NM702 **study exam 2** Questions with
Complete Solutions
Out of the million-ish sperm ejaculated, how many sperm are in the fallopian tube at any given
time? Correct Answ_300-500 sperm
What are the 3 layers of the decidua? Correct Answ_-Decidua Capsularis
-Decidua Basalis
-Decidua Parietalis
Decidua Capsularis Correct Answ_- covers the growing embryo
- is the top
- regresses as the chorion grows and disappears when the embryo fills the uterus
Decidua Basalis Correct Answ_- base of placenta (bottom)
- spongy, vascular bed that the blastocyst rests on, site of where the placenta forms
- will end up forming the maternal placenta
,Decidua Parietalis Correct Answ_- rest of the decidua --> meets and fuses with capularis as
embryo gets bigger
When does the blastocyst "hatch" out of the zona pellucida and what does it become? Correct
Answ_- around 5 days --> rapidly proliferating into throphectoderm
The blastocyst is completely implanted in the endometrium at how many days after fertilization?
Correct Answ_- 10-12 days after fertilization --> is completely implanted
- attaches to endometrium 5-6 days after fertilization
What are the two layers of the blastocyst? Correct Answ_-Synctiotrophoblast
-Cytotrophoblast
What is the Synctiotrophoblast? Correct Answ_- thick, multinuclear cell mass
- no distinct boundaries
- invades (sinks into/oozes into) maternal endometrium and eventually becomes placenta --> this
can cause implantation spotting
- produces hCG --> which maintains the corpus luteum
, What is the Cytotrophoblast? Correct Answ_- monocellular layer around the blastocyst
- forms new cells, chorionic villi, amnion, and generates new trophoblast cells
What are the lacunae? Correct Answ_-capillaries in endometrium
-fill with nutritious substance to feed embryo
-eventually turn into the intervillous spaces in the placenta that fill with maternal blood
Why do we want a hypoxic environment in the first trimester? Correct Answ_- To avoid
oxidative damage to the embryo and allow morphogenesis to occur (can cause early pregnancy
loss)
- Maternal spiral arteries are "plugged" until about 10-12 weeks to prevent to much oxygenated
blood from reaching embryo
What are the three types of chorionic villi? Correct Answ_-Stem Villi: have multiple vessels,
stabilize villous tree (trunk of the tree)
-Intermediate Villi: bigger branches
-Terminal Villi: smallest branches --> where most maternal and fetal oxygen/nutrient exchange
occurs
Complete Solutions
Out of the million-ish sperm ejaculated, how many sperm are in the fallopian tube at any given
time? Correct Answ_300-500 sperm
What are the 3 layers of the decidua? Correct Answ_-Decidua Capsularis
-Decidua Basalis
-Decidua Parietalis
Decidua Capsularis Correct Answ_- covers the growing embryo
- is the top
- regresses as the chorion grows and disappears when the embryo fills the uterus
Decidua Basalis Correct Answ_- base of placenta (bottom)
- spongy, vascular bed that the blastocyst rests on, site of where the placenta forms
- will end up forming the maternal placenta
,Decidua Parietalis Correct Answ_- rest of the decidua --> meets and fuses with capularis as
embryo gets bigger
When does the blastocyst "hatch" out of the zona pellucida and what does it become? Correct
Answ_- around 5 days --> rapidly proliferating into throphectoderm
The blastocyst is completely implanted in the endometrium at how many days after fertilization?
Correct Answ_- 10-12 days after fertilization --> is completely implanted
- attaches to endometrium 5-6 days after fertilization
What are the two layers of the blastocyst? Correct Answ_-Synctiotrophoblast
-Cytotrophoblast
What is the Synctiotrophoblast? Correct Answ_- thick, multinuclear cell mass
- no distinct boundaries
- invades (sinks into/oozes into) maternal endometrium and eventually becomes placenta --> this
can cause implantation spotting
- produces hCG --> which maintains the corpus luteum
, What is the Cytotrophoblast? Correct Answ_- monocellular layer around the blastocyst
- forms new cells, chorionic villi, amnion, and generates new trophoblast cells
What are the lacunae? Correct Answ_-capillaries in endometrium
-fill with nutritious substance to feed embryo
-eventually turn into the intervillous spaces in the placenta that fill with maternal blood
Why do we want a hypoxic environment in the first trimester? Correct Answ_- To avoid
oxidative damage to the embryo and allow morphogenesis to occur (can cause early pregnancy
loss)
- Maternal spiral arteries are "plugged" until about 10-12 weeks to prevent to much oxygenated
blood from reaching embryo
What are the three types of chorionic villi? Correct Answ_-Stem Villi: have multiple vessels,
stabilize villous tree (trunk of the tree)
-Intermediate Villi: bigger branches
-Terminal Villi: smallest branches --> where most maternal and fetal oxygen/nutrient exchange
occurs
