Flashcards in Development, CNS, PNS (Lecture #1) Deck (40):
what does the embryo look like at ~3weeks after conception?
3 layered disk
what happens to the epiblast layer at ~3weeks after conception
develops a depression called the primitive groove
what happens to the primitive groove over time?
it deepens, detaches from epiblast, and closes to form neural tube
progression of neural tube closure
dorsal aspect of cervical region closes first
closure proceeds in both directions (rostrally and caudally)
rostral end closes at 24-26 days
caudal end closes at 26-28 days
when is the neural tube done forming
~4weeks after conception
what happens if the neural tube does not form correctly?
brain and spinal cord do not form correctly
skull and spine do not form correctly
what part of the neural tube becomes the brain?
what part of the neural tube becomes the spinal cord?
everything that is not the rostral end
what happens to the rostral end of the neural tube after its closure?
starts to change shape and develops 3 major vesicles
3 major vesicles developed by rostral end of neural tube after closure
what does prosencephalon develop into
telencephalon (cerebral hemispheres)
what does the mesencephalon develop into?
what does the rhombencephalon develop into?
metencephalon (pons & cerebellum)
parts of the central nervous system
pons & cerebellum
what makes up the brainstem
toward the cerebral hemispheres
toward the sacral end of the spinal cord
what is the diencephalon made up of
thalamus (largest part)
types of glial cells
structural support and metabolism in the nervous system
line ventrical cavities
what is myelin?
lipid-substance covering essentially all axons in CNS and some in PNS
function of myelin
insulate axons to prevent signal loss
myelin formed by
schwann cells (PNS)
do diseases affect myelin the same way in the CNS as in the PNS?
areas primarily containing myelinated axons
areas primarily containing cell bodies
ALL synapses occur here
grey matter areas in brain
Peripheral Nervous System contents
anything outside of brain and spinal cord
cranial nerves and ganglia
spinal nerves and dorsal root ganglia
sympathetic and parasympathetic nerves and ganglia
enteric nervous system (nerves in digestive system)
part of spinal cord that contains sensory axons
part of spinal cord that contains motor and autonomic axons
what is the central canal filled with
which segments of the spinal cord have enlargements
cervical (for controlling UE muscles)
lumbosacral (for controlling LE muscles)
what spinal levels are associated with the sympathtic nervous system
what spinal levels are associated with parasympathetic nervous system
inhibition of digestion
stimulation of glucose release