Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

USMLE > Nervous System > Flashcards

Nervous System Flashcards

You may prefer our related Brainscape-certified flashcards:
USMLE® Step 1 flashcards
1
Q

Neural Crest Cell derivatives

A
  • ANS
  • Celiac Ganglia
  • Adrenal chromaffin cells
  • Dorsal root ganglion
  • Schwann cells
  • Pia
  • Arachnoid
  • Bones (skull)
  • Odontoblasts
  • melanocytes
  • C-cells of thyroid
  • thyroid and laryngeal cartilage
  • Aorticopulmonary septum
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Neuro Cell components

A
  • Neurons are permanent cells that do not divide in adulthood
  • Nissl Substance = found in the cell body and dendrites of neuron
  • GFAP = found in astrocytes used as a marker
  • HIV infected microglia fuse to form multinucleated giant cells in the CNS
  • microglia are derived from mesoderm
  • Schwann cells are damaged in Guillain Barre Syndrome
  • Schwannoma = acoustic neuroma located in the internal acoustic meats CN8; if bilateral = NF2
  • Oligodendrocytes are damaged in MS, Progressive multifocal leukencepholapthy, and leukodystrophies
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Embryo logic Origin

A

Neuro ectoderm

  • neurons
  • ependymal cells that line ventricle of brain
  • Oligodendrocytes and Astrocytes
  • neural crest cells

Mesoderm
- microglia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

BBB

A
  • nonfenestrated endothelial cells with tight junctions
  • basement membrane of capillary
  • astrocytes foot processes

Areas of brain with fenestrated capillaries
- hypothalamus

Mannitol diuretic is given to decrease ICP for short term

Highly lipophilic drugs are able to pass through the BBB

Infarction or neoplasm may destroy endothelial cell tight junction –> vasogenic edema

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

The Hypothalamus, Stages of Sleep

A

454-455

Treat bed wetting = Desmopressin > imipramine
Treat night terrors and sleepwalking = Benzodiazepene

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Insomnia Drugs

A

See Picture

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Cranial Nerves

A

Pg 474-476

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

AFP

A

Increased AFP = neural tube defects

Decreased AFP = Down Syndrome

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Embryology of Branchial Arches

A

564-566

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Teratogens

A
  • Ace inhibitors
  • Valproate
  • Phenytoin
  • Lithium
  • Tetracycline
  • Warfarin
  • Excessive vitamin A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Arcuate Fasciculus

A
  • connects brocas and wernickes area
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Carotid Arteries

A

Come from the aortic arch

- found in the carotid sheath with the internal jugular vein and vagus nerve

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Superior Gluteal Nerve Injury

A
  • the patient will lean toward the affected side to compensate for the hip drop
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Aneurysms

A

Ruptured berry aneurysm = worst headache of life
Pg 465-466

Subarrachnoid Hemorrohage

  • MCC of a non traumatic = ruptured aneurysm
  • MCC of SAH overall = trauma
  • 2nd MCC of a non-traumatic SAH = Ruptured AVM
  • CT scan of brain
  • if no evidence of blood do Lumbar puncture to examine CSF for blood
  • Yellow CSF = xanthochromia = hemoglobin in CSF is broken down into bilirubin
  • Treatment = surgical clip of aneurysm and give Nimodipine

Lumbar Puncture = SEE picture

  • epidural anesthesia = go into the epidural space
  • spinal anesthesia = goes to subarachnoid space
  • in adults = go between L3 & L5 in order to not hit the spinal cord
  • in children = go between L4&5 or L5&S1
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Epidural hematoma

A

Can cause compression of brain and then herniation of brain

  • causing CN3 palsy
  • lucid interval
  • lens shape biconvex
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Subdural Hematoma

A
  • between dura and arachnoid
  • venous bleed that is slow
  • crescent shaped
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Intra ventricular hemorrhage in the newborn

A
  • Hemorrhage into the ventricular system
  • most common in premature/very low weight infants within the first 72 hours of life
  • originates from the germinal matrix in the sub ependymal, subventricular zone that gives rise to neurons and glia during development
  • all infants born at 30-32 weeks should be screened with ultrasound to make sure the child doesn’t have it
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Stroke

A

Pg 467
First thing you do is get a Non-contrast CT scan to see if it’s a hemorrhagic or ischemic stroke
- don’t give anticoagulants to a hemorrhagic stroke patient only give to ischemic stroke

Ischemic Stroke Definitions

  • Symptoms resolve within 24 hours ==> Transient ischemic attack
  • Symptoms last beyond 24 hours ==> STROKE

Contraindications for thrombolytics for Ischemic Strokes
- Active bleeding
- history of intracranial bleeding
- recent surgery
- known bleeding diathesis = hemophilia
- severe hypertension
Give TPA if within 3-4.5 hrs of onset symptoms (if person fell asleep and woke up with stroke more than 4.5 hours later do NOT give TPA)

Parts of the brain that are most susceptible to ischemic damage

  • Cerebellum
  • Neocortex
  • Hippocampus
  • Watershed areas

You’ll know if it’s an embolic stroke if it affects multiple areas

19
Q

CSF

A

467-468

20
Q

Pseudo tumor cerebri

A
  • occurs in young obese females
  • Headaches - daily (worse in the morning) pulsatile, possible nausea/vomiting, possible retro ocular pain worsened by eye movement (pain behind the eye)
  • papilledema
  • vision loss is most worrisome sequelae
  • CT scan: absence of ventricular dilation, no tumor or mass
  • on lumbar puncture = CSF pressure elevated >200 in non obese and >250 in obese = make sure patient is lying down when measuring CSF pressure

