Chapter 12 Flashcards
Uniting of sperm and ovum = ?
Zygote (fertilization)
Implantation occurs how many days after fertilization?
6 to 10 days
Where does a blastocyst burrow during implantation?
The endometrium
Where does fertilization takes place ?
In the ampulla of the fallopian tube
In regards to Implantation, _____________ is the outer layer ?
Trophoblast
What develops out of Trophoblasts ?
Chorionic Villi
After Implantation, the endometrium is now called what ?
decidua basalis
By day ___ the placenta is in place ?
17
Pregnancy lasts for how long ?
- Lunar months: - Weeks: - Days:
Lunar months: 10
Weeks: 40 weeks
Days: 280
The Pre-embryonic or Ovum stage Takes place from day ___ to ___ ?
1 to 14
All tissue and organs develop from what ?
Germ layers
What stage of Embryonic and Fetal development period covers,
- cellular replication
- blastocyst formation
- initial development of embryonic membranes
- establishment of primary germ layers ?
Pre-embryonic or Ovum stage: days 1-14
What are the 3 primary germ layers ?
- Ectoderm
- Mesoderm
- Endoderm
Which primary germ layer is the “outter layer” ?
Ectoderm
The Ectoderm may give rise to what types of things ?
- Nails
- Tissues
- Some external organs
The Mesoderm gives rise to what types of things ?
- Skeleton
- Teeth
The Endoderm gives rise to what types of things ?
Gives rise to innermost systems
- Respiratory system
- Urinary system
- etc,.
Development of the embryo is the most critical time for what ?
organ system development
What is the purpose of the amnion and amniotic cavity ?
Surrounds the growing fetus
What covers the fetal side of the placenta ?
Chorion
Amniotic fluid is typically what color ?
clear
True or False: The amniotic fluid typically has no smell to it ?
True
What is a main function of the Amniotic fluid ?
Maintains constant body temperature !
What are additional function of the Amniotic fluid ?
- Cushion for the baby (to keep baby safe)
- Allows the baby to move around freely
- Antibacterial properties (to keep baby safe)
Amniotic fluid = ?
Fetal urine (sterile)
What is the function of the Yolk sac ?
Transfers oxygen and nutrients to the fetus
The Yolk sac eventually becomes part of what ?
The digestive tract
The umbilical cord contains 3 vessels.
- How many are veins: ?
- How many are arteries : ?
1 vein
2 arteries
What doe the vein in the umbilical cord do ?
returns blood to the embryo
What do the arteries in the umbilical cord do ?
Carry blood from the embryo to the chorionic villi
The umbilical cord is 2cm in diameter, and is ___ to ___ cm at birth ?
30 - 90cm
What structure is a complex system of blood vessels ?
Placenta
The placenta is in place by day 17 from what ?
The Chorionic Villi
The placenta functions as what ?
system of metabolic exchange
What is the Hormone of pregnancy ?
Progesterone !!
Placental functions depend on what ?
Maternal blood pressure
What type of drug acts as a vasoconstrictor ?
Cocaine
What are functions of the placenta ?
- Vasoconstriction
- Early-function endocrine gland
- Metabolic exchange of oxygen and CO2
- Storage for fetal needs (carbs, Ca, Iron, & protein stores)
- Waste products from fetus cross the placental membrane from fetal-maternal
The Embryonic stage takes place between what time frame ?
15th day - 8th week
During what stage of development is the embryo vulnerable to teratogens ?
Embryonic stage : 15th day - 8th week
The Fetal stage takes place when ?
9th week to delivery
___________ development continues long after the embryonic period ?
Neurological
During what stage of development can Stressors on the system possibly still cause damage to the Neurological system ?
Fetal stage : 9th week to delivery
When are all systems formed ?
At the end of the 8th week
When the fetus has reached fetal maturation, it is less vulnerable to teratogens, except for those affecting what ?
The CNS
What is the 1st system to develop ?
Cardiovascular
Tubular heart beats can be heard when ?
4-5 weeks
In regards to the Cardiovascular system, Fetus’s have a special circulatory pathway which does what ?
Bypasses the Lungs
What does the Foreamen Ovale do ?
Connects the Right and Left atria, so blood doesn’t go to the lungs
What does the Ductus arterioles do ?
Fetal artery connecting the Aorta (main body artery) and the Pulmonary artery (main lung artery) .
- Allows the blood to detour away from the lungs before birth
What is Surfactant ?
A hormone that allows expansion of the lungs to occur..
- Makes breathing easier
When is there some surfactant present (weeks) ?
At 32 weeks
The book states that ___ weeks is key for survival outside of the body ?
35 weeks
True or False: There is no gas exchange in the lungs of the fetus ?
True
What is the ratio of the Respiratory surfactants ?
2:1
What does the umbilical vein do ?
Carries oxygen rich blood back to the fetus
Placental blood flow is enhanced when ?
When women are lying on their left side !
- Because the Vena cava is not compromised
The Ductus Venous is the 1st port where ?
In the fetal abdomen
The Ductus Venous connects to where ?
The inferior vena cava
Rhythmic breathing patterns take place during what week of fetal development ?
Week 32
The Ability to Partially control temperature takes place during what week of fetal development ?
Week 32
During which week of fetal development are bones fully developed, but soft and flexible ?
Week 32
What are the two types of Respiratory surfactant ?
- Lecithin
- Sphingomyelin
After 32 weeks, __________ is present in the Alveoli to provide for a good chance of survival ?
Surfactant
What is the Surfactant ratio of Lecithin & Sphingomyelin ? L:S = ?
L:S = 2:1
How many pairs of chromosomes are there ?
23
23 pairs of chromosomes total
- # of autosomes: ___
- # of sex chromosomes: ___
Autosomes = 22 pairs
Sex chromosomes = 1 pair
Total = 23 pairs of chromosomes
Multifactorial inheritance includes both… ?
- Genetic & Environmental factors
Gestation occurs how many days after the LMP ?
280 days
Gestation occurs for how many days after conception ?
266 days (280 days? 40 weeks? is full term?)
