embryo II

Question 1

How does the neural tube form

Answer 1

begins with formation of neural plate, lateral edges elevate and make neural groove
the neural groove then fuses

Question 2

when do the cranial and caudal neuropores of the nueral tube close

Answer 2

cranial closes day 25

caudal closes day 27

Question 3

what does the neural tube become

Answer 3

brain and spinal cord

Question 4

Where do neural crest cells come from

Answer 4

neuroectoderm as the neural tube is closing

Question 5

what do cranial neural crest cells become

Answer 5

bones, cartilag, fascia, ligaments and tendons of face and neck
sensory ganglia, autonomic ganglia

Question 6

what do the spinal neural crest cells become

Answer 6

DRG, autonomic ganglia and the fibrous skeleteon of heart

Question 7

what do both the spinal and cranial neural crest cells become

Answer 7

meninges schwann cells and melanocytes

Question 8

which part of neural tube becomes spinal cord

Answer 8

caudal to 4th pair of somites

Question 9

what are the 3 different regions that form in the nueral tube because of migration

Answer 9

ventricular, mantle and marginal zones

Question 10

In the embryo what is the ventricular zone in neural tube

Answer 10

neuroepithelium-pseudostratified

gives rise to neurons and glia

Question 11

In the adult what is the vetnricular zone from neural tube

Answer 11

simple layer ependymal cells

Question 12

What is the mantle zone of spinal cord in development

Answer 12

superficial to neuroepithelium
neuronal cell bodies
have alar and basal plates that are separated by sulcus limitans

Question 13

what do the alar and basal plates become in development of spinal cord

Answer 13

alar forms sensory dorsal horn

basal forms motor ventral horn

Question 14

describe marginal zone of spinal cord developmentally

Answer 14

outermost layer, have nerve processes like axons and dendrites

Question 15

What type of cells come from neuroepithelium

Answer 15

neuroblasts and gliablasts

Question 16

what do the neuroblasts become

Answer 16

ventral motor horn neurons and dorsal sensory horn neurons

Question 17

what do the gliablasts become

Answer 17

astrocytes and oligodendrocytes

Question 18

What make up a spinal n

Answer 18

ventral nerve root + dorsal nerve root

Question 19

dorsal spinal nn inn what areas

Answer 19

muscles skin joints of back

Question 20

ventral rami from spinal nn inn what areas

Answer 20

limbs, ventral body wall

Question 21

What are the vesicles in the cranial part of neural tube

Answer 21

prosenecephalon (forebrain)
mesencephalon (midbrain)
rhombencephalon (hindbrain)

Question 22

what are the portions of the prosencehalon

Answer 22

telencephalon and diencephalon

Question 23

what are the portions of the rhombencephalon

Answer 23

metencephalon

myelencephalon

Question 24

what are the flexures of the cranial portion neural tube

Answer 24

cervical, cephalic and pontine

Question 25

what are the ventricles of the brain derived from

Answer 25

4th- lumen rhombencephalon cerebral aquaduct- lumen mesencephalon 3rd- lumen of diencephalon lateral- lumen of telencephalon

Question 26

what develops to become choroid plexus

Answer 26

tela choroidea which is pia mater and ependymal cells

Question 27

what areas of the brain make up the brainstem

Answer 27

mesencephalon and rhombencephalon

Question 28

how does gray matter differ as the alar and basal plates ascend into brainstem

Answer 28

discrete nuclei instead of columns, sensory nuclei are displaced laterally b/c of pontine flexure

Question 29

what is the myelencephalon

Answer 29

medulla

Question 30

what CN is the myelencephalon associ with

Answer 30

VIII IX X XII

Question 31

what layer of nueral tube forms most of pons

Answer 31

marginal layer

Question 32

what CN are assoc with the metencephalon

Answer 32

V VI VII VIII

Question 33

what is the metencephalon

Answer 33

pons

Question 34

what forms the cerebellum

Answer 34

alar plates of metencephalon (rhombic lips) | fuse and form cerebellar plate

Question 35

how come gray matter is external and white matter internal

Answer 35

waves of neuroblasts migrate from alar plate through marginal layer to form outer cerebellar cortex

Question 36

What forms midbrain

Answer 36

mesencephalon

Question 37

what CN are assoc with mesencephalon

Answer 37

III IV

Question 38

What structures arise from diencephalon

Answer 38

optic vessels(CN II), pineal gland, thalamus, hypothalamus, pituitary gland

Question 39

what is in the epithalamus

Answer 39

choroid plexus and pineal gland

Question 40

what do the alar plates become in diencephalon

Answer 40

2 swellings separated by hypothalamic sulcus superior-thalamus inferior-hypothalamus

Question 41

describe where neurohypophysis and adenohyphysis come from

Answer 41

neurohypophysis from downgrowth of diencephalon neuroectoderm adenohypophysis from upgrowth of oral ectoderm

Question 42

What does the telencephalon become

Answer 42

cerebral hemispheres and corpus striatum

Question 43

describe how in cerebral Cx gray matter is superficial

Answer 43

waves of neuroblasts migrating through radial glial cells in marginal zone, youngest cells form most external layer

Question 44

what is the corpus striatum

Answer 44

swelling in floor of cerebral hemispheres

Question 45

what CN is assoc with telencephlaon

Answer 45

olfactory tract and bulb

Question 46

What are the main spinal neural tube defects

Answer 46

spina bifida occulta | spina bifida cystic

Question 47

What is meroencephaly or anencephaly

Answer 47

failure of brain to form

Question 48

what is craniorachischisis

Answer 48

closure defect of cranial end neural tube extends into spinal cord

Question 49

what is microcephalys

Answer 49

small cranium from brain undervelopment

Question 50

What causes an encephalocele

Answer 50

defect in skull (usually occipital) allowing portions of CNS to protrude in cyst like way from skull

Question 51

what is a meningocele

Answer 51

only meninges bulge through defect in skull

Question 52

what is a meningoencephalocele

Answer 52

meninges and part of brain bulge into defect of skull

Question 53

what is an meningohydroencephalocele

Answer 53

meninges, brain, and part of ventricular system bulge thorugh skull

Question 54

what is congenital hyrocephalus

Answer 54

increased CSF within ventricles, imbalance of production and absorption CSF results in dilation of ventricles and skull expands causes thinning of bones of calvaria

Question 55

What is Arnold chiari syndrome

Answer 55

herniations of cerebellar hemispheres through foramen magnum; underdevelopment of posteiror cranial fossa often assoc with spina bifida cystica

Question 56

what is holoprosencephaly

Answer 56

failure of forebrain neural tube to form cerebral hemispheres. fore brain is underdeveloped and the lateral ventricles are fused

Question 57

what is the only endocrine gland to come from neural tube

Answer 57

pineal gland

Question 58

what is the cranial-most portion of neural tube

Answer 58

diencephalon, because lamina terminals closes there

Question 59

root cause of spina bifida

Answer 59

neural tube does not fuse, so then vertebral arch does not fuse (posteriorly)

Question 60

what are the 2 most common sites of ventricular blockage

Answer 60

interventricular foramina | cerebral aquaduct