Chapter 6: The Developing Brain Flashcards
cell division is also called
proliferation
migration
neurons move to their final destinations
three layers that emerge in embryonic development
ectoderm, mesoderm, and endoderm
ectoderm cells become
nerve tissue
process of ectoderm cells becoming nerve tissue is called
neural induction
cells divide into
two identical daughter cells
what happens after daughter cells keep splitting?
some go on to keep proliferating and the other may go on to its final stage
cause of microcephaly
protein defects cause symmetric division to become asymmetric division
microcephaly
smaller than normal head in newborns
excessive proliferation causes
megalencephaly
megalencephaly
baby with larger than normal head
what begins to thicken after conception
ectoderm
the three bulges that form will become the baby’s
hindbrain, midbrain, and forebrain
where do neurons travel when they are produced
from the inner surface of neural tube to the outer surface
radial migration
when the neurons that arrive the earliest form the innermost layer of the cortex and the neurons that arrive the latest form the outermost layer of the cortex
axons
produce and transmit signals
dendrites
receive signals
axons do what
they span distances many times the size of their cell body
longest human axons are in the
periphery
a developing axon grows by the
extension of its growth cone
growth cone
enlargement at the tip of the axon
netrins were first found in
worms
synapse
signaling portin of the axon
chemical messengers
neurotransmitters
