Transcript human development/pregnancy notes

Pregnancy and
development
Mrs. Schmit
Begins with….
Fertilization - union of the sperm and
the egg
Happens in the oviduct
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http://health.howstuffworks.com/adam-200048.htm
http://www.pbs.org/wgbh/nova/miracle/program.html (sperms journey)
Haploid Gametes:
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Sperm (23 chromosomes)
Egg (23 chromosomes)
Combine to form a diploid (46
chromosomes) ZYGOTE
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All babies begin as a single
fertilized cell that undergoes
cell division as it moves down
the fallopian tube for 3-5 days
Zygote divides
Journey of Egg
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Zygote continues to Journey
along fallopian tube - about
4-5 days while the cell
divides many times
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11 to 12 days after
fertilization the zygote
becomes a tiny ball of cells
called an embryo
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Uterus prepares spongy
lining for implantation of
egg.
Implantation
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Implantation is where the
blastocyst (ball of cells)
attaches itself to the
uterine lining
The embryo implants by
secreting an enzyme to
breakdown uterine cells as
it burrows into the mother's
uterus.
Implantation of egg to womb (uterus)
takes place 6 -7 days after
fertilization.
IF not, then menstrual cycle begins.
Detecting Pregnancy
Chemical Test – 98% effective
 Morning Sickness – nausea due to change
in hormones
 Ultra Sound – sound waves used to detect
baby in the womb
 http://health.howstuffworks.com/adamroundup.htm
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Names during pregnancy
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Zygote = first cell
Embryo = weeks 0 - 8
Fetus = weeks 9 until birth
What happens during pregnancy?
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Once implantation occurs, the formation
of most internal organs and external
body structures begin.
All cells of the body are classified
as one of three types
Ectoderm- the outer layer.
become the nervous system and skin
 Endoderm - the inner layer of cells
form the lining of the digestive and respiratory
tract, parts of the liver, pancreas and many other
organs
 Mesoderm - forms from an out pouching of the
inner layer tissue of the endoderm.
form muscle, bone, blood and connective tissue.
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Placenta – babe’s house in mom
What is it?
The placenta is an organ attached to the
lining of your womb during pregnancy
What does it do?
It keeps unborn baby’s blood supply
separate from mothers blood supply, as
well as providing a link between the two.
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prevents the ovaries from
releasing eggs
stimulates the ovaries to
produce estrogen and
progesterone
continuously.
carries oxygen and
nutrients from mother to
fetus and wastes from
fetus to mother through
the umbilical cord
Connects placenta to baby
Amnion: membrane
surrounding baby w/
amniotic fluid inside to
cushion
http://www.howstuffworks.co
m/adam-200127.htm
Umbilical Cord:
a. connects babies navel to
placenta
b. 2 arteries – take wastes
away from body
c. 1 vein – brings “goodies”
into baby
Embryo takes shape:
Organ formation begins about
3 weeks after fertilization
The area will then begin to
develop the brain and spinal
cord (neural tube).
Embryo takes shape – first two weeks
http://www.pbs.org/wgbh/nova/miracle/program.html
Week 2-4
heart and major blood
vessels begin to develop
by about day 16 or 17.
Beats 120-160 beats per
minute
heart begins to pump fluid
through blood vessels by
day 20, and the first red
blood cells appear the
next day.
Blood vessels continue to
develop in the embryo
and placenta
Week 5-9
By
the sixth week from
fertilization tiny fingers appear,
followed within days by the
toes.
By the seventh week the baby
has individual fingerprints.
Almost all organs are
completely formed by about 8
weeks after fertilization
9 weeks from the last
menstrual period (7 weeks from
conception)
42 days
9 weeks
Week 10-14
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14 weeks –
sex can be
identified
20 weeks
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Head hair, eyebrows. eyelashes and nails
are growing.
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To protect the baby's skin from prolonged
contact with the amniotic fluid, a greasy
substance called vernix covers the body.
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the baby will gain weight and will develop a layer
of fat beneath the skin.
