Science Questions

Spectrin is an integral part in which of the following intracellular structure(s)?

• Intermediate filaments

• Centrosome

• Basal body

• Desmosome

• Cell cortex

Which protein is necessary to create the forces that result in the bending movements of cilia and flagella?

• Myosin

• Dynein

• Actin

• Kinesin

• Keratin

Which intracellular process would be primarily disrupted by inhibition of Arp2/3 complexes?

• Microtubule nucleation

• Dynamic instability

• Microfilament nucleation

• Treadmilling

• Intracilliary transport

Which type of the anchoring contact is used by the migrating (crawling) fibroblasts?

• Desmosome

• Adherence junction

• Hemidesmosome

• Tight junctions

• Focal adhesion

What is the primary function of tissue fibronectin?

• It binds to laminin

• It binds to collagen

• It binds to desmosomes

• It binds to cadherins

• It binds to actin filaments

Which of the following extracellular matrix components assembles proteoglycans into the gigantic complexes called proteoglycan aggregates?

• Collagen type I

• Hyalumnan

• Heparan sulfate

• Fibronectin

• Laminin

Which type of gene mutations confer a selective growth advantage in cancers?

• Passenger mutations

• Frameshift mutations

• Driver mutations

• Deletions

• Insertions

Ninety-five percent of the mutations in tumors are:

• Deletions

• Insertions

• Translocations

• Frameshift mutations comprise 1.7% of mutations

• Single base substitutions

A man and his wife are carriers of a gene for sickle cell disease (autosomal recessive inheritance). What is the probability that this couple may have a phenotypically normal child?

• 100%

• 25%

• 50%

• 67%

• 75%

A man with porphyria starts a cult which soon increases in number. Many of his descendants were found to have porphyria. A smallpox epidemic soon occurs in the cult. Which one of the following terms best describes this situation?

• Genetic isolation

• Founder effect

• Heterozygote advantage

• Population bottleneck

• Carriers of porphyria have a higher immunity to smallpox

A female alcoholic presents to the emergency department with confusion and memory loss. She also exhibits rolling of her eyeballs. Her diet consists mainly of canned soup. Lack of which vitamin is most likely to be responsible for her symptoms?

• Vitamin C

• Folic acid

• Thiamine

• Vitamin B6 (pyridoxine)

• Vitamin B12

Which vitamin is involved in collagen synthesis?

• Folic acid

• Niacin

• Vitamin B12

• Vitamin C

• Vitamin D

As a pathologist you would like to make sure that the magenta colored staining result of a cancerous liver specimen with Periodic acid-Schiff (PAS) reaction is real. Which enzyme would you use to confirm your positive staining result?

• Amylase

• DNase

• Lipase

• Proteinase

• RNase

Which of the following antigens is the most immunogenic?

• Streptococcal polysaccharide

• DNA from a hepatitis B virus

• RNA from HIV

• The protein toxoid from tetanus

• The lipids isolated from the milk of a cow with an udder infection

Which multilobed lymphatic organ serves as the place for T cell maturation?

• Spleen

• Trachea

• Thymus

• Bone marrow

• Salivary gland

The term redundancy of cytokines means that:

• One cytokine can have many effects

• One cytokine can act synergistically with another

• One cytokine produced by one cell can effect another cell

• One cytokine is antagonistic to another

• More than one cytokine can have the same function

When a cell is infected and presents the antigen of the infection, in which molecule does it present the antigen and which type of cell responds?

• Class II molecule; CD4+ T cell

• Class II molecule; CD8+ T cell

• Class I molecule; CD8+ T cell

• Class I molecule; CD4+ T cell

• Toll-like receptors; macrophages

Compared to a secondary response, a primary response is:

• Faster and higher in amount of IgG

• Slower and lower in amount of IgG

• Slower but higher in amount of IgG

• Slower and lower in amount of IgM

• Faster, more specific but lower in amount of IgG

Which is the most accurate description of the type of organism that a laboratory would try to isolate on MacConkey agar?

