1. The Human Reproductive System
9th BIOLOGY
The Human Reproductive System

2. Human Reproductive System
Male Organs:
Penis
Urethra
Epididymis
Seminiferous tubules
Testes
Scrotum
Vas Deferens
Prostate
Female organs:
Ovaries
Vagina
Cervix
Fallopian tubes
Uterus

3. The Human Reproductive System
Male reproductive system-
Sperm-produced in testicles, stored
Seminal fluid- contains sperm, nutritious liquids, and other substances
Seminal vesicles- secrete sugars, nutrients, proteins and enzymes
Prostate gland- alkaline solution to neutralize the acidic conditions in the vagina

4. Male Reproductive System, cont.
Male hormones-
Testosterone-produced by the testes, needed for sperm production, and secondary sex characteristics
Hair growth on face and chest, deepening of voice, broadening of shoulders,
Influenced by 3 hormones:
GnRH- gonadotropin releasing hormoneanterior pituitary
Increases production of FSH-follicle stimulating hormone and LH-leutinizing hormone.

5. Sperm Production FSH- promotes sperm development in the testes
LH- stimulates testosterone production and secretion
Sperm develop in the seminiferous tubules epididymis for maturation
Released through vas deferens urethra

6. Male Reproductive System

7. Female Reproductive System
Egg cells (oocytes)- produced in the ovaries
Do not mature until release, every 28 days
Upon releaseoviduct (fallopian tube)cervixuterus

8. Female Hormones
Estrogen and progesterone, both steroid hormones, made by ovarian cells
Anterior pituitary produces FSH and LH
Role of estrogen in puberty: breast development, hip widening, increase in fat tissue
Menstrual period- monthly occurrence to prepare for pregnancy

9. Female Reproductive System

10. Sex Cell Production Sperm formation results in 4 haploid gametes
Sperm formation in males continues through out life

11. Sex Cell Production, cont.
Egg production results in 1 haploid gamete and 3 polar bodies
Females are born with every egg they will ever have

12. The Menstrual Cycle Varies from 23-35 days, average about 28 days
Three Phases:
Phase 1-Flow phase: Day 1
Uterine (endometrial) lining is shed, contains blood, tissue fluid, epithelial cells
Lining builds to support pregnancy, when none occurs, lining is shed

13. The Menstrual Cycle, cont.
Phase 2- Follicular phase:
Estrogen level is low
Anterior pituitary increases FSH and LH, stimulating follicles to mature, only one will produce an egg.
Day 12- flood of LH causes follicle to rupture, ovulation occurs

14. The Menstrual Cycle, cont.
Phase 3-Luteal Phase
Cells of follicle change after ovulation corpus luteum
Produces high amounts of progesterone and some estrogen, keeping FSH and LH levels low
End of cycle, corpus luteum breaks down, no more estrogen or progesterone are produced
Low hormone levels cause endometrial lining to detach, and lining is shed

15. Menstrual Cycle

16. FERTILIZATION Sperm is deposited in the vaginal canal.
Sperm can live 48 hours in the female reproductive system, but an unfertilized egg only has 24 hours to live.
The tips of sperm have an acrosome- enzyme filled specialized lysosome, that break down the outer lining of the egg.
After one sperm penetrates, a chemical reaction keeps all others out.

17. FERTILIZATION, cont.
Deposited sperm can fertilize an egg at any time the egg is present.
Intercourse can occur a few days before ovulation, or a few days after, and still result in pregnancy.

18. EARLY FETAL DEVELOPMENT
Fertilized egg zygote
Zygote travels down the fallopian tube toward the uterus.
After 3 days, zygote morula
After 5 days, morula blastocyst, hollow ball of cells
Blastocyst fully implanted in uterine lining by day 10
Continued regular development fetus

19. Fetal Development