Flashcards in Neurology Deck (213)
How are the alar & basal plates organized?
In closed spinal cord, alar plate (sensory) is dorsal & basal plate (motor) is ventral.
In the medulla & pons, the basal plate is medial & the alar plate is lateral. Within these, the visceral nuclei are generally closest to the sulcus limitans.
What are the primary vesicles?
1) Prosencephalon (forebrain)
2) Mesencephalon (midbrain)
3) Rhombencephalon (hindbrain)
What are the secondary vesicles?
What does the telencephalon give rise to?
Cerebral hemispheres & lateral ventricles
What does the diencephalon give rise to?
What does the mesencephalon give rise to?
Midbrain & cerebral aqueduct
What does the metencephalon give rise to?
Top half of 4th ventricle
What does the myelencephalon give rise to?
Bottom half of fourth ventricle
When does the neural tube develop?
Day 18-day 21
What is seen in the amniotic fluid with a neural tube defect?
What are the caudal neural tube defects?
Spina bifida occulta --> bony canal not closed, tuft of hair
Meningocele --> meninges herniate through spinal canal defect
Meningomyelocele --> meninges & spinal cord
What is seen with anencephaly
Polyhydramnios (no swallowing center in brain)
No forebrain, open calvarium
What causes anencephaly?
Lack of folate
Anterior neural tube does not close
What causes holoprosencephaly?
Failure of R & L hemispheres to separate
May be due to sonic the hedgehog defect
What is seen with holoprosencephaly?
Severe form --> cyclopia
What is seen with congenital cerebral aqueduct stenosis?
Enlargement of lateral & third ventricles
Enlarging head circumference (sutures not yet fused)
What is seen with Arnold-Chiari malformation?
Type I - modest herniation, usually clinically silent
What is seen with Dandy-Walker malformation?
Agenesis of cerebellar vermis --> cystically enlarged 4th ventricle
The cerebellum is basically missing.
Hydrocephalus & spina bifida can be seen
Where is the most common site of a syringomyelia?
What is seen with a syringomyelia?
Bilateral loss of pain & temperature sensation in upper extremities
Later stages --> LMN signs of arms; Horner's syndrome
Can extend downward
Fine touch & proprioception are spared
What causes syringomyelia?
Chiari I malformation
Scoliosis is a hint that syringomyelia may be present
What is the sensory innervation of the tongue?
Sensation - V3
Taste - VII
Sensation & taste - IX or X (extreme posterior is X)
What neural cells arise from the neuroectoderm?
How can one stain for the cell bodies of neurons?
Stain for Nissl substance (RER). Only present in the cell body.
What do Meissner's corpuscles sense?
Found on hairless (glabrous) skin
What do Pacinian corpuscles sense?
What do Merkel's discs sense?
Deep static touch
What are the layers surrounding a PNS nerve?
Epineurium surrounds whole nerve
Perineurium surrounds fascicle of nerve fibers
Endoneurium surrounds individual fibers
Where is NE synthesized?