1. Human Reproduction

2. Review
Both males and females produce
specialized sex cells called “gametes.”
Each gamete contains ½ of the genetic
information to form a new individual.
The role of the male reproductive
system is to produce sperm and deliver
them to the female gamete, the egg.

3. The Male Reproductive System
A sexually mature human male,
produces millions of sperm cells
each day.
Sperm are produced in the testes
by meiosis (spermatogenesis).
Review (meiosis)

4. Structure of Sperm
 Tail- used for locomotion.
 Midsection- contains mitochondria. Why?
 Head- holds chromosomes and digestive enzymes which
allow sperm to penetrate into the egg.

5. Male Testicle- Produces fluid that
nourishes sperm

6. The “Pathway” of Sperm
Seminal Vesicle Prostate Gland
Penis
Urethra
Testes
Bulbourethral Vas Epididymis
Gland Deferens

7. The “Pathway” of Sperm
In order for fertilization to occur, sperm must be
released (ejaculated) from the penis.
During ejaculation:
1.) Muscles in vas deferens push sperm toward urethra.
2.) Tube to bladder is blocked off by a valve.
3.) Glands add fluid to sperm.
- Seminal vesicles provide fluid that “nourishes” sperm.
- Bulbourethral gland and prostate gland create a fluid
that makes sperm resistant to acid.
- Sperm + Glandular secretions = SEMEN.

8. Hormones
Chemical messengers sent from one area
of the body to another.
In males and females, different hormones
help to control sperm production and the
menstrual cycle.

9. Female Anatomy
Ovary
Uterus
Urethra
Cervix
Clitoris

10. “The Menstrual Cycle”
Eggs begin to mature in the ovaries
before a female is born.
Growth of the eggs stop before they are
completely developed.
All the eggs remain immature until
puberty.
After puberty, several eggs begin to
mature each month.
Each egg develops inside a “follicle.”

11. “The Menstrual Cycle”
Usually only one egg makes it to maturity.
This egg will burst out of the follicle
(ovulation) and move down the oviduct.
Fertilization may or may not occur.
The uterus must be ready to accept a
fertilized egg.

12. Female Hormones
The females reproductive role is to:
1.) Make and release eggs.
2.) Nourish the developing fetus.
A mix of hormones controls these events
during the “menstrual cycle.”

14. Female Hormones
1.) FSH (Follicle stimulating hormone)
- Causes follicles to mature.
- As follicles grow they release estrogen.
2.) Estrogen
- As estrogen levels rise, another hormone (LH)
begins to rise.
3.) LH (Leutinizing hormone)
- Around day 14, LH levels shoot up. This
causes at least one follicle to burst open.
- Once the egg is released it begins to produce
progesterone.
4.) Progesterone
- If egg becomes fertilized, progesterone levels stay high.
- If egg begins to disintegrate, progesterone levels fall.
- Role of progesterone is to prepare the uterus for possible
pregnancy.

15. Birth Control
1.) Physical forms
- Condoms and diaphragms block the
sperm from getting to the egg.
2.) Chemical forms
- “The pill.” Works by preventing FSH and
LH to be released.
- Result = No ovulation. Normal menstrual
cycle proceeds.

16. Fertilization and Development
Zygote- Newly fertilized egg.
Once it begins to divide, it is called an
embryo.
Embryo continues to release
progesterone. Why?
Embryo must “implant” itself into the
uterine wall.

17. The Placenta
Transports materials back and forth to the
embryo.
Oxygen – Carbon dioxide
Nutrients (carbo’s, protein, fat)
Urea (liquid, cellular waste)
Antibodies
Teratogens

18. Maternal Health
The health of the baby depends on the
health and activities of the mother.
Smoking, drugs, alcohol, radiation, and
pathogens can all harm the fetus.
Pregnancy is divided into three month
segments called “trimesters.”

19. First Trimester
Implantation of zygote.
All vital organs are formed
Heart is formed.
Brain and spinal cord.
Sex organs.
Limbs.
Eyes and ears.

20. Second Trimester
Circulatory system is functioning.
Hair formation.
Major body changes in the mother.

21. Third Trimester
Eyes open.
Fat begins to form under the skin.
Fetus gains lots of weight.
If fetus spends a full three trimesters
inside the uterus, survival outside the
mother is very likely.

22. Birth
At nine months, the baby will position
itself with its head against the cervix.
Oxotycin (hormone) causes uterine
muscles to push baby outwards (labor).
Cervix opens up and baby is forced into
vagina.
“Afterbirth” is expelled.

23. Stopping of the Menstrual Cycle
Between ages 45 – 55 ovulation and
menstruation stop.
The shut down of ovarian and uterine
cycles is known as menopause.