Principles of Anatomy and Physiology Thirteenth Edition Gerard J. Tortora • Bryan H. Derrickson Chapter 28 The Reproductive Systems Copyright © 2012 by John Wiley & Sons, Inc.

Sagittal plane Peritoneum Urinary bladder Ductus (vas) deferens Suspensory ligament of penis Sacrum Pubic symphysis Seminal vesicle Prostate Vesicorectal pouch Deep muscles of perineum Coccyx Bulbourethral (Cowper’s) gland Rectum Ampulla of ductus (vas) deferens Corpus cavernosum penis Spongy (penile) urethra Ejaculatory duct Body of penis Prostatic urethra Root of penis Corpus spongiosum penis Anus Epididymis Corona Testis Glans penis Membranous urethra Scrotum Prepuce (foreskin) (a) Sagittal section External urethral orifice

SUPERIOR Seminal vesicle Urinary bladder (opened) Prostate Ductus (vas) deferens Pubic symphysis Prostatic urethra Corpus cavernosum penis Ejaculatory duct Membranous urethra Corpus spongiosum penis Rectum Body of penis Root of penis Testis Bulbospongiosus muscle Corona Spongy (penile) urethra Glans penis POSTERIOR ANTERIOR (b) Sagittal section

Anterior view of scrotum and testes and transverse section of penis Internal oblique muscle Spermatic cord Aponeurosis of external oblique muscle (cut) Fundiform ligament of penis Superficial (cutaneous) inguinal ring Suspensory ligament of penis Cremaster muscle Inguinal canal Transverse section of penis: Ductus (vas) deferens Corpora cavernosa penis Autonomic nerve Spongy (penile) urethra Testicular artery Corpus spongiosum penis Lymphatic vessel Pampiniform plexus of testicular veins Scrotal septum Epididymis Cremaster muscle Tunica albuginea of testis External spermatic fascia Tunica vaginalis (peritoneum) Dartos muscle Internal spermatic fascia Skin of scrotum Raphe Anterior view of scrotum and testes and transverse section of penis

(a) Sagittal section of testis showing seminiferous tubules plane Spermatic cord Blood vessels and nerves Head of epididymis Ductus (vas) deferens Seminiferous tubule Efferent duct Straight tubule Body of epididymis Tunica vaginalis Rete testis Tunica albuginea Ductus epididymis Lobule Tail of epididymis Septum (a) Sagittal section of testis showing seminiferous tubules

(b) Lateral view of testis and associated structures SUPERIOR Testicular blood vessels, lymphatic vessels, and nerves Body of epididymis Head of epididymis Testis Tunica vaginalis Tail of epididymis POSTERIOR ANTERIOR (b) Lateral view of testis and associated structures

Rete testis Seminiferous tubules Tunica vaginalis Testis Tunica albuginea (c) Sagittal section

(a) Transverse section of several seminiferous tubules Transverse plane Leydig cell Basement membrane Basement membrane Sertoli cell Spermatid (n) LM 40x Secondary spermatocyte (n) Primary spermatocyte (2n) Spermatogonium (2n) (stem cell) LM 160x (a) Transverse section of several seminiferous tubules

(b) Transverse section of part of seminiferous tubule Leydig cell Blood capillary SPERMATOGENIC CELLS: Basement membrane Spermatogonium (2n) (stem cell) Sertoli cell nucleus Primary spermatocyte (2n) Blood–testis barrier (tight junction) Secondary spermatocyte (n) Spermatid (n) Sperm cell or spermatozoon (n) Lumen of seminiferous tubule (b) Transverse section of part of seminiferous tubule

Basement membrane of seminiferous tubule Some spermatogonia remain as precursor stem cells Superficial Spermatogonium 2n 2n Mitosis Some spermatogonia pushed away from basement membrane 2n Differentiation Primary spermatocyte DNA replication, tetrad formation, and crossing-over 2n Meiosis I MEIOSIS Secondary spermatocytes Each chromosome has two chromatids n n Meiosis II Cytoplasmic bridge Spermatids n n n n SPERMIOGENESIS Spermatozoa n n n n Deep Lumen of seminiferous tubule

