2011 module exam Flashcards
In the above figure, the line on the top represents bone conduction ([-) while the line at the bottom represents air conduction (X-). Where would you expect the pathology to be?
a. Middle ear
b. Inner hair cells
c. Outer hair cells
d. Cochlear nerve
a. Middle ear
[The above figure represents conductive hearing loss, where bone conduction is better than air conduction. This is due to the fact that intensity needed for bone conduction is lower than the intensity needed for air conduction. Intensity is represented by the vertical line and frequency the horizontal line. The only choice where a pathology would cause conductive hearing loss is a]
1- Blockage of the anterior spinal artery leads to:
loss of pain and temperature on both sides
Which of the following when lesioned causes Spastic paralysis of the distal muscles on the right?
Damage to the right lateral corticospinal tract
Loss of reflex turning of the head in response to visual stimuli is because of a lesion in:
tectospinal tract
Which of the following receptors is responsible for detection of vibrations?
Pacinian
What is the “labeled-line” theory?
Each receptor is connected to a specific area of the cortex
What is a fast adapting receptor?
Meissner’s
What recognizes various modalities of sensation (or conveys more than one type of signal)?
Free nerve endings
What happens in the reciprocal excitation in golgi tendon reflex?
Activation of Ib afferents and excitation of antagonist muscles
Which of the following is recruited in the adaptive response in the withdrawal reflex elicited by high intensity pain for response amplification?
Propriospinal fibers
[These are the fibers that activate several spinal cord segments with increasing pain intensity in the flexor withdrawal reflex]
Which of the following nuclei is an origin of some of the fibers in the medial leminiscus?
Gracile nucleus (nucleus gracilis)
Which tract conveys information about right leg position?
Right fasiculus gracilus (gracile fasiculus)
How do fast adapting receptors operate?
By detecting the stimulus at the beginning and the end
Through which of these structures does the corticospinal tract pass?
Basilar part of the pons
Which of the following nuclei projects preganglionic parasympathetic fibers to the otic ganglion?
Inferior salivatory nucleus
Which parasympathetic nucleus is associated with the facial nerve?
Superior salivatory nucleus
In which of these nuclei would you find pseudounipolar neurons?
Mesencephalic nucleus of the trigeminal nerve
What carries sensation of pain and temperature from the face?
Spinal nucleus of the trigeminal nerve
A patient has a droopy left upper eyelid. On examination, you find that his left pupil is more constricted than his right pupil. What is the condition?
Horner’s syndrome
[It is a classical triad of ptosis(droopy upper eyelid), miosis (pupillary constriction), and anhidrosis (no sweating) due to disruption of the sympathetic innervation to the face]
What is true regarding lipid metabolism in the brain?
a. Oxidation of very long chain fatty acids in peroxisomes
b. Synthesis of linolenic acid
a. Oxidation of very long chain fatty acids in peroxisomes
myelin has components which aren’t present in any other membrane in the body. To which family do they belong?
protein
What would decreased production of glycosphingolipids lead to?
hypomyelination
Which of the following proteins is mutated in neurofibromatosis 2, which is characterized by the development of schwannomas?
Merlin
In myasthenia gravis there’s discontinuity between the nerve terminal and the muscle. What’s the mechanism that mediates that?
Blocking antibodies
A 35-year-old man on chemotherapy for leukemia develops limb weakness, unsteady gait, and diplopia. He then exhibited memory problems and died a few months later. Autopsy shows softened, granular appearance of the white matter. What is the diagnosis?
Progressive multifocal leukoencephalopathy (PML)
Which condition is characterized by galactocerebroside-β- galactosidase deficiency?
Krabbe’s disease
A 52-year-old man on diuretics with a sodium of 118 mmol/L. What is the condition?
Central pontine myelinosis
Which artery when blocked causes damage to the primary somatosensory cortex?
Middle cerebral artery
In which cortex would you find the large pyramidal cells?
a. Primary motor cortex
b. Premotor cortex
a. Primary motor cortex
The anterior commissure connects which parts of the brain?
The temporal lobes
Which reflex would be altered if the posterior commissure is affected?
Light
neurons from the Ventral posterolateral nucleus (VPL) and the ventral posteromedial nucleus (VPM) go to which of the following parts of the cortex?
Postcentral gyrus [the primary somatosensory cortex]
What is supplied by the posterior cerebral artery?
Primary visual cortex
Damage to the superior temporal gyrus would affect:
Wernicke’s area
What nuclear medicine method is used to asses cerebral perfusion?
Tc-99m HMPAO SPECT
What is used to evaluate the risk of stroke in cerebral ischemia?
