Exam 2 Lecture: Development of the Nervous System

Question 1

What is grey matter made up of?

Answer 1

neuronal cell bodies and glial cells

Question 2

What is white matter made up of?

Answer 2

myelinated and unmyelinated axons

Question 3

Why is white matter white?

Answer 3

high lipid concentration of the myelination

Question 4

Where are tracks of axons located?

Answer 4

in the white matter

Question 5

What is the ascending track?

Answer 5

a track of axons from the spinal cord to the brain

Question 6

What is the descending track?

Answer 6

a track of axons from the brain to the spinal cord

Question 7

What is located in the central canal?

Answer 7

CSF

Question 8

Dorsal root + ventral root =

Answer 8

spinal nerve

Question 9

What type of neurons are in the dorsal root?

Answer 9

sensory

Question 10

What type of neurons are in the ventral root?

Answer 10

motor

Question 11

True or False: the CNS is the first organ system to initiate differentiation as well as the first to be functional

Answer 11

False, it is only the first to initiate differentiation

Question 12

When does the formation of the neural tube normally happen?

Answer 12

2-3 days after gastrolation

Question 13

Of what origin is the neural tube?

Answer 13

the ectoderm

Question 14

How does the neural fold play a role in the development of the neural tube?

Answer 14

they grow up throughout development, once they contact each other, the neural tube separates from the ectoderm and drifts away from the embryo

Question 15

Where does the neural tube begin to form at?

Answer 15

the cervical cranial thoracic area

Question 16

In what direction does the neural tube form?

Answer 16

in a cranial to caudal direction

Question 17

What are the two communications of the neuropore?

Answer 17

the rostral and the caudal

Question 18

Where is the neural crest cell located?

Answer 18

on the surface of the ectoderm as the neural folds are trying to make contact

Question 19

What are the neural crest cell derivatives?

Answer 19

all of the ganglia in the body; sensory ganglia of our cranial nerves, enteric ganglia, dorsal root ganglia, parasympathetic ganglia, synmpathetic ganglia, schwann cells, adrenal medulla

Question 20

What are the components of the structure of the neural tube?

Answer 20

neural canal, ependymal cells, mantel layer, roof and floor plates

Question 21

What are the plates of the mantel layer?

Answer 21

basal plate and alar plate

Question 22

What does the alar plate give rise to?

Answer 22

dorsal horn; sensory predominant structures

Question 23

What does the basal plate give rise to?

Answer 23

ventral horn; motor structures

Question 24

What causes the formation of the fissure and sulcus?

Answer 24

created because the roof plate and the floor plate are not doing anything (replicating)

Question 25

How is the ventral root created?

Answer 25

neurons residing in the ventral horn project their axons out to meet a target

Question 26

How is the dorsal root created?

Answer 26

neurons residing in the dorsal root ganglia project axons out to the periphery and to the dorsal horn

Question 27

What causes the cauda equina?

Answer 27

In early development, the sacral nerves join with a muscle on the other side of the vertebra, as the spinal cord begins to see differential growth, the spinal cord moves in a cranial direction thus elongating the root of the nerve to keep the connection with the muscle

Question 28

What causes spina bifida?

Answer 28

neural tube closing issue

Question 29

spina bifida occulta

Answer 29

the most mild case of spina bifida, usually only affects 1 vertebra

Question 30

Myeloschisis

Answer 30

failure of the neural tube to close

Question 31

Meningiomylocele

Answer 31

meninges prolapses through the area that the vertebral arch should be

Question 32

What does the brain begin as?

Answer 32

a neural tube with a neural canal inside of it, the body wall in the periphery with a mantel and marginal layer

Question 33

What is brain development caused by?

Answer 33

dilations (vesicles)

Question 34

What are the three primary vesicles that brain development begins with?

Answer 34

forebrain, midbrain, hindbrain

Question 35

What does the forebrain divide into?

Answer 35

2 secondary vesicles (1 and 2)

Question 36

What does the midbrain divide into?

Answer 36

nothing, remains the midbrain or 3rd vesicle, does not dilate

Question 37

What does the hindbrain divide into?

Answer 37

2 secondary vesicles (4 and 5)

Question 38

What does the wall and the cavity of the 1st secondary vesicle become?

Answer 38

wall: central hemispheres cavity: lateral ventricles

Question 39

What does the wall and the cavity of the 2nd secondary vesicle become?

Answer 39

wall: thalmus cavity: third ventricle

Question 40

What does the wall and the cavity of the 3rd secondary vesicle become?

Answer 40

wall: midbrain cavity: aqueduct

Question 41

What does the wall and the cavity of the 4th secondary vesicle become?

Answer 41

wall: pons and cerebellum cavity: upper part of the fourth ventricle

Question 42

What does the wall and the cavity of the 5th secondary vesicle become?

Answer 42

wall: medulla cavity: lower part of the fourth ventricle

Question 43

What structures are involved in hind brain development?

Answer 43

basal and alar plate(nuclei are derived from this plate)

Question 44

What structure is vital in forming the cerebellum and pons?

Answer 44

rhombic lip

Question 45

What are the three layers of the rhombic lip?

Answer 45

external germinal layer, purkinje neurons, cerebellar nuclei

Question 46

Which layer of the rhombic lip adds to the majority of the bulk of our cerebellum?

Answer 46

the external germ layer

Question 47

How do the cells of the external germ layer make connections with the purkinje neurons?

Answer 47

they eventually separate from the external germ layer and descent into the cerebellum; this process produces an axon and creates a connection as they pass the purkinje fibers

Question 48

What does panleukopenia and BVD target?

Answer 48

the external germinal layer

Question 49

How does the cerebrum layer develop?

Answer 49

cells in the mantel layer begin dividing and get a signal to migrate so they migrate out to the marginal layer. This process of division and migration continues in order to create more and more layers of cells

Question 50

What is multiple layer migration vital in?

Answer 50

forming the sulcus(depression) and gyrus (elevation)

Question 51

cerebellar hypoplasia

Answer 51

reduced size of the cerebellum

Question 52

anencephaly

Answer 52

'no brain', rostral neural pore fails to close

Question 53

lissencephaly

Answer 53

waves of migration did not occur as they should have

Question 54

cranium bifidum

Answer 54

skull cannot form correctly around the brain

Question 55

hydrocephalus

Answer 55

increased CSF pressure

Question 56

Of what is the pituitary gland in origin?

Answer 56

ectodermal

Question 57

Where does the posterior pituitary develop from?

Answer 57

ectoderm from the forebrain

Question 58

How is the posterior pituitary connected to the brain?

Answer 58

directly via an axon that is connected to a neuron in the brain

Question 59

Where does the anterior pituitary develop form?

Answer 59

ectoderm coming from the mouth

Question 60

How is the anterior pituitary connected to the brain?

Answer 60

the axon connected to the neuron in the brain terminates on the portal vein, then the portal vein connects to the anterior pituitary