Essentials of Anatomy & Physiology, 4th Edition Martini / Bartholomew The Reproductive System PowerPoint® Lecture Outlines prepared by Alan Magid, Duke University Slides 1 to 84 Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Overview of Reproduction Reproductive System Essentials • Gonads (reproductive organs) • Testes in males, ovaries in females • Gametes (reproductive cells) • Spermatazoa in males, ova in females • Fertilization • Fusion of male and female gamete • Zygote • Fertilized egg Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Male Reproductive System Reproductive Organs • Testes • Enclosed by scrotum • Produce spermatazoa (sperm) • Epididymis • Stores sperm • Ductus deferens • Conducts sperm outward • Within spermatic cord Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Male Reproductive System Reproductive Organs (cont’d) • Ejaculatory duct • Accessory organs • Seminal vesicle • Prostate gland • Bulbourethral glands • Urethra • Within penis, an erectile organ Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Male Reproductive System The Male Reproductive System Figure 19-1 Male Reproductive System The Testes • Primary sex organ in males • Hang within scrotum • Dartos muscle wrinkles skin of testes • Cremaster muscle lifts testis toward body • Tunica albuginea encloses testis Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Male Reproductive System The Testes (cont’d) • Septa divide testis into lobules • Seminferous tubules within lobule produce sperm • Interstitial cells surround tubules • Produce testosterone, the main male sex hormone Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Male Reproductive System Seminiferous Tubules • Contain spermatogonia • Stem cells for spermatogenesis • Contain sustentacular cells • Sustain and promote spermatogenesis Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Male Reproductive System The Scrotum, Testes, and Seminiferous Tubules Figure 19-2(a) Male Reproductive System The Scrotum, Testes, and Seminiferous Tubules Figure 19-2(b) Male Reproductive System The Scrotum, Testes, and Seminiferous Tubules Figure 19-2(c) Male Reproductive System Anatomy of a Spermatozoon • Head • Contains nucleus and chromosomes • Middle piece • Contains mitochondria • Tail • Whips the sperm along Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings SPERMATOGENESIS MITOSIS of spermatogonium (diploid) Primary spermatocyte (diploid) DNA replication Primary MEIOSIS I spermatocyte Synapsis and tetrad formation Tetrad (four chromatids) Secondary spermatocytes MEIOSIS II Spermatids (haploid) SPERMIOGENESIS (physical maturation) Spermatozoa (haploid) Figure 19-3 Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings 1 of 5 SPERMATOGENESIS MITOSIS of spermatogonium (diploid) Primary spermatocyte (diploid) Figure 19-3 Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings 2 of 5 SPERMATOGENESIS MITOSIS of spermatogonium (diploid) Primary spermatocyte (diploid) DNA replication Primary MEIOSIS I spermatocyte Synapsis and tetrad formation Tetrad (four chromatids) Secondary spermatocytes Figure 19-3 Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings 3 of 5 SPERMATOGENESIS MITOSIS of spermatogonium (diploid) Primary spermatocyte (diploid) DNA replication Primary MEIOSIS I spermatocyte Synapsis and tetrad formation Tetrad (four chromatids) Secondary spermatocytes MEIOSIS II Spermatids (haploid) Figure 19-3 Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings 4 of 5 SPERMATOGENESIS MITOSIS of spermatogonium (diploid) Primary spermatocyte (diploid) DNA replication Primary MEIOSIS I spermatocyte Synapsis and tetrad formation Tetrad (four chromatids) Secondary spermatocytes MEIOSIS II Spermatids (haploid) SPERMIOGENESIS (physical maturation) Spermatozoa (haploid) Figure 19-3 Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings 5 of 5 Male Reproductive System Spermatozoon Structure Figure 19-4 Male Reproductive System Key Note Meiosis produces gametes that contain half the number of chromosomes found in somatic cells. For each cell entering meiosis, the testes produce four spermatozoa, whereas the ovaries produce only one ovum. Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Male Reproductive System Male Reproductive Tract • Epididymis • Long tubule in which sperm mature • Secretes tubular fluid • Ductus deferens (vas deferens) • Ascends within spermatic cord • Joins with seminal vesicle • Forms ejaculatory duct • Urethra • Extends from bladder to tip of penis • Passageway for urine and semen Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Male Reproductive System The Ductus Deferens Figure 19-5(a) Male Reproductive System The Ductus Deferens Figure 19-5(b) Male Reproductive System The Accessory Glands • Seminal vesicle • Secretes 60% of volume of semen •Secretes fructose to power the sperm • Prostate gland • Contributes about 30% of semen volume • Bulbourethral glands • Secretes alkaline mucus as a lubricant Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Male Reproductive System Semen • Typical ejaculation expels 2–5 ml of semen • Called the ejaculate • Contains 20–50 million sperm per ml Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Male Reproductive System The Penis • Penis skin resembles scrotal skin • Contains three erectile bodies • A pair of corpora cavernosa dorsally • A single corpus spongiosum ventrally • Urethra passes through it • Erection of penis follows dilation of erectile bodies with blood Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Male Reproductive System The Penis Figure 19-6(a) Male Reproductive System The Penis Figure 19-6(b) Male Reproductive System The Penis Figure 19-6(c) Male Reproductive System Hormones and Male Reproductive Function • Pituitary Hormones • Follicle-stimulating hormone (FSH) • Promotes spermatogenesis • Luteining hormone (LH) • Stimulates testosterone production • Gonadotropin Releasing Hormone (GnRH) • Hypothalamic hormone controls pituitary • Androgens (steroids) • Testosterone most important Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Male Reproductive System Hormonal Feedback in the Regulation of Male Reproductive Function Figure 19-7 Female Reproductive System Principal Female Reproductive Organs • Ovaries • Uterine (Fallopian) tubes • Uterus • Vagina • External genitalia (vulva) Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Female Reproductive System The Female Reproductive System Figure 19-8(a) Female Reproductive System The Female Reproductive System Figure 19-8(b) Female Reproductive System The Ovaries • Primary sex organs of females • Site of oogenesis (ovum production) • Monthly ovarian cycle • Several stages in ovum development Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Female Reproductive System The Ovaries (cont’d) • Stages in ovum development • Primordial follicle • Primary follicle • Secondary follicle • Tertiary follicle • Ovulation releases ovum and corona radiata Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings OOGENESIS MITOSIS of oogonium (before birth) Primary oocyte (diploid) DNA replication (before birth) Tetrad MEIOSIS I begins before birth Primary Synapsis and tetrad formation oocyte MEIOSIS I First polar completed body after puberty Secondary (may not oocyte occur) (haploid) MEIOSIS II begun in the Secondary oocyte tertiary follicle ovulated in metaphase and completed of MEIOSIS II only if fertilization occurs If fertilization Second occurs after polar Ovum Maturation ovulation, body (haploid) of gamete MEIOSIS II Is completed Figure 19-9 Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings 1 of 5 OOGENESIS MITOSIS of oogonium (before birth) Primary oocyte (diploid) Figure 19-9 Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings 2 of 5 OOGENESIS MITOSIS of oogonium (before birth) Primary oocyte (diploid) DNA replication (before birth) Tetrad MEIOSIS I begins before birth Primary Synapsis and tetrad formation oocyte Figure 19-9 Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings 3 of 5 OOGENESIS MITOSIS of oogonium (before birth) Primary oocyte (diploid) DNA replication (before birth) Tetrad MEIOSIS I begins before birth Primary Synapsis and tetrad formation oocyte MEIOSIS I First polar completed body after puberty Secondary oocyte (haploid) Figure 19-9 Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings 4 of 5 OOGENESIS MITOSIS of oogonium (before birth) Primary oocyte (diploid) DNA replication (before birth) Tetrad MEIOSIS I begins before birth Primary Synapsis and tetrad formation oocyte MEIOSIS I First polar completed body after puberty Secondary (may not oocyte occur) (haploid) MEIOSIS II begun in the Secondary oocyte tertiary follicle ovulated in metaphase and completed of MEIOSIS II only if fertilization occurs If fertilization Second occurs after polar Ovum Maturation ovulation, body (haploid) of gamete MEIOSIS II Is completed Figure 19-9 Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings 5 of 5 Primordial follicles before puberty Primordial follicles Secondary follicle Tertiary follicle