Tc-99m HMPAO SPECT with acetazolamide
What percentage of stroke patients will be dependent on others for daily activities?
More than 50%
Which neurotransmitter causes neuronal toxicity during ischemia?
L-glutamate
A 60-year-old man with uncontrolled hypertension presents with loss of consciousness. After waking up he can’t speak and has paralysis of the right leg. Which of the following is the most likely cause?
a. Basal ganglia hemorrhage
b. Middle cerebral artery embolus
c. Central pontine myelinosis
a. Basal ganglia hemorrhage
c. Central pontine myelinosis
[a is the correct answer because an intraparanchymal hemorrhage would increase the intracranial pressure and produce a mass effect, leading to herniation of the cingulate gyrus (a subfalcine/cingulate herniation). This herniation would compress the anterior cerebral artery leading to leg weakness.
MCA embolus would not cause leg weakness, and the history and presentation is not that of central pontine myelinosis]
A 37-year-old female was sitting at her desk when she experienced a severe headache. Her CSF shows red blood cells without pleocytosis. What could be the cause?
Ruptured berry aneurysm
A 55-year-old male had his mean arterial pressure drop to 40 mmHg due to heart failure. What would be a consequence of this drop on the hemodynamics of the brain?
a. Reduced cerebral blood volume
b. Increased intracranial pressure
b. Increased intracranial pressure
[Dr. Zoran confirmed this]
Which of the following is responsible for regulating cerebral blood flow under normal conditions?
Neuronal release of glutamate
Which of the following increases Cerebral blood flow in normal conditions?
Glutamate release
Which of the following produces minimal change in CBF?
Increased O2 in the interstitial fluid
Which of the following decreases cerebral blood flow?
1- Release of arachidonic acid by astrocytes
2- Increased pH of interstitial fluid
1- Release of arachidonic acid by astrocytes
2- Increased pH of interstitial fluid
[Dr. Zoran counted BOTH as correct]
Cerebral blood flow was reduced to 20 ml/min/100g for 90 minutes and then was restored to the normal value of 50 ml/min/100g. What would be the consequence?
Transient impaired function with full recovery
[this is the concept of the penumbra]
What will be the defect when a person has bilateral injury to the posterior lateral partietal cortex?
Unable to reach for objects
A patient has a lesion in the occipital association cortex. What will be observed?
He can name objects but he can’t draw them
When there is a defect in perception of shape, color, and texture, what part of the association cortex is affected?
Temporal association cortex
A lesion in the parietal association cortex would result in:
the patient neglecting his left side
An 83-year-old suffered from a stroke immediately after a hip fracture. What might be the cause?
Fat embolism [long bone fracture=fat embolism]
Which party of the brain when lesioned would affect the working memory?
Anterior association area (prefrontal cortex)
Fibers carrying information from the posterior spinocerebellar tract giving information about limb movement go to which part of the cerebellar cortex?
Intermediate
Which part of the cerebellum when damaged would cause nystagmus?
Flocculonodular lobe
Damage to the cerebellum causes:
a. incoordination of movement because they cannot perceive their
limb position
b. unable to control movement although the patient is totally aware of the abnormality
b. unable to control movement although the patient is totally aware of the abnormality
Where do we find neuromelanin pigmented neurons?
Substantia nigra
Substantia nigra
Which of the following cells has the same lineage as monocytes?
Microglia
In an epidemiological study, you investigate a screening test for iron deficiency anemia has a pretest probability is 10%. However, you encounter a patient who has a Pre-test probability of 90%. What will be the effect on the test parameters?
Sensitivity and specificity: Same
PPV: increase
NPV: decrease
Sensitivity and specificity: Same
PPV: increase
NPV: decrease
What’s a general characteristic of CAG expansion repeats?
They are transcribed and translated
What is true of the CGG repeats in fragile X syndrome?
They occur in the promoter region of the gene
Entacapone is a Levodopa optimizer given with it to enhance its CNS concentration. What is its mechanism of action?
Inhibition of catechol-o-methyl-transferase
What mediates the go-stop pattern of the cerebellum?
a. Inhibitory influence from the purkinje cells
b. Because both mossy and climbing fibers are excitatory
a. Inhibitory influence from the purkinje cells
[b is not correct. It was a mistake in the 2009 tafree’3. We asked Dr. Pavlik and he confirmed the first choice]
The cerebellar learning of fast skilled movements is based on changes in the cerebellar cortex excitation by induced by stimulation of climbing fibers. What is this mechanism?
Long-term depression
What is the characteristic of the output of the cerebellum?
Go-stop character
What does the cerebellum use for coordination of skilled movement?
Feed-forward mechanism
stimulation of the most medial part of Brodmann’s area 4 would result in:
a. wiggling of the toes
b. abnormal sensation in the feet
a. wiggling of the toes
What is a gold-standard test used for?
To identify diseases and non-diseased individuals
What would be disinhibited upon activation of the striatal neurons?
The thalamus in the direct circuit
what would increased muscle tone for both flexors and extensors would result in?
rigidity
What would increased signaling of indirect circuit result in?
a. bradykinesia
b. akinesia
b. akinesia
[Both were in the choices, and Dr. Pavlik said that it wasn’t he who put both akinesia and bradykinesia in the choices and that akinesia is the best choice even though he would not put both bradykinesia and akinesia together in the same question]
What would subthalamic infarction result in?
hemiballism
Which part of the brain is affected in parkinson’s disease?
Substantia nigra
Which of the following most likely represents the action of dopamine at the striatum?
a. Acts on D2 receptors to inhibit Calcium channels
b. Its action is terminated by re-uptake
b. Its action is terminated by re-uptake
In which part of the developing brain is the pontine flexure present?
Metencephalon
2- What is the embryological origin of the spinal nucleus of the trigeminal nerve?
Alar plate
The cerebellum develops from:
rhombic lips
Damage to the corticospinal tract in the upper level of the medulla would cause:
contralateral paralysis
Khalid is depressed due to a recent loss of a family member. As a doctor, you think the best approach is to focus solely on correcting his irrational and maladaptive thoughts to treat him. Which approach is this?
a. Cognitive
b. Psychoanalytical
c. behavioral
a. Cognitive
[It is not behavioral!!!!]
Which Model views alcohol and drug abuse as a unique, irreversible, and progressive process?
Disease model
A 25-year-old male student in a lecture suddenly starts staring into space for 60 seconds. His friend notices him picking his buttons and making some chewing movements. When his friend calls his name he is unresponsive. What type of seizure is this?
Complex partial seizure
Which of the following is a characteristic of generalized epilepsy with febrile seizure plus (GEFS+)?
a. Caused by a mutation in sodium channel genes
b. Autosomal recessive
c. Febrile seizures only in childhood
a. Caused by a mutation in sodium channel genes
Which drug is redistributed in fat and thus has a very short half life?
Thiopental
How would benzodiazepines mediate their anti-epileptic activity?
Enhance GABA-A transmission through increased chloride ion influx
Which of the following drugs has anxiolytic but no sedative or hypnotic effects?
Buspirone
Which of the following drugs causes fatty liver upon chronic administration?
Ethanol
Carbamazepine is prescribed to a patient. At first it has a half-life of 10-20 hours. After chronic administration the half-life decreased to 4 hours. What is the cause?
It induces CYP enzymes and accelerates its own destruction
Which of the following inhibits phosphodiesterases?
Caffeine
What is the mechanism of action of cocaine?
Inhibits re-uptake of monoamines
EEG of an epileptic patient on treatment shows interictal discharge. What is the mechanism behind this?
Paroxysmal depolarization shift
A person is watching TV and beta activity is recorded over the occipital region. What wave activity over the occipital cortex would be observed when the TV is turned off?
Alpha
[we checked wit Dr. Pavlik]
What would be the result of a being hit on the head with a hammer?
Localized depressed fracture
A12-year-oldboyfellfromathe7th storywithastrongforce impact on the pelvis. What would be the result of that?
Ring fracture of the base of the skull
A 20-year-old male sustained a blow to the right side of the head, due to which he lost consciousness. He was found to have a fissure fracture of the temporal bone. He awoke a few minutes later and was taken to the hospital, where he lost consciousness two hours later. What is the diagnosis?
Right extradural hematoma
An baby is brought by his mother because he has problems sleeping. The physician prescribes drug X, which resolves the problem but the mother then reports that it produces a bad odor from his mouth. What was the drug prescribed?
Chloral hydrate
In which region/zone of the hypothalamus are the mammillary bodies located?
a. Medial Zone
b. Paraventricular zone
c. Tuberal region
d. Chiasmatic egion
e. Lateral zone
a. Medial Zone
to which thalamic nucleus does the mammillothalamic tract project?
Anterior thalamic nucleus
Which system is activated by psychoactive drugs?
Motivational system
How does Alzheimer’s disease develop?
Change in protease activity
Brain samples from the frontal, parietal, temporal cortices and the hippocampus from a 71-year-old demented patient revealed the presence of intracellular eosinophilic inclusions that are immunoreactive for tau. What might these inclusions be?
Neurofibrillary tangles
What might be found in the substantia nigra of a patient with Parkinson’s disease?
Lewy bodies
What is the mechanism of action of memantine?
NMDA antagonist
What is the mechanism of action of donepezil?
a. Acetylcholinesterase inhibitor
b. Butyrylcholinesterase inhibitor
a. Acetylcholinesterase inhibitor
What is a property of local anesthetics?
They are weak bases
Which general anesthetic could cause malignant hyperthermia?
Halothane
What would you use to maintain anesthesia in someone with heart disease and has vitamin B12 deficiency anemia who is undergoing a three-hour-long knee procedure?
Isoflurane
[You can’t use Nitric oxide since it causes bone marrow depression neither can you use halothane since it sensitizes the heart to catecholamines]
Which drug is given before a procedure to reduce anxiety and ease amnesia?
Midazolam
What is involved in encoding procedural memory?
Cerebellum
Which area of the hypothalamus is responsible for thirst?
Lateral hypothalamus
[also for hunger. Ventromedial is for satiety]
What hormone is responsible for synchronization of the circadian rhythm of the suprachiasmatic nucleus with light?
Melatonin
A patient with bilateral removal of the hippocampus. What will be defective?
Formation of new long-term memories
What would you find in biopsy of a 70-year-old female with Alzheimer’s disease?
Amyloid plaques
a 39-year-old female presented with rapid and severe decline in cognitive and mental function [and other symptoms we don’t remember]. She died a few months later. microscopy reveals vacuoles in the brain. What is the diagnosis?
Prion disease
Which neurotransmitter is needed to maintain wakefulness?
Orexin from orexigenic neurons in the hypothalamus
What is an essential part of the Wernicke-Geshwind model of language?
Angular gyrus
What is the action of leptin?
Inhibiting NPY neurons (NPY: neuropeptide Y)
Which part of the brain is involved in the reward system?
Nucleus accumbens
In an experiment involving transgenic (gene knockout) mice, it was observed that they lacked the ability to produce the PrPc polypeptide. Which of the following would be most likely regarding these mice?
It would be impossible for them to develop prion disease
Which of the following in a tissue sample would indicate the presence of PrPsc?
[not sure if it was written this way but the idea of the question is that he’s asking about the characteristics of abnormal prion proteins [PrPsc]
Prions resistant to protein degradation
What is the mode of inheritance of Wilson’s disease?
Autosomal recessive
How could a human contract variant Creutzfeldt-Jakob disease (vCJD)?
By eating animals infected with BSE (bovine spongiform encephalitis)
A patient with a bone marrow transplant develops a cerebral abcess. What is the most common causative organism?
Aspergillus fumigatus
[NOT CANDIDA!!!! EVEN THOUGH 2010 TAFAREE’3 SAY ITS CANDIDA, WE ASKED THE DOCTOR AND HE SAID ASPERGILLUS IS THE #1 CAUSE OF FUNGAL CEREBRAL ABCESS]
What would cause Guillain-Barre syndrome in a 45-year-old man?
CMV infection
What virus causes a poliomyelitis-like symptoms in an 8-year-old child?
Enterovirus
Which virus causes acute disseminated encephalomyelitis?
Herpes simplex virus
[I think this was the one on the exam. Dr.Sahar gave tables in her lecture with all the organisms causing the disease so just refer to that for all the possible causes]
A 69-year-old man with fever, neck stiffness, headache, and photophobia. What is the most common organism to cause this condition?
Streptococcus pneumoniae
A 2-year-old boy presents with meningitis associated with increased intracranial pressure and abducent (6th nerve) nerve paresis. What is the most likely organism?
Hemophilus infleunzae
A 1-week-old neonate develops meningitis. Which of the following organisms is the most likely cause?
Listeria monocytogenes
[This was the only organism out of the three that cause neonatal meningitis presented in the choices. The other two are: E.coli and streptococcus agalactiae (group B streptococcus)]
What is the mechanism of action of ampicillin?
Inhibition of bacterial cell wall synthesis
A 50-year-old man with bronchiectasis presents with…[we don’t remember the symptoms]. On autopsy a focal lesion was found and upon biopsy it showed central area of suppurative necrosis surrounded by exuberant granulation tissue. What is the diagnosis?
Pyogenic cerebral abcess
A 52-year-old man presented with a cerebral mass. Biopsy reveals sheets of cells with spherical nuclei and a clear halo around the nuclei with accompanied capillaries. What is the diagnosis?
Oligodendroglioma
A brain tumor shows serpentine pattern of necrosis, nuclear palisading, glomeruloid body formation, and hemorrhage. What’s the type of tumor?
