Flashcards in Embryology Deck (21):
When the egg and sperm fuse, during ovulation, what is the structure they form called? & what happens to those that do not undergo fertilization?
They are reasbsorbed by the body
What is fertilisation and where does it occur?
When a sperms chromosomes combine with those of an egg to form a zygote ( fertilised egg)
-in the ampullary region of the fallopian tube
How long is a sperm viable? Egg?
Sperm is viable for 5 days
Secondary oocyte for 12-24hrs
What does capacitation mean?
Making the tail of sperm move faster ( enhance mobility), secretion of female ftract remove some of their protective membranes
Surface proteins on sperm cells are nonself (foreign), even for the male that is making them! So why doesnt the body produce antibodies against them? How can infection be a consequence?
Bc inside the testes, the sertoli cells form tight junctions that form a barrier btw the blood and sperm cell to avoid contact.
Infection may disrupt this barrier and the sperm cell can come into comtact with the t& B lymphocytes and form antibodies
Define embryonic age and gestational age
Embryonic age >> time since fertilisation
Gestational age>> time since last menstrual cycle
(Embyonic age minus 2 wks)
Where does implantation take place?
In the uterus ( most commonly upper part and posteriorly)
What stimulates meiosis 2?
Describe the steps of fertilisation
Describes steps of implantation
What happens during "hatching"
The blastocyst must loose its "zona pellucida" so it can implant!
(Zona pellucida is though to prevent this adherence)
What will the trophoblast differentiate into? ( become later on)
Yolk salk and placenta
What is hemotrophic nutrition
Nutrition provided by mothers blood
What is ectopic pregnancy?
What is placenta previa?
An obstetric complication in which the placenta is inserted partially or wholly in the lower uterine segmen
During implantation, as the trophoblast makes comtact with the endometrium, it differentiates into 2 layers_________
Cytotrophoblast and syncytiotrophoblast
During implantation, The embryoblast differentiates into what?
A bilaminar embryonic disk >> 1) epiblast 2) hypoblast
Describe the process that happens during 2nd week of development
By day ______ the unterus is completely embedded in the uterine wall
One the Zygote has gone through cleavage to the point of 16 cells, it is called a/an
Morula ( mulberry)