The male reproductive system produces and delivers sperm. The testes produce sperm in the seminiferous tubules which then travel through the epididymis, vas deferens and urethra. During ejaculation, sperm mix with fluids from the seminal vesicles, prostate and bulbourethral glands to form semen. The female reproductive system prepares for possible pregnancy each month by releasing an egg. If fertilized, the uterus nourishes the embryo through gestation and birth. The menstrual and ovarian cycles coordinate to release an egg and prepare the uterus.
3. What do you think the following picture is a picture of?
Be creative, do not discuss, and write a paragraph (5
sentences) as to why you think it is that.
6. Role
• Produce sperm cells
• Deliver sperm cells to the female reproductive
system to fertilize an egg cell
7. Testes or Testicles
• Located in the scrotum
• Produce sperm
• Contain seminiferous tubules where sperm are produced through
meiosis
• Sperm then move to the epididymis to mature - most sperm are
stored here
• Sperm then move through the vas deferens into the urethra to
exit the body
• Same place urine exits
8. Vasectomy
• A minor operation performed on adult males as a
method of birth control.
• In a vasectomy, both vas deferens are cut to stop
sperm from exiting the body
• Does this affect any secondary sex
characteristics?
9. Semen
• Mixture of fluid and sperm
• When sperm cells move into the urethra, they mix with fluid from
glands
• These fluids nourish the sperm and help them through the female
reproductive system
• Seminal vesicles: fluid for energy for sperm
• Prostate gland: fluid to neutralize acids in female RS
• Bulbourethral glands: neutralized traces of acidic urine in the
urethra
10. Penis
• Deposits sperm in the female RS
• Contains 3 cylinders of spongy tissue where
blood collects
• Sperm exit through ejaculation
• 300-400 million sperm, 3.5 mL of semen are
expelled
11. Random
• Pigs ejaculate 50-400 mL of semen and 5-20 minutes to
complete ejaculation
• Honey Bee’s have exploding testicles
• Female hyenas have pseudopenis’
• It takes 40 years for Galapagos giant tortoises to reach
sexual maturity
• Argonaut’s have a detachable penis
• https://www.youtube.com/watch?v=eI_quJRRGxk
12. What age?
• Can a women no longer become pregnant and give
birth?
• Can men no longer father children?
• The possibility of birth defects increases with maternal
age, beginning about age 35, but not with paternal age.
Why?
• Random: Oldest mother to give birth was 74, died 18
months after. Youngest was 5 years old. Oldest man
(in 2012) to father child was 96.
14. Female Reproductive
System
• Prepares for a possible pregnancy each month by
releasing a mature egg cell
• If fertilization happen, the female RS will nourish
and protect it through 9 months of pregnancy
15. Ovaries
• At birth, they contain 2 million
immature eggs
• Begin meiosis at puberty
• Normally only one matures each month
• Called ovum - 1 released about every
28 days
• Moves to the fallopian tube, toward the
uterus (takes 3-4 days)
16. Fertilization
• For fertilization to happen, sperm are deposited in
the vagina, they must pass through the cervix into
the uterus then to the egg in the fallopian tube.
• If the egg is not fertilized it will die within 24-48
hours
17. Cervix
• Means “neck” in Latin
• Why do you think this is an appropriate term by
looking at the picture?
18. Ovarian Cycle - Changes in
the Ovaries
• Ovaries prepare and release in a series of events called
the ovarian cycle
• Eggs mature in the follicle - follicular phase
• Egg is released when follicle bursts - ovulation
• Prevention of new follicles by the corpus luteum - luteal
phase
• If fertilization happens this phase continues
• If no fertilization, cycle begins again
19. Ovarian Cycle
1. In an ovary,
an egg cell is
enclosed inside a
follicle
2. The follicle
nourishes the
maturing egg cell
3. At ovulation,
the ovum
(mature egg)
bursts from the
follicle into the
fallopian tube
4. After the ovum is release,
the follicle breaks down
20. Menstrual Cycle - Changes
in the uterus
• Prepares for pregnancy each month
• Lasts approximately 28 days
• Influenced by hormone levels in the ovarian cycle
• Before ovulation the uterus wall thickens
• After ovulation it stays the same
• If no pregnancy then the thick lining of the uterus
sheds = menstruation
22. Menstruation
• Lining breaking causes blood vessels to break
• This is why there is bleeding
• Happens approximately 14 days after ovulation
• Happens at the same time as the Luteal phase
• All the cycles then start again
23. Fertilization
• For fertilization to occur, a sperm cell must swim to a
fallopian tube
• When it reaches the egg, the sperm penetrates the
outer layer
• The sperm and ovum (haploid sex cells) fuse together
• This produces a diploid cell called a zygote
• Zygote then moves through the fallopian tube toward
the uterus
24.
25. Cleavage
• A series of internal divisions
• Happens in the first week after fertilization
• Produces many new cells in the zygote
• All this happens as the zygote is moving through
the fallopian tube toward the uterus
• When it reaches the uterus, it is a hollow ball of
cells called a blastocyst
26. Implantation
• About 6 days after
fertilization
• Blastocyst burrows
into the lining of the
uterus
28. Random
• Pigs are pregnant for 3 months 3 weeks and 3
days
• Hamster - 16 days
• Cow - 280 days
• Elephant - 2 years
• Opposum - 13 days
29. First Trimester
• Embryo grows rapidly
• Membranes for protection and nourishment develop
• Amnion: Encloses and protects the embryo
• Chorion: Forms the placenta
• Placenta develops: nourishes the embryo
• Mother and baby usually never mix blood
• Nutrients from mother’s blood diffuse into the placenta and are carried to the embryo
through blood vessels in the umbilical cord
• Waste products along with nutrients get passed (drugs and alcohol) - this is why you
should not drink or do drugs while pregnant!!!
• FYI - Doctors say there is no benefit to eating placenta (placentophagy) - in animals it is
used to cover the birth and for nutrition (we are already well-nourished)
30. First Trimester Cont.
• Embryo: First 8 weeks
• End of 3rd week: blood vessels and gut develop, embryo is about
2mm (.08 in) long
• 4th week: arms and legs begin to develop, embryo doubles in
length, all major organs begin to form, heart begins to beat
• 2nd month: arms and legs take shape, internal organs can be
seen, embryo is 22mm (.9 in) and weighs 1 g
• Fetus: from 8th week until birth
• By the end of the 1st trimester: sex can be distinguished, has
recognizable body features, organ systems have begun to form
31. Second Trimester
• Uterus enlarges
• Fetus’s heartbeat can be heard
• Skeleton begins to form
• Layer of soft hair (lanugo) grows over the skin
• Fetus begins to wake and sleep
• Begins to move, swallows, sucks its thumb
• Can make a fist, hiccup, kick and curl its toes
• By the end: approximately 13.4 in long and 2 lbs
32. Third Trimester
• Fetus grows quickly
• Organs become functional
• Can see light and dark
• Can react to music and loud sounds
• Fat deposits develop to insulate the body
33. Birth
• About 38 weeks after fertilization
• Uterus begins to contract
• Amniotic sac breaks
• Muscular contractions and other events = labor
• Walls of uterus contract, pushes the fetus out through the vagina
• Placenta and umbilical cord exit after the baby (collectively called
afterbirth)
• After birth - lungs expand for the first time