Glioblastoma
A biopsy of a tumor from the cerebellum of a 7-year-old girl reveals sheets of primitive cells with formation of Homer-wright rosettes. What is the diagnosis?
Medulloblastoma
A lesion in the meninges reveals obliterative endarteritis with perivascular infiltrate rich in plasma cells and lymphocytes. What is the diagnosis?
Neurosyphilis
A biopsy of the brain revealed enlarged cells with nuclear and cytoplasmic inclusions. What is the diagnosis?
Cytomegalovirus encephalitis
Which infection is associated with neuronal cowdry type A inclusions?
Herpes simplex virus type 1
What are the round to oval cytoplasmic inclusions in neurons of the brainstem and the purkinje cells of the cerebellum?
Negri bodies of rabies virus
Which bacteria causes Waterhouse-Friedrichsen syndrome?
Neisseria meningitides
A mass was found on the parasagittal aspect of the convexity and attached to the dura matter. What’s the cell or origin?
Arachnoid cap cells
Which eye structure is refractory?
a. Cornea
b. Ciliary body
c. Iris
d. Pupil
a. Cornea
Which cell participates in the formation of the blood retinal barrier?
RPE (Retinal Pigmented Epithelium)
dysfunction of which of the following would cause night blindness?
Rod cells
A patient comes to you suffering from attacks of diplopia. During examination of his extra-ocular muscles, you ask him to move his eyes inward and down. He is able to move his left eye inward, but he is not able to move it down. Which nerve is damaged in this patient?
Trochlear nerve
[concept is: the muscle paralyzed here is the superior oblique, since the loss of function in this patient is depression of the eye when it is adducted, which is a function of the superior oblique. This muscle is supplied by the trochlear nerve. The abducent nerve supplies the lateral rectus, which abducts the eye. The occulomotor nerve supplies all other muscles]
Which of the following is true regarding diabetic retinopathy?
75% of diabetics after 20 years will have some form of diabetic retinopathy
A mutation in the gene coding for the RPE65 protein would lead to LCA blindness (they didn’t give the full name in the exam, but I looked it up and it is: Leber congenital amaurosis. This question wasn’t in any lecture or learning topic). What is the function of this protein?
Regeneration of cis-retinal
Which mechanism is responsible for inhibition of phosphodiesterases in the dark?
Binding of PDE-alpha subunit
[This wasn’t explained in any lecture or learning topic]
Which of these receives most of the efferent fibers within the cochlear nerve?
Outer hair cells
A patient presents with left-sided hearing loss but a normal right- sided hearing. Which of the following is damaged?
Left cochlear nerve
(concept is: damage to any structure from the hair cells of the organ of corti till the cochlear nuclei will result in unilateral hearning loss. However, damage to any structure beyond the cochlear nuclei [superior olivary nucleus, lateral leminiscus, inferior colliculus, medial geniculate body, or the cortex] will result in bilateral decrease (but not total loss) of hearing)
Trapezoid body is formed by:
cochlear nuclei
A Lesion of which nerve would cause paralysis of the stapedius muscle?
Facial nerve
Which lymph nodes are responsible for the lymphatic drainage of the lower part of the auricle including the lobule?
Superficial cervical
Which receptor maintains the proper tonus for stable posture during standing?
Muscle spindle
Which receptors mediate central sensitization of pain in the spinal cord?
NK-1 and NMDA
How does the NK-1 receptor work?
Increase the release of calcium from intracellular stores by increasing the synthesis of inositol triphosphate (IP3)
Which of the following is not an effect of opioids?
Diarrhea
they cause constipation
Tolerance does not develop to which of the following effects of opioids?
Pupillary constriction
[constipation]
When you turn your head to one direction, what happens to the Action potential frequency of firing transmitted by the vestibular nerve in the crista ampullaris?
Increased vestibular nerve firing on one side and decreased firing on the other side
What is responsible for balancing the pressure between the middle ear and the external ear?
The auditory tube
Which cells of the inner ear aid in fine tuning of inner hair cells( or it was: fine tuning of ear sensitivity)?
Outer hair cells
What is the action of morphine on adenylate cyclase, K+ channels, and Ca2+ channels?
Inhibits adenylate cyclase, activates K+ channels, inhibits Ca2+ channels
A patient doesn’t have a problem with detecting frequency and intensity of the sound heard. However, he couldn’t precisely locate sounds coming from the right ear. He also had trouble understanding words. Where is the lesion most likely located?
a. Left cochlear nucleus
b. Right cochlear nucleus
c. Right auditory cortex
d. Left auditory cortex
d. Left auditory cortex