Acrosome HEAD Nucleus Neck Mitochondria Middle piece TAIL Principal piece End piece

Testosterone decreases release of GnRH and LH Hypothalamus GnRH Testosterone decreases release of GnRH and LH Anterior pituitary Inhibin decreases release of FSH Gonadotroph Together with testosterone, FSH stimulates spermatogenesis LH stimulates testosterone secretion FSH LH Inhibin Testosterone ABP Spermatogenic cells Leydig cells secrete testosterone Sertoli cells secrete androgenbinding protein (ABP) Dihydrotestosterone (DHT) Key: LH LH receptor FSH FSH receptor Testosterone Androgen receptor Male pattern of development (before birth) Enlargement of male sex organs and expression of male secondary sex characteristics (starting at puberty) Anabolism (protein synthesis)

Receptors Control center Effectors Some stimulus disrupts homeostasis by Increasing Blood level of testosterone Receptors Cells in hypothalamus that secrete GnRH Decreased GnRH in portal blood Input Control center Return to homeostasis when response brings blood level of testosterone back to normal Anterior pituitary gonadotrophs Decreased LH in systemic blood Output Effectors Leydig cells in testes secrete less testosterone Decrease in blood level of testosterone

(a) Posterior view of male accessory organs of reproduction Right ductus (vas) deferens View Urinary bladder Left ureter Ampulla of ductus (vas) deferens Hip bone (cut) Seminal vesicle Prostate Seminal vesicle duct Prostatic urethra Ejaculatory duct Membranous (intermediate) urethra Deep muscles of perineum Crus of penis Bulbourethral (Cowper’s) gland Bulb of penis Corpora cavernosa penis Corpus spongiosum penis Spongy (penile) urethra (a) Posterior view of male accessory organs of reproduction

(b) Posterior view of male accessory organs of reproduction Urinary bladder Hip bone Left ureter Right ductus (vas) deferens Pelvic diaphragm Seminal vesicle Obturator internus muscle Ampulla of ductus (vas) deferens Deep muscles of perineum Prostate Bulbospongiosus muscle (b) Posterior view of male accessory organs of reproduction

External urethral orifice Urinary bladder Internal urethral orifice Prostate Prostatic urethra Orifice of ejaculatory duct Deep muscles of perineum Membranous urethra Bulbourethral (Cowper’s) gland ROOT OF PENIS: Bulb of penis Crus of penis BODY OF PENIS: Corpora cavernosa penis Corpus spongiosum penis Spongy (penile) urethra Corona GLANS PENIS Frontal plane Prepuce (foreskin) External urethral orifice (a) Frontal section

(b) Transverse section Skin Deep dorsal vein Superficial (subcutaneous) dorsal vein Dorsal artery Subcutaneous layer Fascia Transverse plane Dorsal Corpora cavernosa penis Tunica albuginea of corpora cavernosa Deep artery of penis Corpus spongiosum penis Spongy (penile) urethra Ventral Tunica albuginea of corpus spongiosum penis (b) Transverse section

(c) Transverse section plane Superficial dorsal vein Deep dorsal vein Skin Dorsal artery Subcutaneous layer Corpora cavernosa penis Tunica albuginea of corpora cavernosa Deep artery of penis Spongy (penile) urethra Corpus spongiosum penis Tunica albuginea of corpus spongiosum penis (c) Transverse section

Uterine (fallopian) tube Fimbriae Sagittal plane Ovary Uterus Sacrum Round ligament of uterus Uterosacral ligament Cervix Posterior fornix of vagina Urinary bladder Rectouterine pouch (pouch of Douglas) Pubic symphysis Vesicouterine pouch Mons pubis Coccyx Clitoris Rectum Urethra Labium majus Anus External urethral orifice Vagina (a) Sagittal section Labium minus

