Transcript Human Growth and Development Powerpoint

Human Growth and
Reproduction
Female System Terms
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Vagina/birth canal
Cervix
Ovary
Egg (ovum/ova)
Fallopian tubes
(oviduct)
• Uterus
• follicle
• Menstration - release of tissue & blood
through the vagina; usually occurs each
month two weeks after ovulation and lasts 3
to 7 days
• Hypothalamus - small portion of the brain that
controls hormone release
• Pituitary - "The Master Gland“; located in
brain and responsible for the functioning of all
other glands including thyroid, adrenals, and
sex glands
• Follicle Stimulating Hormone (FSH) – a
hormone secreted in the pituitary that
Stimulates growth & development of the
ovarian follicle in females
• FSH in males stimulates the production of
sperm
• Follicle - small sac near the surface of the
ovary that contains the developing egg cell
• Luteinizing Hormone (LH) - hormone
produced in the pituitary gland that stimulates
the development of the corpus luteum
• Estrogen – female hormone that regulates
development of secondary sex characteristics
• Progesterone – secreted by corpus luteum;
regulates the build up of endometrial tissue in
the uterus
• Testosterone – male hormone that regulates the
development of secondary sex characteristics
• Ovulation - release of mature egg cell
from its follicle in the ovary
• corpus luteum - yellow mass that forms
in the cavity of a ruptured follicle that
releases progesterone
• Fertilization - union of the egg and the
sperm which results in conception
(formation of a zygote)
• cell division – (Cleavage/Mitosis) - shortly
after fertilization the egg, now called a zygote,
starts to divide into 2 cells, then 4, 8, etc.
• Implantation - the zygote attaches to the
uterine lining and starts to draw nutrition from
the blood supply (occurs between 6th & 11th
days after fertilization)
• Endometrium – lining of the uterus; where
zygote implants
• Oviduct – passageways where egg is released
form ovaries; site of fertilization; also called
“fallopian tubes”
• Cervix – opening at lower end of uterus
• Vagina – muscular organ that receives the penis
and sperm
Male System terms:
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Penis
Testicles
Scrotum
Epididymis
Urethra
Vas Deferens
Prostate Gland
Seminal Vesicles
Cowper’s (Bulburethral) Glands
Seminiferous Tubules
• Penis – delivers sperm to female reproductive tract
• Testicle – produces sperm & testosterone
• Epididymus – sperm is stored in this tightly coiled
tube
• Scrotum – sac containing the testes; extension of
abdomen; functions to keep the testes at a
temperature slightly lower than that of the rest of
the body. (for human beings, the temperature
should be 1 or 2 degrees lower)
• Vas Deferens – thin muscular tube that
transports sperm from epididymus to the
urethra
• Seminal Vesicle - a pair of simple glands
inferior to the urinary bladder; secretes
alkaline fluid that adds to semen &
neutralizes acidity of vagina
• Bulbourethral (Cowpers) glands – produce a
clear secretion known as pre-ejaculate which
helps to lubricate the urethra so sperm can
easily pass through; also neutralizes traces of
acidic urine in urethra
• Prostate Gland – walnut-sized gland
encircling urethra that stores & produces
seminal fluid
• Urethra – tubes that connects urinary bladder
to outside of body; travels through penis and
carries semen as well as urine
• Seminiferous tubules – located in testicles;
location of meiosis (creation of sperm)
A new study conducted by Chicago
researchers shows that internal
mucosal layers of foreskin are more
susceptible to HIV infection than
cervical tissue or the external layers of
foreskin, which explains why
uncircumcised men seem to be at much
higher risk for HIV acquisition than men
who are circumcised…this is not proven
beyond a reasonable doubt…more
testing is needed!
A fertile man makes around 1000 new sperm per second,
in the testes.
Each sperm carries half the chromosomes (n or haploid)
packed into its head.
The rest of the cell is a long tail, which propels the sperm
towards the egg at about three millimeters per minute.
The neck is crammed with mitochondria, which help
make the energy needed for the journey.
Once they're released, sperm usually survive for 48
hours.
A human egg (oocyte) is about 100 micrometers in diameter, which
is large for a cell.
