Genetics, Conception, & Fetal Development Flashcards
Gamete
Union of egg and sperm
Meiosis
Germ cell (reproductive cells) division yields cells with ½ genetic material (23 chromosomes).
Gametogenesis
Process of forming sex cells or gametes
Spermatogenesis
sperm production
Oogenesis
Egg formation
What increase fallopian tube motility to propel the oven to the uterus?
High estrogen levels
At ovulation the ovarian follicle releases a ______.
Mature ovum
Of are fertile for _____
24hrs
If no fertilization, what happens to the ovum?
It is reabsorbed
Ejacuation contains how many sperm?
200-500
They remain viable for how many hours?
49 to 72
What is capacitation
Enzymes that promote acrosome (protective covering) removal so sperm can penetrate the egg.
Where does fertilization take place?
in lower 1/3 of the fallopian tube.
When fertilization occurs the egg & sperm become _______ to any more sperm?
Impenetrable
When does Mitotic replication (cleavage) occur?
Begins as zygote travels toward uterus.
How long is transit?
3-4 days
What does the zone pelucida do?
Protects cells
How many cells does the zygote contain when it enters the uterus?
Called a morula and contains 16 cells
As cells continue to divide the structure develops & becomes known as ______?
Blastocyst
What is a woman’s window of conception?
3 days
What happens to the the blastocyst between days 6-10?
Embeds into endometrium (usually fundal region)
What is the embedding of the blastocyst called?
Implantation
What are chorionic villi?
fingerlike projections that develop to tap into rich endometrial blood supply (obtain O2 and dispose of CO2 here).
What happens after implantation?
The endometrium termed the decidua
What does pregnancy counting begin with?
First day of the last menstrual period.
Pregnancy actually occurs ______ wks after last pregnancy.
2 wks
This would be a pregnancy actually lasting
38 wks or 266 days
What is a woman’s EDC with a LMP of 01/01/2015
10/08/14
What is a woman’s EDC with a LMP of 09/28/13?
07/05/14
When is the most dangerous time fore exposure to teratogens?
8 wks. Still a zygote.
Amniotic cavity develops and eventually houses?
Amniotic sac
Amniotic fluid contains
800 to 1200 mL at birth
What does amniotic fluid maintain?
Fetal temp
What is the source of oral fluid & outlet for fetal waste?
Amniotic fluid
What does the amniotic fluid help expand?
baby’s alveoli
Oligohydramnios
<300mL of fluid. Fetal renal abnormalities .