Before We Go Any Further…
 This is a safe place to talk about anything you are interested in or are
confused about.
 This means there are some ground rules.
 1) We will be talking about the biology of sex. I am NOT here to tell
you how to have sex, when or where to have sex, or what positions or
techniques are ‘the best’.
 If you have questions, of course I’ll do my best to answer them, but keep in
mind: “I don’t know”, “Ask your doctor”, and “That is far too intimate of a
question” are also answers I can and will give.
 2) If anyone becomes uncomfortable with how someone in the class is
acting (making inappropriate jokes, gestures, comments) or I see it
out right, come talk to me and that person will be asked to leave and
will not come back until the unit it over.
 There is an alternate assignment for you in that case.
 3) We will using only the biological terms. It’s not ‘dick’, it’s penis. It’s
not ‘pussy’, it’s vagina.
 4) I will be very open with you about questions you have. I expect you
all to be respectful of these rules, of me, and of each other.
Show Me What You Know
 Divide into three equal groups and complete the activity and
worksheet.
 Once everyone is finished, we’ll go over the structures and
hormones, and we’ll find out where they all belong.
And the Reveal! – Both Males and
Females
 This category probably will cause the most confusion.
 Ureter
 Urethra
 Testosterone
 Estrogens
 Androgens
 Progesterone
 Leutinizing hormone (LH)
 Follicle-stimulating hormone (FSH)
 Symphysis pubis (pubic bone)
And the Reveal – Females Only
 Ovaries
 Primordial








follicles
Uterine tubes
(fallopian tubes)
Uterus
Cervix
Vagina
Hymen
Labia (majora
and minora)
Clitoris
Eggs cells
And the Reveal! – Males Only
 Testes
 Seminiferous tubules
 Epididymis
 Sperm cells
 Vas deferens
 Seminal vesicles
 Prostate
 Semen
 Scrotum
 Penis
It’s a Fact of Life
 Reproduction is one of the driving forces of all life forms.
 They want to eat, drink, survive, and have sex to make more of
themselves.
 The four F’s of survival: Fight, Flight, Feed, Fornicate
 Mating isn’t necessary for an individual to survive, but it is
necessary in order for a species to pass on their genes, which
is the entire point of natural selection and evolution.
 https://www.youtube.com/watch?v=_7rsH2loIY8
Journey of a Sperm Cell
 Take a look at this student video and we’ll talk about why
they did what they did:
 http://sewilsonteachingportfolio.weebly.com/anatomy1.html
Structures and Functions - Male
 Testicles (testes plural):
 Males usually have two testicles.
 Each teste is subdivided into
compartments by the seminiferous
tubules and this is where the
immature sperm cells are made.
 Scrotum:
 The scrotum holds the individual
testes in separate sacs to keep them
at the right temperature.

Fun fact: tight jeans and underwear
make the testes too hot, and disrupts
sperm production.
 Epididymis:
 This is the resting tube coiled along
each testicle (6 meters long!).
 Immature sperm cells wait there,
not quite mobile yet.
Vas deferens
Structure and Functions – Male
 Vas deferens:
 A muscular tube (45 cm long) from
each teste that carries sperm
through muscular contractions
(peristalsis).
 Seminal vesicle:
 Sac-like structure attached to the
vas deferens near the base of the
bladder.
 They secrete a liquid to control the
pH of the sperm fluid, sugars for
energy, and an enzyme that helps
the sperm move inside a female.
 Prostate:
 A gland that secretes a milky fluid
that also helps to control the pH of
the sperm (neutralizes the acidity of
wastes produced by sperm).
Structure and Functions – Male
 Semen:
 This is the liquid mix produced by all
secretions that nourishes and helps transport
the sperm.
 Once the sperm reach the prostrate, the liquid
can be called semen.
 Urethra:
 This is the tube sperm empties into before
ejaculation.
 Also used to urinate, the urethra extends from
the bladder through the penis.
 Penis:
 This is a cylindrical organ that allows for the
transport of urine and semen from the
internal to the external environment.
 An erection has to do with the tissue filling
with blood AS WELL AS the formation of the
tissue fibers.
 Ejaculation occurs when the sperm and
semen is pushed through the urethra and out
of the tip of the penis.
Structure and Functions – Female
 Ovary:
 Females usually have two.
 Each ovary has the primordial
follicles, the special cells that
produce the half-matured egg cells.

