Nervous System in Development

Question 1

nerual plate

Answer 1

at 17 days old

Question 2

endoderm

Answer 2

lining of viscera (internal organs)

Question 3

mesoderm

Answer 3

bones and muscles

Question 4

ectoderm

Answer 4

skin and bervous system —-> neural plate

Question 5

neuralation

Answer 5

at 22 days old
neural plate divides into neural groove and folds which develop into:
neural tube - CNS = ventricular system
neural crest - PNS
the groove invaginates to form a cavity - ventricular system
somites form vertebrae and skeletal muscle

Question 6

what neurons form from neural crest

Answer 6

neurons of PNS:
sensory neurons whose cell bodies lie in dorsal root ganglia
autonomic neurons e.g. ganglioninc parasynpathetic and eneteric neurons

Question 7

folic acid

Answer 7

1/500 babies had neural tube defects - failure to close properly
specific seq of genes expressed which are influenced by environment
folic acid = 90% reduction = influences DNA synthesis

Question 8

neural tube diseases

Answer 8

usually middle closes first, defects usally are in closing of top/bottom
failure to close top = anencephaly - fatal
failure to close bottom = spina bifida - meninges over spinal cord dont come together

Question 9

differentiation

Answer 9

changing to different types of tissues

Question 10

3 primary brain vesicles

Answer 10

in top of neural tube, rest forms spinal cord
prosencephalon - forebrain
mesencephalon - midbrain
rhombencephalon - hindbrain

Question 11

secondary brain vesicles of forebrain

Answer 11

1 - telencephalic vesicles - form cerebral hemispheres, cortex, amygdala and basal ganglia - move posterially and laterally as they grow, over diencephalon
2 - diencephalon - hypothalamus
3 - optic vesicles - optic stalk and cup

Question 12

optic stalk

Answer 12

optic nerve

composed of axons of retinal ganglion neurons

Question 13

optic cup

Answer 13

retina

only part of CNS derived tissue that exists outside of CNS - e.g. out of brain and spinal cord

Question 14

forebrain differentiation

Answer 14

olfactory bulbs - neurons for smell
thalamus - gateway to and from cortex
basal telencephalon - has structures for fear, emotion and movement and contains basal nuclei
corpus callosum - transfer info
internal capsule - all info to and from cerebral cortex: to thalamus and back or down into midbrain and pons

Question 15

midbrain

superior colliculus

Answer 15

porcess vision

Question 16

midbrain

periaqeductual gray

Answer 16

control of pain

Question 17

midbrain

substantia nigra and red nucleus

Answer 17

movement

Question 18

midbrain plasticity

Answer 18

if hearing/sight is lost, opposite system can move into space

Question 19

hindbrain

Answer 19

rhombic lips - form cerebellum
cerebellum - densely packed with neurons
meduallry pyramids - allow white matter tracks

Question 20

cerebellum

Answer 20

integration of info
cooridnation of movement, balance and posture
10% CNS volume : 50% CNS neurons

Question 21

cerebellar cortex and deep nuclei

Answer 21

send info back into cortex

Question 22

pontine nuclei

Answer 22

project into cerebellar cortex

Question 23

folia

Answer 23

increase surface area in brain to fit more neurons