Fimbriae Ovary Uterine (fallopian) tube Fundus of uterus Body of uterus Rectouterine pouch (pouch of Douglas) Cervix of uterus Urinary bladder Vesicouterine pouch Pubic symphysis Mons pubis Vagina Clitoris Rectum Urethra Labium minus Labium majus (b) Sagittal section

Superior view of transverse section ANTERIOR Rectus abdominis muscle Urinary bladder Uterus View Transverse plane Round ligament Ovarian ligament Mesovarium Uterine (fallopian) tube Ovary Cecum Rectouterine pouch (pouch of Douglas) Broad ligament Vermiform appendix Suspensory ligament Cardinal ligament Ureter Uterosacral ligament Ileum Common iliac artery Sigmoid colon POSTERIOR Superior view of transverse section

(a) Frontal section Primordial follicle Secondary follicle Germinal epithelium Primary follicle Ovarian cortex Frontal plane Follicular fluid Mature (graafian) follicle Blood vessels in hilum of ovary Ovarian medulla Corpus hemorrhagicum (ruptured follicle) Corpus albicans Corona radiata Ovulation discharges secondary oocyte Degenerating corpus luteum Blood clot Corpus luteum (a) Frontal section

Blood vessel in hilum of ovary Germinal epithelium Ovarian cortex Ovarian medulla Blood vessel in hilum of ovary Degenerating mature (graafian) follicle (b) Hemisection LM 20x

(c) Ovulation of a secondary oocyte Ovary Secondary oocyte LM 30x (c) Ovulation of a secondary oocyte

(a) Primordial follicle Primary oocyte Follicular cells Basement membrane Stromal cell Collagen fiber (a) Primordial follicle

(b) Late primary follicle Basement membrane Zona pellucida Granulosa cells Collagen fiber Primary oocyte Theca folliculi (b) Late primary follicle

(c) Secondary follicle Zona pellucida Basement membrane Antrum Corona radiata Theca folliculi: Theca externa Theca interna Primary oocyte Stromal cell Collagen fiber Granulosa cells Blood vessels (c) Secondary follicle

(d) Mature (graafian) follicle Basement membrane Zona pellucida Antrum filled with follicular fluid Corona radiata Primary oocyte Theca folliculi: Theca externa Theca interna Granulosa cells (d) Mature (graafian) follicle

Primary follicle granulosa cells Germinal epithelium Tunica albuginea Primordial follicle Ovarian cortex Primary follicle granulosa cells Theca folliculi Zona pellucida Primary oocyte Secondary follicle granulosa cells Secondary follicle Corpus luteum LM 30x (e) Ovarian cortex

(f) Secondary follicle Primary oocyte Zona pellucida Corona radiata Secondary follicle granulosa cells Antrum filled with follicular fluid Theca folliculi LM 70x (f) Secondary follicle

2n 2n n n n n n n n n n 2n During fetal development meiosis I begins. Oogonium After puberty, primary oocytes complete meiosis I, which produces a secondary oocyte and a first polar body that may or may not divide again. 2n Meiosis I Primary oocyte n n First polar body Secondary oocyte The secondary oocyte begins meiosis II. Ovulation n n A secondary oocyte (and first polar body) is ovulated. n n Sperm cell + Secondary oocyte Meiosis II Fertilization After fertilization, meiosis II resumes. The oocyte splits into an ovum and a second polar body. n n n Ovum Second polar body The nuclei of the sperm cell and the ovum unite, forming a diploid (2n) zygote. 2n Zygote

All polar bodies degenerate Fetal period 2n Oogonium Mitosis 2n Primary oocyte Primordial follicle Meiosis in progress Primary oocyte (in prophase I) 2n Childhood (no development of follicles) Primary oocyte (still in prophase I) 2n Primary follicle Puberty to menopause each month Secondary follicle 2n Primary oocyte Meiosis I completed by one primary oocyte each month n n Secondary oocyte (in metaphase II) Mature (graafian) follicle First polar body Ovulation Meiosis II of first polar body may or may not occur Sperm cell n Ovulated secondary oocyte n Meiosis II completed if fertilization occurs n n n 2n Second polar body Ovum All polar bodies degenerate

