7 Development Of Nervous System

Question 1

Gastrulation occurs during the _____ week of embryogenesis.

What are the 3 structures to develop first?

What gives rise to the CNS?
What gives rise to the PNS and other structures?

Answer 1

Third

Notochord, neural tube, neural crest.

Neural tube
Neural crest

Question 2

The CNS develops from the primitive ________. The first step of neural system development is formation of the _______ plate. Invaginates and forms ______ groove. At the end of the 3rd week, the groove becomes the ______ tube.

What segments of the spinal cord are formed by secondary neurulation?
The caudal eminence joins the ______ tube.

Answer 2

Ectoderm.
Neural.
Neural
Neural

Sacral and coccygeal
Neural

Question 3

Development of the CNS

During the ______ week the anterior neuropore closes. Three primary brain vesicles formed dividing the brain into:

___________ (forebrain)
___________(midbrain)
___________(hindbrain)

Two flextures, the ______ flexture is between hindbrain and spinal cord. The second is at the level of the midbrain called the ___________ flexure.

Answer 3

Fourth

Proencephalon
Mesencephalon
Rhombencephalon

Cervical
Mesencephalic

Question 4

During the _____ week the 3 primary brain vesicles divide into 5 secondary vesicles.

The optic cup and nerves bulge from the diencphalon to form the ___.

Answer 4

Fifth

Eye

Question 5

In the brainstem, the neurons provide preganglionic ______________ innervation to the peripheral ganglia that serve visceral structures.

Regarding the cerebellum, what appears first: the posterolateral fissure or the primary fissure?

Answer 5

Parasympathetic

Posterolateral fissure is first to arise, primary is second.

Question 6

Defect in migration of cells of neural crest can result in the constant contraction without relaxation in the bowels which causes abdominal pain and chronic constipation is called?

Defects of prosencephalization are commonly associated with 3 major environmental exposures: ________, Retinoic ____, and genetic ________.

Answer 6

Hirschprung

Alcohol. Acid. Anomalies (trisomy 13 and 18)

Question 7

The forebrain can be divided into 2 secondary parts:

__________, which houses CN-I, and _________, which houses CN-II.

Answer 7

Telencephalon

Diencephalon

Question 8

The midbrain’s secondary brain vesicle is ___________.

There are two cranial nerves found here: CN-___ and CN-_____.

Answer 8

Mesencephalon

CN-III oculomotor
CN-IV trochlear

Question 9

The hindbrain’s secondary divisions include
_______, which houses the pons and cerebelum, and the _______, which houses the medulla oblongata. Cranial Nerves ________ can be found in the hindbrain.

Answer 9

Metencephalon
Myelencephalon

CN's:
V trigeminal
VI abducens
VII facial
VIII vestibulocochlear
IX glossopharyngeal
X vagus
XI hypoglossal

Question 10

The spinal cord develops from ______ portions of the neural ______.

Answer 10

caudal

neural tube

Question 11

During the formation of the spinal cord, a pair of anteriorly located cell masses, the basal plates, will develop to become the _______ and the posteriorly located cell masses, the alar plates, will develop to become the _______.

The basal and alar plates are separated by a longitudinal groove called the _______.

Answer 11

anterior horns (motor)
posterior horns (sensory)

sulcus limitans

Question 12

The portion of the spinal cord that originates from the interface of the alar and basal plates is called ______. It will go on to become the ______.

Answer 12

intermediate zone (lateral horn)

sympathetic nervous system

Question 13

Anterior horn motor neurons innervate ______ and are called ________.

Answer 13

skeletal muscle

somatic efferent (SE)

Question 14

Lateral horn motor neurons project to _______ and are classified as _________.

Answer 14

autonomic ganglia (visceromotor ganglia)

visceral efferent (VE)

Question 15

The visceral efferent (VE) column stretch, called the intermediolateral cell column, extends from ___ to ____ and it’s sacral visceromotor nucleus stretch extends from ____ to _____.

Answer 15

T1-L2

S2-S4

Question 16

How does the neural tube form from the flat ectodermal layer? What causes this process to begin? What pathology results from failure of the rostral end of the neural tube (anterior neuropore) to close? From failure of the posterior end (posterior neuropore) to close? What is the difference between meningoencepahlocele and meningohydroencepahlocele? What is the difference between meningomyelocele and meningohydromyelocele? What is the difference between cranioschisis and myeloschisis? What are some causes and a preventative factor for spina bifida?

Answer 16

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Question 17

Draw a simple sketch of the hollow neural tube segments or “brain vesicles”, label one side ventral or the other side dorsal, and label the parts of the neural tube that eventually become the following regions: telencephalon, thalamus, hypothalamus, midbrain, pons, cerebellum, medulla, and spinal cord

Answer 17

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Question 18

What are the different embryological origins of the CNS versus PNS? What specific parts of the nervous system are derived from the neural crest? What is Hirschsprung disease and the developmental defect that causes it?

Answer 18

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Question 19

(LO) In the developing spinal cord, what is the alar plate, basal plate, and sulcus limitans? What adult structures or functions do the alar and basal plates form? What develops in the intermediate zone (along the border between the alar and basal plates?

Answer 19

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Question 20

(LO)
In the developing brainstem, describe how the arrangement of sensory, visceral, and motor structures differs from the developing spinal cord..

Answer 20

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Question 21

(LO) Describe how the pons and cerebellum develop from the neural tube. What is Dandy-Walker Syndrome? What are the clinical signs and abnormal findings on brain imaging?

Answer 21

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Question 22

(LO) What is the difference in the malformations seen in Chiari type I and type II?

Answer 22

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Question 23

(LO) Explain the normal sequence of events in formation of the cerebrum starting with the single brain vesicle it forms from onward to the formation of 2 cerebral hemispheres? What are the major detects in this process? What are some known causes?

Answer 23

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Question 24

(LO) In the development of the ventricular system, what event leads to the replacement of amniotic fluid in the ventricles with choroid plexus? What are the consequences of defective development of the cerebral aqueduct?

Answer 24

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Question 25

(LO) Describe the process that leads to formation of the 6 layers of the cerebral cortex. Where does cell division (mitosis) and proliferation of neurons occur? Where do new neurons migrate to? What is the role of radial glia?

Answer 25

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