Ns: 09 And 10 Neurodevelopment

Front 1

the zygotic ends at week __ with the formation of the ___

Back 1

week 2; embryonic disc

Front 2

the embryonic stage ends at __ wks with the formation of the ___

Back 2

week 8; neural tube

Front 3

the majority of myelination occurs prenatally/postnatally?

Back 3

postnatally

Front 4

the majority of neurons are formed prenatally/postnatally?

Back 4

prenatally

Front 5

5 stages of neural development?

Back 5

1. neurulation
2. proliferation
3. migration
4. differentiation
5. synaptogenesis / targetting

Front 6

neurulation occurs prenatally/postnatally?

Back 6

totally prenatally

Front 7

the PNS is derived mainly from ___

Back 7

neural crest cells

Front 8

2 parts of the blastocyst and what they form

Back 8

1.trophectoderm - the placenta
2.inner cell mass - everything else, including the embryo proper

Front 9

2 parts of the embryonic disc and what they form

Back 9

1.epiblast - forms the embryo proper
2.hypoblast - forms part of the yolk sac

Front 10

describe the process of gastrulation.

Back 10

3rd week
in the embryonic disc, epiblast cells migrate medially and dive down into the center of the embryonic disc, creating the primitive groove. the first epiblast cells that dive in become the endoderm. the next epiblast cells that dive in become the mesoderm. the epiblast cells that dont dive in become the ectoderm

Front 11

what germ layer forms the excretory system and gonads?

Back 11

mesoderm

Front 12

what germ layer forms the glands, including the pancreas and liver?

Back 12

endoderm

Front 13

the notocord is formed from ___

Back 13

midline axial mesoderm

Front 14

the ___ induces ectoderm to become neural tissue

Back 14

notocord

Front 15

what is the neural plate?

Back 15

prior to neurulation, the notocord induces the overlying ectoderm to thicken and differentiate into neurectoderm, which makes up the neural plate.

Front 16

the part of the neural plate that is midline and directly over the notocord

Back 16

floor plate

Front 17

the part of the neural plate found at its lateral margins

Back 17

neural crest

Front 18

what is primary neurulation

Back 18

when the sides of the neural plate fold up to form the neural tube

Front 19

what is the neural groove?

Back 19

the midline fold of the neural plate as the neural folds rise up to become the sides of the neural tube

Front 20

what causes closure of the neural tube? what time does this occur?

Back 20

4th week

the neural folds are brought close together and form cell-cell junctions at the dorsal midline.

Front 21

what is wedging?

Back 21

the change in cell shape in parts of the neural tube where the basal domain becomes much larger than the apical domain resulting in a hinge point.

Front 22

where does neural groove begin to fuse?

Back 22

the 4th somite. extends rostrally and caudally. rostral neuropores fuse first

Front 23

how does segmentation of the rostral neural tube occur?

Back 23

there are constrictions dividing the rostral neural tube into 3 vesicles: the prosencephalon, mesencephalon, and rhombencephalon. some sections have weaker cell-cell interactions and are more easily expanded by fluid pressure (blown up like a balloon?)

Front 24

what is flexure of the neural tube?

Back 24

the cephalic flexure occurs at the mesencephalon allowing the forebrain to tuck under the hindbrain. the cervical flexure occurs b/t the hindbrain and spinal cord and allows for bulging and segmentation.

Front 25

where and why is there a transient blockage in the neural vesicles?

Back 25

between the hindbrain and spinal cord during the bulging of segmentation.

Front 26

what parts of the ventricular system do the vesicle cavities form?

Back 26

prosencephalon - 1,2,3 ventricles
mesencephalon - cerebral aqueduct
rhombencephalon - 4th ventricle

Front 27

the apical pole cells of the spinal cord face ___

Back 27

the central canal

Front 28

basal and apical pole cells are linked by _____

Back 28

junctional complexes

Front 29

the furrow between the alar and basal plates?

Back 29

sulcus limitans

Front 30

which neurons of the PNS do not arise from the neural crest cells?

Back 30

1. motor neurons - their cell bodies lie in the ventral horn and their axons grow into the somites
2. preganglionic autonomic neurons - their cell bodies lie in the lateral horn (symp) or in the brain? (para)
3. placodal ectoderm gives rise to certain cranial nerve sensory neurons.
ex. sensory epithelia of the nose, inner ear, lens, some neurons of the sensory ganglia

Front 31

what is the placodal ectoderm?

Back 31

the area just outside the neural crest. not neurectoderm. gives rise to sensory epithelia of the nose, inner ear, lens, ant. pituitary, and some neurons of sensory ganglia of cranial nerves

Front 32

origin of the sensory epithelia of the nose and inner ear?

Back 32

placodal ectoderm

Front 33

give rise to the branchial arches and periocular tissues

Back 33

cranial neural crest cells

Front 34

give rise to melanocytes, schwann cells, chromaffin cells, and others

Back 34

trunkal neural crest cells

Front 35

malignant melanoma is a tumor associated w/ __

Back 35

NCC's (melanocyte)

Front 36

neurofibromatosis is a tumor associated w/ __

Back 36

NCC's

Front 37

caused by inappropriate closing of the posterior neural tube during the first month of pregnancy (wk 4?)

