Development & Birth Flashcards
Pregnancy begins with ___ and ends with ___
Begins with fertilization and ends with childbirth
How many weeks is gestation from fertilization
38 weeks
Prenatal period begins at ____ and continues until ____
Begins at conception and continues until birth
What combine their genetic information in fertilization
Nuclei of the egg and sperm
Fertilization to implantation takes how many days
10
Zygote = sperm + egg which have how many chromosomes
Full 46 chromosomes
After implantation has occurred what phase is beginning
Embryonic phase
Beginning of 3rd month is what phase
Fetal phase
What is the placenta
Flat, circular organ that consists of a spongy network of filled channels and capillary containing villi
The placenta consists of both
Maternal and embryonic tissue
Do the blood of the mother and the offspring mix?
No
What is the function of the placenta
Organ of nutrition respiration excretion for developing offspring
What carries blood back and forth from the embryo/fetus to the placenta
Umbilical cord
Blood bypasses what because they are nonfunctional
Fetal lungs
Once the lungs are functional the adaptations must close. The foramen ovale must close or it will result in
Congenital heart defects
Umbilical vein from placenta carries what kind of blood to the fetus
Oxygen rich blood
What shunts blood to inferior vena cava (high O2), bypassing the liver
Ductus venosus
Foramen ovale in atrial septum bypasses what
Right ventricle and pulmonary circuit
What does the ductus arteriosus connect
Connects pulmonary artery to descending aorta
Two umbilical arteries return blood to
Placenta for oxygenation
Two umbilical arteries return blood to
Placenta for oxygenation
Circulatory adaptations in order to bypass the nonfunctional lungs close after?
Birth of the baby
*failure to close results in congenital defects
What are the 5 placenta hormones
hCG (human chorionic gonadotropin)
Progesterone
Estrogen
Relaxin
Human placental lactogen (hPL)
hCG is produced by the blastocyst; it is
Diagnostic of pregnancy
What does progesterone do
Maintains pregnancy and helps prepare breasts for milk secretion
*inhibits myometrial contractions
What hormone promotes enlargement of the uterus and breasts
Estrogen
The hormone relaxin does what
Softens the cervix and relaxes the sacral joints and the pubic symphysis to widen birth canal for delivery
What hormone stimulates breasts to grow for lactation and regulates the levels of nutrients in the mothers blood to keep them available for the fetus
Human placental lactogen (hPL)
From fertilization to 8 weeks
Embryo
From 9th week to birth
Fetus
Entire gestation period is divided into how many trimesters
3
What is the time period of the first trimester
Week 1 to end of week 12
When is the first heartbeat?
Week 4
What form by end of first month
Limb buds
Human appearance at end of what month
Second month
During the first trimester the developing embryo is highly sensitive to
Harmful substances and poor maternal nutrition
Primitive nervous system is evident in week
3
What is the time frame of the second trimester
Weeks 13-27
The most rapid growth occurs when
Months 4-6
Fetal skin is protected by
Vernix caseosa
What can you determine in second trimester
Sex
During the second trimester the amniotic sac fills with amniotic fluid this surrounds the fetus for
Protection
*breaks before birth aka water breaking
Third trimester time frame is
Weeks 28 until birth
The mother undergoes physical and metabolic changes in order to
Accommodate the growing fetus
Induced by hormone production
What are the 4 physical/metabolic changes the mother undergoes to accommodate the fetus
-Heart pumps more blood to supply needs of the uterus and fetus
- lungs provide more oxygen by increasing the rate and depth of respiration
-kidneys excrete nitrogenous wastes from both the fetus and the mother
-digestive system supplies additional nutrients to maternal organs
An ultrasound is used to
Diagnose pregnancy
Judge fetal age
Determine location of placenta
Show excess amniotic fluid and fetal abnormalities
What stimulates contractions
Stretching of uterine muscles
Pressure on cervix stimulates release of
Oxytocin
*which stimulates uterine contractions
Childbirth is what kind of feedback loop
Positive feedback (intensifies a response)
Parturition is aka
Labor
How many stages of labor
4
What is stage 1 of labor characterized by
Onset of uterine contractions until dilation of cervix is complete
Stage 2 of labor begins when the cervix is
Fully dilated and ends with the birth of the baby
Stage 3 of labor begins and ends when
After the child is born and ends with the expulsion of the placenta
Stage 4 of labor begins after expulsion of the placenta and constitutes a
Period
Fraternal twins is fertilization of
2 different eggs by two different sperm cells
* 2 placentas (just like regular siblings)
Identical twins is
A single zygote
Usually single placenta
Always same sex with same traits
A term infant is between how many weeks
37 and 42 weeks
Preterm infant refers to
Arrival before 37 weeks or less that 5.5lbs
Abortion can be spontaneous (miscarriage) or induced and it is the loss of the embryo before week
20 or 1.1lbs
After week 20 the fetus is deemed viable meaning
It can live outside of the uterus
*if born before week 24 there is a 50% chance of survival
Fetal death is characterized by loss of fetus after
Week 20
Stillbirth means
Infant born lifeless
Lactation is not functional until
The end of pregnancy
What is pregnancy induced hypertension known as
Preeclampsia
*hypertension, protein in urine, general edema, sudden weight gain
Eclampsia may occur if
Pregnancy induced hypertension is untreated
Eclampsia may occur if
Pregnancy induced hypertension is untreated
Eclampsia leads to
Convulsions; lead to kidney failure and coma. Could result in death of mother and baby
Placenta previa is growth of placenta at or near the cervical opening. What can it interfere with
Can interfere with fetal oxygen supply
Abruptio placentae is what
Placenta separates from uterine wall prematurely around 20 weeks.
*most common with women who have had multiple pregnancies or are older than 35, may require terminating pregnancy to save mother
