Early Human Development Flashcards
What is the name for an immature egg cell?
Oocyte
Name the outermost layer of oocytes (immature egg cell)
Corona radiata
Name the second outermost layer of oocytes (immature egg cell)
Zona Pellucida
Are sperm and egg cells haploid or diploid?
haploid
What is the name of the stage where a sperm enters the oocyte? (immature egg cell)
Fertilisation
Where does Fertilisation, cleavage of zygote and morula formation occur?
Fallopian Tube
What is the name of the stage that happens 1 day after fertilisation?
Cleavage of Zygote (into 2 blastomere cells)
What is the name of the stage that happens 4 days after fertilisation?
Formation of Morula
What is the name of the stage that happens 5 days after fertilisation?
Formation of Blastocyst
Name the three main components of a Blastocyst
Trophoblast, Blastocyst Cavity and Inner cell mass
What is the name of the stage that happens 6 days after fertilisation?
Implantation
Where does implantation occur?
In the endometrium of the uterus
Name the Outer Germ Layer
Ectoderm (Blue)
Name the Middle Germ Layer
Mesoderm (Red)
Name the Inner Germ Layer
Endoderm (Yellow)
Name the two cell types that the trophoblast differentiates into.
Syncytio-trophoblasts and Cyto-trophoblasts
When the trophoblasts differentiates, which cell type is loosely packed and invades into the endometrium?
Syncytiotrophoblast
blue layer of embryonic disc consists of
Hypoblasts
yellow layer of embryonic disc consists of
Epiblasts
The Hypoblast and Epiblast cells form the ______ embryonic disc.
bi-lamina
Which cell type will eventually form a dome containing the amniotic cavity?
Epiblasts (blue)
Which cell type eventually gives rise to the yolk sac?
Hypoblasts (yellow)
What is the name of the small cavities that start to form within the Syncytiotrophoblast?
Lacunae Networks
What is the provides a source of primordial germ cells?
Yolk sac
What 2 types of cells the inner cell mass differentiate into?
Hypoblast and Epiblast
Was is the first sign of Gastrulation?
Formation of Primitive Streak
How is the Primitive Streak Formed?
Cells from top of Ectoderm burrow down below, this creates a cleft to form in the surface of Ectoderm
Primitive streak starts from which end?
Tail End
The Notochordal process is formed by cells burrowing through the ___________
and is part of the _______
layer.
Primitive Node and Mesoderm
Ectodermal cells above the Notochordal process begin thickening, what is forming?
Neural Plate
Describe the structure of Notochordal process
a hollow tube
The process of the folding of the neural plate is called
Neurulation
Eventually the Notochordal process forms a solid rod called
The Notochord
A key function of the Notochord is to
Instruct neighbouring tissue
The organ which instructs neurulation and formation of somites is the
Notochord
The process of the folding of the neural plate forms the
Neural Tube
Once formed, where is the Neural tube?
Seperate from Ectoderm Layer, Floating in Mesoderm
What forms during the initial stage of neurulation?
Neural Grooves
What forms during the Intermediate stage of neurulation?
Neural Folds
How is the neural tube formed during neurulation?
The neural folds meet and fuse together.
what type of cells migrates away from the Neural Tube once formed?
Neural Crest Cells
Which type of cell eventually gives rise to melanocytes?
Neural Crest Cells
Which type of cell eventually gives rise to nerves?
Neural Crest Cells
