Conception, Implantation, and Placental Development Flashcards
Pre-embryonic development begins with
fertilization
Fertilization is followed by
a generation of a ball of cells
After the generation of a ball of cells, there is
differentiation of inner cell mass from the outer cell mass
The point where there is a differentiation between inner and outer cell mass is called the
blastocyst
What step follows blastocyst formation?
Implantation into the uterine wall
Pre-embryonic development takes place during which weeks of development
Weeks 1 and 2
What process follows implantation and when does it begin?
Gastrulation and week 3
The basic axes of the body are laid out and major germ layers are generated during
gastrulation and neurulation
By when does the embryo have basic body form?
Week 8
When is the embryonic period and when does it end?
Weeks 3-8
What period follows the embryonic period and when does it occur?
Fetal period and Weeks 9-38
Name the stage:
Two cells unite to make a zygote
Fertilization
Name the stage:
Large egg mass divided into smaller cells by slow divisions
Cleavage
Name the stage:
Opening of fluid filled cavity in ball of cells, inner cell mass is future embryo and outer cells are future extra-embryonic membranes
Blastocyst
Name the stage:
Outer cells make contact with uterine wall and begin to differentiate into supporting membranes of the placenta
Implantation
Name the stage:
Sweeping cellular movements generate 3 key cell layers: ectoderm, mesoderm, and endoderm
Gastrulation
Name the layer:
Will give rise to skin, hair, and sweat glands
Ectoderm
Name the layer:
Will give rise to the nervous system
Ectoderm
Name the layer:
Gives rise to the neural tube
Ectoderm
Name the layer:
Gives rise to the central nervous system
Neural tube (ectoderm)
Name the stage and the outcome:
in-folding of the outer ectoderm in the dorsal midline
Neurulation and gives rise to the neural tube
Neural crest is derived from _____ which is derived from the _____ layer
neural tube; ectoderm
The brain and spinal cord are derived from _____ which comes from the ______ layer
neural tube; ectoderm
The posterior pituitary is derived from _____ which comes from the ______ layer
neural tube; ectoderm
The optic vesicle is derived from____ which comes from the_____ layer
neural tube; ectoderm
The retina is derived from____ which comes from the____ layer
neural tube; ectoderm
The optic nerve is derived from____ which comes from the_____
neural tube; ectoderm
The cranial and spinal motor nerves are derived from_____ which comes from_____
neural tube; ectoderm
The sensory neurons are derived from the____ which comes from the_____
neural crest; ectoderm
The glia of the dorsal root ganglia are derived from the____ which comes from the_____
neural crest; ectoderm
Which cells of the ectoderm are migratory?
Neural crest cells
In the bilaminar disc, the inner cell mass is divided into _____ and _______
epiblast; hypoblast
primordial germ cells are derived directly from_____
epiblast
The placenta is derived from the ______
trophoblast
The thymus is derived from _______ which comes from the ______ layer
pharyngeal pouches; endoderm
The parathyroid glands are derived from ______ which come from the ______ layer
pharyngeal pouches; endoderm
The C-cells of the thyroid glands are derived from ______ which come from the ______ layer
pharyngeal pouches; endoderm
The epithelium of the Eustachian tube is derived from_____ which come from the ______ layer
pharyngeal pouches; endoderm
The middle ear cavity is derived from _____ which come from the ______ layer
pharyngeal pouches; endoderm
The palatine tonsil is derived from ______ which come from the _____ layer
pharyngeal pouches; endoderm
The intestine is derived from _____ which comes from the ______ layer
primitive gut tube; endoderm
The liver is derived from ______ which comes from the _____ layer
primitive gut tube; endoderm
The pancreas is derived from the ________ which comes from the _______ layer
primitive gut tube; endoderm
The pharynx is derived from the _____ which comes from the ______ layer
primitive gut tube; endoderm
The trachea is derived from the _____ which comes from the ____ layer
primitive gut tube; endoderm
The lungs are derived from the ______ which comes from the _____ layer
primitive gut tube; endoderm
The bladder is derived from the _____ which comes from the ______ layer
primitive gut tube; endoderm
The urethra is derived from the _____ which comes from the _____ layer
primitive gut tube; endoderm
The prostate is derived from the _____ which comes from the ____ layer
primitive gut tube; endoderm
The Allantois is derived from the ____ which comes from the _____ layer
primary gut tube; endoderm
