Lesson 2- Embryology Flashcards
What are the functions of the Trophoblast?
- it burrows into the uterine lining during implantation
- builds the chorion that surrounds the embryo and fetus
- helps to form the placenta
What does the epiblast turn into?
The amnion sac
What does the hypoblast turn into?
The yolk sac
What is the inner cell mass made of?
Epiblast and hypoblast
What is the blastocyst made of?
Inner cell mass, blastocoel, trophoblast
What is the blastocoel?
A fluid filled area
What is cleavage?
When the zygote splits into multiple cells and turns into the morula
What happens to the morula?
It turns into the blastocyst and implants on the uterine wall
What does the epiblast layer turn into?
It becomes the embryo
What weeks are the pre-embryonic period, embryonic period, and fetal period?
Pre-embryonic: 1-2 weeks
Embryonic: 3-8 weeks
Fetal: 9-38 weeks
What happens weeks 3-8? (Development)
Primitive streak
Gastrulation
Body folding
Neurulation
Limb buds form
Organogenesis
What is the primitive streak for?
For cells to enter into the embryo
Other than amnion sac, what does the epiblast turn into?
The mesoderm
What are the derivatives of the ectoderm?
Skin and the nervous system
What are the derivatives of the mesoderm?
The heart, kidneys, muscular and skeletal systems
What are the derivatives of the endoderm?
The digestive and respiratory system
What happens in organogenesis?
- organ development follows gastrulation and body folding
- upper and lower limbs form
- rudimentary organ systems have developed by week 8
- embryo is approximately one inch long by week 8
What does the chorion from the trophoblast and endometrium of the uterus make?
The placenta
What happens during the fetal period?
Growth and maturation of existing organs
What is the trophoblast made of?
Cytotrophoblast and syncytiotrophoblast