• Gram-positive coccus

• Gram-negative enteric bacillus

• Gram-positive bacillus

• Yeast-like fungus

• Spirochetal bacteria

The designated purpose of the “A” (bacitracin)-disc is to distinguish:

• Alpha-hemolytic bacteria from beta-hemolytic bacteria


• Staphylococcus aureus from other staphylococcal bacteria

• Staphylococcus aureus from streptococcus pyogenes

• Streptococcus pyogenes from other beta hemolytic streptococcus


• Streptococcus pneumoniae from other alpha-hemolytic streptococcus

You suspect that your patient may have an infection. You send a patient sample to the clinical microbiology lab for analysis. The lab cultures an organism on blood agar which is catalase positive. A coagulase test is done next and the result is clumping of the test plasma. The likely cause of this patient’s infection is:

• Streptococcus pyogenes

• Streptococcus pneumoniae

• Staphylococcal aureus

• Staphylococcal epidermidis

• Staphylococcal saprophyticus

What type of epithelial tissue is normally keratinized?

• Simple cuboidal epithelium of the kidney tubules

• Transitional epithelium of the ureter

• Simple squamous epithelium of a blood vessel

• Stratified squamous epithelium of skin

• Mesothelial lining of the lungs

Which of the tissues/organs listed below is most likely to be lined by transitional epithelium?

• Bladder

• Large intestine

• Skin

• Esophagus

• Uterus

Which of the following features does cardiac muscle have in common with skeletal muscle?

• Peripheral, multiple nuclei

• Voluntary control

• Striations

• Location

• Intercalated discs

A 66-year-old woman has multiple bladder stones and undergoes a cystoscopy. Irregular areas of her bladder mucosa are biopsied and reveal that the normal transitional epithelium has been replaced in areas by mature normal appearing squamous epithelium. What is this process known as?

• Pathological hyperplasia

• Metaplasia

• Atrophy

• Physiological hypertrophy

• Dysplasia

A pathologist is examining tissue under the microscope and sees an area where the cells are necrotic and the nuclei of the cells are pyknotic and have undergone karyorrhexis and karyolysis. The enzymes responsible for these changes were activated by a molecule which enters the cell because of:

• Loss of intracellular Na+

• Increased pH

• Increased ATP production

• Failure of the Ca+2 pump

• Decrease in anaerobic glycolysis

A 4-year-old girl has recurrent acute bacterial infections. During the most recent bout of acute bacterial cellulitis of her arm, caused by Staphylococcus aureus, she has an elevated white blood cell count with an increased percentage of neutrophils in her peripheral blood. A biopsy taken from an area of soft tissue necrosis shows many bacteria but very few neutrophils. An analysis of neutrophil function shows a defect in rolling. Which of the following is most likely to be dysfunctional?

• Complement C3b

• Selectins

• Integrins

• NADPH oxidase

• Leukotrienes

A 20-year-old woman has two days of low grade fever with malaise, cough, and nasal congestion. Physical examination reveals clear breath sounds. A white blood cell count shows mild to moderate elevation in lymphocytes. The most likely etiology for this woman’s condition is:

• Acute, bacterial infection

• Parasitic infection

• Allergic reaction

• Viral infection

• Anaphylaxis

A 33-year-old morbidly obese man undergoes a colectomy with a large incision because of difficulties during the surgery. During recovery after the surgery, he experiences severe nausea and has an episode of vomiting without fever. Which of the following complications is most likely to be a deterrent in his surgical wound healing?