A fertile woman usually releases one egg a month, from one of her
two ovaries.
Unless the egg is fertilized within the next 24 hours, it dies.
At its center, the egg contains half the chromosomes (n or haploid)
number for its species.
The rest of the cell is a rich food store for the fertilized egg during
the first few days of its life.
A baby girl is born with around .5-1.5 million eggs already formed in
her undeveloped ovaries.
However, only about 500 are released in her lifetime, between
puberty (15) and menopause (55).
Ovulation
• An egg (orange), almost
ready to be released by a
woman's ovary.
• During a healthy cycle, a
woman will release one
or perhaps two eggs
which should slowly
travel down, hopefully
meeting sperm on the
way so it can be
fertilized.
Fertilization
Fertilization
Occurs in Fallopian Tubes (200 million sperm
to one egg)
When 1 sperm penetrates the zona pellucida
(clear zone around egg), cortical granules
are released that prevent any other sperm
from penetrating the egg
After fertilization, the egg and sperm and
nuclei fuse, and a new diploid human zygote
results (2n) - the first cell of the new animal...
The egg’s journey from ovulation to
fertilization to implantation
Chromosomes in fertilization:
After Fertilization…
In the first days
& weeks after
conception,
mitosis begins,
converting the
zygote to a
multicellular
organism
24 hour embryo (zygote)
Cleavage (Mitotic Divisions)
Cleavage
2-day old embryo
Morula – Day 4
16-32 cell stage
The solid Morula develops into
a hollow Blastula:
Gastrulation: major cell
reorganization into 2 or 3
tissue layers
Gastrulation
1. Ectoderm –
skin, nervous
system
2. Endoderm –
lining of gut
& internal
organs
3. Mesoderm –
muscles,
bones,heart
Placenta
• For 9 months, it feed & nourishes the
fetus with the blood supply and
nutrients necessary for survival
• Also disposes of the toxic waste
• Develops from the sperm & egg cells
that formed the fetus
• Placental Barrier does NOT allow the
blood from the placenta to mix with the
mother’s blood…WHY?
• The mother’s blood DOES NOT mix
with placental blood in order to
avoid the possible transfusion of
different blood types form mother
to baby
Embryo at Day 5
Days 10 to 14
-Fluid filled amniotic cavity starts to form
-Yolk sac starts to form (will make blood
cells, germ cells)
-Embryo starts to form from embryonic
disc
- Chorion (placenta) starts to form
• At the end of this stage, a woman will have
just missed her period!
Days 10 to 14:
Days 15 to 21
Neural Groove (future spinal cord and
brain) begins to form
Somites (bands of tissue that will become
muscles and bones) begin to form
Pharangeal arches (future face, neck,
mouth, nose) begin to form
18-25 DAYS:
• The baby is only 1/100 of an inch long
• his tiny heart is already beating
• By the 20th day, the foundation for the nervous
system is laid down.
• WEEK FOUR: By now, blood circulation is wellestablished. The larynx and inner ear are beginning
to form, as are the legs and arms. The liver,
pancreas, lungs, and stomach are also forming. By
this point, the baby is 4-6 millimeters long from head
to rump.
• WEEK FIVE: The baby is now about 7-9 mm from
head to rump. In the process of developing, the
baby will go through three sets of kidneys. This
week, the last set of kidneys appears.
Day 21 on…
• Development of all
organ systems
• Day 22: Cardiac
cells (early heart)
begins to beat
• Day 24 embryo
shown at right
4 Weeks
Week 4
• After implantation, the cells of the embryo
started to specialize to form the outline of the
body.
• the embryo measures approximately 5 mm;
the head is distinct
• the heart beats, and the arms and budding
fingers are visible.
• the placenta continues to develop, bringing
the fetus all the necessary nutrients from the
mother's blood.
Week 4
Week 4
Week 5
Week 6
• Heart will begin to beat
• Blood will start to circulate throughout
baby’s body
• Umbilical cord will start to form
• Head, eyes, intestines, & liver all start
to form
Fetus at 6 weeks
• 42 DAYS: The skeleton is complete and
reflexes are present. Brain waves (the
presence or absence of which are used as a
legal means to declare a born person living or
dead) can be detected.
