201 - First Three Weeks of Development

fertilization

week 1 of embryological development:

implantation

week 2 of embryological development:

gastrulation

week 3 of embryological development:

ampulla

where does fertilization normally occur?

endometrium

where does implantation normally occur?

corpus luteum

identify the structure

fimbriae

identify the structure

infundibulum

identify the structure

ampulla

identify the structure

endometrium

identify the structure

corpus luteum

Remnants from the ruptured follicle form the:

HCG

what hormone keeps the corpus luteum alive?

(“Fancy Cats Bake Mini Cookies Before Breakfast”)

fertilization
cleavage
blastomere
morula
compaction
blastocyte

name the 6 steps of development that occur in week 1: fertilization (in order):

fertilization stage

stage where capacitation and fertilization occur

cleavage stage

identify the stage of fertilization:

blastomere stage

identify the stage of fertilization:

morula stage

identify the stage of fertilization:

compaction

identify the stage of fertilization:

blastocyst stage

identify the stage of fertilization:

capacitation

maturation step for sperm

acrosomal reaction

final maturation step that allows sperm to penetrate egg

uterus

where does blastocyte formation take place?

cleavage stage

stage: At about 30 hours post-fertilization the zygote undergoes the first cell division also known as cleavage into 2 cells.

blastomere stage

stage: cells produced as the result of cleavage

morula stage

stage: Between 3 and 4 days there are about 12 to 16 blastomeres adhered together that appear under a microscope to look somewhat like a mulberry

compaction

stage: Blastomeres change how they attach to each other

blastocyst stage

stage: Embryo begins to absorb fluid forming a cyst,

embryoblast

in the blastocyte stage of development, inside the cyst a compact inner cell mass forms at one side of this cavity

embryo

the embryoblast will eventually become the:

trophoblast

The cells on the outside the blastocyte organize into a thin, single-layered epithelium called the:

placenta

the trophoblast will eventually become the:

trophoblast

which cells proliferate and begin to invade into the uterine epithelium during implantation?

syncytiotrophoblast
cytotrophoblast

Trophoblast differentiates into 2 distinct cell types:

syncytiotrophoblast

which cells initiate uteroplacental circulation?

syncytiotrophoblast

what part of the embryoblast produces HCG?

syncytiotrophoblast

produces human chorionic gonadotropin, erodes the endometrium, isolated cavities called lacunae, form an interconnected lacunar network

epiblast

embryoblast layer of columnar shaped cells closer to the uterus:

hypoblast

embryoblast layer of cuboidal cells adjacent to the blastocyst cavity:

epiblast
hypoblast

what two cells form the bilaminar disc?

epiblast
cytotrophoblast

the amniotic cavity forms from fluid filling in between what two sets of developing cells?

epiblast

the amniotic cavity differentiates from what group of cells?

amniotic cavity

Layer of epiblast cells migrates and differentiates into a thin membrane separating the new cavity from the cytotrophoblasts and forms the:

yolk sac

Hypoblast cells proliferate and migrate along the cytotrophoblast, extending from hypoblast around the blastocyst cavity and forms the:

hypoblast

the yolk sac differentiates from what group of cells?

trophoblast

the outer layer of the chorion is made of what cells:

inner extraembryonic mesoderm

the inner layer of the chorion is made of what cells:

chorionic cavity

Extraembryonic mesoderm splits into two layers forming the:

inner extraembryonic mesoderm

the bilaminar disc along with the amnion and definitive yolk sac, is suspended within the chorionic cavity by a thickened portion of__________ called the connecting stalk.

gastrulation

the primitive streak appears in what stage of development?

primitive streak

day 15 a thickening containing a midline groove forms along the midsagittal plane of the embryonic disc:

primitive streak

defines the embryo's craniocaudal axis, dorsal and ventral surfaces, and right and left sides?

prechordal plate

epiblast and hypoblast cells fuse to become site of future mouth:

mouth

the prechordal plate will eventually be the:

ingression

As cells of the epiblast reach the primitive streak, they change shape and pass through it on their way to forming new layers beneath (ventral to) the epiblast:

epiblast

which cells of the bilaminar disc participate in ingression?

definitive endoderm

which 'derm' layer develops first?

intraembryonic mesoderm

which 'derm' layer develops 2nd?

definitive endoderm

First ingressing epiblast cells invade the hypoblast and displace its cells, so that the hypoblast eventually is completely replaced by a new layer called the:

definitive endoderm

gives rise to the lining of the future gut and gut derivatives

intraembryonic mesoderm

epiblast cells migrating through the primitive streak into the space between epiblast and the newly formed endoderm to form 2nd germ layer:

cardiogenic
paraxial
intermediate
lateral plate

4 fates from migrating mesoderm:

notochordal process

A fifth population of epiblast cells migrates cranially from the primitive node in the midline to form a thick-walled midline cord called the:

sacrococcygeal teratoma

Remnants of the primitive streak that persist after birth, contains tissues derived from all three germ layers in incomplete stages of differentiation:

primitive streak

sacrococcygeal teratomas are remnants of what developmental structure?

cranio-caudal

what direction does the notochord form?

notochord

this structure serves as the basis for the development of the axial skeleton

notochord

the vertebral discs are remnants of what embryological structure?

paraxial mesoderm

this section of the mesoderm will develop into cartilage, tendons, muscles and bones:

lateral plate mesoderm

this section of the mesoderm will develop into
-body wall
-circulatory system, gut wall:

intermediate mesoderm

this section of the mesoderm will develop into urogenital and reproductive systems:

embryonic ectoderm

this derm layer is the epiblast after the migration through the primitive streak that formed the definitive endoderm, mesoderm and notochord is complete:

embryonic ectoderm

this derm layer will develop into neural crest, neural tube

neural tube

what embryologic structure does the CNS derive from?

neural crest

what embryologic structure does the PNS derive from?

neural crest

dorsal root ganglia are derived from what embryonic tissue?

neural tube

the spinal cord is derived from what embryonic tissue?

PNS

the neural crest will give rise to what nervous system?

CNS

the neural tube will give rise to what nervous system?

intermediate mesoderm

the kidneys are derived from what embryonic tissue?

intermediate mesoderm

the bladder is derived from what embryonic tissue?

definitive endoderm

the stomach is derived from what embryonic tissue?