• Infection

• Malnutrition

• Foreign body

• Dehiscence

• Contracture

A 33-year-old woman undergoes successful surgery for a ruptured appendix. Approximately five to seven days post-operatively, the healing skin suture site predominantly contains:

• Neutrophils

• Collagen

• Granulomas

• Keloid

• Granulation tissue

A 37-year-old woman has a Pap smear which is abnormal. A subsequent colposcopy shows a 1 cm flat red area on her cervix which is excised, and is diagnosed as carcinoma-in-situ. This lesion:

• Is commonly associated with metastatic disease

• Will most likely not recur once completely excised

• Derives from mesenchyme and is invasive

• Occurred because of previous cervical hyperplasia

• Is genetically transmitted and is not influenced by environmental factors

A large, bulky retroperitoneal mass is removed from a 58-year-old woman. Microscopic examination reveals no distinct glands, keratin, or other structures and the cells are extremely disorganized. There is marked anaplasia and pleomorphism with increased mitoses, including bizarre mitotic figures. Special stains are needed to make a final diagnosis. This tumor is most likely:

• Benign

• Well-differentiated

• Slow-growing

• High grade

• Well-circumscribed

A 69-year-old man has guaiac positive stools and weight loss. He undergoes a colonoscopy and a large ulcerating mass is discovered in his sigmoid colon. A biopsy of the mass reveals invasive, irregular, crowded glands with pleomorphic nuclei. There is invasion into blood vessels and lymphatics. What is the tumor best classified as?

• Leiomyosarcoma

• Melanoma

• Fibroadenoma

• Papiloma

• Adenocarcinoma

An 8-year-old boy falls on his elbow while running on a sidewalk. He does not sustain an open skin wound but the area first becomes red and then swells up. Pain develops and his mother decides to bring him to the emergency department for an X-ray. Which of the following contributes to the initial redness of the injury?

• Constriction of vascular smooth muscle

• Formation of the membrane attack complex

• Increased intravascular oncotic pressure

• Expression of integrins on endothelium

• Release of histamine from trauma injury

Which of the following is a signal that mammalian cells use to communicate between themselves?

• Light

• Sound

• Smell

• Heat

• Gas

Beta 2 adrenergic receptor has a Kd of 10-10 M for epinephrine and 10-8 for norepinephrine. This means that:

• Epinephine will produce a greater end effect in the target cell at saturation

• The affinity for epinephrine is greater

• The receptor will bind epinephrine faster

• The receptor will bind norepinephrine faster

• The receptor will cycle norepinephrine on/off more slowly

Which of the following statements is true regarding Cholera toxin and Pertussis toxin?

• Both inhibit adenylyl cyclase activity

• Both inhibit G protein alpha subunit

• Both activate G protein alpha subunit

• Both increase adenylyl cyclase activity

• Both decrease cAMP production

Which of the following statements is true regarding the second messenger cAMP?

• cAMP is generated downstream of an activated Gq subunit

• the enzyme adenylyl cyclase converts AMP to cAMP

• cAMP activates protein kinase C

• cAMP modifies existing proteins as well as affecting gene expression resulting in new protein synthesis

• The enzyme cAMP phosphodiesterase helps terminate a cAMP-mediated response by converting cAMP to ATP

Which of the following statements is true regarding PIP2 (Phosphatidylinositol 4,5-bisphosphate) and PIP3 (Phosphatidylinositol 3,4,5-trisphosphate)?

• PIP2 and PIP3 are membrane-bound inositol phospholipids

• PIP3 is broken apart by phospholipase C to produce Inositol trisphosphate (IP3) and Diacylglycerol 
(DAG)

• PIP2 recruits Akt to plasma membrane where Akt is activated

• PIP2 is made from PIP3 by the action of phosphatidylinositide 3-kinase (PI-3-kinase)

• PIP3 is a second messenger that carries the message directly from Gαq

If a healthy adult carries a Robertsonian 21:21 translocation, what is the approximate chance that any of their live-born biological offspring will have Down syndrome?

• 0%

• 100%

• 50%

• 25%

• 5%

Which of the following genetic disorders is caused by a chromosomal abnormality usually not detectable on routine karyotype but usually detectable using a specific FISH (Fluorescent In-Situ Hybridization) probe?

• Down syndrome

• Edwards syndrome

• DiGeorge syndrome

• Patau syndrome

• Turner syndrome

A patient taking a particular antiepileptic medication is given an antimicrobial agent that is metabolized by CYP3A4. Because of drug interaction involving CYP3A4, the dose of the antimicrobial is increased, according to the manufacturer’s recommendations. The CYP3A4 inducer is most likely:

• Carbamazepine

• Erythromycin

• Itraconazole

• Probenecid

• Ritonavir

An adult with a history of prescription drug abuse presents to the emergency department with signs and symptoms consistent with morphine overdose. The drug’s therapeutic and toxic effects are both related to its activity on specific G protein-coupled receptors. The seriousness of the drug’s toxic effects is proportionately related to the drug concentration. This is an example of:

• Dose dependent toxicity

• Gentoxicity

• Idiosyncratic toxicity

• Supra-additive toxcitiy

• Unpredictable toxicity

A cancer patient is given an antineoplastic drug that causes damage to the cancer cells’ DNA which ultimately activates intracellular signaling leading to programmed cell death. This phenomenon is termed:

• Apoptosis

• Fibrosis

• Mutagenesis

• Necrosis

• Teratogenesis

A patient presenting with a morphine overdose is given a rapid-acting antidote that acts at the same receptors and reverses the effects of the morphine. (Morphine is a mu receptor agonist.) The mechanism of this antidote-agonist drug action is:

• Allosteric antagonism

• Chemical antagonism

• Partial antagonism

• Physiologic antagonism

• Receptor antagonism

A patient’s sputum sample is sent to the microbiology laboratory for culture and susceptibility testing. The pathogen is found to have intermediate resistance to the first-line antibiotic. As a result of this resistance, the drug exhibits reduced:

• Efficacy

• Half-life

• Potency

• Selectivity

• Spectrum

A pharmaceutical company investigating an experimental antibiotic finds that the drug produces a faster kill rate and more extensive degree of killing as the drug concentrations increase. Additionally, the drug produces prolonged, persistent antibacterial effects. This activity profile is best described by which one of the following?

• EC50 right shift

• Emax decrease

• Peak/MIC

• T>MIC

• 24h-AUC/MIC

Which of the following provide glutamatergic input to granule cells?

• Stellate cells

• Purkinje cells

• Climbing fibers

• Mossy fibers

• Parallel fibers

Cerebellar efferents destined for the right red nucleus exit through which peduncle?

• Left inferior peduncle

• Left middle peduncle

• Left superior peduncle

• Right inferior peduncle

• Right superior peduncle

Striatal neurons possessing D1 receptors:

• Exhibit decreased excitability with dopamine

• Excite the globus pallidus external

• Inhibit the globus pallidus external

• Inhibit the substantia nigra pars reticulata

• Inhibit the subthalamic nucleus

This basal ganglia disorder has a strong genetic component:

• Hemiballismus

• Dementia pugilistica

• Idiopathic Parkinson's disease

• MPTP

• Wilson's disease

Which of the following basal ganglia nuclei receive direct input from the cerebral cortex?

• Globus pallidus external

• Globus pallidus internal

• Substantia nigra pars compacta

• Substantia nigra pars reticulata

• Subthalamic nucleus

The presence of these neuron-embedded protein aggregations are a hallmark of Parkinson’s disease:

• Amyloid plaques

• Lewy bodies

• Melanin

• MPTP

• Neurofibrillary tangles

The cell bodies of which neurons are found in the middle layer of the cerebellar cortex?

• Climbing fibers

• Deep cerebellar nuclei

• Granule cells

• Inhibitory interneurons

• Purkinje cells

Primary somatosensory cortex receives direct input from which nuclei?

• Gracile and cuneate nuclei

• Medial dorsal nuclei (MD)

• Mesencephalic trigeminal nucleus

• Reticular formation

• Ventral posterior lateral nuclei (VPL)

A lesion to this neural substrate would blunt the sensation of light touch along the left forehead:

• Left spinal trigeminal nucleus

• Left pontine trigeminal nucleus

• Left mesencephalic trigeminal nucleus

• Left ventral posterior medial nucleus

• Right ventral posterior lateral nucleus

Which sensation would be least affected by blocking the activity of myelinated afferent fibers?

• Limb position

• Muscle force

• Sharp pain

• Vibration

• Warmth

Accurate two-point discrimination is dependent on which sensory organ?

