Introduction/Basic Physiology Flashcards

1
Q

What is the helpful pneumonic for thinking through the differential diagnosis of neuropathology?

A
  • VITAMIN C
    • Vascular
    • Infectious
    • Traumatic
    • Age-related/degenerative
    • Metabolic/nutritional/toxic
    • Inflammatory
    • Neoplastic
    • congenital
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2
Q

What are the 4 foundational cases for understanding the role of the brain and nervous system?

A
  • 1848 - Phineas gage - importance of frontal lobe for behavioral inhibitions
    • 1861 - Paul Broca’s patient - stroke in a specific area of the brain causing an inability to form language, combine with other patients and see that that area is the language center
    • 1953 - H.M. - removal of temporal lobe sections bilaterally, or part of hippocampus, and no short term memory, or permanent anterograde amnesia
    • 1999 - transient, reversible depression from Deep Brain Stimulation
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3
Q

What are brodmann’s areas?

A
  • Cytoarchitectonic variation in the cerebral cortex
    • An accepted way of organizing the architecture of the brain into functional domains
    • 52 total areas now based off of similarities on cellular and tissue level
    • Oversimplified, but still used
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4
Q

Where, in relation to the central sulcus, do the primary motor and somatosensory cortices lie?

A
  • Primary motor cortex VENTRAL to central sulcus

* Primary somatosensory cortex DORSAL to central sulcus

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5
Q

What are the given examples for behavioral therapies?

A
  • Psychotherapy
    • Counseling
    • Biofeedback
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6
Q

What are the given examples for physical therapies?

A
  • Surgery
    • Exercise
    • Spinal manipulation
    • Electroconvulsive therapy
    • accupuncture
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7
Q

What are the given examples for pharmacotherapies?

A
  • Perscription medications
    • Non-prescritpion drug use
    • Herbal remedies
    • Diet/nutritional therapies
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8
Q

The end goal of therapy for neuropathology is what?

A

• It all overlaps, produce lasting changes in behavior, lasting functional changes in the circuitry of the nervous system that underlie the behavior

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9
Q

What are the given elements of the neurologic exam?

A
  • Mental status exam/psychiatric exam
    • Reflex exam
    • Sensory exam
    • Motor exam
    • Cranial nerve exam
    • Examination of coordination and gait
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10
Q

What are the given elements for determining neuropathologies?

A

• The pneumonic - VITAMIN C

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11
Q

What are the given elements of the neuroanatomical localization?

A
  • Generalized vs. localized
    • Muscle
    • NMJ
    • Peripheral nerve
    • Spinal cord
    • Brainstem
    • Subcortical (Basal ganglia, cerebellum)
    • Cortical (vascular problems?)
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12
Q

What are the questions used while determining neuroanatomical localization?

A
  • Can the symptoms be explained by an identifiable pathologic change?
    • Can you account for symptoms with a process affecting the NS generally, or can a single focal/multifocal process explain the pattern?
    • If focal can explain symptoms, is it at muscle? NMJ? Peripheral? Spinal cord? Brainstem? Cortical? Subcortical?
    • Does the problem line up with a vascular problem?
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13
Q

What is meant by commissure?

A

In Neurology - A bundle of nerve fibers passing from one side in the brain or spinal cord to the other. - connecting one side of the brain to another as well
* a commissure is neuronal connection between symmetrical sides of the CNS (brain or SC)

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14
Q

The fissure of Roland refers to what structure?

A
  • Central sulcus

* Separates the frontal and parietal lobes

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15
Q

The Sylvian Fissure refers to what structure?

A
  • Lateral sulcus

* Separates the temporal lobe from the frontal and parietal lobes

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16
Q

How many “layers” of the cortex are there?

A

• 6, and they have to do with cell body layers histologically from superficial (I) to deep (VI)

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17
Q

What is meant by somatotopy?

A

• Topographic association of positional relationships of the body to functional areas of the cerebral cortex

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18
Q

What is meant by homunculus?

