stages of neural development Flashcards
neurulation timing and defination
3 to 4 weeks
formation of neural tube
neurulation disorders
encephalocele- defects in neural tube closure in brain
myelomeningocele- defects in neural tube closure in spinal cord
(motor and or cognitive impairments)
ventral induction time and definition
5-6 weeks
formation of basic structures and brain subdivisions
ventral induction disorders
Holoprosencephaly- failure of cleavage of prosencephalon leaving deficit in middle facial development (facial structure, feeding, and cognitive impairment ranging from mild developmental delay to severe intellectual disability and CP)
Agenesis of corpus callosum- lack of development of corpus callosum
(bilateral coordination, visual perception, motor control, motor learning and cognitive impairments ranging from mild developmental delay to severe intellectual disability and CP)
neuronal proliferation time and definiton
8-16 weeks
neural and glial cells form and proliferate
neuronal proliferation disorder
microencephaly- reduced brain size and weight
(cognitive and motor impairments, including abnormal muscle tone, postural control, and motor coordination, raging from mild developmental delay, severe intellectual disability, and CP)
macroencephaly- increased brain size and weight
neuronal migration time and definition
12-20 weeks
neurons move from ventricular and subventricular zones to final destination
neuronal migration disorders
generalized or focal seizures- abnormal excessive electrical activity in brain
Lissencephaly
schizencephaly
focal cerebral dysgenesis
Lissencephaly
abnormalities in gyral development and cortical surface area
schizencephaly
abnormal cavities or cysts in the brain
focal cerebral dysgenesis
lack of development of specific cortical sites
neuronal organization time and definition
24 weeks to 2-3 years
establishment and differentiation of subplate neurons
alignment, orientation, and layering of neurons
growth of axons and dendrites
synaptpgenesis
selective elimination of neurons, neuronal processes, and synapses
glial cell proliferation and differentiation
neuronal organization disorders
frequently associated with other earlier, neural developmental abnormalities
Lack of organization and extensive network of circuits, intrinsic and extrinsic to cerebral cortex
cognitive sensory or motor control impairment raging from mild coordination and learning disorders to CP
Myelination time and definition
23 weeks to adulthood
development of myelin membrane around axons
myelination disorder
cerebral white matter hypoplasia- deficient or absent myelin production decreased number of tracks between brain and the spinal cord slow transmission along tracks
Mild to severe posture and motor control, control, and coordination problems, difficult producing quick movements