• Joint receptors

• Merkel disks

• Muscle spindles

• Pacinian corpuscles

• Ruffini corpuscles

Neurons of the corticobulbar tract:

• Are "lower motor neurons"

• Arise from the medial portion of the primary motor cortex

• Mostly terminate bilaterally in the brainstem

• Mostly terminate contralaterally in the brainstem

• Mostly terminate ipsilaterally in the brainstem

What percentage of pyramidal tract fibers form the ventral corticospinal tract?

• 5%

• 15%

• 50%

• 85%

• 95%

Which of the following is characteristic of a lower motor neuron lesion?

• Atrophy of the muscle

• Muscle spasms leading to altered limb posture

• Extension of hallux evoked by stroking the foot sole

• Sustained limb oscillations to a tendon tap

• Tremor present during passive rest

What is the lateral-medial representation within primary motor cortex?

• Face-arm-hand-trunk-leg

• Face-hand-arm-trunk-leg

• Hand-face-arm-trunk-leg

• Leg-trunk-arm-face-arm

• Leg-trunk-arm-hand-face

A carotid angiogram demonstrates occlusion of the left middle cerebral artery. Based on the location of this occlusion, you expect to see which of the following deficits?

• Paralysis and sensory deficits in the right leg and perineuim, weakness of the right face, tongue and upper limb, and anosmia

• Paralysis of the lower right side of the face and right arm and bilateral hemianopsia of the contralateral visual fields of both eyes

• Paralysis of the right-side of the body, right-sided hemianopsia, and left-sided blindness

• Paralysis of the lower left side of the face and left arm, bilateral hemianopsia of the contralateral 
visual fields of both eyes, and global aphasia

• Paralysis and sensory deficits in the left leg and perineuim, weakness of the left face, tongue and 
upper limb, and anosmia

An 8-year-old male is brought in by ambulance to the emergency department after being hit in the head by a fast moving foul ball at a baseball game. He is currently awake and alert, and responds to questions and commands. However, a CT scan of the head shows a collection of blood that does not cross suture lines. The most likely source of this blood is a(n):

• Rupture of the bridging veins

• Tear of the middle meningeal artery

• Rupture of a berry aneurysm

• Embolus to the left posterior cerebral artery

• Rupture of a Charcot-Bouchard microaneurysm

A 55-year-old Caucasian male presents to the emergency department with left-sided loss of pain and temperature sensation to the upper and lower limb. While conducting a neurological exam, you also note that his right eye is exhibiting ptosis and miosis. After conducting an MRI, it is verified that the patient has a lesion to the right caudal pons. Which of the following symptoms might this patient also have presented with based on the location of the lesion?

• Left facial paralysis

• Left facial paralysis with sparing of the forehead

• Decreased gag reflex

• Right facial paralysis

• Right facial paralysis with sparing of the forehead

An 80-year-old African American female is brought into the emergency department via ambulance from her nursing home facility. The paramedics activated the advanced care life support protocol for a code stroke based on the patient’s signs and symptoms. Once you begin examining her, you note that she has left-sided hemiparesis, right-sided total facial paralysis, and right-sided conjugate gaze paralysis. Before sending your patient for an MRI you suspect she is suffering from which of the following syndromes?

• Raymond's syndrome

• Wallenberg's syndrome

• Millard-Guebler syndrome

• Weber's syndrome

• Foville's syndrome

A patient with receptive aphasia presents to the emergency department. Neuroimaging reveals no injury to Wernicke’s area. What other neural structure might exhibit injury/lesion to produce this clinical presentation?

• Occipital lobe

• Middle cerebellar peduncle

• Arcuate fasciculus

• Cerebral peduncle

• Precentral gyrus

An unconscious patient presents to the emergency department with left-side parietal lobe injury evident in neuroimaging. Which of the following might a clinician suspect will be present in this patient upon return of consciousness?

