Lecture 29: Nervous System Development III Flashcards
What is the difference between the positioning of grey matter in the brain vs spinal cord?
Spinal cord: gray matter centrally located
Brain: gray matter in cortices built on top of white matter
Classical definition of a cortex
Consists of multiple layers of gray matter and is built from the inside out
What is the role of radial glial cells in building a cortex?
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
What nervous tracts does the basal plate give rise to?
Motor tracts
What nervous tracts does the alar plate give rise to?
Sensory tracts
Name the major derivatives of the metencephalon
Pons, Cerebellum
What induces the rhombic lips?
Interaction between roof plate and neural tube via BMP signaling
What are the superior cerebellar peduncles?
Massive fiber bundles b/w cerebellum and mesencephalon
What are the major derivatives of the mesencephalon?
Tectum, superior and inferior colliculi
What is the function of Otx-2 in relation to Shh?
Confines Shh to basal part of midbrain
Where do cerebral peduncles form, what is their function?
Ventrolateral region of mesencephalon; carry fibers b/w hemispheres and spinal cord
What are the major derivatives of the diencephalon?
Epithalamus, thalamus, hypothalamus
Whatis the Arnold-Chiari malformation and how does it relate to hydrocephalus?
Cerebellum herniates into foramen magnum, preventing escape of CSF from skull - leads to hydrocephalus
Rachischisis
Blatant closure defect of spinal cord
What substance, when elevated in amniotic fluid, is diagnostic of closure defects?
Alpha-fetoprotein
List closure defects from least to most serious
Spina bifida occulta, spina bifdia meningocele, spina bifida myelomeningocele, rachischisis, cranioschisis
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
E. Shh
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
A. basal plate
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
D. Spina bifida occulta
Growth cones adhere strongly to a substrate containing:
A. Ach B. Laminin C. Epinephrine D. Norepinephrine E. Shh
B. Laminin
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
D. Rachischisis
Rhombomeres are segmental divisions of the:
A. Forebrain B. Midbrain C. Hindbrain D. Spinal cord E. None of the above
C. Hindbrain
Rathke’s pouch arises from:
A. Diencephalon B. Stomodeal ectoderm C. Mesencephalon D. Pharyngeal endoderm E. Infundibulum
B. Stomodeal ectoderm