Treatment options

  • CT and MRI to rule out any other pathology
  • Discontinue any inciting agents (vitamin A, tetracyclines, corticosteroid withdrawal
  • weight loss is helpful if patient is obese
  • First line treatment = Acetozolamide
  • invasive treatment options = serial lumbar puncture (removes any excess fluid), optic nerve sheath decompression, and limbo peritoneal shunting
21
Q

Damage to the orbital floor

A
  • causes damage to the infra orbital nerve which is a branch of the maxillary nerve
  • also the inferior rectus muscle can become entrapped, limiting superior gaze
  • numbness and parenthesia of the upper cheek, upper lip, and upper gingiva
22
Q

Thiamine

A

Is needed for erythrocytes transketolase activity

Chronic thiamine deficiency impairs glucose utilization in the CNS due to it being a cofactors in multiple enzymes

23
Q

Beta Endorphin

A
  • opioid peptide derived from POMC

- POMC is cleaved to produce beta endorphins (bind to mu and alpha receptors), MSH, and ACTH

24
Q

Important

A
  • Lowering PCO2 is one of the measures used to reduce ICP in mechanically ventilated patients with cerebral edema = a drop in PCO2 due to hyperventilation causes vasoconstriction, increasing vascular resistance and reducing cerebral blood flow
25
Q

Liquefactive Necrosis

A
  • caused by a release of lysosomal enzymes from ischemic neurons that result in degradation of the tissue in the ischemic region
  • Phagocytic cells migrate into the area and remove the necrotic tissue leaving a cavity, and astrocytes proliferate around the necrotic area with the formation of a scar (gliosis)
  • hypoxic injury to the brain
26
Q

Forebrain anomalies

A

Anencephaly = maternal type 1 diabetes and decreased folate

Holoprosencephaly = Patau syndrome and fetal alcohol syndrome

Chiari 2 = presents with lumbosacral meningomyelocele paralysis below the defect

27
Q

Sleep Pattern in the Depressed

A

decreased slow wave sleep

increased REM and increased REM latency

28
Q

Diabetic Meningitis

A

Most likely to be due to Mucor

29
Q

HIV/AIDS meningitis

A

most likely to be due to

  1. Toxoplasma gondii
  2. Cryptococcus
  3. JC virus
30
Q

Cauda Equina

A

dorsal and ventral roots of lumbar, sacral, and coccygeal spinal nerves

31
Q

Spinal Cord

A
  • gray matter in the center
  • White matter surrounds
    Dorsal ramus = supplies skin of back and neck and deep intrinsic back muscles (erector spinae)
    Ventral ramus = everywhere else

Ventral Horn

  • extensors are ventral
  • flexors are dorsal
32
Q

Wernickes Encephalopathy

A

must give thiamine before given glucose in order to prevent wernicke korsakoff syndrome

33
Q

Common Brain lesions

A
  • Hippocampus bilateral = inability to make new memories
  • PPRF - eyes will look away from side of lesion
  • FEF = eyes will look towards side of lesion
  • Superior colliculi damage = paralysis of upward gaze = parinauds syndrome = cant look up
34
Q

Random Treatments

A

Subarachnoid Hemorrhage = nimodipine
ALS = raluzole treatment modestly increases survival by decreasing presynaptic glutamate release
Wet macular degeneration = Ranbizumab (Anti-Vegf)
Multiple Sclerosis = B-interferon and natalizumab

35
Q

Midbrain Lesions

A

Above midbrain = Decorticate rigidity
- postural flexion of arms and extension of legs

Below midbrain = Decerebrate ridgidity
- postural extension of arms and legs

36
Q

Auditory Pathway

A

Basal cochlea = high frequency sounds
Apex of cochlea = low frequency sounds

Presbycusis

  • bilateral high frequency loss and difficulty with speech discrimination
  • epithelial atrophy with loss of hair cells and supportive organ of Corti cells
  • begins in basal cochlea and progresses to apex

Any lesion after the cochlear nucleus in the brainstem = bilateral sensorineural hearing loss

37
Q

Vestibular System

A
  • Utricle and Saccule = respond to linear acceleration and gravitational pull ==> via macula (detects head positional changes with gravity)
  • Semicircular canals = rotation ==> respond to angular head acceleration and deceleration

Vestibulo-ocular reflex
- horizontal head turning –> horizontal eye movement in opposite direction

Nystagmus

  • rhythmic oscillation of eyes slowly to one side follwed by a fast reflexive movement to opposite side
  • named by fast phase
  • slow phase is in response to path

COWS
- based on the fast phase of the nystagmus

38
Q

Subacute combined degeneration

A

demyelination of dorsal columns, lateral corticospinal tracts, and spinocerebellar tracts
pg 472

39
Q

Reflexes

A 
L1-L2 = testicles move (cremaster reflex) 
S3-S4 = winks galore (anal wink reflex)
40
Q

Vagal Nuclei

A

476

41
Q

Guillain Barre

A

increased CSF protein with normal cell count

increased protein may cause papilledema

42
Q

Adrenoleukodystrophy

A

X-linked genetic disorder typically affecting males

  • disrupts metabolism of very long chain fatty acids
  • excessive buildup in nervous system, adrenal gland, testes
  • Progressive disease that can lead to long term coma/death and adrenal gland crisis
43
Q

Neurocutaneous Disorders

A

pg 491

USMLE (14 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions