OB Exam2 Flashcards
What is responsible for passing on genetic traits?
chromosomes
What is the number of chromosomes in a mature sperm or egg cell?
23
When is a recessive gene expressed?
When it is received from both parents
What type of chromosome does an ovum contribute, and what type of chromosome does a sperm contribute?
Ovum- X
Sperm X or Y
What does a dominant gene do?
Expresses itself
What is the most important function of the amniotic fluid?
To protect the fetus
What is the function of the anion and chorion?
Together they form the amniotic sac
Which of the four layers of the cell is thick with villi on the outer surface?
chorion
What is the second layer of the cell
anion
What is the third layer of the cell
yolk sac
What is the function of the yolk sac?
only needed during embryonic life, initiates the production of the RBCs
What are the three stages of prenatal development?
1, zygote
2, embryo week 2 to 8
3, fetus- week 9 to birth
What is the age of viability?
week 20
what is considered full term?
week 38-40
The fetal side of the placenta looks like?
gray and shiny
What does the maternal side of the placenta look like?
bloody red and flesh like
True or False: the placenta allows most medications to pass to the fetus?
True
What are the four hormones produced by the placenta?
Progesterone, estrogen, HCG (human chorionic gonadotropin, and hPL (human placental lactogen)
What is the function of progesterone?
maintains uterine lining for implantation
reduces uterine contractions
prepares glands of the breast for lactation
stimulates testes to produce testosterone, which aid the mail fetus in developing their reproductive tract
What is the function of estrogen?
stimulates uterine growth
increases the blood flow to the uterine vessels
stimulates development of the breast ducts to prepare for lactation
What is the function of hCG?
hCG signals the corpus luteum to continue and produce estrogen and progesterone to sustain pregnancy,
When is hCG detectable in maternal blood?
7 to 9 days after fertilization
What is the function of hPL
causes decreased insulin sensitivity and utilization of glucose by the mother, this makes more glucose available to the fetus.
What is located between the fetus and the placenta?
The umbilical cord
What separates the three vessels (AVA ) and cushions the cord?
Whartons jelly
What are the three shunts of fetal circulation?
ductus venosus
foramen ovale
ductus arteriosus
What does the ductus venosus divert?
diverts some blood away from the liver as it returns from the placenta
What does the foramen ovale divert?
diverts most blood from the right atrium directly to the left atrium, rather than circulating it to the lungs
What does the ductus arteriosus divert?
diverts most of the blood from the pulmonary artery to the aorta.
define dizygotic and monozygotic?
dizygotic - fraternal twins, develops from two eggs
monozygotic- identical twins, develops from one egg
How many placentas do dizygotic twins and monozygotic twins have
dizygotic - two
monozygotic- one
What is the purpose of chorionic villus sampling
helps to identify chromosome abnormalities or other defects. obtain a small part of the developing placenta to analyze fetal cells at 10-12 weeks gestation
What conditions might AFP (alpha fetoprotein) testing discover?
identifies high levels of AFP which are associated with defects such as spina bifida, anencephaly, or gastroschisis.
What does folic acid help to prevent?
Neural tube defects
What are the two types of spina bifida?
occulta (hidden)
cystica (sac or cyst)
What is the most serious type of spina bifida cystica?
meningomyelocele
what may be used to feed an infant after cleft lip surgery?
a dropper until the wound is healed.
children with a cleft palate are prone to what two medical conditions later in their development?
hearing loss, and speech difficulties
What may an infant with hip dysplasia present with?
one leg shorter than the other if the head of the femur is completely displaced
What is one treatment used for infants with hip dysplasia between 1-6 months old?
The pavlik harness
What is tetrology of fallot?
a congenital heart defect with four defects
What are the s/s of tetrology of fallot ?
excessive c
rying
heart murmurs
cyanosis around the mouth and lips
What is PKU
Phenylketonuria, a genetic disorder caused by faulty metabolism of phenylalanine.
If PKU is not addressed what could it result in?
severe retardation
What is the test for PKU and when is it done
guthrie blood test- a heel stick done at about 48-72 hours after birth,
What is the treatment for PKU
low phenylanine diet
What is TaySachs
fatal inherited disease of the central nervous system found in jewish populations, death usually happens before the child turns 5
How can sickle cell anemia be detected?
Before birth with chorionic villi sample
What is a screening test for sickle cell?
sickledex
What is Thalassemia
group of hereditary blood disorders in which a pts body cannot produce enough hemoglobin
How is Thalassemia treated?
diet high in iron
what are the s/s of thalassemia?
enlarged spleen, fever and distended abdomen
What is downs syndrome?
chromosomal abnormality
What are the three types of downs syndrome
Trisomy 21
mosaicism
translocation of a chromosome