A
  • The figure of a human, projected with a “scale” to the area of the cortex dedicated to it
    • Projected on the brain surface
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19
Q

What is a decussation?

A
  • A place in the CNS where fibers from contralateral sides of the brain cross each other
    • Depicted in the brain stem
    • Looks like a roman numeral X or 10
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20
Q

What important concept did Cajal help define in 1906?

A
  • Neuron doctrine, neurons are the discrete functional units of information processing
    • They were surrounded by glia, a more support role cell
21
Q

What important discovery did Kandel elucidate?

A

• The “epigenetic” component of memory and learning

Neuronal stimulation leads to longer term changes like gene regulation (CREB)

22
Q

What important concept did Hebb postulate in 1949?

A
  • Synaptic plasticity - building and removing connections in the brain
    • Neurons that fire together wire together, and thus the cellular basis of learning
    • Hebb’s rule: if cell A fires a lot under a certain stimulus, it’s connections with cell B will grow stronger (more pronounced with neurons firing concurrently)
23
Q

What important concept did Sherrington elucidate in the 1930’s?

A
  • That neurons functioned by electrochemical mechanisms

* Electricity will result in a chemical release which in turn affect electrical current

24
Q

What direction is the information flowing in the dendrite? The axon?

A
  • From dentrite to soma, from soma through axon

* Dentrite is afferent, axon is efferent

25
Q

How many ventricles in the brain?

A
  • 4, two lateral and then III and IV
    • The lateral ventricles feed into the midline III ventricle which goes into the IV ventricle, the farthest back in the neural tube
    • Lateral ventricles are in the cerebral cortex
    • The C shape of the lateral ventricles is a big clue to the folding of the neural tube
    • The forebrain portion of the neural tube bends down and “under” to make the C shape
26
Q

What does CSF look like and where is it produced?

A
  • CSF is normally clear, made by choroid plexus, a specialized structure within the ventricles
    • Specialized secretory tissue sitting within lateral ventricles
    • Ventricles hold about 10mL of fluid
    • From the IV ventricle CSF goes into the subarachnoid space, surrounding the entire CNS
    • You make way more CSF than the whole system can hold
    • There are apertures in the IV ventricle that allows for CSF to get into the rest of the system, and if there is any block, there is a buildup of fluid because choroid plexus doesn’t change the production
    • The result is hydrocephaly, and the ventricles expand into the neighboring tissues, eventually causing damage to neuronal tissue
27
Q

What vessels supply blood to the anterior surface of brain vs. posterior portions?

A
  • Posterior = from vertebral artery
    • Anterior = from internal carotid
    • Very little overlap between the two systems normally
    • But very few brains are normal. There are often variations in the patterns of cerebral arterial architecture
28
Q

What is the cellular basis for fMRI?

A
  • Synaptic activity results in local increases in blood flow
    • Due to coupling of glial responses with vessel dilation
    • Astrocytes monitor synaptic activity via metabotropic glutamate and ATP receptors
    • Increases in extracellular ATP or glutamate (consistent with lots of NT release) will increase intracellular Calcium through IP3 signalling
    • Astrocytes respond to increased calcium through releasing metabolites of the COX-1 pathway
    • Result is smooth muscle relax and vessel dilation
    • Can be blocked by COX inhibition
29
Q

What are the white matter terms vs. grey matter terms?

A

• Ie. Peduncles, tracts, nucleus, etc.

30
Q

Do neurons have direct access to capillaries?

A
  • NOPE. They are surrounded by glial cells
    • Thus a CNS drug MUST be highly lipophilic and have a high volume of distribution
    • The glial cells and the endothelial cells in BBB are densely packed with selective, active transport mechanisms
31
Q

How do astrocytes deal with the circulatory system?

A
  • They help establish and maintain the BBB
    • Astrocytes surround cerebral blood vessels to regulate blood flow and keep crap from leaking out
    • Astrocytes maintain endothelial cell tight junctions
    • Endothelial transplant cells will, when astrocytes are present, go from being fenestrated to having tight junctions, showing astrocytes are responsible for that signaling pathway
32
Q

In PNS, what glial response helps regenerate an axon?

