Embryology Flashcards
What is the nervous system derived from?
Ectoderm
What is neurulation?
The folding process that occurs in vertebrate embryos, which includes the transformation of the neural plate into the neural tube (precursor to the CNS)
What is the ectoderm?
Following fertilisation, the embryo’s inner cell mass develops into 3 layers: ectoderm, mesoderm and endoderm
How does the ectoderm form the neural plate?
Neuroectodermal tissues differentiate from the ectoderm and thicken to form the neural plate.
The neural plate border separates the ectoderm from the neural plate.
Ect - NPborder - NP - NPborder - Ect
How does the neural plate become the neural crest?
The neural plate bends dorsally (upwards)
The two ends eventually join at the neural plate border.
The neural plate borders are now called the neural crest.
What do the cells of the neural crest differentiate into?
Most of the peripheral nervous system
What happens to the neural crest when the neural tube closes?
It is disconnected from the epidermis
What happens to the notochord after the neural tube has closed?
Degenerates and only persists as the nucleus pulposus of intervertebral discs
At 3-4 weeks there are 3 primary brain vesicles - name them!
Prosencephalon (forebrain)
Mesencephalon (midbrain)
Rhombencephalon (hindbrain)
PMR
What does the Prosencephalon become at 5 weeks?
Telencephalon
Diencephalon
Does the mesencephalon become anything at 5 weeks?
No, just stays as the mesencephalon
What does the rhombencephalon become at 5 weeks?
Metencephalon
Myelencephalon
How many secondary brain vesicles are there at 5 weeks? Name them from front to back.
5 Telencephalon Diencephalon Mesencephalon Metencephalon Myelencephalon
What does the telencephalon give rise to?
Cerebrum
and basal ganglia
What does the diencephalon give rise to?
Thalamus, hypothalamus & epithalamus
And optic cup (gives rise to retina)
