Test 1 Flashcards
Fertilization, or the union of the sperm cell and the mature ovum, occurs in the ________.
Outer third of the fallopian tube
From the time of conception, the fetus begins a ______-week progress of growth and development that leads to a fully developed baby.
40-week
In the first month alone, the fetus grows in weight by nearly -_____%.
3000 percent
What is the most common time reference of human pregnancy in the clinical setting?
40 weeks
What does gestational age refer to?
The time since conception
The duration of human pregnancy is referred as ____.
- 10 lunar months of 4 weeks each
- 9 calendar months, 3 trimesters of 3 months each
- 40 weeks
Development and growth are divided into how many distinct stages?
Three
The first stage of development and growth is the period from ______________ to ____________.
From conception to the completion of implantation or about 12-14 days.
During the first stage of development and growth, the developing organism is called an _________.
Ovum
During the 40 weeks of gestational development, the ____________ acts as the organ of respiration for the fetus.
Placenta
The cells that are produced during this rapid cleavage are called ________.
Blastomeres and are surrounded by a transparent tissue, the zona pellucida.
Which stage of development and growth does this describe?
Soon after the ovum enters the uterus, the cells grow substantially in number and form a ball called a morula. It is at this stage of growth that the ovum, consisting of 16-50 cells enters the uterus.
First stage
During the second stage of development and growth, what is the organism called?
An embryo
Describe a neonate.
Used from delivery to the first month of life.
Describe an infant.
1 month to 1 year of life.
Describe a child.
Identifies the patient above 1 year of age.
Structures arising from the three germ layers.
Endoderm
- Respiratory tract
- Epithelium of the digestive tract, bladder, thyroid
- Primary tissue of the liver and pancreas
Structures arising from the three germ layers.
Mesoderm
- Dermis
- Muscles
- Bone, connective tissue, lymphoid tissue
- Reproductive organs
- Cardiovascular system
Structures arising from the three germ layers.
Ectoderm
- Epidermis
- Hair, nails
- Lens of the eye
- Central and peripheral nervous system
- Skin glands
The intrauterine structures include the _____________.
- Placenta
- Umbilical cord
- Amnion
- Amniotic fluid
It is through the ___________ that the growing fetus receives nutrients and oxygen and rids itself of CO2 and other wastes.
Placenta
During the third stage of growth and development, the organism is called a ______.
Fetus, which is what it will remain until the end of pregnancy.
During which stage of growth and development can exposure to drugs, infections or radiation lead to severe congenital malformations?
Second stage
What is the first stage of fetal lung development called?
Embryonal stage
Which stage of fetal lung development covers the first eight weeks of gestation?
Embryonal stage
Scant or decreased amount of amniotic fluid is known as _____.
Oligohydramnios
The amount of amniotic fluid is greatest at about 34 weeks and averages about _____.
800 mL. The amount slowly diminishes to reach 600 mL at full term.
A term fetus swallows around ________ per day and excretes about ____________ of hypotonic urine per day.
A term fetus swallows around 500 mL per day and excretes about 500 mL of hypotonic urine per day.
Abnormally large amounts of fluid, usually over 2000 mL indicate ___________.
Hydramnios or polyhydramnios, which occurs in about 1% of pregnancies.
What is the major complication for the fetus with polyhydramnios?
The risk of premature rupture of the amniotic membranes. This condition leads to a possible prolapse of the umbilical cord and premature delivery.
The _________ is the lifeline between the mother and fetus.
Umbilical cord
What is the sac that surrounds the growing fetus and contains the amniotic fluid called?
Amnion
_____________ insulates and protects the umbilical vessels.
Wharton’s Jelly
Because of constant movement of the fetus in the utero, it is possible that the umbilical cord could bend and pinch off, stopping the flow of blood to the infant. What prevents this from occurring?
Wharton’s Jelly
What are the functions of amniotic fluid? (3)
- Protection from traumatic injury
- Thermoregulation
- Facilitation of fetal movement
The pseudogranular stage covers which weeks?
7 to 16 weeks
________________ is the substance found on the alveolar wall that lowers surface tension.
Surfactant
Describe Laplace’s law as it applies to the alveoli.
As the radius of the alveoli decreases, the surface tension increases.
The first appearance of pulmonary surfactant coincides with the development of ________.
Type II pneumocytes
The first surfactant to be produced lacks PG, and is termed immature surfactant. This is seen at approximately _____________________.
24 weeks gestation.
In this text, gestation refers to what?
To the time since conception
__________, otherwise known as stretch receptors, stimulate bradycardia and hypotension.
Baroreceptors
________________ are sensitive to PaO2, PaCO2 and pH and play a role in regulation of ventilation.
Chemoreceptors
What is the first major organ to be developed?
