Term
| When does Neurulation begin? |
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Definition
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Term
| What signals the medial ectoderm to specialize into neuro-ectoderm? |
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Definition
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Term
| How is Ectodermal phenotype maintained? |
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Definition
Process of autocrine signalling. The ectoderm cells secrete BMP-4 to maintain cell phenotype
Binds causing a phosphorylation event
-smad transcription factors |
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Term
| How does the notocord signal ectoderm into neuro-ectoderm? |
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Definition
Releases BMP-4 antagonists
Chordin
Noggin
Follistatin |
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Term
| Primary neurulation has how many "zipper points"? |
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Definition
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Term
| What results from a closure failure at segment 2? |
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Definition
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Term
| What results from a closure failure at segment 5? |
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Definition
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Term
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Definition
| Neural tube defects of primary neurulation |
|
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Term
| Why do Neural Tube defects secondarily deform overlying tissue? |
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Definition
| Because neural tubes are responsibly for much of the signalling of surrounding tissue |
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Term
| What sort of deficiencies can cause a neural tube defects? |
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Definition
| Folate or B12 deficiency causes a decrease in methionine synthesis which then causes neural tube defects |
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Term
| What is the most common congenital brain malformation? |
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Definition
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Term
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Definition
partial brain (meroancephaly)
meninges absent or hypoplastic
sometimes acrania
cranioshisis
facial abnormalities
common cause of polyhydramnios |
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Term
| Why is anencephaly a common cause of polyhydramnios? |
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Definition
| Result in facial and neural deformities that keep the fetus from swalling appropriately and increase amniotic volume |
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Term
| What is an Arnold-Chiari malformation? |
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Definition
Herniation of cerebellar vermis and medulla through foramen magnum.
Caused by a small posterior cranial fossa |
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Term
| What is the name for an incomplete cranial closure allowing sacular protrusions through skull openings? |
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Definition
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Term
| What is the most common site for a cranial bifida? |
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Definition
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Term
| How would a Cranial meningocele be characterized? |
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Definition
| A cranial bifida in which CSF and Dura-arachnoid sleeve compose the sacular protrusion |
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Term
| How would a Meningoencephalocele be characterized? |
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Definition
| A cranial bifida in which cerebral tissue is contained within the sacular protrusion |
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Term
| How would a meningohydroencephalocele be characterized? |
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Definition
| A Cranial Bifida in which the the brain ventricle makes up the contents of the sacular protrusion |
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Term
| What are the three classes of Spina Bifida? |
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Definition
| Spina Bifida Occulta, Meningocele, and Myelomeningocele |
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Term
| Which is the only spina bifida presenting with sever neurological deficits? |
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Definition
Myelomeningocoele.
signs present inferior to lesion
motor/sensory deficits for lower extremity
parasympathetic dysfunction, incontinence |
|
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Term
| What is a myelodysplasia? |
|
Definition
| Congenital neural tube defect of the secondary neurulation |
|
|
Term
| What forms S3-S5 and coccygeal cord segments? |
|
Definition
|
|
Term
| What is the most common myelodysplasia? |
|
Definition
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Term
| What is Tethered cord syndrome? |
|
Definition
defective filum terminale
-abnormally taut
-caused by congenital thickening, local lipoma formation, or scarring from meningomyelocele repair |
|
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Term
| Where is the conus medullaris located at 8 weeks of gestation? |
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Definition
|
|
Term
| Where is the conus medullaris located at 24 weeks of gestation? |
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Definition
|
|
Term
| Where is the conus medullaris located on a newborn? |
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Definition
|
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Term
| Where is the Conus Medullaris located on an adult? |
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Definition
|
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Term
| What are the common presenting symptoms of tethered cord? |
|
Definition
Saddle anesthesia
urinary incontinence
motor signs to lower extremity |
|
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Term
| How is tethered cord treated? |
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Definition
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Term
| What are the three primary brain vesicles that are initially derived in the cranial region? |
|
Definition
Prosencephalon: Forebrain
Mesencephalon
Rhombencephalon: hindbrain |
|
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Term
| What are the two flexures in the neural tube? Which one remains in adults? |
|
Definition
Cephalic Flexure (Remains in adults)
Cervical Flexure |
|
|
Term
| Prosencephalon differentiates into which vesicles? |
|
Definition
Telencephalon
Diencephalon |
|
|
Term
| Thombencephalon differentiates in which vesicles? |
|
Definition
Metencephalon
Myelencephlon |
|
|
Term
| What does the Mesencephalon and Rhombencephalon become in adults |
|
Definition
Mesencephalon: Midbrain
Rhombencephalon
-Metencephalon: Pons
-Myelencephalon: Medulla |
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Term
| What cranial nerve is associated with the telencephalon? |
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Definition
|
|
Term
| What cranial nerve is associated with the diencephalon? |
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Definition
|
|
Term
| What cranial nerves are associated with the mesencephalon? |
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Definition
|
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Term
| What cranial nerves are associated with the metencephalon? |
|
Definition
| Trigeminal Abducens and Facial |
|
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Term
|
Definition
|
|
Term
| What cranial nerve is associated with the metencephalon/myencephalon junction? |
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Definition
|
|
Term
| What cranial nerves are associated with the myelencephalon? |
|
Definition
| Glossopharyngeal Vagus and Hypoglossal |
|
|
Term
| What cranial nerve is associated with the myelencephalon/Cord? |
|
Definition
|
|
Term
| What is the name of the disease in which prosencephalization fails? |
|
Definition
|
|
Term
| Each cerebral hemisphere contains: |
|
Definition
| Corpus Callosum, Basal Ganglia, Hippocampus, Lateral ventrical, and gray and white matter |
|
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Term
| What are the Diencephalon adult derivatives? |
|
Definition
| Thalamus, Hypothalamus, Pineal Gland, CN II, Retina, Posterior Pituitary |
|
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Term
| What are the signalling molecules responsible for dorsal-ventral polarity in the neural tube? |
|
Definition
BMP (Dorsal)
Shh (Ventral) |
|
|
Term
| What secretes Shh for neural tube ventral signalling? |
|
Definition
|
|
Term
| What secretes BMP for ventral neural tube signalling? |
|
Definition
| Dorsal ectoderm and roof plate |
|
|
Term
| BMP dorsal signalling eventually forms the ___ ____ which then becomes the dorsal horn |
|
Definition
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|
Term
| Shh ventral signalling eventually forms the ___ ___ which then becomes the ventral horn |
|
Definition
|
|
Term
| How is Dorsal ventral patterning done in proencephalization if the notocord does not reach that high? |
|
Definition
SHH secreted by midline ventral structures
-creates medial and lateral ganglionic eminences (LGE=basal ganglia) |
|
|
Term
| What are the master control genes of segementation in the body? |
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Definition
|
|
Term
| What initiates hindbrain segementation? |
|
Definition
| Shh and the Isthmic Organizer (IO) |
|
|
Term
| What induces the isthmic organizer? |
|
Definition
| Signalling from notochord and head-organizing regions |
|
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Term
|
Definition
| 7 designated hindbrain segments induced by Shh and Io |
|
|
Term
| What causes defective rhombomere formation? |
|
Definition
| Retinoids, powerful teratogen than inhibits hox expression |
|
|
Term
| Why are underage pregnant females such a high risk group for disrupted Hox gene expression? |
|
Definition
| Retinoic Acid is marketed for acne (commonly taken by teenagers) |
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