Nur 113 The Growing Fetus Ch 9

Front 1

ENDOMETRIUM

Back 1

The endometrium is the mucous membrane that lines the inside of the uterus (womb). The endometrium changes throughout the menstrual cycle. It becomes thick and rich with blood vessels to prepare for pregnancy. If the woman does not get pregnant, part of the endometrium is shed, causing menstrual bleeding.

Front 2

3 Layers of the UTERUS:

Back 2

1. endometrium
2. Myometrium
3. Perimetrium

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The muscular outer layer of the uterus

Back 3

Myometrium

Front 4

Fertilization:

Back 4

-72 h after Ovulation
-AKA: conception and impregnation) is the union of an ovum and a spermatozoon.
- occurs in the outer third of a fallopian tube, the ampullar portion

Front 5

Fimbriae

Back 5

fine, hairlike structures that line the openings of the fallopian tubes. A combination of peristaltic action of the tube and movements of the tube cilia help propel the ovum along the length of the tube.

Front 6

IMPLANTATION:

Back 6

- 6 -8- 10 days after fertilization

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1. Zygote
2. Embryo
3. Fetus

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1. From fertilization to implantation
2. From implantation to 5-8 weeks
3. From 5-8 weeks until term

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What are the 3 factors that determine FERTILIZATION?

Back 8

1. equal maturation of both sperm and ovum,
2. the ability of the sperm to reach the ovum,
3. the ability of the sperm to penetrate the zona pellucida and cell membrane and achieve fertilization

Front 9

Developing embryo or fetus and placental structures throughout pregnancy

Back 9

Conceptus

Front 10

Age of Viability

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The earliest age at which fetuses could survive if they were born at that time, generally accepted as 24 weeks, or fetuses weighing more than 400 g

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**Where does Fertilization occur?

Back 11

outer third of the fallopian tube

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It's where the Union of sperm and egg takes places and it's the beginning of Pregnancy?

Back 12

-Fertilization

Front 13

How does sperm travel the fallopian tube?

Back 13

-their Flagella (tails) and
-uterine contractions

Front 14

Normally,only 1 spermatozoon is able to penetrate the cell membrane of the ovum. Once it penetrates the cell, the cell membrane changes composition to become impervious to other spermatozoa. What is an exception to this formation?

Back 14

hydatidiform mole, in which multiple sperm enter an ovum; this leads to abnormal zygote formation

Front 15

a complication of pregnancy in which the placenta grows in the lowest part of the womb (uterus) and covers all or part of the opening to the cervix

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Placenta Previa

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At what point is the Endometrium called DECIDUA?

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Implantation: contact b/w the growing structure and the uterine endometrium

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Occurs approx. 8 to 10 days after fertilization?

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Implantation

Front 18

a fertilized egg has implanted outside the uterus

Back 18

Ectopic pregnancy
-most common site fallopian tubes
-baby can not survive
-caused by a condition that blocks or slows the movement of a fertilized egg through the fallopian tube to the uterus. This may be caused by a physical blockage in the tube.

Front 19

What "estogen" (hormone) causes the uterine endometrium to continue to grow in thickness and vascularity, instead of sloughing off as in a usual menstrual cycle.

Back 19

HCG (human chorionic gonadotropin), secreted by the trophoblast cells p 193.

Front 20

This phase follows ovulation and lasts from about day 15 to day 28. After the follicle ruptures as it releases the egg, it closes and forms a corpus luteum.

Back 20

Front 21

As early as the 11th or 12th day, miniature villi that resemble probing fingers, reach out from the single layer of cells into the uterine endometrium to begin formation of the placenta. At term, almost 200 such villi will have formed

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chorionic villi

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Fetal side of the placenta,
where the gases will exchange b/w the mother and the fetus?

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-Chorionic villi

Front 23

sprout from the chorion in order to give a maximum area of contact with the maternal blood.

Embryonic blood is carried to the villi by the branches of the umbilical arteries, and after circulating through the capillaries of the villi, is returned to the embryo by the umbilical veins.

