Lecture 29: Nervous System Development III

Question 1

What is the difference between the positioning of grey matter in the brain vs spinal cord?

Answer 1

Spinal cord: gray matter centrally located

Brain: gray matter in cortices built on top of white matter

Question 2

Classical definition of a cortex

Answer 2

Consists of multiple layers of gray matter and is built from the inside out

Question 3

What is the role of radial glial cells in building a cortex?

Answer 3

Migrating bipolar neurons uses long process of radial glial cell as a guiding mechanism to reach surface where they can begin to layer the cortex

Question 4

What nervous tracts does the basal plate give rise to?

Answer 4

Motor tracts

Question 5

What nervous tracts does the alar plate give rise to?

Answer 5

Sensory tracts

Question 6

Name the major derivatives of the metencephalon

Answer 6

Pons, Cerebellum

Question 7

What induces the rhombic lips?

Answer 7

Interaction between roof plate and neural tube via BMP signaling

Question 8

What are the superior cerebellar peduncles?

Answer 8

Massive fiber bundles b/w cerebellum and mesencephalon

Question 9

What are the major derivatives of the mesencephalon?

Answer 9

Tectum, superior and inferior colliculi

Question 10

What is the function of Otx-2 in relation to Shh?

Answer 10

Confines Shh to basal part of midbrain

Question 11

Where do cerebral peduncles form, what is their function?

Answer 11

Ventrolateral region of mesencephalon; carry fibers b/w hemispheres and spinal cord

Question 12

What are the major derivatives of the diencephalon?

Answer 12

Epithalamus, thalamus, hypothalamus

Question 13

Whatis the Arnold-Chiari malformation and how does it relate to hydrocephalus?

Answer 13

Cerebellum herniates into foramen magnum, preventing escape of CSF from skull - leads to hydrocephalus

Question 14

Rachischisis

Answer 14

Blatant closure defect of spinal cord

Question 15

What substance, when elevated in amniotic fluid, is diagnostic of closure defects?

Answer 15

Alpha-fetoprotein

Question 16

List closure defects from least to most serious

Answer 16

Spina bifida occulta, spina bifdia meningocele, spina bifida myelomeningocele, rachischisis, cranioschisis

Question 17

What molecule produced by the notochord is responsible for inducing the floor plate of the neural tube?

A. Hoxa-5
B. Retinoic acid
C. Pax-3
D. Msx-1
E. Shh

Answer 17

E. Shh

Question 18

The cell bodies of motor neurons of spinal nerves arise from the:

A. basal plate
B. marginal zone
C. floor plate
D. roof plate
E. alar plate

Answer 18

A. basal plate

Question 19

An infant with a tuft of hair over the lumbar region of the vertebral column undergoes surgery for a congenital anomaly in that region. During surgery, it was found that the dura and arachnoid layers over the spinal cord were complete, but that the neural arches of several vertebrae were missing. What condition did the infant have?

A. Meningocele
B. Myelomeningocele
C. Encephalocele
D. Spina bifida occulta
E. Rachischisis

Answer 19

D. Spina bifida occulta

Question 20

Growth cones adhere strongly to a substrate containing:

A. Ach
B. Laminin
C. Epinephrine
D. Norepinephrine
E. Shh

Answer 20

B. Laminin

Question 21

Complete failure of the neural tube to close in the region of the spinal cord is:

A. SB occulta
B. Meningocele
C. Cranioschisis
D. Rachischisis
E. Myelomeningocele

Answer 21

D. Rachischisis

Question 22

Rhombomeres are segmental divisions of the:

A. Forebrain
B. Midbrain
C. Hindbrain
D. Spinal cord
E. None of the above

Answer 22

C. Hindbrain

Question 23

Rathke’s pouch arises from:

A. Diencephalon
B. Stomodeal ectoderm
C. Mesencephalon
D. Pharyngeal endoderm
E. Infundibulum

Answer 23

B. Stomodeal ectoderm