Posterior view of uterus and associated structures Isthmus of uterine tube Fimbriae of uterine tube Fundus of uterus Infundibulum of uterine tube Ampulla of uterine tube Suspensory ligament Infundibulum of uterine tube Uterine (fallopian) tube Uterine cavity Ovary Endometrium Ovarian ligament Myometrium Broad ligament Perimetrium Body of uterus Internal os Ureter Cervix of uterus Isthmus Cervical canal Uterosacral ligament Lateral fornix External os Rugae Vagina View Posterior view of uterus and associated structures

(a) Details of epithelium Transverse plane Uterine tube Cilia Peg cell (nonciliated) with microvilli Ciliated simple columnar cell Lamina propria (areolar connective tissue) Lumen of uterine tube LM 400x (a) Details of epithelium

(b) Details of epithelium in surface view Cilia of ciliated simple columnar epithelial cell Peg cell (nonciliated) with microvilli SEM 4000x (b) Details of epithelium in surface view

Lumen of uterus Endometrium: Stratum functionalis Stratum basalis Myometrium: Inner longitudinal layer Middle circular layer Outer longitudinal layer: (a) Transverse section through the uterine wall: second week of menstrual cycle (left) and third week of menstrual cycle (right) Perimetrium LM 10x LM 8x

(b) Details of endometrium Lumen of uterus Simple columnar epithelium Stratum functionalis Endometrial gland Stratum basalis LM 115x (b) Details of endometrium

Anterior view with left side of uterus partially sectioned Perimetrium Myometrium Endometrium Uterine cavity Radial artery Endometrial gland Arcuate artery Endometrium: Stratum functionalis Uterine artery Stratum basalis Straight arteriole Radial artery Cervix Details of portion of uterine wall Spiral arteriole Vagina Uterine artery Anterior view with left side of uterus partially sectioned

Mons pubis Prepuce of clitoris Labia majora (spread) Clitoris Labia minora (spread exposing vestibule) External urethral orifice Hymen Vaginal orifice (dilated) Anus (a) Inferior view

(b) Transverse section through vaginal wall Lumen of vagina Mucosa: Nonkeratinized stratified squamous epithelium Lamina propria Muscularis: Inner circular layer Transverse plane Vagina Outer longitudinal layer LM 15x Adventitia (b) Transverse section through vaginal wall

Nonkeratinized stratified squamous epithelium Lumen of vagina Mucosa: Nonkeratinized stratified squamous epithelium Lamina propria LM 100x (c) Details of mucosa

Pubic symphysis Bulb of the vestibule Clitoris Ischiocavernosus muscle External urethral orifice Greater vestibular (Bartholin’s) gland Vaginal orifice (dilated) Superficial transverse perineal muscle Bulbospongiosus muscle UROGENITAL TRIANGLE ANAL TRIANGLE Ischial tuberosity External anal sphincter Anus Coccyx Gluteus maximus Inferior view

(b) Anterior view, partially sectioned Rib Suspensory ligament of the breast (Cooper’s ligament) Pectoral fascia Pectoralis major muscle Intercostal muscles Lobule containing alveoli Secondary tubule Mammary duct Lactiferous sinus Areola Lactiferous duct Nipple Nipple Areola Adipose tissue in subcutaneous layer Sagittal plane (a) Sagittal section (b) Anterior view, partially sectioned

GnRH Hypothalamus GnRH stimulates release of FSH and LH Anterior pituitary gland FSH LH FSH stimulates LH stimulates Growing follicles Ovaries Ovulation Corpus luteum Initial development of ovarian follicles Secretion of progesterone, estrogens, relaxin, and inhibin by corpus luteum Further development of ovarian follicles and their secretion of estrogens and inhibin Estrogens Progesterone Relaxin Inhibin Promote development and maintenance of female reproductive structures, feminine secondary sex characteristics, and breasts Increase protein anabolism Lower blood cholesterol Moderate levels inhibit release of GnRH, FSH, and LH Works with estrogens to prepare endometrium for implantation Prepares mammary glands to secrete milk Inhibits release of GnRH and LH Inhibits contractions of uterine smooth muscle During labor, increases flexibility of pubic symphysis and dilates uterine cervix Inhibits release of FSH and, to a lesser extent, LH

