Kaplan- Neuro 1

Question 1

what are intrafusal (spindle) fibers and what purpose do they serve

Answer 1

intrafusal fibers (also known as spindle fibers) are muscle fibers that lost the ability to contract;
they are connected to muscle spindles and when they are stretched the cause the muscle spindle to generate an afferent impulse

Question 2

what does the Golgi tendon apparatus do

Answer 2

controls fine movement and posture control my regulating muscle tension (not involved in DTR’s)

Question 3

what’s the difference between intrafusal and extrafusal fibers

Answer 3

intrafusal fibers do not contract and are involved in transmitting tension to muscle spindles
extrafusal fibers contract and are what generate the muscle contraction

Question 4

what nerve supplies the posterior half of the external auditory meatus

Answer 4

vagus nerve

Question 5

what are Negri bodies and what condition are they diagnostic for

Answer 5

elongated intracytoplasmic neuronal inclusions;

diagnostic of Rabies

Question 6

what main motor functions does the radial nerve serve

Answer 6

forearm extension, wrist extension, metacarpophalangeal extension, supination

Question 7

what main motor functions does the musculocutaneous nerve serve

Answer 7

forearm flexion and supination

Question 8

Herpes simplex can cause necrotizing, hemorrhagic acute encephalitis usually in which parts of the brain

Answer 8

temporal lobe and orbital regions of frontal lobe

Question 9

a single focal lesion causing right-sided loss of all sensation in both face and body is probably located where

Answer 9

the ventroposterior thalamus (VPL for body sensation and VPM for facial sensation)
note: at the thalamus both tracts have already decussated so the UPN’s (2nd order) going to the thalamus will relay impulses from the same side of the body

Question 10

a cerebral hemispheric and subarachnoid hemorrhage that is causing seizures can likely arise from what structural abnormality (exclude trauma)

Answer 10

arteriovenous malformation

note: not berry aneurysm because that would be localized more toward the base of the brain

Question 11

which class of drugs is used to treat alcohol withdrawl and which drug of this class is best to use

Answer 11

benzodiazepines;

lorazepam (shorter half-life, inactive metabolites)

Question 12

a wide-based, drunken sailor type gait with normal FTN and RAM testing is indicative of what kind of lesion

Answer 12

this is truncal ataxia ==> vermis

Question 13

sensorineural hearing loss due to excessively loud noises or ototoxic drugs involves damage to which part of the inner ear

Answer 13

hair cells of the organ of Corti

Question 14

what is presbycusis

Answer 14

age related hearing loss by which high frequency sounds are lost due to hair cell loss at the base of the cochlea

Question 15

what main motor function does the femoral nerve serve

Answer 15

knee extension

Question 16

what nerve is primarily responsible for hip abduction and what spinal nerves does it consist of

Answer 16

superior gluteal nerve; L4-S1

Question 17

which brain tumor tends to cross the corpus callosum

Answer 17

glioblastoma

Question 18

what sphingolipidosis is associated with beta-glucocerebrosidase deficiency?
beta-galactocerebrosidase deficiency?
arylsulfatase A deficiency?
sphingomyelinase?
hexosaminidase A?

Answer 18

beta-glucocerebrosidase:  Gaucher
beta-galactocerebrosidase:  Krabbe
arylsulfatase A:  metachromatic leukodystrophy
sphingomyelinase:  Neiman-Pick
hexosaminidase A:  Tay-Sachs

Question 19

what is the main mechanism of action of tricyclic antidepressants? name a few TCA’s

Answer 19

inhibiting reuptake of biogenic amines (5-HT and NE);

amitriptyline, nortriptyline, doxepin, desipramine

Question 20

what nerve supplies sensation to the anterior half of the external auditory canal

Answer 20

auriculotemporal

Question 21

what other anatomical abnormality is associated with Chiari II malformation

Answer 21

myelomeningocele

Question 22

what is the inheritance pattern of Huntington’s disease

Answer 22

autosomal dominant

Question 23

damage to what kind of vessel is associated with subdural hematoma

Answer 23

bridging veins

Question 24

what is cerebral perfusion pressure

Answer 24

CPP= MAP - ICP

Question 25

what will the body do to MAP in response to high ICP

Answer 25

increase MAP, by upregulating cardiac output in order to restore CPP

Question 26

what do pharyngeal arches 1 and 2 become

Answer 26

maxillary and stapedial arteries, respectively

Question 27

what do pharyngeal arches 3 and 4 become

Answer 27

arch of the aorta and right subclavian

Question 28

what do pharyngeal arches 5 and 6 become

Answer 28

nothing and the pulmonary arteries and ductus arteriosis, respectively

Question 29

which neurotransmitter is used at the NMJ

Answer 29

ACh

Question 30

craniopharyngiomas often contain what non-pituitary structure

Answer 30

tooth (enamel)

Question 31

a patient recently developed urinary incontinence, ataxia, broad-based bradykinetic gait, confusion, memory loss and loss of executive function, what treatment would you start

Answer 31

VP shunt; “wet wobbly wacky”, this patient has normal pressure hydrocephalus

Question 32

where are the centers for vertical gaze found and what is the most common tumor to compress it

Answer 32

tectum;

pineal germinoma

Question 33

what is imipramine and how does it work

Answer 33

imipramine is a TCA; acts by inhibiting reuptake of serotonin and NE

Question 34

which neurotransmitter is needed for induction of REM sleep

Answer 34

acetylcholine

Question 35

what usually preceeds onset of Guillain-Barre syndrome

Answer 35

upper respiratory or GI infection

Question 36

how is Guillain-Barre syndrome similar to Multiple Sclerosis

Answer 36

both are autoimmune demyelinating syndromes

Question 37

sparing of what part of the pons allows a patient to be conscious during “locked-in syndrome”

Answer 37

tegmentum

Question 38

what is the typical age range of Huntington’s onset

Answer 38

20s-40s

Question 39

if a patient can adduct during conversion, but not during conjugate gaze what is the name of their condition and what part of the brainstem is damaged

Answer 39

internuclear opthalmoplegia due to damage to medial longitudinal fasciculus

Question 40

MAO-A preferentially metabolizes _________ while MAO-B preferentially metabolizes _________

Answer 40

MAO-A preferentially metabolizes NE and serotonin

MAO-B preferentially metabolizes dopamine

Question 41

what is the mechanism of action of selegiline

Answer 41

MAO-B inhibitor (prevents metabolism of dopamine by MAO-B)

Question 42

explain how uvula deviation can help localize cranial nerve lesions

Answer 42

the resting uvula will deviate towards the hypoglossal nerve lesion and upon pharynx stimulation the uvula will deviate away from the vagus nerve lesion