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receive maternal antibodies against some
infections
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Women feel movements within week 16-20
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Full term 40-42 weeks.
Feeding the growing fetus
http://www.pbs.org/wgbh/nova/miracle/program.html
Changes in Mom
Emotional – hormones change
urinary bladder is squished
other abdominal organs are crowded
weight changes (ideally no more than 24
pounds gained)
5. Breasts enlarge
6. Lactation – milk production
1.
2.
3.
4.
Labor
Position of baby during labor varies:
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Lengthwise 99%
a. head down / face up – most common
b. face down (5.5 %)
c. Sideways (1 %)
d. Breech (3.5%)
e. Caesarean Birth also known as a Csection
Three stages
First Stage - Labor
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Early or latent phase Begins with contractions
and ends when the cervix
is 100 percent effaced
and dilated to 10
centimeters
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Average length ranges
from 10-16 hrs
Active Phase
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Regular contractions
become longer, stronger
and closer together.
Recommend going to the
hospital when
contractions are 5
minutes apart and last 60
seconds.
Amnionic Sac – bag of
water breaks, 1 – 1.5 qt. –
time to go to hospital
Transition phase
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Most difficult and
shortest – 30 minutes
to two hours.
Cervix opens from 7 –
10 cm and baby
descends into the
birth canal.
Second stage – baby is born.
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Begins when the
cervix is completely
effaced and dilated
and ends with the
birth of the baby.
Average length for a
first time mother
ranges from 1 to-2
hours and shorter for
subsequent births
Third Stage – after birth
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Begins with the birth of the baby and ends with
the delivery of the placenta.
Average length for all vaginal deliveries ranges
from 5 - 15 minutes.
What treatments are given during birth if
want too?
 Pain killers
 Epideral – needle in your spine
http://www.howstuffworks.com/adam200113.htm
Once born
Umbilical cord is cut using a clamp
 20 minutes later the placenta and cut
umbilical cord are pushed out by the
uterus (after birth)
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Apgar Test
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Tests
done
once
baby is
born
Lactation
Milk Secretion
1. Prolactin hormone starts milk production
right after birth
2. actual milk comes in 2 days
Advantages to breast feeding
contain proper nutrition at right temp.
right price – cost effective
Contains what mom eats and drinks
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Abrupt changes for baby
1.
2.
3.
4.
5.
temperature change
lungs begin to be used
food getting
waste disposal
blood circulation
Problems during Pregnancy
 Anemia – not enough blood cells
circulating in the mother's blood.
Fairly Common – two types
1 - dilutional anemia - increase of circulating
blood sometimes up to 40-50% in order to
sustain the growing baby.
2 - iron deficiency anemia - when a woman's
iron-level is insufficient and red blood cells
aren't being made in a great enough level.
 Treatment – take iron supplements
Pre-eclampsia
Only happens when pregnant
 high blood pressure
 protein in the urine
 an increased swelling in the legs and feet.
Symptoms
 persistent headaches
 flashing light
 blurred vision and seeing spots
 upper abdominal pain
 sudden excessive lower leg swelling
Treatment is often bedrest and monitor baby’s blood
pressure
Group B Strep:
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Bacteria – many carry without developing
infection or illness.
is the leading cause of infections in newborns.
(Not group A strep which is strep throat).
Doctors find Group B Strep through cultures
during pregnancy.
 Can be treated by giving antibiotics during
labor so infection does not pass to baby
Gestational Diabetes:
develops during pregnancy, when a
woman's body is not making enough
insulin.
 Develops usually in second trimester.
 Cannot be treated by pills, most treatment
is through diet or insulin.
Low Birth Weight:
Caused by poor nutrition, substance use
(cigarettes, alcohol, drugs).
 Can be an effect of a STD, other contagious
diseases, or no pre-natal care.
 When a baby is born pre-maturely, it stays in the
hospital for up to four months.
 Babies who are born at a low birth rate run the
risk of respiratory infections, blindness, learning
disabilities, cerebral palsy, and heart infections.