Thus, the villi are part of the border between maternal and fetal blood during pregnancy

Back 23

Front 24

What is the purpose of HCG?

Back 24

act as a fail-safe measure to ensure that the corpus luteum of the ovary continues to produce progesterone and estrogen. This is important b/c, if the corpus luteum should fail and the level of progesterone fall, the endometrial lining will slough and the pregnancy will be lost.

Front 25

What is the purpose of the Chorionic Membrane?

Back 25

purpose is to form the sac that contains the amniotic fluid
-outermost fetal membrane

Front 26

A second membrane lining the chorionic membrane, ______ _____, or Amnion, forms beneath the chorion.

Back 26

Amniotic membrane

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"hormone of mothers"

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-Progesterone: necessary to maintain the endometrial lining of the uterus during pregnancy, as a result of the continuation of the Corpus Luteum.

Front 28

"Hormone of Women"

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estrogen:contributes to the mammary gland development in prep. for lactation and stimulates uterine growth to accommodate the developing fetus

Front 29

At what week does oxygen and other nutrients, such as glucose, amino acids, fatty acids, minerals, vitamins, and water, osmose from the maternal blood through the cell layers of the chorionic villi into the villi capillaries

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by the 3rd week

Front 30

What is able to cross into fetal circulation from the mother?

Back 30

it is important that a woman take no nonessential drugs (including alcohol and nicotine)

Front 31

What is a potential complication of twins?

Back 31

nutrients vessels may fuse in utero, causing one twin to receive more blood than the other (twin-to-twin transfusion)

Front 32

Fertilizied egg has implanted outside the uterus?

Back 32

Ectopic pregnancy

Front 33

When is Uterine perfusion, and thus placental circulation most efficient?

Back 33

when the woman lies on her left side. This position lifts the uterus away from the inferior vena cava, preventing blood from being trapped in the woman's lower extremities

Front 34

What happens to the placental circulation if the woman lies on her back and the weight of the uterus compresses the vena cava?

Back 34

placental circulation can be so sharply reduced that supine hypotension (very low maternal blood pressure and poor uterine circulation) occurs

Front 35

what is the weight of the placenta at term?

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400 to 600 g (1 lb)

Front 36

Placenta weighs less than normal (400 to 600 g), what does this suggest?

Back 36

suggests that circulation to the fetus may have been inadequate

Front 37

Placenta weighs > 400 to 600 g, what does this indicate about the circulation?

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circulation to the fetus was threatened

Front 38

The fetus of a woman with diabetes may also develop a larger-than-usual placenta, Why?

Back 38

b/c of excess fluid collected between cells.

Front 39

first placental hormone produced,can be found in maternal blood and urine as early as the first missed menstrual period (shortly after implantation has occurred

Back 39

hCG

Front 40

Test used as proof that placental tissue is no longer present after birth

Back 40

hCG test

Front 41

purpose of hCG?

Back 41

act as a fail-safe measure to ensure that the corpus luteum of the ovary continues to produce progesterone and estrogen

Front 42

Corpus Luteum:

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(yellow body) it's going to die, unless you are pregnant and then it will continue to grow & secrete hormones, hCG and progesterone to maintain pregnancy

Front 43

How can you tell if the mother has lost the baby without doing an ultrasound?

Back 43

-progesterone levels and hCG levels will be low

Front 44

What is the 2nd hormone produced that contributes to the woman's mammary gland development in preparation for lactation and stimulates uterine growth to accommodate the developing fetus?

Back 44

Estrogen

Front 45

What hormone reduces the contractility of the uterus during pregnancy, preventing premature labor?

Back 45

Progesterone

Front 46

Human Placental Lactogen (growth-promoting and lactogenic (milk-producing) properties:

Back 46

promotes mammary gland (breast) growth in preparation for lactation in the mother

Front 47

Place where gases & blood will exchange b/w the mother & embryo?

