MCN MIDTERMS Flashcards
- Immediately before and after birth
- Begins at 22 completed weeks of gestation and
ends 7 completed days after birth - “Perinatal and maternal health are closely
linked” (WHO)
Perinatal Period
- Time span from fertilization to birth.
- First day of woman’s last menstrual period to
38 weeks.
Gestation Period
- Before birth
- Embryological development
➢Embryo – developing human for first
2 months after fertilization
➢All major adult organs are present
Prenatal Period
➢Fetus – from 9 weeks until birth
➢By end of 3rd month, placenta is
functioning
Fetal Development
➢First 42 days after birth
➢First 4 weeks of a child’s life –
changes are very rapid
NUCAMA340
©LPD
Neonatal Period
From ovulation to fertilization
Ovum
From fertilization to implantation
Zygote
From implantation to 5–8 weeks
Embryo
From 5–8 weeks until term
Fetus
Developing embryo and placental
structures throughout pregnancy
Conceptus
The earliest age at which fetuses
survive if they are born is generally
accepted as 24 weeks or at the point a
fetus weighs more than 500–600 g
Age of viability
(first 2 weeks,
beginning with fertilization)
Pre-embryonic
(weeks 3 through 8)
embryonic
(from week 8 through
birth
Fetal
also referred to as conception or
impregnation
Fertilization
the union of an ovum and a
spermatozoon
fertilization
Occurs in the outer third of a fallopian
tube, termed the ampullar portion.
Never a certain occurrence, depending on
the following factors:
Equal maturation of both sperm and
ovum
Ability of the sperm to reach the
ovum
Ability of the sperm to penetrate the
zona pellucida and cell membrane of
ovum and achieve fertilization
Fertilization
a ring of mucopolysaccharide
fluid surrounding the ovum upon extrusion from
the Graafian follicle.
Zona Pellucida
a circle of cells protecting the
ovum.
Corona radiata
- a proteolytic enzyme released by
the spermatozoa and dissolves the Corona radiata.
Hyaluronidase
2.5 mL
Sperm per ejaculation: 400 million (20 to 200
million per mL)
Average semen volume
latin for “falling off” because it
will be discarded after birth of the child.
decidua
secreted by the trophoblast cells; causes
the uterine endometrium to continue to
grow in thickness and vascularity.
Human Chorionic Gonadotropin
– lies directly under
the embryo and communicates with
maternal blood vessels
Decidua basalis
– stretches and
encapsulates the embryo
Decidua capsularis
– remaining
portion of the uterine lining
Decidua vera/parietalis
Miniature, resembling probing fingers
▪ Arise from the trophoblast cells and
form the placenta as early as the 11th
or 12th day after fertilization.
Surrounded by a double layer of cells
▪ produce placental hormones (hCG,
hPL, estrogen, and progesterone)
▪ protect the growing embryo from
certain infectious organisms
▪ Disappear between the 20th and
24th week of pregnancy
Chorionic Villi
Latin for “pancake” descriptive of its
appearance and size at term.
▪ Weighs about 400-600 grams at term (1/6
of the fetus’ weight)
▪ Grows from trophoblastic cells at the
beginning of pregnancy to an organ 15 to
20 cm in diameter and 2 to 3 cm in depth
▪ Covers about half the surface area of the
internal uterus at term.
Placenta
Functions of Placenta?
Nutrition
Respiration
Hormone production
Excretion
Protection
smooth, shiny; separated
from the center; blood clots are usually
contained within the membranes →
less bleeding
Schultz
‘dirty’, rough and irregular;
separated from the edges; blood clots
are not contained within the
membranes → more visible bleeding.
Duncan
classified
according to how much of the
cervix is covered by the
placenta. Here are the main
Placenta previa
the
placenta completely covers
the cervix.
Complete Placenta Previa
the
placenta partially covers the
cervix.
Partial Placenta Previa
the
placenta is located at the edge of the
cervix.
Marginal Placenta Previa
the placenta is
near the cervix but does not cover it.
Low-Lying Placenta
▪ Form beneath the chorion
▪ Dual-walled sac (chorion –
outermost; amnion – innermost)
containing the amniotic fluid.
These walls fuse together as the
pregnancy progresses.
▪ Does NOT have nerve supply
▪ Support and produce amniotic
fluid.
▪ produce a phospholipid that
initiates the formation of
prostaglandins, which may be the
trigger that initiates labor
Amniotic membranes (amion)
At term, it amounts to 800 to 1,200 mL
▪ Slightly alkaline (pH 7 - 7.5)
▪ Constantly being newly formed and
absorbed (every 3 hrs) by direct contact
with the fetal surface of the placenta.
▪ Major methods of absorption:
▪ The fetus continually swallows the
fluid
▪ Absorbed from the fetal intestine
into the fetal bloodstream → to the
umbilical arteries and to the
placenta.
