1. Human Reproductive Systems
Dr. Jason R. Mayberry
Castle View High School

2. Organ Systems Reproductive Endocrine Nervous Muscular Skeletal
Cardiovascular
Digestive
Respiratory
Urinary
Immune
Integumentary

3. Gonads and Kidneys both form from mesoderm
Urogenital Formation
Gonads and Kidneys both form from mesoderm
Gonad: organ that produces gametes (testicle or ovary)
Kidney: organ that filters blood and produces urine.
Gonads are “indifferent” at first and can become either testes or ovaries.
Gamete producing cells are stored near the umbilical cord, and migrate into the gonads as they begin to form
Urogenital Ridge
Gonad
Kidney

4. Primary Sexual Differentiation
Different tubes connect the male and female gonad to the external world
Precursor tubes to both the male (Vas Deferens) and female (Fallopian Tubes) tubes form in all embryos
If the Y chromosome is present (specifically the SRY gene)
The gonad becomes a testicle
The female tubes degenerate
If no Y chromosome (i.e. two X chromosomes)
The gonad becomes an ovary
The male tubes degenerate.
Kidney
“Indifferent” Gonad
Male Tubes
Ureter
Female Tubes
Male
Female

5. External Genitalia
Indifferent Genitalia
Indifferent Genitalia: External Genitalia for male and female begin development identically (end of 8th week).
If Testes form, testosterone will cause the male genitalia to form.
Without testosterone, the genitalia form as a female.
External genitalia can be distinguished in a sonogram by the end of the 3rd or 4th month
Genital Tubercle
Labioscrotal fold
Urogenital Fold
6 Weeks
Male Development
8 Weeks
Female Development
10 Weeks
12 weeks

6. Descent of the Testicles
Testicles descend from original location in the abdomen into the scrotum.
Lower temperature in the scrotum is needed for sperm production.

7. Anatomy of the Male Reproductive System
Ampulla of Vas Deferens: widening of Vas Deferens at distal end
Accessory Glands: Produce nutrients, pH buffers, lubrication, and enzymes
Seminal Vesicles
Ejaculatory Duct: Transport of mature sperm to the urethra; paired
Prostate
Bulbourethra
Urethra: Transport of mature sperm out of the penis (Prostatic, Membranous, and Penile); not paired
Vas Deferens: Transport of mature sperm to the Ejaculatory duct in the Prostate (sometimes called the Ductus Deferens)
Epididymis: Site for sperm maturation and storage
Erectile Tissue: With arousal becomes engorges with blood causing an errection.
Testicle: location for sperm development within seminiferous tubules (primary reproductive organ; all others are accessory); paired
Penis: Delivers Semen to the Female Vagina
Scrotum: 2-sided Pouch for the Testes (divided by septum)

8. Testicle and Sperm Production
Vas Deferes
Epididymis
Leydig Cells: produce Testosterone
Seminiferous Tubule: site for sperm production
Immotile Sperm
Spermatogonia: sperm stem cells
Sertoli Cells: Protect and nurture the developing sperm

9. 2n
Spermatogonia
Before Birth Spermatogonia divide by mitosis then become dormant until puberty
Mitosis
From Birth To Puberty 2n
Mitosis 2n
Spermatogonia
1o Spermatocyte 2n
2o Spermatocytes
Spermatid 1n
Mitosis
Spermatogonia 2n 2n 1n
Mitosis
Spermatogonia 2n 2n 1n
Mitosis
Spermatogonia 2n 1n 2n

10. Endocrinology of Sperm Production
A complex interaction of hormones is required for sperm formation
Hormones produced in the Brain:
Hypothalamus produces Gonadotrophic Releasing Hormone (GnRH)
Pituitary produces Follicle Stimulating Hormone (FSH), and Leuitinizing Hormone (LH)
Hormones produced in the Testicle
Testosterone promotes sperm formation
Testosterone also promotes male specific charactistics
GnRH
FSH and LH
Testosterone
Inhibin
ABP
ABP

11. Internal Anatomy of the Female Reproductive System
Fallopian Tubes (also called Uterine Tubes or oviduct)
Fimbriae
Ampulla
Ovary
Ovarian Ligament
Uterus
Round Ligament
Clitoris
Vagina

12. External Female Genitalia
Vulva: External Female Genitalia
Clitoris
Labia Majora
Labia Minora
Pubis Bone
Urethra Opening
Vagina
Anus