Maturation of the eggs halts once a
baby girl is born and kicks back in
after puberty.
 Fallopian tubes:
 These tubes open near the ovaries,
penetrate the uterine walls and
open into the uterus.
 Cells along the walls of the
fallopian tubes secrete mucus and
small hairs called cilia push a
mature egg towards the uterus.
 Eggs are usually fertilized near the
end of the fallopian tube.
Structure and Functions – Female
 Uterus:
 This is the hollow muscular organ that
supports a developing zygote.
 The shape changes greatly during
pregnancy.
 Cervix:
 This is the lower 1/3 of the uterus,
where it narrows.
 Muscles around the cervix attach to
the pelvis and anchor the uterus in
place.

Mucus also plugs the cervix to prevent
foreign bodies from entering the uterus.
 Vagina:
 This is the muscular tube where the
penis fits into and delivers uterine
secretions outside the body.
Structure and Functions – Female
 **All the external structures are grouped
together and called the vulva.**
 Clitoris:
 A small projection near the top of the vulva.
 Corresponds to the penis and has a similar
structure  erectile tissue and large supply
of nerves.
 Labia:
 The labia form protective barriers over
certain parts of the vulva.


Majora - corresponds to male scrotum –
protects the vaginal opening
Minora – corresponds to the tip of the male
penis - clitoral hood
 Hymen:
 This is a thin membrane that partially
covers the vaginal opening.
 It’s very elastic, and may be torn through
exercise, tampon use, menstrual cups, or
pelvic exams.
Hormones
 There really are no such things as ‘male’ hormones and
‘female’ hormones – both sexes have some of all kinds of
hormones.
 Hormones are…
 Chemical messages released by cells
 Instigators of reactions within the body
 ‘Drugs’ that affect how our bodies work
 Hormones are necessary for all processes the body has to go
through for survival.
Hormones
 Testosterone:
 Women also produce testosterone, just in
smaller amounts  comes mostly from
the testes and ovaries.

One of many androgens, ‘male’ hormones.
 T. stimulates formation of male sex organs
during development, but after birth also
stimulates an increase in bone density,
libido, and muscle mass.

Males also get more hair and deeper voices.
 Estrogen:
 Men also produce estrogen.
 E. stimulates formation of female sex
organs in development, but after birth
stimulates an increase in metabolism, fat
stores, and is necessary for sexual desire.

Females also get thicker vaginal and uterine
walls.
Hormones
 Progesterone:


Highly involved in the female
menstrual cycle and pregnancy –
stimulates labor, inhibits milk
production until after delivery.
In general, it reduces spasms of
smooth muscle and normalizes blood
clotting.
 LH:


Male: promotes development of
testicular interstitial cells that secrete
hormones.
Female: stimulates ovarian cells to
secrete precursor molecules.
 FSH:


Male: stimulate supporting cells of
seminiferous tubules to respond to T.
Female: maturation of ovarian
follicles.
That’s great and all, but what
actually happens during sex?
 When people become sexually aroused, their body begin
secreting more and more hormones as well as mucus and
liquids to lubricate their genitals.
 In males this means their penis will fill with blood (the veins will
contract to a certain point to keep blood in the penis) and the penis
will become erect with the help of their special tissue arrangement.
 In females the vagina widens slightly and the labia draw back to
expose the clitoris.
 For reproductive purposes, the males will insert their erect penis
into the vagina and thrust in a rhythmic motion. The friction
will stimulate nerve endings in both the male and the female (if
done properly) for both to reach orgasm, the culmination of
physical and psychological stimulation.
 Before male ejaculation, precum might be secreted by the male –
this liquid doesn’t hold sperm before the first ejaculation.
 Females can ejaculate vaginal liquid, but it’s usually not nearly as
forceful as male ejaculation.
Sex
 If the male ejaculates into the vagina, the sperm then have
to fight against the female defense system to get to the egg.
 http://safeshare.tv/w/SfzFRwJygf
 The pH of the female reproductive system is different from
what the sperm is used to, and swimming through the
cervix the sperm have a much more difficult time
swimming straight.
 Once through the mucus plug of the cervix and in the
uterus, the sperm are pushed to one side and up through
one of the fallopian tubes. If the egg is not there, the sperm
cells eventually will die, absorbed by the female.
 If there is an egg, huzzah!
 But only the first sperm to reach the egg cells membrane will
actually fertilize the egg.
 When the egg membrane is penetrated by the first sperm, all
other sperm can’t get through the reinforced membrane.
Contraception
 There are many forms of contraception, but all of them exist
to prevent the female from becoming pregnant (“birth
control”).
 Some also prevent the spread of Sexually Transmitted Diseases
(STDs), but not all do.
 What are some you know? Use the space in your notes to
write a list of all the methods of contraception you can think
of and explain how they prevent a preganancy.
Conception to Birth
 https://www.youtube.com/watch?v=sqpmzEefWrk
Pregnancy
 Once a sperm reaches an egg and fertilizes the egg, all other
sperm cells degenerate and are absorbed by the female’s
body.
 They have no function.
 While the male’s job is done reproduction-wise, the female’s
job has just begun.
 Through the pregnancy, her hormone levels will increase and
decrease with very little notice, her internal organs will have
to move aside for the growing fetus, and she will have to eat
for two.
 Her uterus will balloon to up to 500 times it’s original size!
 The cravings a pregnant woman usually has are her body and
the growing fetus telling her what substances she needs more
of.
Pregnancy
Stages of Pregnancy – Ovulation,
Fertilization and Implantation
Terms
 Zygote: the first few cell divisions after an egg is fertilized.
 Embryo: the term for a fertilized egg after implantation
during the first few weeks of development.
 Fetus: the term for the developing baby from the last part of
the first trimester to the end of the nine/ten month
development.
Fetal Development
Development
 Once an embryo has implanted on the uterine wall,
differentiation occurs.
 Rapid growth occurs and the main external features of the
embryo begin to become clear.
 The various cell types are produced during this early stage.
 Spontaneous abortions or miscarriages that might occur in
the first trimester are due to:
 Major genetic abnormalities
 Alcohol, drug, and other toxins
 Infections
 Radiation (X-ray)
 Nutritional deficiencies
Weekly Development
 All weeks given are measured from the last menstruation of
the pregnant female.
 Gestational age is measured from the actual fertilization.
Embryonic Development by Week
 Week 3
 Mitosis and cell division occurs, but no change
in overall size.
 Week 4
 Beginning of the placenta is formed.
 Yolk sac is formed.
 Week 5
 Vertebra, brain, and spinal cord begin to form.
 Primitive heart tube forming.
 Week 6
 First heartbeats. [Can’t hear them until Week 912]
 Ears and lungs begin to form.
 Arm buds and a tail are visible.
Embryonic Development by Week
 Week 7
 Brain divides into sections.
 Leg buds and hands form.
 Rudimentary blood pumped.
 Week 8
 Digits form, but may be still webbed.
 Lymphatic system begins to develop.
 External genitalia formation begins.
 Week 9
 Nipples and hair follicles begin to form.
 All essential organs have begun to form.
Fetal Development by Week
 After the 10th week, the developing baby is
referred to as a fetus.
 Week 10-12
 Head is ½ the size of the fetus.
 Tooth buds form in the mouth.
 Fetus can make a fist.
 Genitals well differentiated.
 Week 13-16
 Bones harden.
 Fetus actively moves and makes sucking
motions with the mouth.
 External genitalia development finished by
week 15.
Fetal Development by Week
 Week 21
 Nails, eyebrows, and eyelashes visible.
 “Quickening” – mother can feel the baby
moving.
 Week 23
 Fetus has a startle reflex.
 Footprints and fingerprints are forming.

How do fingerprints and footprints form?
 Alveoli begin forming.
 Week 26
 Brain development is rapid.
 Nervous system is developed enough to
control some body functions.
 Gas exchange now possible in the lungs.
Fetal Development by Week
 Week 31
 Rhythmic breathing occurs, but lungs are not
fully mature.
 Bones are fully formed, but are still soft.
 Fetus begins storing iron, calcium, and
phosphorus.
 Week 35
 Fingernails reach the end of the fingertips.
 A baby can be born now with a high chance of
survival, but medical intervention could be
necessary.
 Week 36-40
 Small breast buds are present on both sexes.
 Head hair is course and thick.
Development of Genitalia
 Before a baby is born, the external genitalia must form.
 The sex of the baby is determined first by genetics.
 XX is female, XY is male.
 There are specific processes that must occur for the genitalia
to form.
 http://education-portal.com/academy/lesson/externalgenital-development-in-males-and-females.html#lesson
 http://safeshare.tv/w/kvDJBGjeUi
Ectopic Pregnancies
 This is a pregnancy that occurs
outside the uterus.
 The egg might implant on the
fallopian tube , part of the ovary,
or even the cervix or vagina. The
fallopian tubes are the most
common place for ectopic
pregnancies.
 The complications that arise from
this can be devastating for both
the mother and the fetus.
 Usually the fetus will die, and if
the fetus isn’t removed soon
enough the mother may die
Lithopedions
 Otherwise known as “stone
babies”.
 If a fetus dies anywhere from 14
weeks to full term, the female
body will usually eject the dead
tissue.
 If this doesn’t occur, the body has
another defense mechanism 
calcification of the foreign tissue.