Embryology Flashcards
The embryonic period is controlled by which structure?
Primitive Node
In the embryonic period of development, the cells develop from which side?
Rostral to caudal
Which process gives rise to a distinct, 3-layer embryo?
Gastrulation
Skin, hair and neural tissue comes from which embryo layer?
Ectoderm
Muscle, vasculature, bone and cartilage come from which layer of embryo?
Mesoderm
Gut and respiratory system comes from which embryo layer?
Endoderm
What is the first well-defined structure in embryo development?
Neural tube (around 20-27 days in)
The foetal period lasts from which weeks/months in pregnancy?
Week 9 to term
When do the primary sulci develop (brain)?
Weeks 8-26
What % of neurones will die by apoptosis pre-natally?
50%
Synaptic exuberance and pruning describe what
Exuberance is an over-abundance of neurones in development & pruning describes their natural death (apoptosis)
Myelination occurs in the womb, T/F?
False - mostly in the first 2 years but ongoing into 20s
What is the physiological/anatomical reasoning for teenagers being moody?
Anatomical reorganisation of the brain is occurring (synaptic pruning) - this occurs in a “back to front” process (the back of the brain serves the emotional centres roughly while the front is higher reasoning / control).
Pelizaeus-Merzbacher disease is caused by a mutation in which gene & what does this damage?
PLP1 gene (on X-chromosome) which leads to death of myelin sheaths. Can result in neurone death (hypotonia, ataxia, spasticity)
When does the human brain begin to develop in gestation?
Week 3
