normal 1st trim. pt.1 Flashcards
What day is ovulation in a 28 day cycle?
Day 14
How long after ovulation does fertilization occur?
24 to 36 hours
Where does ovulation most commonly occur?
Ampulla of the fallopian tube ( rapid cell division occurs here )
How many chromosomes does each fertilized egg contain?
46 chromosomes (23 pairs)
What is the male and female reproductive cell (the ovum and sperm) called?
Gamate
The single cell fertilized egg prior to cell division
Zygote
Dividing fertilized egg at 2 cell and 4 cell stages
blastomere
Where is the blastomere located?
Within the ampulla of the fallopian tube
The mass of dividing cells which resemble a Mulberry
Morula
Where is the morula located?
in the isthmus of the tube and entering the uterus
An organized collection of cells which implant into the endometrium about 7 days after fertilization.
blastocyst
What produces the progesterone to keep the uterine lining stable?
Corpus luteum
What produces beta human chorionic gonadotropin or BhCG which perpetuates the life of the corpus luteum?
trophoblast (found in the outer lining)
What is the inner fluid filled cavity called that contains the intercell mass?
Blastocele
**What will the inner cell mass inside the blastocyst become?***** KNOW THIS
Yolk sac and embryonic disk and amnion
What is the glycoprotein called that is produced by the trophoblastic cells initially, and later by the placenta?
HCG human chorionic gonadotropin
How is BhCG detected?
In maternal blood and urine
What hormone turns a pregnancy test positive?
BhCG
When is BhCG detectable in the bloodstream?
7-10 days after ovulation, 3 weeks after LMP
What glycoprotein doubles every 2-3 days and plateaus at 8-9 weeks then declines?
HCG
How can BhCG be measured? 2 ways
Qualitative and Quantitative
qualitative–positive or negative
quantitative–specific number
What is the most common way the laboratory reports beta hCG levels?
with the 3rd international reference preparation
3rd IRP
What is the formula for the 2nd IRP?
2nd IRP= IRP/2
What is the formula for the 3rd IRP?
3rd IRP= 2 x SIS (second international standard)
In the blastocyst cavity, the inner cell mass is differentiated from the bilaminar disc (2 layer) into what?
Trilaminar embryonic disk (3 layer)
What are the 3 germ layers that comprise the embryonic disk by 5 weeks after LMP?
Endoderm, Mesoderm, Ectoderm
The innercell layer (of embryonic disk)
Endoderm
The middle layer ( of embryonic disk)
Mesoderm
The outer layer (of embryonic disk)
Ectoderm
What does the endoderm become?
GI and respiratory systems
What does the mesoderm become?
Musculoskeletal and circulatory systems
What does the ectoderm become?
brain and nervous system and skin
When do all major internal and external structures begin to form?
6-10 weeks of fetal life
When does the fetal heart begin to beat?
6 weeks
What are we referring to when we say “week of fetal life”
1st day of last mestrual period
What does the trophoblast of the blastocyst become???? **KNOW
Chorion