• WEEK SIX: Now the baby is about 8-11 mm.
Although the mother won't be able to feel the
baby's kick for many weeks to come, he is
now moving in his amniotic sac. The baby
has all the internal organs of an adult. The
process of ossification (the hardening of the
bones) begins.
Week 6
Week 8
Fetus at 7 weeks
Fetus at 8 weeks
Week 10
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End of embryonic stage of development
Now known as a fetus
External genitalia begin to form
Facial features & limbs become more
apparent
• Vital organs will be formed and begin to
work
Fetus at 11 weeks
Week 12
Fetus at 12 weeks
Fetus at 12 weeks
Week 14
• Reproductive organs are developing
• Growing hair as well as forming eyelids,
fingernails, & toenails
• Head growth occurs rapidly
• Bone formation forms rapidly
• Digestive organs begin to function
Fetus at 14 weeks
Fetus at 14 weeks
Fetus at 16 weeks
Fetus at 16 weeks
A fetus at 16 to 20 weeks begins to
hear and may even be able to hear
its mother’s voice!
Its tiny heart pumps about 25 quarts
of blood each day!
Week 18
• Finger and toe pads have formed
• Bones in inner ear have developed
enough that fetus may start responding
to loud outside sounds
• Bones are distinct in X-rays
• Heartbeat detected by physician
• Sex organs are fully formed
Fetus at 20 weeks
Week 22
• Senses are well developed
• Sweat glands begin to develop
• Brain begins to quicken its development
• Fine, downy fuzz covers the entire body
• Ears & nose begin to develop cartilage
Fetus at 24 weeks
Fetus at 26 weeks
Week 28
• Development of the retinas will be
completed
• Eyes will begin to open and blink
• Cerebral cortex of brain develops
rapidly
• If born now, baby would have a 50%
chance of survival with proper medical
care
Week 32
• Subcutaneous fat is deposited for later use
• Fingernails reach beyond the fingertips
• Skin becomes less transparent as fat deposits
develop under skin and other areas
• May respond to loud noises
• Organs are almost fully mature except for the
lungs
Fetus at 32 weeks
Fetus at 32 weeks
Fetus at 36 weeks
Week 36
• Hair covering the entire body is shed
• Organ systems function actively
• Vernix (protective substance that
blankets the baby) is present over the
entire body
• Fetus settles into position for birt
Labor & Delivery Process
• In early labor, mom will feel the first
contractions
• Her cervix will gradually dilate
• Contractions will be more frequent and
painful
• This stage can last for hours
Active Labor
• Contractions are more frequent &
painful
• Cervix begins to dilate, stretching from
about 3 cm to the full 10 cm that is
needed for delivery to begin
• When mother is dilated sufficiently, she
can receive medication for her pain if
she chooses
Transition Stage
• Cervix reaches its full dilation
• Contractions become stronger and more
frequent, possibly coming every three
minutes and last up to a minute each
• Baby is descending into the birth canal
• As baby moves down, mother may feel
pressure and an urge to push
• This stage may last anywhere from a few
minutes to a few hours
Apgar Score
• Assesses health of newborn immediately after
childbirth
• (Assessment is made one and five minutes
after birth of baby)
• Determined by evaluating the newborn baby
on 5 simple criteria on a scale from 0 to 2
• The Apgar score is a number calculated
by scoring the heart rate, respiratory
effort, muscle tone, skin color, & reflex
irritability (response to a catheter in the
nostril). Each of these objective signs
can receive 0, 1, or 2 points.
• A perfect Apgar score of 10 means an
infant is in the best possible condition
Activity (muscle tone)
0 — Limp; no movement
1 — Some flexion of arms and legs
2 — Active motion
Pulse (heart rate)
0 — No heart rate
1 — Fewer than 100 beats per minute
2 — At least 100 beats per minute
Grimace (reflex response)
0 — No response to airways being suctioned
1 — Grimace during suctioning
2 — Grimace and pull away, cough, or sneeze during suctioning
Appearance (color)
0 — The baby's whole body is completely bluish-gray or pale
1 — Good color in body with bluish hands or feet
2 — Good color all over
Respiration (breathing)
0 — Not breathing
1 — Weak cry; may sound like whimpering, slow or irregular breathing
2 — Good, strong cry; normal rate and effort of breathing
Remember…
The process of growth & development
all need to occur at a precise time and
place –
that is why poor maternal nutrition,
fever, drugs, alcohol, (particularly in the
1st trimester) all have potentially
serious effects of the developing baby.
