Development of the Human Nervous System Flashcards
Differentiate between the…
- Neural Plate
- Neural Groove
- Neural Tube
- Neural Crest
Neural Plate-> An embryonic structure that will eventually dev. into the nervous system.
Neural Groove-> A groove develops down the neural plate before completely separating it into two parts.
Neural Crest-> An embryonic structure that dev. into the PNS.
Neural Tube-> An embryonic structure that dev. into the CNS.
What does it mean for a cell to have Totipotential?
Totipotent refers to a cell that has the ability to develop into any kind of specialized cell. However, once they specialize, they’re stuck with that specialization.
What is Neural Proliferation?
Neural Proliferation is a stage of development in which cells rapidly divide and develop specializations for different regions of the brain.
What are Radial Glial Cells? What do they do?
Radial Glia are long (ray-like) cells that form a scaffolding for developed neurons to travel to where they are needed in relation to their specialization.
What is a Growth Cone?
These are amoeba-like structures found at the tips of the forming neurons. They direct dendrite/axon growth.
(These are the traffic conductors of the stabilizing neurons)
What is Neuron Death?
At the end of the second trimester, a mass neuron purge, known as Neuron Death, occurs.
Walk yourself through the six processes of early neural development.
(PMAFNM- Penguins March Across Freeways Navigating Mountains)
- Proliferation
- Migration
- Aggregation
- Process Growth-Synapse Formation
- Neuron Death
- Myelination
Describe the process of Growth-Synapse Formation.
GROWTH->This is the stage in which neurons grow dendrites and axons. (they’re stretching their arms)
SYNAPSE-> the formation of synaptic gaps (aka, connection for electrical signaling)
Three swellings become visible at the anterior end of the human neural tube during the 4th week of prenatal development. Name the three swellings.
- Forebrain
- Midbrain
- Hindbrain
In the fifth prenatal week, the three embryonic swellings develop into five swellings. What are these growths named?
- TEL encephalon
- DI encephalon
- MES encephalon
- MET encephalon
- MYEL encephalon
What are the two theories that explain how a growth cone knows where it’s going?
- The Chemoaffinity Theory
- The Blueprint Theory
Describe the Chemoaffinity Theory.
How do growth cones know where to go?
-> Searching and receiving neurons release specific chemical signals, so a cell will follow the “scent” of said chemical until it reaches its destination.
Describe the Blueprint Theory.
How do growth cones know where to go?
-> Every neuron/axon was created with the knowledge of where it must go, so it is simply following its “instincts” or “instructions” to its final destination.
What is a Pioneer Growth Cone?
This is the FIRST growth cone in a bundle of axons to reach its target.
(the rest of the axons in the bundle typically follow it)
What is Fasciculation?
This is a fancy term for the tendency of growing axons to grow along the same path as their neighbors.
What is Adult Neurogenesis? Where do we see this take place?
- This term refers to the growth of NEW NEURONS in an adult brain. (insane, btw)
- The Hippocampus
The Olfactory Bulbs
What are the Olfactory Bulbs?
Track the process of smell from nose to brain.
- These are bulbous structures that process odors.
- nose-> olfactory nerves-> olfactory bulbs-> olfactory tracts-> brain
What is the Hippocampus?
A structure that is part of the Limbic System. The hippocampus helps form memories.
