Neurology - Part 1 Flashcards
The notochord forms the _____ _______ of the intervertebral
Nucleus pulposus
The notochord is derived from the _____
Mesoderm
Stimulation of the ectoderm then creates the _____ _____ cells
Neural crest
The neural tube is derived from the ______ ______
medial ectoderm
The neural tube creates what two bodily structures?
The brain and spinal cord
What helps protect against neural tube defects during pregnancy?
Folic Acid
What medication is generally safe to use during pregnancy for management of gestational diabetes?
Metformin
The dura mater has embryologic origins of ______ tissue
mesodermal
The epidural space has what two clinical correlations?
Epidural anesthesia and epidural hematoma
The arachnoid mater is derived from _____ ______ cells
Neural crest
The subarachnoid space is known for what three clinical aspects?
Contains CSF, subarachnoid hemorrhage, lumbar puncture
Pia mater is derived from where?
Neural crest cells
The thalamus and hypothalamus originate from the _________
Diencephalon
What is the embryologic origin of the forebrain?
Prosencephalon
What are the vesicles of the forebrain?
The Diencephalon and Telencephalon
What are the derivatives of the diencephalon?
Hypothalamus, thalamus, and pineal gland
What are the derivatives of the telencephalon?
Cerebral hemispheres and basal ganglia (not all basal ganglia)
What is the embryologic origin of the midbrain?
Mesencephalon
What is the vesicle of the midbrain?
The mesencephalon
What is the derivative of the midbrain?
The midbrain
What is the embryologic origin of the hindbrain?
The rhombencephalon
What are the vesicles of the hindbrain?
Metencephalon and myelencephalon
What are the derivatives of the metencephalon?
Cerebellum and pons
What are the derivtives of the Myelencephalon?
Medulla
the Telencephalon is not derived from where?
the neural tube
What are the three primary vesicles the neural tube develops into?
The prosencephalon, mesencephalon, and the rhombencephalon
________ is commonly due to failure of closure of the rostral neuropore
Anencephaly
anencephaly is commonly due to what?
Failure of closure of the rostral neuropore
Anencephaly can be found by an elevation of what marker from the mother?
Elevated AFP (alpha fetal protein)
Anencephally is absence of the ______
Forebrain
Is anencephaly compatible with life?
No
Lissencephaly is the lack of?
Cortical sulci and gyri
The lack of cortical sulci and gyri is called?
lissencephaly
What are the sign and symptoms of Lissencephaly?
Microcephaly, ventriculomegaly, hydrocephalus, and craniofacial abnormalities
Caudal neuropore is for what condition?
Spina bifida
Myelomeningocele is classically associated with ________ malformations
Chiari II
Spina bifida occulta most likely presents with normal _____ levels
AFP ( Alpha fetal protein)
Spina bifida is a _____ defect
Vertebral
What are the sign and symptoms of spina bifida?
a skin dimple or “patch of hair”
A ____ is a hernia defect where the meninges nor spinal cord are in the hernia
Meningocele
What are the sign and symptoms of Meningocele?
+/- motor impairment, developmental delay, bladder and bowel incontinence
________ is associated wit high amniotic fluid index (polyhydramnios) due to impaired fetal swallowing
Anencephaly
Anencephaly is associated with high _______ due to impaired?
high amniotic fluid index (Polyhydramnios) due to impaired fetal swallowing
Schwann cells are derived from what origin?
Neural crest cell
Schwann cells are associated with which nervous system?
Peripheral nervous system
One Schwann cell myelinates _____ axon
One
What is the classical marker for schwann cell pathology?
S100 positive
Schwann cells are efficient in wallerian ______ and _______
Degeneration and regeneration
What are the classical pathology associations of schwann cells?
Acoustic neuroma and Guillan-Barre syndrome
Oligodendrocytes are apart of which nervous system?
Central nervous system
One oligodendrocyte myelinates _____ axons
Many
Schwann cells come from what origin?
Neural crest cells
What is the origin of Oligodendrocytes?
neuroectoderm
___________ are not effective in wallerian degeneration and regeneration
Oligodendrocytes
What are the classical pathologies associated with oligodendrocytes?
Multiple sclerosis, progressive multifocal leukoencephalopathy (PML), and oligodendroglioma
What do astrocytes assist in?
maintanence of the blood brain barrier
Where do astrocytes originiate from?
Neuroectoderm origin
The glial fibrillary acidic protein (GFAP) marker is important for which cells?
Astrocytes
Astrocytes are associated with which classic pathology?
Glioblastoma multiforme
Microglia are the _____ of the CNS
phagocytes
Where do microglia originate from?
Mesoderm
What pathology are microglia associated with?
HIV associated dementia
HIV associated dementia is associated with which cells
Microglia
What pathology should be remembered in patients with bilateral schwannomas
Neurofibromatosis type 2
What kind of tumors have a “friend egg” appearance under the microscope?
