Development of Nervous System

Question 1

What does the neural tube form?

Answer 1

the CNS, neural plate, neural fold, neural groove

Question 2

Embryonic ectoderm becomes what on the body?

Answer 2

skin

Question 3

What does the neural crest become?

Answer 3

PNS and ANS

Question 4

Cranial 2/3 becomes what?

Answer 4

future brain

Question 5

Caudal 1/3 becomes what?

Answer 5

spinal cord

Question 6

How many days does it take for the cranial/rostral neuropore to close?

Answer 6

25 days

Question 7

How many days does it take for the caudal neuropore to close?

Answer 7

27 days

Question 8

The walls of the neural tube are initially composed of what?

Answer 8

pseudostratified columnar

Question 9

What is the sulcus limitans?

Answer 9

• differential thickening of lateral walls
• separates alar and basal plate

Question 10

The neuroepithelial cells constitue what zones?

Answer 10

• intermediate
• ventricular
• marginal

Question 11

What is the intermediate zone?

Answer 11

• contains alar and basal plates
• gray matter

Question 12

What is the ventricular zone?

Answer 12

gives rise to macroglial cells and neurons

Question 13

What is the marginal zone?

Answer 13

• consists of outer parts of neuroepithelial cells
• becomes white matter

Question 14

What is the process for the formation of neuroblasts?

Answer 14

• mesenchymal cell -> microglial cell
• apolar neuroblast -> neuron

Question 15

The alar is responsible for what neurons and forms what horn of the spinal cord?

Answer 15

sensory; dorsal

Question 16

Where does the conus medullaris end on an adult and at birth?

Answer 16

• birth: L3
• adults: L1-L2

Question 17

Schwann cells are derived from what cells?

Answer 17

neural crest cells

Question 18

Oligodendrocytes are derived from what?

Answer 18

neural tube

Question 19

What is spina bifida occulta?

Answer 19

• most common
• unfused arch
• occurs at L5/S1
• presents with small dimple and tufted hair/dermal sinus

Question 20

What is spina bifida meningocele?

Answer 20

• unfused arch
• meninges

Question 21

What is spina bifida meningomyelocele?

Answer 21

• unfused arch
• meninges
• spinal cord

Question 22

What is spina bifida myeloschisis?

Answer 22

• most severe
• spinal cord is open
• neural folds failed to close
• results in permanent paralysis/wekness in lower limbs

Question 23

What is dermal sinus?

Answer 23

failure of surface ectoderm to detatch from neuroectoderm and meninges that envelop it

Question 24

The lumen of neural tube becomes what?

Answer 24

brain ventricles

Question 25

What is the path of the forebrain (prosencephalon)?

Answer 25

* telencephalon> cerebral hemispheres> lateral ventricles * diencephalon> thalami> 3rd ventricle

Question 26

What is the path of the midbrain (mesencephalon)?

Answer 26

mesencephalon> midbrain> aqueduct

Question 27

What is the path for the hindbrain (rhombencephalon)?

Answer 27

* metencephalon> pons and cerebellum> upper part of 4th ventricle * mylencephalon> medulla> lower part of 4th ventricle

Question 28

What is the neurohypophysial diverticulum in pituitary gland development?

Answer 28

* neuroectodermal downgrowth from diencephalon * forms neurohyphysis * post. pituitary

Question 29

What is the hyperphysial diverticulum in pituitary gland development?

Answer 29

* ectodermal upgrowth from stomodeum * forms adenohypophysis * ant. pituitary

Question 30

What is the role of the pontine flexure?

Answer 30

divides hindbrain into metencephalon and mylencephalon

Question 31

What is the special somatic afferents?

Answer 31

sense of balance and gravity

Question 32

What is the special visceral afferents?

Answer 32

"special sense" taste and olfaction

Question 33

What is the special visceal efferents?

Answer 33

skeletal muscles of branchial arch origin

Question 34

What does the ventral portion of the metencephalon include?

Answer 34

pons

Question 35

What does the dorsal portion of the metencephalon include?

Answer 35

cerebellum

Question 36

The roof of the 4th ventricle include what?

Answer 36

* choroid plexus * 3 foramina: foramen of Luschka (2) and foramen of Magendie

Question 37

What is the cranial most extent of the sulcus limitans?

Answer 37

mesencephalon

Question 38

What does the lumen within the mesencephalon include?

Answer 38

cerebral aqueduct

Question 39

What is the end of the neural tube?

Answer 39

diencephalon

Question 40

What do the lateral walls of diencephalon contain?

Answer 40

thalamus, hypothalamus, epithalamus

Question 41

The nuclei within the diencephalon is composed of what?

Answer 41

alar lamina

Question 42

The rostral wall is formed by the what?

Answer 42

lamina terminalis (cranial most end of the original neural tube)

Question 43

The lumen of the diencephalon is what ventricle?

Answer 43

3rd

Question 44

What does the telencephalon form?

Answer 44

cerebral hemispheres and lateral ventricles

Question 45

Where is the telencephalon located?

Answer 45

on either side of diencephalon

Question 46

What is cranial meningocele?

Answer 46

meninges with CSF

Question 47

What is meningocephalocele?

Answer 47

* meninges with CSF * portion of cerebellum

Question 48

What is meningohydroencephalocele?

Answer 48

* meninges with CSF * portion of occipital lobe * portion of post. horn of lateral ventricle

Question 49

What is the hydrochalus disease?

Answer 49

* excess CSF * enlargement of the head

Question 50

What is merocephaly disease?

Answer 50

forebrain, midbrain, most of hindbrain is absent

Question 51

What is microcephaly disease?

Answer 51

reduction in brain growth but face is normal size