Amniotic fluid
meconium-stained
greenish
Red wine
abruptio placenta
may indicate
infection
cloudy with odor
Formed from the fetal membranes –
amnion and chorion
▪ Provides a circulatory pathway
connecting the embryo to the
chorionic villi of the placenta.
Umbilical chord
a gelatinous
mucopolysaccharide making up the
bulk of the cord; gives the cord body;
and prevents pressure on the arteries
and vein that pass through it.
Wharton jelly
is a unique system that allows the fetus to receive oxygen and nutrients from the mother while bypassing the lungs, which are not yet in use.
fetal circulation
Acts as the site of gas
exchange, providing oxygen and
nutrients to the fetus and removing
waste products
Placenta
The arteries carry
deoxygenated blood from the fetus to
the placenta, while the vein carries
oxygenated blood back to the fetus.
Umbilical Cord
A vessel that allows
oxygenated blood from the umbilical
vein to bypass the liver and flow
directly into the inferior vena cava.
Ductus Venosus
An opening between
the right and left atria of the fetal
heart, allowing blood to bypass the
lungs
Foramen Ovale
A vessel
connecting the pulmonary artery to
the aorta, further bypassing the lungs
by directing blood from the
pulmonary artery into the aorta.
Ductus Arteriousus
Stem Cells = ???
Zygote Cells
undifferentiated cells
with potential to form a complete
human being (first 4 days of life)
Totipotent
differentiated cells
expected to become specific body cells
(8 days of life)
Pluripotent
Zygote growth is called??
cephalocaudal
very specific cells to
become or create a distinct body organ
(mature cells)
Multipotent
Forms a linning of organs
Endoderm
specific tissue layers that develop into body organ
systems.
Germ Layers
What are the 3 germ layers?
Ectoderm
Mesoderm
Endoderm
forms the exoskeleton
Ectoderm
develops into organs
Mesoderm
Body portions formed
What is this germ layer?
-Central Nervous System (Brain and Spinal Cord)
-Peripheral Nervous System
-Skin, hair, nails and teeth enamel
-Sense Organs
-Mucous membranes of the anus, mouth and nose
-Mammary Glands
Ectoderm
-Supporting structures of the body (connective tissue, bones, cartilage, muscle, ligaments and tendons)
-Upper portion of the urinary system (kidney and uterus)
- Reproductive system
-Heart, lymph, circulatory systems and blood cells
Mesoderm
-Linning of the pericardial,pleura, peritoneal cells
-Linning of the gastrointestinal tract, respiratory tract, tonsils, parathyroid, thyroid and thymus glands
Endoderm
What is organogenesis?
organ formation
Are substances or factors that can cause congenital abnormalities or increase the risk of pregnancy complications
Testratogens
what are the 8 testratogens?
Alcohol
Cigarettes
Recreational Drugs
Medications
Infections
Exposure to Chemicals
Radiation
Nutrional deficiencies
Staining of the tooth enamel and inhibit growth of long bones
Tetracycline
Damage to the 8th cranial nerve leads to poor hearing and deafness
Stretptomycin/ Quinine
Leads to hemolysis or destruction of RBC
Vitamin K
Enlargement of thyroid gland or goiter
Iodides
Amelia (Absence of extremities)
Thalidomides
Congenital malformations, ebsteins anamoly (right heart defect)
Lithium
IUGR, craniofacial, dsysmorphism, microephaly, nail, hypoplasia, heart deffects
Dilatin
Congenital deafness, microtia, CNS Defects, CHD
Isotretinoin (accutane)
At what week does the Central Nervous system starts to develop and ends?
Week 3 to week 38
At what week does the heart starts to develop and ends?
Week 3 to week 8
At what week does the upper limbs start to develop and when does it end?
Week 4 to week 8
At what week does the eyes start to develop and when does it end?
week 4 to week 38
at what week does the palate start to develop and when does it end?
week 6 to week 9
At what week does the lower limbs start to develop and when does it end?
Week 4 to 8
when does the external genitalia start to develop and when does it end?
week 7 to week 38
at what week does the teeth start to develop and when does it end?
week 6 to week 38
at what week does the ears start to develop and when does it end?
week 4 to week 16
The length of the embryo is about 0.75 cm;
weight is about 400 mg.
* The spinal cord is formed and fused at the
midpoint.
* The head is large in proportion and represents
about one-third of the entire structure.
* The rudimentary heart appears as a prominent
bulge on the anterior surface.
* Arms and legs are bud-like structures;
rudimentary eyes, ears, and nose are
discernible.
End of 4th gestational week
- The length of the fetus is 7 to 8 cm; weight is about 45 g.
- Nail beds are forming on fingers and toes.
- Spontaneous movements are possible, although they are usually too
faint to be felt by the mother. - Some reflexes, such as the Babinski reflex, are present.