Heart
Baroreceptors have the ability to detect change in pressure and are located where?
In the bifurcation of the carotid arteries and in the aortic arch.
The amount of amniotic fluid present at birth is dictated by what?
How much the fetus swallows and urinates.
The earliest development of the lung begins at ______________ following conception.
24 days
Describe the canalicular stage.
- Covers week 17 through 26
- Respiratory and terminal bronchioles continue multiplying
- Lungs become vascularized
- Alveoli begins to develop
True or False.
There is no contact between the blood supply of the mother and fetus.
True
The fetal blood has high levels of _______, but is low in ______.
The fetal blood has high levels of CO2 and waste materials, but is low in oxygen and nutrients.
The maternal blood has high levels of _______, but is low in ______.
The maternal blood has high levels of oxygen and nutrients, but is low in CO2 and waste materials.
A cross section of the umbilical cord reveals three vessels surrounded by a tough, gelatinous material called _____.
Wharton’s Jelly
Following delivery, ubrupt temperature changes cause Wharton’s Jelly to collapse the umbilical vessels within about _____.
5 minutes
The umbilical cord consists of how many veins and arteries?
2 smaller arteries and one large floppy vein.
Amniotic fluid is dynamic which means?
It is constantly being absorbed and replenished.
Polyhydramnios may indicate what?
A problem with the swallowing mechanism of the fetus.
What are possible anomalies that may cause hydramnios?
- CNS malformations
- Orogastric malformations
- Disorders such as Down syndrome, congenital heart disease, infant of diabetic mothers and prematurity.
What is a cause associated with oligohydramnios?
Defect in the urinary system of the fetus.
Implications for the fetus with oligohydramnios include ___.
Risk of asphyxia secondary to compression of the umbilical cord and the danger of significant skeletal deformities from intrauterine growth restriction.
During labor and deliver, the presence of _______________ helps dilate and efface the cervix.
Amniotic fluid
Embryonal Stage
It is during this stage that the diaphragm begins its development and is fully formed by the end of ____ weeks.
7
What is the second stage of fetal lung development?
Pseudogranular
What are the 5 stages of fetal lung development?
- Embryonal
- Pseudograndular
- Canalicular
- Saccular
- Alveolar
Describe the saccular stage.
- Covers week 26 to 34-36 weeks
- By week 24-26, lungs are completely formed
- Terminal airways do not contain true alveoli
- Saccules exist awaiting the development of alveoli
It is during the which period that mature pulmonary surfactant is produced in increasing amounts by the Type II alveolar cells?
Alveolar stage
At which stage of fetal growth and development does the lungs appear as a small pouch, arising from the laryngotracheal groove in the developing pharynx?
Embryonal stage
During which lung development stage does the fetal lung undergo a tremendous amount of vascularization?
Canalicular stage
Canalicular stage: In these primitive alveoli, the epithelial tissue, which is now capable of producing fetal lung fluid, is able to differentiate into its two separate types.
Type I forms the ___.
Alveolar-capillary membrane
Canalicular stage: In these primitive alveoli, the epithelial tissue, which is now capable of producing fetal lung fluid, is able to differentiate into its two separate types.
Type II produces the ___.
Pulmonary surfactant
Canalicular Stage
Capillaries are present in proximity to the alveolar cavity during week 20 to 21, but its not until week ________ that they are close enough to allow for adequate gas exchange.
24 to 25
A basic understanding of surface tension stems from the knowledge that similar molecules _________.
Attract each other from all directions.
As the alveoli became smaller, the surfactant thickens on the alveolar surface, weakening surface tension and preventing what?
The alveoli from collapsing.
The first appearance of pulmonary surfactant coincides with the development of ________.
Type II pneumocytes.
Conditions that delay surfactant production.
- Acidosis
- Hypoxia
- Shock
- Overinflation
- Underinflation
- Pulmonary edema
- Mechanical Ventilation
- Hypercapnia
- Infants of diabetic mothers class A B C
- The smaller of twins
- Erythroblastosis fetalis
Conditions that accelerate surfactant production.
- Maternal hypertension
- Maternal infection
- Placental insufficiency
- Abruptio placentae
- Maternal administration of betamethasone or thyroid hormone
- Infants of mothers with gestational diabetes
- Maternal heroin addiction
- Premature rupture of membranes
From the time the immature surfactant first appears, it can be measured in a sample of _______.
Amniotic fluid
The fetal lungs are considered mature when the L/S ratio reaches ____.
2:1
The combination of the L/S ratio and testing for PG is called the ____.
Lung profile
Explain the shake or foam test. (Test for lung maturity)
Procedure is done by mixing amniotic fluid with ethanol which is shaken for 15 seconds.