Oligodendrogliomas
What cells are primarily responsible for reactive gliosis following CNS neuronal injury?
Astrocytes
The derivatives of the neural tube (CNS) consist of?
The brain, CNS neurons, oligodendrocytes, astrocytes, ependymal cells, pineal gland, and spinal cord
The neural crest cell derivatives consist of?
(EMO PASS)
Enterochromaffin cells
Melanocytes
Odontoblasts
PNS ganglia
Adrenal medulla
Schwann cells
Skull bones
What forms nissle substance?
Collections of Rough ER
Of a neuron, what is the:
-Body
-Output
-Input
Body: Soma
Output: Axon
Input: Dendrite
neuron anatomy, the soma primarily contains cell ______ including __________
organelles; including nissle substance
What is the role of the axon?
To send out action potentials
What is the role of the dendrite?
-Also contains?
To recieve input
-Also contains nissle substance
Kinesin is the motor protein for ___________
Anterograde transport
Dinein is the motor protein for __________
Retrograde transport
When there is neuronal injury, what two things are evident?
Cellular edema (peripheral nuclei) and chromatolysis
The ________ _______ cannot be visualized with nissle staining
Neuronal axon
Which nervous system is the Wallerian degeneration more efficient?
Peripheral nervous system
What is the general idea of Wallerian degeneration?
The proximal axonal membrane is retained by axonal retraction and distal degeneration and clearing of axonal debris
Axotomy PNS is (more/less) efficient than Axotomy of CNS?
More
What is the mechanism of Axotomy PNS?
-What removes the axonal debris?
Schwann cells separate myelin into fragments and promote regeneration; Macrophages remove axonal debris
Axotomy of the CNS is not _____________;
-Why?
Efficient;
-Because oligodendrocytes are inefficient at removing myelin, macrophages must cross blood brain barrier.
Axonal damage in the brain can be associated with what specific pathology?
Stroke
What fibers are responsible for transmission of painful sensations?
Alpha delta and C fibers
What are the characteristics of Alpha Delta fibers (sensory receptors)
Myelinated, primary sensory transmission of temperature and pain, fast conduction velocity, higher space constant, and lower time constant
What are the characteristics of C fibers?
Unmyelinated, Primary sensory transmission of general pain, slow conduction velocity, lower space constant and higher time constant
Space constant is also referred to as?
Length constant
A higher space time means a ______ time
Shorter
A shorter time means there’s a _______ conduction rate
Faster
What cell has a “onion skin” appearance on histology slides?
Pacinian Corpuscles
Meissner Corpuscles:
-Size and myelination
-Primary sense
- Hi-yield
-Histology
1.) Can vary in size and myelination
2.) Fine and light touch; Low frequency vibration
3.) Located in areas without hair
4.) Dermal papillae
Pacinian Corpuscles:
- Size and myelination
-Primary sense
- Histology
1.) Large, myelinated
2.) Deep touch and pressure; high frequency vibration
3.) Onion skin
Merkel Discs:
- Size and myelination
-Primary senses
-Location?
1.) Large, myelinated
2.) Pressure; Proprioception
3.) Fingertips and areas with hair follicles
Ruffini corpuscles:
-Size and myelination
- Primary senses
- Location
1.) Large, myelinated
2.) Low frequency vibration; Sustained pressure
3.) Located in joints
What is proprioception also referred to as?
Kinesthesia
What is proprioception?
Sense of own bodies position without visual input
What tract is responsible for pain and temperature sensation?
Lateral spinothalamic tract
Within the spinal cord tracts, the spinothalamic tract sensations travel how many spinal levels and in which direction prior to decussation?
1-2 levels superiorly
What tract is primary sensation for crude touch and pressure?
Anterior spinothalamic
Which tracts are the sensory tracts and which are the motor tracts?
Ascending tracts are sensory tracts and descending are motor
What does decussate mean?
To cross over
What are the most high yield sensations associated with the anterolateral system?
Pain and temperature
What tract is responsible for vibration and proprioception sensation?
the Dorsal column-medial lemniscus
What is the sensory and function of the Dorsal column-medial lemniscus?
Fine touch; Low frequency vibrations; proprioception; Pressure and high frequency vibration;
The DCML ______ at the medulla
Decussates
What neuronal tract effects T6 and all its lower extemities?
The Fasciculus gracilis
Where is the fasciculus gracilis located?
located Medially in dorsal column
What neuronal tract effects T5 and ascending?
The Fasciculus cuneatus
Where is the Fasciculus Gracilis located?
Located laterally in dorsal column
What tracts are responsible for unconscious proprioception?
Spinocerebellar
All fibers carry data to the _______ cerebellum. This may involve double ________
Ipsilateral; Decussation
