Term
| When does fusion of neural folds begin? Where does folding begin? How long does it last? What is this process called? |
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Definition
| 21 days; proceeds from middle in a cranio-caudal fashion; 4 days; neurulation |
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Term
| What is the cranial portion of the neural tube destined to become? |
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Definition
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Term
| What is the caudal portion of the neural tube destined to become? |
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Definition
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Term
| The inner layer of the newly formed neural tube is lined with neuroepithelial cells. What do these become? |
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Definition
| neuroepithelium--->de-differentiate to become either neuroblasts (neuron precursors) or ependymal cells, which line the central canal of the neural tube and the ventricles of the brain. |
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Term
| What do the collection of neuroblasts make up? |
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Definition
| cell bodies make up the mantle layer (gray matter) of spinal cord, processes become marginal layer (white matter) |
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Term
| Which ventricles of the brain make up the choroid plexus that will eventually produce CSF? What cells line these ventricles? |
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Definition
| lateral, third, and fourth ventricles; ependymal cells |
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Term
| The alar or basal plates, or the dorsal and ventral columns, respectively, become which parts of the spinal cord? What does the intermediolateral cell column become? |
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Definition
alar/dorsal column=dorsal horn of spinal cord, sensory information
basal/ventral column=ventral horn of spinal cord, motor information
intermediolateral cell column=autonomic neurons |
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Term
| Which root grows into the laterally placed somites? At which spinal level would these roots contain autonomic information? |
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Definition
| ventral root; T1-L2 and S2-S4 |
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Term
| How does the outgrowing axons of the newly forming ventral roots grow towards the dermamyotome? |
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Definition
| The growth cone contains filopodia that direct them into the direction of the appropriate muscle masses |
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Term
| How do the sensory nerves in the dorsal root ganglia connect with the spinal cord? |
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Definition
| When the ventral root gets close enough to the dorsal root ganglia to form the spinal nerve, the sensory fibers grow until they reach the dorsal horn of the spinal cord. |
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Term
| What do sensory neurons that grow towards the spinal cord synapse with once they enter the dorsal horn of the spinal cord |
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Definition
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Term
| What is the dorsally located mass of cells derived from a somite called? The ventrally located? What do they become? |
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Definition
dorsal-epimere (neck/back)
ventral-hypomere (thoracic/abdominal walls) |
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Term
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Definition
| A group of muscles that are primarily innervated from a single spinal nerve. |
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Term
| What is the condition that arises when the entire neural tube fails to close? When it partially closes? |
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Definition
| craniorachischisis totalis; partial rachischisis, which usually occurs in lumbosacral region |
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Term
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Definition
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Term
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Definition
| brain is located outside of the skull |
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Term
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Definition
| the stimulation of a specific developmental pathway in one group of cells by a closely approximated group of cells. |
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Term
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Definition
vertebral arch fails to form completely due to disruption of induction;
occulta=incomplete arch; site covered by hair
cystica=meninges protruding into cyst through opening in arch
meningocele=herniation of meninges only
meningomyelocele=herniation with spinal cord/spinal nerve involvement. leads to hydrocephaly |
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Term
| What do the neural crest cells become? |
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Definition
| dorsal root ganglia, sympathetic chain ganglia, preaortic sympathetic ganglia, microscopic enteric ganglia, adrenal medulla cells, melanocytes |
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Term
| What is the cause of Hirshsprung's disease (congenital megacolon)? What are its symptoms? |
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Definition
| lack of ganglia in walls of large intestine; absence of peristalsis causes constipation |
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Term
| What is a pheochromocytoma? How is it formed? |
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Definition
| neural crest cells that fail to become part of the adrenal medulla become a catchecholamine-producing tumor, symptoms: HBP episodes, headaches, palpitations, nervousness |
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