13. Uterus and the Menstrual Cycle
Fundus
Perimetrium connective tissue that surrounds the outside
Myometrium is a thick layer of muscle
Endometrium
Epithelial Layer lining the inside of the Uterus
Stratum Basale
Supported by “straight arteries”
Permanent layer which gives rise to the Stratum Functionalis
Stratum Functionalis
Supported by spiral arteries
Contains Uterine “milk” glands
Menstrual Cycle: Strat. Functionalis is built up and Sloughed off in connection with the Ovarian Cycle
Cervix: Opening to the Uterine Cavity
External Os opens to Vagina
Internal Os opens to Uterine Cavity
Mucous Plug in the cervix helps to block infections from entering the Uterus or Peritoneal cavity.
Fundus is the top of the Uterus
Endometrium
Internal Os
Myometrium
External Os
Perimetrium
Strat. Functionalis
Endometrium
Strat. Basalis
Myometrium

14. Mammary Gland Development
Adipose Tissue
Suspensory Ligaments
Areola
Nipple
Lactiferous Sinus
Lactiferous Duct
Lobe of Mammary Glands (25-50 per breast) produces milk
Before pregnancy the glandular tissue is undeveloped and differences in breast size are due largely to adipose tissue
Estrogen during pregnancy stimulate Prolactin release from the Anterior Pituitary (in the brain)
Prolactin causes glandular tissue to develop and begin producing milk
Progesterone contribute to breast development during pregnancy
Oxytocin stimulates cells surrounding the glands to contract resulting in milk release.

15. Developing Primary Follicle
structures within the ovary that contain the Oocyte producing cells.
found at different stages of development.
Ovulation: After puberty, one follicle matures each month and is released at.
Maturing Follicles
Graffian Follicle
Corpus Albicans
Corpus Luteum
Ovulation
Secondary Follicle
Developing Primary Follicle
Primary Oocyte: undergoes meiosis to produce an oocyte.
Thecal Cells: produce Testosterone
Granulosa Cells: convert Testosterone to Estrogen

16. Female Gametogenesis Meiosis
Oogonia 2n
Meiosis
begins in a woman’s ovary before she is born.
resumes in follicles as they develop after puberty
Only completes IF fertilized.
Mitosis
Oogonia 2n
Oogonia 2n
Final Mitosis 2n
1o Oocyte 2n
1o Oocyte
Meiosis
Meiosis Begins
Meiosis Begins 2n
Prophase I of Meiosis 2n
Prophase I of Meiosis
Birth
Ovulation
If Fertilization DOES Occur 1n
2o Oocyte 1n
2o Oocyte
Metaphase II
If Fertilization Does Not Occur 2n
Zygote
Mitosis 2n 2n
Embryo

17. Gametogenesis: Male Female Comparison
Spermatogonia
Mitosis
1o Spermatocyte
2o Spermatocytes
Spermatids
Birth and Puberty
Oogonia
Final Mitosis
Meiosis
1o Oocyte
1o Oocyte
Birth to Ovulation
If Fertilization Occurs
2o Oocyte
2o Oocyte
If Fertilization Does Not Occur
Zygote

18. Cyclic Pituitary and Ovarian Hormone Interactions.
GnRH
FSH LH
Low Estrogen
Pro-gesterone
Mod Estrogen
High Estrogen 28 14
FSH
Pituitary Hormones LH
Progesterone
threshold
Estrogen
Ovarian Hormones

19. Ovarian Cycle 7 14 28 Menstrual Phase Proliferative Phase
GnRH
FSH LH
Mod Estrogen
Low Estrogen
High Estrogen
Pro-gesterone
Loss of Progesterone
Causes spiral arteries to constrict
Endometrial Layer degenerates and is sloughed off
Estrogen
Causes Endometrium to Thicken
Causes Glands and Blood Supply develop
Progesterone
Maintains Endometrium
Causes Glands to secrete “Uterine Milk” (nourishes embryo before placental develops)
Increases blood flow 7 14 28
Menstrual Phase
Proliferative Phase
Secretory Phase

20. Ovarian Cycle FSH LH Progesterone Estrogen 7 14 28 Proliferative Phase
GnRH
FSH LH
Mod Estrogen
Low Estrogen
High Estrogen
Pro-gesterone 28 14
FSH
Pituitary Hormones LH
Progesterone
threshold
Estrogen
Ovarian Hormones 7 14 28
Proliferative Phase
Secretory Phase
Menstrual Phase
Estrogen
Loss of Progesterone
Progesterone

21. Hormonal Regulation of the Ovarian Cycle: Luteal Phase
If a Pregnancy does NOT occur then the cycle of hormones continues indefinitely.
If pregnancy DOES occur
Developing placenta produces Human Chorionic Gonadotropin (HCG)
HCG maintains Corpus Luteum for ~8 weeks
After 8 weeks the Placenta takes over Estrogen and Progesterone production – maintaining the pregnancy
Placental HCG
Placental Progesterone and Estrogen
8 weeks