Lesson 3A (Part 1) Flashcards
What are the 2 things needed in order for conception to occur?
- 2° oocyte
- mature ovum - Spermatozoon
When does conception occur?
Within 24-36 hrs of ovulation
- day 14-15 of cycle
What region of the the fallopian tube does conception occur?
Ampulla
What does conception form?
Single-cell zygote
How many chromosomes does a zygote have?
46
- diploid number
How many chromosomes do parent cells contribute?
23 chromosomes each
- haploid number
What is happening through the traveling through the fallopian tube?
The embryo is developing
Cleavage
The zygote rapidly divides
- with each division the cell number doubles
What is the size of the zygote?
The same size as the morula
What is still intact when the embryo goes through the fallopian tubes?
Zona pellucida
How many cells make up a morula?
12-15
What will a morula develop?
A fluid-filled cavity
What is the embryo called at the stage of the morula developing a fluid filled cavity?
Blastocyst
What is a blastocyst also known as?
A blastula
What are the 3 distinct parts of a blastula?
- Trophoblast
- Embryoblast/inner cell mass
- Blastocele
Trophoblast
Future placenta
- embryonic part
What does the trophoblast produce?
hCG
- this supports the CL
What will the embryoblast/inner cell mass develop into?
The embryo
What is the blastocele?
A fluid filled cavity
What day do blastocysts implant on?
Day 20-23 of LMP
- 5 days after ovulation
What does the embryo do as it burrows in the endometrium?
Develope
What does the development of an embryo involve? (6)
- Decidua
- Blastocyst
- embryo - Amniotic Cavity
- Chorion
- Yolk sac
- Gastrulation
- 3 germ cell layers
What is the decidua?
The ‘endometrium’ of the pregnancy
What does the amniotic cavity do?
House the pregnancy within the gestational sac