If there is a ring of bubbles in the ethanol after 15 minutes, it shows there is enough lecithin present to create a stable foam.
SHAKE OR FOAM TEST
If the foam is not present following the 15-min period, what should happen next?
L/S ratio
Studies show that the administration of _________ to women in premature labor increases the rate of lung maturity and decreases the incidence of RDS.
Glucocorticoids
What are the limitations of administering glucocorticoids to the mother to increase lung maturity?
Give it when the fetus is between 27-34 weeks gestation. It needs to be given 48 hours before delivery, and delivery is recommended within 7 days of administration.
What are other factors influencing lung maturation?
- Thyroxine
- Thyrotropin-releasing hormone
- B-adrenergic drugs
- Estrogen
- Prolactin
- Epidermal growth factor
True or False.
The fetal produces and secretes its own fluid.
True
How does fetal lung fluid differ from amniotic fluid?
- Lower pH, protein and bicarb
- Higher sodium and chloride
If a fetus is delivered vaginally, one third of the fluid is removed by the squeezing of the thorax as the fetus descends through the maternal pelvis. What happens to most of the remaining lung fluid?
It is rapidly absorbed by the pulmonary lymphatic system.
Neonates who fail to remove lung fluid adequately are prone to _____________.
- Transient tachypnea of newborn
- RDS Type II
It is not uncommon for neonates delivered by cesarean section to retain a larger amount of fluid. Why?
Lack of squeezing action on the the thorax as occurs with vaginal delivery.
The truncus arteriosus will develop into the ______.
Pulmonary artery and aorta.
During fetal circulation, systemic blood pressure is much lower than blood pressure in adult circulation. Why?
Presence of the placenta as part of the circulatory process. Roughly 50% of fetal blood resides in the vasculature surface of the placenta.
Upon clamping the umbilical cord, the low-pressure placenta is removed from the circulation process. This causes what?
Systemic BP to rise and a drop in right heart pressures. This change from fetal to adult circulation is called transition.
Closure of the ductus arteriosus occurs slowly over the next ______ with 20% closure in the first 24 hrs.
80% closure within 48 hrs.
100% closure by 96 hrs.
96 hours
What is the third and most familiar shunt?
Ductus arteriosus, located where the pulmonary artery branches into the lung.
An opening between the right and left atrium.
Foramen ovale
Soon after the blood enters the abdominal cavity, the first shunt is encountered. What is it called?
Ductus venosus
___________ are located in the carotid arteries and aorta and are called aortic and carotid bodies.
Chemoreceptors
Where are baroreceptors located?
The bifurcation of the carotid arteries and in the aortic arch.
Which of the following may occur following C-Section?
TTN
Which receptor aids in the initiation of the first breath?
Chemoreceptors
The modern ultrasound machine used ____________ to locate and visualize organs and tissues.
High-frequency sound waves
As the sound waves come in contact with different-density tissues, some are absorbed and others are ___________.
Reflected to the transducer. The reflected waves are converted into a screen image, visually duplicating the targeted organ.
Uses of Sonography (12)
- Identification of pregnancy
- Identification of multiple fetuses
- Determination of appropriate fetal age, growth and maturity
- Detection of fetal anomalies
- Determination of placenta previa
- Identification of placental abnormalities
- Observance of polyhydramnios and oligohydramnios
- Determination of fetal position
- Determination of fetal death
- Location of the placenta and fetus for amniocentesis
- Examination of FHR and respiratory effort
- Detection of incomplete miscarriages and ectopic pregnancies
What is the first sensation of fetal movement called?
Quickening
Quickening generally occur between _____ weeks.
16-22 weeks
Gravida means ______.
number of pregnancies
Primigravida means _______.
1st preganancy
Multigravida means ______.
Multiple preganancies
Nulligravida means ____.
Never been pregnant
Parity or para means ______.
of previous live births.
Variability
Healthy, fetus has a constantly changing HR, usually between ______.
5-10 bpm
How is fundal height measured?
A tape is measure is placed on the abdomen and the distance from the symphysis pubis to the top of the fundus is measured.
The process of giving birth is called _______.
Parturition
What are the 5 stages of the birth process?
- Rupture of the membranes
- Dilation of the cervix
- Contraction of the uterus
- Separation of the placenta
- Shrinking of the uterus
Define placenta previa.
The placenta completely or partially covers the opening the cervix (uterus).
What are some problems associated with umbilical cords?
- Prolapsed cord
- Kinked cord
- True knot
- Neucal or tight neucal cord
What is dystocia?
Prolonged difficult labor and delivery.
What is dystocia caused by?
A large or awkwardly positioned fetus or by smallness of the maternal pelvis.
__________ always includes the current pregnancy!
Gravida
Determination of the heart beat is usually heard between week _____.
