Introduction to embryology Flashcards
what layer of the trilaminar disc does the respiratory system develop from?
the endoderm
what layer of the trilaminar disc does the cardiovascular system develop from?
lateral plate mesoderm
how many pairs of somites are there?
43 pairs
what do the somites break up into? and what do these form?
dermatome - dermis of skin
myotome - muscle
sclerotome - bone
what induces the ectodermal cells to form the neural tube?
the notochord
what is the notochord formed from? at at what week does this occur?
the primitive streak
week 3
what weeks are the organogenic period?
4th - 8th weeks
what is the order of formation in the first week?
zygote - morula - blastocyst (containing blastocystic cavity, inner cell mass and trophoblast)
what is the chorion form from?
the trophoblast
what is the function of the chorion?
has a role in implantation (due to chorionic villi)
forms part of the placenta
secretes human chorionic gonadotrophin (HCG)
what forms the bilaminar disk? and when does this occur?
the inner cell mass
week 2
what are the 2 layers in the bilaminar disc?
epiblast
hypoblast
(also contains amniotic cavity on top and yolk sac below)
when is the implantation into the endometrial layer?
day 7
what is the name for the myometrium deep to the implanted conceptus?
decidua basalis
