm
Secondary oocyte undergoes meiosis II, forms mature egg
Egg nucleus and sperm nucleus fuse to form diploid zygote

34. Fertilization oviduct ovary Ovulation uterus follicle cell
opening of cervix
egg nucleus
vagina
zona pellucida
Fig , p.472

35. Fertilization
Fertilization

36. Prevent fertilization
Birth Control Options
Prevent fertilization
Prevent ovulation
Block implantation

37. Contraception Effectiveness

38. Medical Manipulations
In vitro fertilization (IVF)
Hormone injections
Removal and fertilization of eggs
Reinsertion of dividing cells
Abortion
Spontaneous
Induced

39. Sexually Transmitted Diseases
Human papillomavirus infection (HPV)
Trichomoniasis
Chlamydia
Genital herpes
Gonorrhea
Syphilis
AIDS

40. Sexually Transmitted Diseases

41. Bacterial STDs Can be cured with antibiotics
Syphilis
Gonorrhea
Chlamydia
Pelvic Inflammatory Disease (PID)
Scarring
Tubal pregnancy
Infertility

42. Viral STDs Cannot be cured HIV/AIDS Genital herpes Genital warts
Human papillomaviruses (HPV)
Can cause cancers

43. Table 27-1, p.475

44. Pregnancy Averages 38 weeks from fertilization
Takes 2 weeks for blastocyst to form
Weeks 3 to 8: embryonic period
Weeks 9 to birth: fetal period

45. trophoblast (surface layer of cells of the blastoyst)
fertilization
uterine cavity
endometrium
implantation
endometrium
blastocoel
inner cell mass
inner cell mass
DAYS 1-2
DAY 3
DAY 4
DAY 5
DAYS 6-7
Fig a, p.476

46. First two weeks of development
Implantation
First two weeks of development

47. Human Chorionic Gonadotropin (HCG)
Hormone secreted by blastocyst
Prevents degeneration of corpus luteum
maintains endometrium
prevents menstruation
Can be detected by week 3 with a home pregnancy test

48. The Placenta Interlocking fetal and maternal tissues
Nutrients and wastes exchanged across membrane separating bloodstreams

49. 4 weeks
8 weeks
12 weeks
Fig a, p.478

50. Embryonic Period Weeks 3 to 8 By week 8 Embryo appears human week 4
length 4mm
week 8
length 2 cm

51. Fig a,b, p.480

52. Fetal Period Weeks 9 to birth 22 weeks: fetus cannot survive birth
28 weeks: lungs still developing
36 weeks: survival is 95 percent
38 weeks: full term birth

53. Fetal Period
Fetal development

54. Prenatal Care Nutrition Infection Drugs and alcohol
must be provided from maternal diet through placenta
Infection
mother’s viruses can affect fetus
Drugs and alcohol
harm developing fetus
Children of smokers
at risk for heart defects and death

55. Fetal Alcohol Syndrome

56. Birth (Labor) Cervical canal dilates Amniotic sac ruptures
Uterine contractions drive fetus from uterus
Placenta is expelled as afterbirth

57. Birth
Birth

58. Lactation
During pregnancy, progesterone and estrogen stimulate gland development
After birth, prolactin induces synthesis of enzymes for milk production
Oxytocin triggers contractions that expel milk

59. Stages of Human Development: Prenatal
Zygote: single cell
Morula: solid ball of cells
Blastocyst: ball with fluid-filled cavity
Embryo: 2 weeks to 8 weeks
Fetus: 9 weeks to birth

60. Stages of Human Development: Postnatal
Newborn: birth to 2 weeks
Infant: 2 weeks to 15 months
Child: infancy to 10 or 12 years
Pubescent: during puberty
Adolescent: puberty to maturation
Adult
Old age