A
  • Need to get better info on this
    • Microglia are activated, schwann cells help re-establish connections
    • In CNS, the astrocytes inhibit axonal re-growth
33
Q

What happens to the saturating neurotransmitter in the synapse?

A
  • That’s one of the functions of the astrocytes. They suck up the extra neurotransmitter with high affinity receptors
    • Either recycle it back to the axon terminals or it enymatically destroys it
    • The neuron terminals themselves have limited re-uptake?
    • Astrocytes can modulate the activity of the synapse, and in part because of this re-uptake mechanism/job
34
Q

Is it the transmitter that determines the valence of a synapse?

A
  • Valence is inhibitory/excitatory.

* NO, the transmitter is received by a receptor that dictates the response

35
Q

Do microglia only react to local damage?

A
  • No. evidence from mice suggest that microglia will be activated at the brain-termini even from a nerve that has been cut in the periphery
    • They are ripping out now-useless terminals from damaged nerves. Don’t waste brain space
    • Play a role in the plasticity of the brain
36
Q

Do microglia come from the same embryonic place as the rest of the nervous system?

A

• Nope. They do not come from ectoderm
• Think of them as the macrophages of the brain and they arise accordingly from hematopoietic areas
• Migrate into brain before BBB forms
If there is a high concentration of ATP in a tissue, what is that indicative?
• Tissue damage/injury
• Think of the microglia movie where they attacked the ATP leak in the brain

37
Q

Schwann cells do what?

A
  • Determine axonal regeneration
    • In the PNS, not the CNS
    • Produce myelin
38
Q

Oligodendrocyte does what?

A
  • Wraps axons with myelin
    • Also called oligodendroglia
    • Lays on top of the axon and wraps it with lipid rich myelin
    • They live within the CNS. Not PNS. Marks the change
    • Essentially form a barrier to axonal regeneration. Thus injury in CNS stays as such
39
Q

What is chromatolysis?

A

• Loss of coloring by histologic stain due to the negative feedback loop, think of a motor unit no longer needed because of injury or something

40
Q

What is retrograde signal?

A
  • Feedback mechanisms from axon terminal that determines continued sending of proteins along cytoskelaton or not
    • Like a muscle that is now injured, that neuron innervating the motor unit will have feedback to stop spending so much energy on it
41
Q

Glial cells in the PNS permit what?

A
  • Regeneration, which doesn’t happen in CNS?

* Yes, there is a glial “barrier” to regeneration in the CNS

42
Q

Glial cells in the PNS permit what?

A
  • Regeneration, which doesn’t happen in CNS?

* Yes, there is a glial “barrier” to regeneration in the CNS

43
Q

What are the three main types of glial cells?

A

• Myelinating glia, microglia, astrocytes

44
Q

What is axoplasmic flow?

A
  • Transported proteins from soma to periphery
    • Protein synthesis is NOT in the axon mostly (very few ribosomes in the axons or dendrites)
    • When axons are separated, the peripheral end degenerates while the proximal end, attached to soma, is fine
    • Another reason why neuronal regeneration can get a bit weird. Axons grow where they may and the plasticity of the brain re-interprets the new informational architecture
45
Q

What are Nissl bodies?

A
  • The tons of densely packed ribosomes on the RER

* Neurons make a ton of proteins (big cell, long processes, and tons of cellular transport)

46
Q

What is a Nissl stain and what does it do?

A
  • Very common neurological histology stain, preferentially stains RNA, helpful for seeing nucleolus of soma
    • The nucleus of the soma by comparison are quite clear
47
Q

What is the axon hillock?

A
  • Specialized (electrically) area as soon as the axon comes off the soma
    • Determines whether an action potential will be propagated
48
Q

What property of water molecules can be harness for a fMRI?

A

• The fact that water molecules tend to move “down” the tract of axons so you can “map” the direciton of water molecules and thus tracts through the brain