Presentation is loading. Please wait.

Presentation is loading. Please wait.

Reproduction and Development

Similar presentations

Presentation on theme: "Reproduction and Development"— Presentation transcript:

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

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

Download ppt "Reproduction and Development"

Similar presentations

Ads by Google