Back 47

Chorionic Villi- Fetal side of placenta
-embedded in the endometrium

Front 48

outermost fetal membrane. Its purpose is to form the sac that contains the amniotic fluid

Back 48

Chorionic membrane
-no nerve supply

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second membrane lining the chorionic membrane

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amniotic membrane or amnion, forms beneath the chorion
-no nerve supply

Front 50

constantly being newly formed and reabsorbed
- never becomes stagnant
-aid in fetal growth: muscular development b/c it allows the fetus to move)
-maintains temp

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Amniotic fluid
-shock absorber-pressure
-umbilical cord compression preventor

Front 51

most important purpose of amniotic fluid?

Back 51

shield the fetus against pressure or a blow to the mother's abdomen

Front 52

excessive amniotic fluid, (more than 2000 mL in total, or pockets of fluid larger than 8 cm on ultrasound?

Back 52

hydramnios
-fetus is unable to swallow the amniotic fluid
-occur in women with diabetes

Front 53

A disturbance of kidney function may cause _______, or a reduction in the amount of amniotic fluid (less than 300 mL in total, or no pocket on ultrasound larger than 1 cm)

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oligohydramnios

Front 54

pH of Amniotic fluid?

Back 54

7.2
urine pH : 5.0-5.5

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umbilical cord

Back 55

provides a circulatory pathway that connects the embryo to the chorionic villi of the placenta

Front 56

gives the cord body and prevents pressure on the vein and arteries that pass through it.

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Wharton's Jelly: if there is a compression of the blood vessels then you will cutoff the blood, nutrients and O2

Front 57

An umbilical cord contains:

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only one vein (carrying blood from the placental villi to the fetus) but two arteries (carrying blood from the fetus back to the placental villi

Front 58

The number of veins and arteries in the cord is always assessed and recorded at birth, why?

Back 58

1% to 5% of infants are born with a cord that contains only a single vein and artery
-From 15% to 20% of these infants are found to have accompanying chromosomal disorders or congenital anomalies, particularly of the kidney and heart

Front 59

percutaneous umbilical blood sampling [PUBS]

Back 59

Blood can be withdrawn from the umbilical vein or transfused into the vein during intrauterine life for fetal assessment or treatment

Front 60

can be determined by ultrasound examination during pregnancy?

Back 60

adequacy of blood flow (blood velocity) through the cord
-both systolic and diastolic cord pressure,

Front 61

nuchal cord?

Back 61

loose loop of cord is found around the fetal neck at birth

Front 62

contributes to hemostasis and helps prevent hemorrhage of the newborn through the cord.

Back 62

-constriction of the smooth muscle
(walls of the umbilical cord arteries are lined with smooth muscle)

Front 63

Name Germ Layer: Central nervous system (brain and spinal cord)
Peripheral nervous system Skin, hair, and nails
Sebaceous glands
Sense organs

Back 63

Ectoderm

Front 64

Mesoderm

Back 64

Supporting structures of the body (connective tissue, bones, cartilage, muscle, ligaments, and tendons)
-Dentin of teeth
- Upper portion of the urinary system (kidneys and ureters)
-Reproductive system
-Heart, Circulatory system
-Blood cells
-Lymph vessels

Front 65

Lining of pericardial, pleura, and peritoneal cavities
-Lining of the gastrointestinal tract, respiratory tract, tonsils, parathyroid, thyroid, thymus glands
- Lower urinary system (bladder and urethra)

Back 65

Entoderm

Front 66

Why is it important to know which structure arise from each germ layer?

Back 66

b/c co existing congenital defects found in newborns arise from the same layer
-will arise to the development of organs and systems

Front 67

What virus is capable of infecting all three germ layers, or causing congenital anomalies in a myriad of body systems.

Back 67

Rubella

Front 68

one of the first systems to become functional in intrauterine life

Back 68

cardiovascular system

Front 69

heartbeat may be heard with a Doppler instrument as early as?

Back 69

10th to 12th week of pregnancy

Front 70

The heart rate of a fetus is affected by?

Back 70

oxygen level, activity, and circulating blood volume, just as in adult life

Front 71

During what time is the growing structure most vulnerable to invasion by teratogens?

Back 71

time of organogenesis: organ formation
(at 8 weeks' gestation (the end of the embryonic period)

Front 72

When does fetal blood begin to exchange nutrients with the maternal circulation across the chorionic villi?

