Embryology of the Nervous System Flashcards Preview

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Flashcards in Embryology of the Nervous System Deck (31):
1

When does most neuronal production and migration occur?


•third through fifth months of development•

The formation of neural connections (neuropil) and production of myelin sheaths continue after birth
 

2

When does gliogenesis take place?

during the second and third trimesters of pregnancy and early postnatal development

3

What does the mesoderm provide to the ectoderm

neural-inducing morphogens

4

what is required for formation of the neural plate?

What does the plate come from

Notochord

overlying ectoderm

5

What  is neurulation? 

What does it involve?

process of forming the neural tube from ectoderm 


•Neurulation involves:
–1) Formation of a neural plate
–2) Neural plate becomes neural groove surrounded by crests
–3) Groove becomes closed neural tube in highly ordered fashion 
 

 

6

What does spina bifida result from?

Incomplete caudal neural tube closure

7

What does anencephaly result from? 

What is something that may prevent this?

Incomplete rostral neural tube closure.

Folate?

8

What does the neural tube develop into?

CNS

9

What are the3 vesicles that develop into the future brain?

Prosencephalon of forebrain

Mesencephalon of midbrain

Rhombencephalon of hindbrain

10

What are the flexures composed of, (structures)

What are the 5 secondary vesicles after seperation?

 

  1. –Cephalic flexure bet. Mesencephalon and prosencephalon 
  2. –Cervical flexure bet. Rhombencephalon and spinal cord
  3. –Rhombencephalon sep. to metencephalon and myelencephalon at level of pontine flexure
  4. –Prosencephalon sep. to diencephalon and telencephalon

11

Talk through the specific structures that arise from each vesicle.

See slide 16 to check yourself.

Cerebral cortex, basa ganglia

thalamus, hypothalumus, retina

midbrain

cerebellum, pons

medulla

12

What does the lumen of the neural tube become?

What is the choroid plexus?

Ventricular system


•Choroid plexus is vascular tissue + pia + ependymal cells
–Makes CSF
–Not in aqueduct nor spinal cord
 

 

13

What forms the C shape of the brain?

cortical development around the insula

14

What are the two signaling systems that pattern the dosoventral axis?

Sonic hedgehog (Shh) = secreted signaling molecule; initially expressed in the notochord (N)- planar signaling

Bone morphogenetic proteins (BMPs) = secreted signaling proteins with a variety of functions; expressed in ectoderm (ECT)- lateral signaling

Shh = ventral; expressed in notochord and floorplate (F)

BMPs = dorsal; expressed in epidermis

 

15

What happens once the nural tube is closed?

Once the neural tube is closed, the roofplate expresses one signal and the floorplate expresses a second signal.  These signals are responsible for patterning dorsal and ventral regions of the spinal cord, respectively.

16

What is the Bell-Magendie law?

HUH?

17

What does the mantle zone become?

Marginal?

Where do neurons start out?

Mantle zone becomes gray matter,

marginal zone becomes white matter.

Neurons start out in the ependymal zone (also known as the ventricular zone). Mantle zone is also known as the intermediate zone. Ependymal zone becomes less populated as neurons move out. Use this to desribe how you work your way out.

18

Describe neurogenesis?

Progenitors become radial glia and then can develop into either neurons or glia.

 Both neuroepithelial and adial glia are considered pluripotent.

19

At what point in development is it decided wether a cell will become a neuron or a glia?

?

20

Where does Adult take place?

?

21

In the formation of the brainstem: myelencephalon, what does the roof plate form?

Alar plate

Basal plate

ependymal.... choroid plexus

sensory nuclei for CN VII-X

motor nuclei or CN VII-XII

22

Metencephalon forms two divisions, what are they and what do they become?

1)Dorsal division looks like medulla
A)Alar plate forms cerebellum

1. Develops from Rhombic Lip

B)Sensory Cranial Nuclei (V)

2) Ventral division, basal pons contains pontine nuclei. This doesn’t follow typical dorso-ventral patterning

23

What does the mesencephalon form?

Alar plate of the mesencephalon forms the  corpora quadrigemina

  (Inferior colliculi and     Superior colliculi)

GSA of CN V is another alar-derived nucleus

 

Tegmentum

Basal plate of the mesencephalon forms GSE and GVE of CN III

GSE of CN IV

24

What does the diencephalon form?

Alar plate is largely thalamus

Basal plate is largely hypothalamus

Roof and alar plates give rise to epithalamus (habenula and pineal)

Optic cup, another derivative, becomes CN II

25

What are the two waves of formation for the telencephalon?

Initial pattern of gray and white matter development is similar to that of the rest of the neural tube.

The neocortex (or neopallium) undergoes a second pattern of development to allow for many layers (6)

26

What role do radial glia have in addition to acting as neural progenitors?

?

27

Formation of the Neocortex is......?

Laminar. oldest neurons are deepest

28

What are the layers of the neocortex?

Layer I—Mostly die (latest to develop)

Layer II--Small and med. pyramidal neurons

  LAYERS II and III connected between hemispheres via corpus callosum

Layer III—Small and med. pyramidal neurons

Layer IV—Stellate and granule

  MOSTLY RECEIVE SENSORY INFO

Layer V—Large pyramidal neurons

Layer VI (first to develop)

29

What is the fate of neural crest cells?


•Neural crest forms the majority of the peripheral nervous system
–Autonomic Ganglia
–Spinal nerves
–Schwann cells
–Melanocytes
–Adrenal medullary cells
–Pia
–Arachnoid
–Tendons of facial musculature
 

30

Where are cranial nerves derived from?

neural crest around axis of neural tube.

 

A image thumb
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