What NOT to do during
pregnancy!
http://www.hip-chick-pregnancyguide.com/childbirth-video.html
Miscarriages
• About 15% of pregnancies end in miscarriage
• Most within the first trimester
• Most miscarriages occur due to chromosome abnormalities, a
problem with either the egg or the sperm
• Women over 35 are at greater risk for these abnormalities
and/or miscarriages than younger women
• Other causes of miscarriages include Infections, hormonal
problems, illnesses, or diseases
• Drinking alcohol, smoking, and taking certain drugs also
increase the risk
Ectopic pregnancy
Infertility
• A condition of the reproductive system that
impairs the conception of children
• Affects approx 6.1 million individuals
throughout the United States
• Diagnosis is usually given to couples who
have been trying to conceive for one year
without success
Conception & Pregnancy depend on:
• Production of healthy sperm by the man
• Healthy eggs produced by the woman
• Unblocked fallopian tubes that allow the sperm to
meet the egg
• The sperm’s ability to fertilize the egg when they
meet
• The ability of the fertilized egg (embryo) to become
implanted in the woman’s uterus
• Sufficient embryo quality
In-vitro Fertilization
• In IVF, doctors want to
"harvest" as many eggs as
possible from a woman to
improve the chances of
having one or more
embryos to put back.
• To do this, many patients
are given hormones to
stimulate the ovaries to
produce more eggs and
have them ready for
"collection" on a set day.
• This means daily injections
of hormones - which can
have side-effects.
• A total of 10,000-50,000
spermatozoa are added to
medium containing the oocyte.
motile
culture
• After insemination, the oocyte is left
for 12-13 hours and then inspected in a
petri dish containing culture medium.
• Any abnormal oocyte is noted and such
embryos are not used for transfer.
• The first cleavage takes place 24-30
hours after insemination
• each subsequent division should occur
within 10- 12 hours thereafter
• If cleavage does not occur within 24
hours, this suggests abnormal oocyte,
which should not be used for transfer
• There is a “window of
implantation” that lasts 7 days
• Before & after this “window”,
plantation will not occur
• IVF failure is mostly due to embryo
quality and NOT uterine issues
• Human blastocysts should hatch
from the shell and begin to implant
1-2 days after day 5 IVF blastocyst
transfer
• In a natural situation (not IVF),
the blastocyst should hatch and
implant at the same time - about 6
to 10 days after ovulation
Surrogate Mothers…
• Surrogacy is a method of reproduction
whereby a woman agrees to become
pregnant and deliver a child for a contracted
party
• She may be a relative of the child or she
may, as a gestational carrier, carry the
pregnancy to delivery after having been
implanted with an embryo that is not hers.
The legality of it ….
• New York law holds surrogacy agreements
void and unenforceable.
• However, at least one court has recognized
the rights of intended parents in an assisted
reproduction situation absent a contract.
• In one 1994 divorce proceeding, a husband
sought sole custody of the two children of the
marriage on the basis that his wife was their
gestational, but not genetic, mother.
• The wife had undergone an in vitro
fertilization procedure in which she was
impregnated with an anonymous donor
egg fertilized with her husband’s sperm.
• The Court found the gestational mother
to be the legal mother of the children,
based on the intent of the parties
regarding parentage.
• In one case in 1990, decided before the
statutory ban on surrogacy agreements was
passed, a married couple had entered into an
extensive contract with a surrogate, including
a $10,000 “surrogate fee.”
• The Court found the surrogate’s commitment
to relinquish the child she carried could not
be truly voluntary because of the financial
inducement.
• The Court went on to find that its conclusion
might be altered by a sworn statement by the
surrogate that the child’s best interests lie
with the contracting couple,