Back 72

As early as the third week of intrauterine life

Front 73

Why does fetal circulation differs from extrauterine circulation ?

Back 73

b/c the fetus derives O2 and excretes CO2 not from gas exchange in the lung but from gas exchange in the placenta.

Front 74

Blood arriving at the fetus from the placenta is highly oxygenated. This blood enters the fetus through the ?

Back 74

umbilical vein (called a vein even though it carries oxygenated blood, because the direction of the blood is toward the fetal heart).

Front 75

Blood flows from the umbilical vein to the _____ ______, an accessory vessel that directs oxygenated blood directly to the fetal liver.

Back 75

ductus venosus

Front 76

opening in the atrial septum?

Back 76

Foramen ovale (connects the RA & LA)

Front 77

Ductus Arteriosus:

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connects pulmonary artery & the aorta

Front 78

Name The 3 Fetal shunts (will redirect the flow of blood)?

Back 78

a. ductus venosus
b. foramen ovale
c. ductus arteriosus

Front 79

What is the fetal heart rate during pregnancy?

Back 79

120-160 beats per minute

Front 80

The rapid fetal heart rate during pregnancy is necessary
why?

Back 80

necessary to supply oxygen to cells, because the red blood cells are never fully saturated

Front 81

1.newborn's hgb level?
2.newborn's hct level?

Back 81

1. 17.1 g/100 mL
2. 53%

Front 82

The bulk of fetal hgb has matured to adult hgb composition, at what age?

Back 82

6 mths ( when clinical sx of sickle cell anemia are apparent

Front 83

produces Amniotic fluid?

Back 83

Amniotic membrane

Front 84

produces Amniotic fluid?

Back 84

Amniotic membrane

Front 85

What shunt connects the pulmonary artery and the aorta?

Back 85

ductus arteriosus

Front 86

Why are there 3 shunts?

Back 86

1. lungs of baby are Not functioning inside the womb
2. blood has to circulate through the baby from head to toe

Front 87

B/c there is no need for the bulk of blood to pass through the lungs, it is shunted, as it enters the RA, into the LA through an opening in the atrial septum, called the ?.

Back 87

foramen ovale

Front 88

blood flow from the descending aorta is transported by the ______ _____ (called arteries, even though they are now transporting deoxygenated blood, because they are carrying blood away from the fetal heart) back through the umbilical cord to the placental villi, where new oxygen exchange takes place.

Back 88

umbilical arteries

Front 89

How to calculate EDB?

Back 89

, count backward 3 calendar months from the 1st day of a woman's LMP and add 7 days.

Front 90

EDB

Back 90

a pregnancy ending 2 weeks before or 2 weeks after the calculated EDB is considered well within the normal limit (38-42 weeks)

Front 91

What is measured w/ a Nonstress Test?

Back 91

Response of fetal heart rate in relation to fetal movements

Front 92

What is the Normal findings w/ Nonstress Test?

Back 92

-Two or more accelerations of fetal heart rate of 15 beats/min lasting 15 sec or longer following fetal movements in a 20-min period

Front 93

What is the safety consideration w/ Nonstress test?

Back 93

Woman should not lie supine to prevent supine hypotension syndrome

Front 94

What is measured w/ Contraction Stress Test?

Back 94

Response of fetal heart rate in relation to uterine contractions produced by nipple stimulation

Front 95

Normal Finding w/ Contraction stress test?

Back 95

no late decelerations w/ contraction

Front 96

Safety consideration w/ contraction test?

Back 96

In addition to preventing supine hypotension syndrome, observe woman for 30 min afterward to see that contractions are quiet and preterm labor does not begin

Front 97

What are the risk for Amniocentesis?

Back 97

hemorrhage from penetration of the placenta, infection of the amniotic fluid, and puncture of the fetus. If it leads to irritation of the uterus, it can initiate premature labor

Front 98

Preparation for Amniocentesis

Back 98

-empty bladder
-sterile technique (aseptic)
-schedule b/w 14 to 16 week