• Voluntary motor control deficits

• Auditory deficits

• Hemi-neglect

• Expressive aphasia

• Vertigo

Neurons in the neocortex with pyramidal morphology and dendritic spines release which of the following neurotransmitters?

• Acetylcholine

• Gamma amino-butyric acid

• Glutamate

• Norepinephrine

• Serotonin

Genetic mutations affecting this cellular process have been implicated in microcephaly?

• Neurotransmitter release

• Dendritic growth

• Cell division

• Axonal sprouting

• Neuronal excitability

Which of the following best describes the developmental sequence for neocortical layer IV?

• Layer IV neurons are born after layer III


• Layer IV neurons are born before layer III neurons and migrate closer to the pial surface than layer III neurons


• Layer IV neurons are born after layer V neurons and migrate past layer V neurons

• Layer IV neurons are born before layer V neurons and migrate past layer V neurons


• Layer IV neurons are born after layer V neurons and migrate further away from the pial surface than layer V neurons

Which of the following best describes the function of the massa intermedia?

• Constitutes the speech-language pathway

• Connects the cerebral hemispheres

• Connects the thalamic hemispheres

• Connects the thalamus and cortex

• Connects the mammillary bodies and thalamus

Which of the following constitutes the axonal pathway connecting the thalamus and neocortex?

• Arcuate fasciculus

• Corpus callosum

• Internal capsule

• Massa intermedia

• Mammilothalamic tract

Neurons in the primary auditory cortex project to which of the following thalamic nuclei?

• Only the medial geniculate

• Only the reticular nucleus

• Medial geniculate and reticular nucleus

• Medial dorsal and reticular nucleus

• Medial geniculate and medial dorsal

A patient with sudden onset blindness is brought to the emergency department. Imaging of the eye and visual cortex reveals no obvious pathology. The next brain region to examine for possible lesions would include which of the following thalamic nuclei?

• Ventral posterior medial

• Ventral posterior lateral

• Lateral geniculate

• Medial dorsal

• Medial geniculate

Which of the following hypothalamic nuclei is the feeding center of the brain?

• Lateral nucleus

• Medial preoptic nucleus

• Arcuate nucleus

• Ventromedial nucleus

• Mammillary nucleus

Which of the following hormones participates in the short-term control of pre-meal hunger and meal initiation?

• Agouti-related peptide

• Corticotropin-releasing factor (CRF)

• Ghrelin

• Leptin

• Glucagon

Which of the following hypothalamic nuclei is the satiety center of the brain?

• Lateral nucleus

• Suprachiasmatic nucleus

• Supraoptic nucleus

• Paraventricular nucleus

• Ventromedial nucleus

A 7-year-old girl presents to your office with severe obesity (body mass index of >40), hyperphagia and metabolic neuroendocrine and immune dysfunction. Sequencing of the ob gene for both the proband and her parents reveals the child to be homozygous for deletion of a single guanine nucleotide in codon 133 of the ob gene reading frame. Based upon these findings, you would suspect the above mutation to be localized to cells of the:

• Hypothalamus

• Brown adipose tissue

• Pituitary

• Duodenum

• Proximal small intestine

Stringing together unrelated or inappropriate facts, as often seen in patients with chronic alcohol consumption, is known as:

• Confabulation

• Diplopia

• Vertigo

• Hyperorality

• Hyperphagia

A 42-year-old man is brought to the emergency department from the site of a collapsed building after an earthquake. Suspecting a brain injury, the attending physician orders a CT (computerized tomography) scan. This reveals bilateral damage to rostral aspects of the temporal lobes. After recovering from the initial trauma, this man displays compulsive exploratory behavior around the hospital and repeatedly examines objects by placing them in his mouth. These behavioral aberrations, when correlated with the CT findings, suggest which of the following syndromes?

• Foster-Kennedy syndrome

• Kluver-Bucy syndrome

• Wernicke-Korsakoff syndrome

• Wallenberg syndrome

• Septal rage syndrome

This clinical condition results from a thiamine (vitamin B1) deficiency and is characterized by ocular disturbances and nystagmus, gait ataxia and cognitive deficits. Brain pathology includes lesions to the mammillary nuclei, dorsomedial nucleus of the thalamus, periaqueductal gray and pontine tegmentum. What is the name of this condition?