- Bone ossification centers begin to form.
- Tooth buds are present.
- Sex is distinguishable on outward appearance.
- Urine secretion begins but may not yet be evident in amniotic fluid.
- The heartbeat is audible through Doppler technology
End of 12th gestational week (first trimester)
- The length of the fetus is about 2.5 cm (1 in.);
weight is about 20 g. - Organogenesis is complete.
- The heart, with a septum and valves, beats
rhythmically. - Facial features are definitely discernible; arms
and legs have developed. - External genitalia are forming, but sex is not
yet distinguishable by simple observation. - The abdomen bulges forward because the
fetal intestine is growing so rapidly. - A sonogram shows a gestational sac, which is
diagnostic of pregnancy
End of 8th gestational week
- The length of the fetus is 10 to 17 cm; weight
is 55 to 120 g. - Fetal heart sounds are audible by an ordinary
stethoscope. - Lanugo is well formed.
- Both the liver and pancreas are functioning.
- The fetus actively swallows amniotic fluid,
demonstrating an intact but uncoordinated
swallowing reflex; urine is present in
amniotic fluid. - Sex can be determined by ultrasonography
End of 16th gestational week
- The length of the fetus is 25 cm; weight is 223 g.
- Spontaneous fetal movements can be sensed by
the mother. - Antibody production is possible.
- Hair, including eyebrows, forms on the head;
vernix caseosa begins to cover the skin. - Meconium is present in the upper intestine.
- Brown fat, a special fat that aids in temperature
regulation, begins to form behind the kidneys,
sternum, and posterior neck. - Passive antibody transfer from the pregnant
person to fetus begins. - Definite sleeping and activity patterns are
distinguishable as the fetus develops
biorhythms that will guide sleep/wake patterns
throughout life.
End of 20th gestational week
- The length of the fetus is 28 to 36 cm;
weight is 550 g. - Meconium is present as far as the rectum.
- Active production of lung surfactant
begins. - Eyelids, previously fused since the 12th
week, now open; pupils react to light. - Hearing can be demonstrated by
response to sudden sound. - When fetuses reach 24 weeks, or 500 to
600 g, they have achieved a practical
low-end age of viability if they are cared
for after birth in a modern intensive care
nursery.
End of 24th gestational week ( second trimester)
- The length of the fetus is 48 to 52 cm (crown
to rump, 35 to 37 cm); weight is 3,000 g (7 to
7.5 lb). - Fetus kicks actively, sometimes hard enough
to cause the pregnant person considerable
discomfort. - Fetal hemoglobin begins its conversion to
adult hemoglobin. - Vernix caseosa starts to decrease after the
infant reaches 37 weeks gestation and may
be more apparent in the creases than the
covering of the body as the infant
approaches 40 weeks or more gestational
age. - Fingernails extend over the fingertips.
- Creases on the soles of the feet cover at least
two-thirds of the surface.
End of 40th gestational week (third trimester)
- The length of the fetus is 35 to 38 cm; weight is 1,200 g.
- Lung alveoli are almost mature; surfactant can be demonstrated in amniotic fluid.
- Testes begin to descend into the scrotal sac from the lower abdominal cavity.
- The blood vessels of the retina are formed but thin and extremely susceptible to damage
from high oxygen concentrations (an important consideration when caring for preterm
infants who need oxygen).
End of 28th gestational week
- The length of the fetus is 38 to 43 cm; weight is 1,600 g.
- Subcutaneous fat begins to be deposited (the former stringy, “little old man” appearance
is lost). - Fetus responds by movement to sounds outside the pregnant person’s body.
- An active Moro reflex is present.
- Iron stores, which provide iron for the time during which the neonate will ingest only
breast milk after birth, are beginning to be built. - Fingernails reach the end of fingertips
End of 32nd gestational week
how many BPM is the does the fetal beat per min?
120 -160 Bpm
- The length of the fetus is 42 to 48 cm;
weight is 1,800 to 2,700 g (5 to 6 lb). - Body stores of glycogen, iron,
carbohydrate, and calcium are
deposited. Additional amounts of
subcutaneous fat are deposited. - Sole of the foot has only one or two
crisscross creases compared with a full
crisscross pattern evident at term. - Amount of lanugo begins to diminish.
- Most fetuses turn into a vertex (head
down) presentation during this
month
End of 36th gestational week
At what week can you hear the fetal heart rate by using a doppler?
10th to 11th week
Bpm range of week 6?
85 - 103 Bpm
At what week can you hear the fetal heart rate by using a normal stethoscope?
18TH - 20TH Week
Bpm range of week 5?
80 - 85 Bpm
Bpm range of week 7??
126 - 149 Bpm
Bpm range of week 8?
149 - 172 Bpm
Bpm range of week 9?
155 - 195 Bpm
Bpm range of week 12?
120 -180 Bpm
