Nervous system development

Question 1

Why does the neural fold fuse except for the cranial and caudal ends?

Answer 1

They are left open to communicate with the amniotic cavity

Question 2

When does anterior/cranial neuropore close?

Answer 2

day 25

Question 3

when does posterior/caudal neuropore close?

Answer 3

day 28

Question 4

What are the three primordial dilations (primary brain vesicles) of the cranial end of the neural plate?

Answer 4

Prosencephalon, mesencephalon, rhombencephalon

Question 5

What is the neuroepithelial layer

Answer 5

thick pseudostratified layer of neuroepithelial cells

Question 6

what processes occur in neuroepithelial layer?

Answer 6

neurogenesis and gliogenesis occur simultaneously here. Neurogenesis is more prominent in embryo, gliogenesis is more prominent later

Question 7

What are ependyma cells and where are they?

Answer 7

they ar remaining cells of innner layer which line central canal of s cord and ventricles

Question 8

Intermediate layer/mantle zone

Answer 8

formed by neuroblasts, becomes GRAY zone of spinal cord

Question 9

Outer layer/marginal zone

Answer 9

Formed by neuronal processes that give rise to WHITE matter of spinal cord

Question 10

what are the columns of the mantle layer of the spinal cord?

Answer 10

Ventral and Dorsal thickeing, sulcus limitans, rood and floor plates

Question 11

Ventral thickening

Answer 11

basal plates= ventral motor horn cells

Question 12

Dorsal thickening

Answer 12

=alar plates=sensory area of spinal cord

Question 13

sulcus limitans

Answer 13

groove on each side of spinal cord, separates alar from basal

Question 14

roof and floor plates

Answer 14

no neuroblasts, pathwars for nerve fibers crossing from one side to the other

Question 15

alar plates

Answer 15

dorsay (gray) horns, differentiate into sensory afferent interneurons

Question 16

basal plate

Answer 16

ventral (gray) horns, differentiate into voluntary motor neurons to innervate skel muscle

Question 17

intermediate zone

Answer 17

lateral horns, differentiate into autonomic or involuntary motor neurons

Question 18

Neural crest cells migrate dorsolaterally to give rise to

Answer 18

dorsal root ganglion

Question 19

List the primary vesicles

Answer 19

prosencephalon, mesencephalon, rhombencephalon,

Question 20

List five vesicles after division

Answer 20

Telencephalon, diencephalon, mesencephalon, metencephalon, myelencephalon

Question 21

what does metencephalon give rise to

Answer 21

pons cerebellum walls. Upper part of 4th ventricle

Question 22

what does myelencephalon give rise to

Answer 22

medulla walls, lower part of 4th ventricle

Question 23

what forms anterior lobe/ adenohypophysis

Answer 23

Rathke’s pouch, ectoderm invagination oral ectoderm

Question 24

what are the 3 parts of the adenohypophysis

Answer 24

pars distalis, pars tuberalis, and pars intermedia

Question 25

what forms posterior lobe or neurohypophysis?

Answer 25

neuroectoderm,

Question 26

what are the 3 parts of the posterior pituitary

Answer 26

median eminence, infundibular stem, pars nervosa