Chapter 6: The developing brain Flashcards
What are the 3 layers of an embryo?
- Ectoderm
- Mesoderm
- Endoderm
Define neural induction
Signalling to ectoderm to turn into neural cells
The high degree of exposure to the sonic hedgehog (SHH), a signalling molecule secreted from ________, causes nerve tissues to convert into _____ _____
Mesoderm
Mid-degree of exposure cause: nerve tissues to convert into ___motor neurones (used for controlling muscles)
Glial cells
Low degree of exposure cause
interneurons
Define proliferation
Rapid growth/division of cells
What happens if cells in the embryonic brain begin to divide asymmetrically earlier?
Microcephaly - smaller brain
What happens if cells in the embryonic brain begin to divide asymmetrically later?
Megacephaly - bigger brain
Define migration
Neural cells move to their final locations in the brain
What cells guide the neurons to their permanent position?
Radial glial cells
What are growth cones?
Head of the neurone (axon) to explore and grow in that direction
What do attractive cues do?
Attract growth cones in their direction
What do repellent molecules do
Repel growth cones in their direction
What is the function of Astrocytes?
- Neurotransmitter uptake
- Structural support
- Synaptic environment
Where are the Nodes of Ranvier?
Unmyelinated areas between the myelinated areas of the axon
