Development Of The Nervous System

Front 1

when the neural tube closes, what five things does it form?

Back 1

neural crest, spinal cord, and the brain. the three vesicles of the brain are the prosencephalon, mesencephalon, and the rhombencephalon.

Front 2

what are rhombomeres?

Back 2

neuromeres in the rhombencephalon

Front 3

how many secondary vesicles form from the three primary vesicles?

Back 3

five

Front 4

which primary brain vesicles turn into 2 secondary vesicles?

Back 4

-prosencephalon into telencephalon and diencephalon.
-rhombencephalon into metencephalon and myelencephalon

Front 5

where does the neural tube begin closure?

Back 5

occipito-cervical juncture

Front 6

at how many days does the posterior neuropore close?

Back 6

26 days

Front 7

what is the medullary cord and how/what does it develop?

Back 7

secondary neurulation where the cord develops beyond the posterior neuropore, cavitates, and joins with the main neural tube. It forms the lowest sacral/coccygeal portion of the spinal cord

Front 8

spina bifida occulta

Back 8

incomplete vertebral arch, but no protrusion of vertebral canal contents.

Front 9

what two abnormal external structures are associated with spina bifida cystica?

Back 9

meningocoele (just meninges), meningomyelocele (meninges and spinal cord)

Front 10

why is obstructed CSF flow associated with spina bifida cystica?

Back 10

tethered spinal cord pulls cerebellum into foramen magnum, which obstructs the flow

Front 11

where is anterior neuropore closure on a grown fetus?

Back 11

forehead/nasal bridge region

Front 12

what three cysts can result from failure of anterior neuropore closure?

Back 12

meningocele, meningoencephalocele, meningohydroencephalocele

Front 13

what condition is due to failure of neural tube closure caudal to the anterior neuropore?

Back 13

anencephaly

Front 14

what three zones result from cytodifferentiation of the neural tube?

Back 14

-Deeper ventricular zone contains mitotic cells and glioblasts.
-More superficial mantle zone is the future gray matter.
-Most superficial zone is the marginal zone and is the future white matter.

Front 15

what two spinal cord things form from the mantle zone?

Back 15

an alar plate (dorsal horn) and a basal plate (ventral horn).

Front 16

what forms from the alar and basal plates?

Back 16

Cells of basal plate form motor neurons.
-Cells of alar plate form association neurons that receive sensory information.

Front 17

what forms peripheral ganglia?

Back 17

neural crest cells

Front 18

what are the three peripheral ganglia?

Back 18

sensory (dorsal root) ganglia, autonomic and enteric ganglia, chromaffin (adrenal medulla) cells

Front 19

what do association neurons form from?

Back 19

neural tube.

Front 20

what do motor neurons (somatic and preganglionic visceral) form from?

Back 20

neural tube

Front 21

what do post-ganglionic visceral motor neurons form from?

Back 21

neural cret

Front 22

what do sensory neurons (somatic and visceral) form from?

Back 22

neural crest

Front 23

what demarcates the hindbrain from the spinal cord? What does it eventually become?

Back 23

cervical flexure eventually becomes the site of the foramen magnum

Front 24

what divides the rhombencephalon into the myelencephalon and metencephalon?

Back 24

pontine flexure

Front 25

what does the metencephalon become?

Back 25

pons and cerebellum

Front 26

what does the cavity of the hindbrain become?

Back 26

4th ventricle and the central canal

Front 27

what does the caudal myelencephalon resemble both developmentally and structurally?

Back 27

resembles the spinal cord

Front 28

what forms the central canal of the myelencephalon?

Back 28

neural canal of the neural tube

Front 29

what is different (from the spinal cord) about the neuroblasts from the alar plate in the myelencephalon?

Back 29

they migrate into the marginal zone to form more areas of isolated gray matter

Front 30

what has a wide and flat roofplate surrounding the 4th ventricle?

Back 30

rostral myelencephalon

Front 31

what do peripheral ganglia of cranial nerves form from?

Back 31

neural crest or ectodermal placodes

Front 32

what does the cerebellum form from?

Back 32

from the dorsal parts of the alar plates: cerebellar swellings

Front 33

what do some neuroblasts of the mantle zone do?

Back 33

migrate to the marginal zone and differentiate into cerebellar cortex and nuclei, and nuclei of the trigeminal nerve

Front 34

how does the cerebral aqueduct form?

Back 34

neural canal narrows

Front 35

how are the superior and inferior colliculi formed?

Back 35

neuroblasts migrate from alar plates into roof and aggregate.

Front 36

what is often the cause of impaired CSF circulation (and thus hydrocephaly)?

Back 36

aqueductal stenosis

Front 37

what is different about the gray matter of the diencephalon?

Back 37

does not form basal and alar plates

Front 38

in the diencephalon, what are the three swellings that develop in the walls of the third ventricle?

Back 38

thalamus, hypothalamus, and epithalamus

Front 39

what does the pineal gland form from?

Back 39

as a median diverticulum of the caudal roof of the diencephalon

Front 40

what are the 2 sources that the pituitary gland forms from?

Back 40

1. downgrowth from neuroectoderm of the diencephalon: neurohypophysial diverticulum.

2. An upgrowth from the stomodeum: Rathke's Pouch

Front 41

where do the lateral vesicles develop?

Back 41

telencephalon

Front 42

what is the corpus striatum?

Back 42

prominent swelling in floor of each cerebral hemisphere