Back 37

spina bifida

Front 38

caused by failure of the anterior neural pore to fuse

Back 38

anencephaly

Front 39

a herniation of brain tissue through a hole in the skull

Back 39

encephalocoele

Front 40

failure of the lobes of the brain to separate

Back 40

holoprosencephaly

Front 41

condition in which the cerebellar tonsils slip into the foramen magnum

Back 41

Arnold Chiari formation

Front 42

what is the placodal ectoderm?

Back 42

the area just outside the neural crest. not neurectoderm. gives rise to sensory epithelia of the nose, inner ear, lens, ant. pituitary, and some neurons of sensory ganglia of cranial nerves

Front 43

origin of the sensory epithelia of the nose and inner ear?

Back 43

placodal ectoderm

Front 44

give rise to the branchial arches and periocular tissues

Back 44

cranial neural crest cells

Front 45

give rise to melanocytes, schwann cells, chromaffin cells, and others

Back 45

trunkal neural crest cells

Front 46

malignant melanoma is a tumor associated w/ __

Back 46

NCC's (melanocyte)

Front 47

neurofibromatosis is a tumor associated w/ __

Back 47

NCC's

Front 48

caused by inappropriate closing of the posterior neural tube during the first month of pregnancy (wk 4?)

Back 48

spina bifida

Front 49

caused by failure of the anterior neural pore to fuse

Back 49

anencephaly

Front 50

a herniation of brain tissue through a hole in the skull

Back 50

encephalocoele

Front 51

failure of the lobes of the brain to separate

Back 51

holoprosencephaly

Front 52

condition in which the cerebellar tonsils slip into the foramen magnum

Back 52

Arnold Chiari formation

Front 53

in humans, the ___ induces the ectoderm to become the nervous system by blocking ___

Back 53

notocord; BMP

Front 54

noggin, chordin, and follistatin block the ____ signalling pathway

Back 54

BMP

Front 55

___ acts on the ectoderm to cause formation of epidermis

Back 55

BMP

Front 56

the default pathway of the ectoderm is development into ___

Back 56

neural tissue

Front 57

fusion of the neural folds require the cell adhesion molecules ___ and ____

Back 57

N-cadherin and N-Cam

Front 58

gradients of molecules establish dorsal-ventral patterning of the neural tube. the dorsal epidermis establishes a gradient of __ and the notocord establishes a gradient of ___

Back 58

dorsal epidermis - BMP (BMP 4,7,and dorsalin)

notocord - Sonic hedge hog (Shh)

Front 59

what establishes the alar and basilar plates of the spinal cord

Back 59

a dorsal gradient of BMP established by the dorsal epidermis

a ventral gradient of Sonic hedge hog established by the notocord

Front 60

holoprosencephaly results from a mutation of ____

Back 60

Shh (sonic is such a bastard!)

Front 61

Wnt, BMP, retinoic acid, and FGF are examples of ____

Back 61

anteriorizing and posteriorizing factors

Front 62

transcription factors differentially expressed along the anterior-posterior axis that regulate other transcription factors involved in development

Back 62

hox (homeobox domain) genes

Front 63

describe the process of corticogenesis

Back 63

the whole brain develops from a single layer of neuroepithelium
"progenitor cells" capable of becoming cortical neurons or glia proliferate in the ventral epithelium. they then migrate to the intermediate zone and then along radial glia to the cortical plate. layer VI (the innermost layer) forms first. Layer I forms last. the cortex forms from the inside outwards. the cells destined to become glia keep dividing once they reach the cortical plate

Front 64

why does the ventricular epithelium appear pseudostratified?

Back 64

it is the proliferative zone, and the cells are at different stages of proliferation. the nucleus changes relative position as the cells prepare to divide and divide.

Front 65

ApoER2 and VLDLR are two signalling receptors involved in ____

Back 65

neuronal migration (to the cortex)

Front 66

___ span the length of the cortex and allow for a high degree of correspondence b/t where neurons are produced and where they migrate to in the cortex

Back 66

radial glia cells

Front 67

where does neurogenesis occur postnatally?

Back 67

hippocampus
subventricular region of the cortex

Front 68

Reelin is an extracellular matrix molecule involved in ____

Back 68

migration

Front 69

cell adhesion molecules like N-Cam and N-cadherin, along with neurotrophic factors like BDNF are important in which stage of nervous system development?

Back 69

synaptogenesis /targetting

Front 70

which stage of nervous system development does not end until six months postnatally

Back 70

differentiation

Front 71

proneural genes and gliogenic genes

Back 71

genes whose expression determine whether a progenitor cell will develop into neuron or glia

Front 72

when neurons lose in the competition for neurotrophic factors, what happens?

Back 72

they undergo synaptic elimination or apoptosis

Front 73

which cells in the brain are not derived from neurectoderm?

Back 73

microglia