16 and 22
Presence of meconium is determined by ____.
Amniocentesis or visualized when the amniotic sac is ruptured.
Presence of meconium may lead to ____.
MAS - Meconium aspiration
Presence of meconium may result from a ________.
Fetal asphyxia episode
Explain Nagele’s rule.
3 months are subtracted from the first day of the last menstrual period, then add 7 days.
If fetal blood is impaired, it can be detected through _____.
Drop in pH
Fetal scalp pH is a secondary tool used to monitor ____.
Fetal well-being
Define decelerations.
FHR drop below 120 for less than 2 minutes.
Define accelerations.
FHR exceeds 160 bpm for less than 2 minutes.
Define tachycardia.
Baseline HR is consistently above 180 bpm.
What is the most common cause of tachycardia?
Maternal fever or infection
What is the most dangerous cause of bradycardia?
Asphyxia
Define bradycardia.
FHR less than 100 bpm
How would you help a fetus that is experiencing bradycardia caused by asphyxia?
Oxygen administration to the mother to decrease severity.
What is the average HR for term babies?
160 bpm
What is the average HR for preemies?
140 bpm
What is a tocodynamometer used for?
Monitoring uterine contractions
Tocodynamometer is strapped to mother abdomen’s at the level of the _____.
Uterine fundus
What are ways to measure FHR?
- Measured by auscultation
- External abdominal transducer
- Fetal scalp electrode is most common
(Electrodes placed on the abdomen to pick up electrical activity of the maternal and the FHR)
Rh Immunization
Mothers who are Rh-_________ should have RhoGAM shot during their pregnancy.
Negative
Only ___% of the world’s population is Rh-negative.
15
RhoGAM is the injection used to prevent ____________.
Rh incompatibility from developing during pregnancy.
What is the gold standard for determining feta development?
Amniocentesis
AFP is used to check what?
Baby’s risk of birth defects and genetic disorders, such as Down syndrome.
Fetal blood pH is considered to be normal above ______.
7.25
The firs pattern is the baseline HR, determined by watching the rate tracing for at least ____.
10 minutes
Normal baseline HR will range between ____.
120-160 bpm
Doppler velocimetry is used to measure what?
Relative blood flow through the umbilical, placental and fetal vessels in the umbilical cord of term infants.
What is the main serum in the developing fetus?
AFP - Alpha-fetoprotein
A high level of AFP and acetylcholinestrase is an objective sign to some degree of _______.
neural tube defect
The in utero sampling of fetal umbilical cord blood.
Cordocentesis
The biophysical profile, uses information from five separate tests. Those test include:
- Fetal breathing
- Fetal movement
- Fetal limb tone
- NST
- Amniotic fluid
The BPP (biophysical profile) is typically done during which trimester?
Third
______________ is the most commonly performed and considered to be a primary examination (gold standard) or assessment for prenatal diagnosis.
Midtrimester amniocentesis
What are complications of amniocentesis?
- Fetal trauma
- Infection
- Intrauterine hemorrhage
AFP normally peaks near the ____ week of gestation and then gradually decreases.
12th
A low measurement of AFP has been useful in detecting the presence of ___.
Down syndrome in the fetus
The level of bilirubin in amniotic fluid is an aid in detecting _____.
Hemolytic diseases such as Rh incompatibility.
Increases in amniotic bilirubin levels are proportional to the degree of ______.
Hemolysis (blood loss)
What helps determine kidney maturity?
Creatinine levels
The cellular elements found in amniotic fluid include cells from the ________.
Skin, amnion and tracheobronchial tree
Fetal cardiac status is measured by?
Simple auscultation
Which way of monitoring contractions is mainly used during prolonged, difficult labors?
Intrauterine catheter
Ways to monitor uterine contractions:
- Tocodynamometer
- Intrauterine pressure catheter
Does para include miscarriages and abortions?
No.
What are the three hypotheses of what starts labor?
- Withdrawal of progesterone
- Estrogen causing uterine contraction
- Stimulation of the uterus factors such as oxytocin and prostaglandins
Stages of Labor & Delivery:
1st stage
- Begins with the first onset of the 1st true contraction
- 1st contractions are usually 10-15 minutes and last 30-90 seconds
Stretching or thinning of the cervix is called _________________.
Effacement
Widening of the cervix is called _________________.
Dilation
Adaptation of Extrauterine Life
- Conversion of circulation (clamping of the cord)
- Must begin with spontaneous ventilation and respiration (First breath)
Surgical incision through the maternal abdomen and uterus is called _______________________.
Cesarean section
Cesarean section should only be done in the presence of the indications:
- Prior cesarean section
- Dystocia
- Breech presentation
- Fetal distress
Roughly ____ end in premature labor.
12%
