Vosko Embryology

Question 1

precocious nervous system

Answer 1

• No 2 nervous systems ever develop the same way
• About halfthe protein coding genes are also in some way involved in development of the nervous system
• Most neuronal production and migration occurs during the third through fifth months of development
• The formation of neural connections (neuropil) and production of myelin sheaths continue after birth

Question 2

gliogenesis

Answer 2

Takes place during the second and third trimesters of pregnancy and early postnatal development

neurons - peak 3rd month

astrocytes peak 6.5 month

oligodendrocytes peak right before birth

Question 3

glia outnumber neurons

Answer 3

10:1

Question 4

glial abnormalities are related to

Answer 4

alzheimers ms schizophrenia and depression

Question 5

neuralation

Answer 5

follows gastrulation from morphogens acting on ectoderm

how the neural tube forms, the first step

Question 6

neural inducing morphogens

Answer 6

provided by mesoderm to ectoderm

default is to become nervous tissue

bmp changes ectoderm into epidermis

Question 7

notochorc

Answer 7

mesoderm-derived, later fomrs into the nucleus propulsus of the spine

Question 8

noggin

Answer 8

secreted by notochord to stop bmp

area around neural tube gets it and becomes nervous tisssue

Question 9

neuralation steps

Answer 9

–1) Formation of a neural plate
–2) Neural plate becomes neural groovesurrounded by crests
–3) Groove becomes closed neural tubein highly ordered fashion

Question 10

closing order

Answer 10

middle, top, then bottom

full closure day 28

most machinery is for closure of the top not the bottom

Question 11

spina bifida

Answer 11

results from incomplete caudal neural tube closure

occulta - 20% of people have, just missing some bone, hair tufts

meningocele - spinal cord not floating but still dangerous

meningomyelocele- spinal cord floats and is very dangerous

Question 12

chiari malformation

Answer 12

drooping of brainstem into fomaren magnum causes hernia and is very dangerous

Question 13

anencephaly

Answer 13

incomplete rostral neural tube closure

Question 14

2 vesicles of neural tube

Answer 14

prosencephalon - forebrain

mesencephalon - midbrain

rhombencephalon - hindbrain

Question 15

3 bulges

Answer 15

“primary vesicles”
–Cephalic flexurebet. Mesencephalon and prosencephalon
–Cervical flexurebet. Rhombencephalonand spinal cord

Question 16

2 additional bulges

Answer 16

5 “secondary vesicles”
–Rhombencephalonsep. to metencephalonand myelencephalonat level of pontineflexure
–Prosencephalonsep. to diencephalon andtelencephalon

Question 17

prosencephalon becomes

Answer 17

telencephalon - cerebral cortex and basal ganglia

diencephalon - thalamus, hypothalamus, retina

Question 18

mesencephalon becomes

Answer 18

midbrain

Question 19

rhomboencephalon becomes

Answer 19

metencephalon - cerebellum and pons

myelencephalon - medulla

Question 20

ventricular system overvies

Answer 20

lumen of neural tube becomes ventricular system

Each vesicle contains different “ventricle”
•Choroid plexus is vascular tissue + pia+ ependymalcells
–Makes CSF
–Not in aqueduct nor spinal cord

Question 21

where is choroid plexus not found?

Answer 21

mesencephalon

Question 22

what portions of neural tube make up what ventricle

Answer 22

telencephalon- lateral ventricles

diencephalon - third ventricle

rhombencephalon - fourth ventricle

spinal cord - central canal

Question 23

insula

Answer 23

a c shape ermerges with cortical development around the insula

cell division

corpus callosum, basal ganglia form a c shape