(a) Hormonal regulation of changes in the ovary and uterus Hypothalamus GnRH Anterior pituitary Follicular phase FSH Luteal phase LH Mature (graafian) follicle Corpus Hemor- rhagicum Primordial follicles Primary follicles Secondary follicle Ovulation Corpus luteum Corpus albicans Ovarian cycle Progesterone and estrogens Estrogens Secretory phase Menstruation Uterine (menstrual) cycle Proliferative phase Stratum functionalis Menstruation Stratum basalis Days Menstrual phase Preovulatory phase Postovulatory phase Ovulation (a) Hormonal regulation of changes in the ovary and uterus

Hormone concentration LH Progesterone Estrogens Hormone concentration FSH Days (b) Changes in concentration of anterior pituitary and ovarian hormones

Hypothalamus GnRH 1 High levels of estrogens from almost mature follicle stimulate release of more GnRH and LH 2 GnRH promotes release of FSH and more LH Anterior pituitary LH 3 LH surge brings about ovulation Ovulated secondary oocyte Ovary Almost mature (graafian) follicle Corpus hemorrhagicum (ruptured follicle)

Hypothalamus GnRH Anterior pituitary LH FSH Ovary Ovarian hormones High levels of estrogens (without progesterone) stimulate release of GnRH, LH, and FSH Moderate levels of estrogens inhibit secretion of GnRH, FSH, and LH Low levels of progesterone and estrogens promote secretion of GnRH, FSH, and LH Inhibin inhibits secretion of FSH and LH Anterior pituitary FSH LH Ovary Growth of primary and secondary follicles Maturation of one dominant follicle Formation of corpus luteum Formation of corpus albicans Ovulation Ovarian hormones Increasing secretion of estrogens and inhibin by granulosa cells Increased secretion of progesterone and estrogens by cells of corpus luteum No secretion of progesterone and estrogens by corpus albicans Increased secretion of inhibin by cells of corpus luteum Uterus Preparation of endometrium for arrival of fertilized ovum Repair and proliferation of endometrium Menstruation

Paramesonephric (Müllerian) duct Mesonephros Mesonephros Gonadal ridges Paramesonephric (Müllerian) duct Gonadal ridges Mesonephric (Wolffian) duct Paramesonephric (Müllerian) duct Mesonephric (Wolffian) duct Urogenital sinus Urogenital sinus Anterior view Undifferentiated stage (fifth–sixth week) Anterolateral view MALE DEVELOPMENT FEMALE DEVELOPMENT

MALE DEVELOPMENT FEMALE DEVELOPMENT Ovary Efferent duct Uterine (fallopian) tube Testis Epididymis Paramesonephric (Müllerian) duct degenerating Mesonephric (Wolffian) duct degenerating Mesonephric (Wolffian) duct Prostatic utricle Urogenital sinus Fused paramesonephric (Müllerian) ducts (uterus) Seventh–eighth week Eighth–ninth week

MALE DEVELOPMENT FEMALE DEVELOPMENT Seminal vesicle Ductus (vas) deferens Uterus Prostate Uterine (fallopian) tube Urethra Vagina Bulbourethral (Cowper’s) gland Remnant of mesonephric duct Epididymis Ovary Efferent duct Testis At birth At birth

Undifferentiated stage (about five-week embryo) Genital tubercle Urethral folds Urethral groove Labioscrotal swelling Urogenital sinus Anus Perineum Undifferentiated stage (about five-week embryo) Glans penis Clitoris Urethral folds Labioscrotal swelling Perineum Anus Ten-week embryo External urethral orifice Clitoris Glans penis Labia majora Penis Labia minora External urethral orifice Vestibule Scrotum Vaginal orifice Anus Near birth