Embryology Flashcards
Between what weeks is the embryonic phase?
0-3 weeks
Between which weeks is the embryonic phase?
4-8 weeks
Between which weeks is the foetal phase?
9-40 weeks
What is spermatogenesis?
The formation of sperm
What is oogenesis?
The formation of the ovum
By what cellular process do gametes divide?
Meiosis
What is the spermatogonium?
The cell that produces sperm
What is the oogonium?
The cell that produces the ovum
What is the cell formed at fertilisation called?
The zygote
Does just one sperm surround the ovum?
No several
How many sperm penetrate the egg?
Just one
What part of the sperm penetrates the ovum?
The pro-nucleus
Why does mitochondrial inheritance come from the mother?
Because the sperms organelles are pushed out at fertilisation
What is the first cell in the body?
The zygote
Is the zygote diploid or haploid?
Diploid
How does the zygote divide?
By mitosis
What is the morula?
Ball of cells that have divided from the zygote
Why does a cavity develop in the morula?
To get nutrients to the central core of the cells
What is the cavity that develops in the morula known as?
Blastocystic cavity
What does the morula become?
A blastocyst
What is the outer lining of cells on the blastocyst called?
Trophoblast
How does the egg or fertilised zygote move along the oviduct?
Ciliated epithelium moves it along
How long does the first cell division take?
36 hours
If cilia function in the fallopian tubes is faulty what can occur?
An ectopic pregnancy
How many days does it take fir the blastula to have formed ready to implant in the uterine cavity?
5 or 6
Where does implantation occur?
In the endometrial layer
What is the function of the chorion?
To help the embryo burry into the endometrium
To go on and form part of the placenta
To secrete HCG
What does HCG hormone do?
Tells the body to keep producing oestrogen and progesterone to maintain the endometrium
Also is used to test for pregnancy