• Amnestic syndrome

• Foster-Kennedy syndrome

• Korsakoff syndrome

• Strachan's syndrome

• Wernicke's enceophalopathy

Which of the following nuclei is associated with the neural control of micturition?

• Supraoptic nucleus

• Raphe nucleus

• Barrington's nucleus

• Edinger-Westphal nucleus

• Nucleus of Maynert

Which of the following conditions is a common side effect of opioid medication?

• Hemorrhoids

• Constipation

• Ascites

• Proctorrhea

• Diarrhea

Which of the following brain regions modulates the phenomenon of stimulus-induced analgesia?

• Ventral tegmental area

• Suprachiasmatic nucleus of the hypothalamus

• Amygdala

• Hippocampus

• Periaqueductal gray area

A 50-year-old man with a history of severe insomnia presents to the neurology department complaining of bizarre sensations in his legs such as “pulling, searing, crawling and shimmering”. On examination, he is noted to have iron-deficiency anemia. Which of the following diagnoses should you suspect?

• Obstructive sleep apnea

• Restless leg syndrome

• Narcolepsy

• Delayed-sleep syndrome

• Circadian-rhythm disorder

Which of the following physical exam findings are clinical features of narcolepsy?

• Confabulation

• Retrograde amnesia

• Hypnagogic hallucinations

• Dysphagia

• Anorexia

Which of the following neuropeptides plays an essential role in maintaining wakefulness and regulating transitions between sleep and wake cycles?

• Orexins

• Melanocortins

• Indoleamines

• Cannabinoids

• Endorphins

At what vertebral level can one most easily introduce a needle into the dural sac without piercing the spinal cord?

• C5/6

• L3/4

• S3/4

• T4/5

• T8/L1

Which neural structure is located on the ventral medulla?

• Gracile tubercle

• Inferior olive

• Mammillary bodies

• Medial eminence

• Superior colliculus

What neural structure is immediately inferior to the inferior colliculus?

• Gracile tubercle

• Inferior olive

• Pyramidal decussation

• Superior colliculus

• Trochlear nerve

The tonsils belong to what part of the cerebellum?

• Anterior lobe

• Floculonodular lobe

• Inferior vermis

• Posterior lobe

• Uvula

Impaired temperature and pain sensation from the right leg would result from a lesion to which white matter tract of the spinal cord?

• Left antero-lateral tract

• Left gracile fasciculus

• Right antero-lateral tract

• Right cuneate fasciculus

• Right gracile fasciculus

Which is the largest descending tract of the spinal cord?

• Cuneate fasciculus

• Lateral corticospinal tract

• Rubrospinal tract

• Ventral corticospinal tract

• Vestibulospinal tract

Which portion of the spinal cord is involved in processing pain information?

• Onuf's nucleus

• Phrenic nucleus

• Nucleus dorsalis

• Spinal accessory nucleus

• Substantia gelatinosa

Damage to which of the cerebral lobes is likely responsible for the majority of expressive aphasia cases?

• Left cerebellar lobe/hemisphere

• Left frontal lobe

• Left parietal lobe

• Right occipital lobe

• Right temporal lobe


Which cortical invagination divides the primary motor cortex from the primary sensory cortex?

• Central sulcus

• Lateral fissure

• Longitudinal fissure

• Pre-occipital notch

• Sylvian fissure

Which cerebral lobe controls primary motor movement on the right side of the body?

• Left frontal lobe

• Left parietal lobe

• Left temporal lobe

• Right frontal lobe

• Right parietal lobe

Which of the following general statements applies to the human brain?

• Female brains tend to contain more glial cells than male brains

• Human brains consist of more neurons than glial cells

• Human brains do not grow anymore after birth

• Male brains are generally heavier than female brains

• Male brains generally contain more neurons than female brains

Which process/event initiates the invagination of neuroectodermal tissue and is thereby responsible for the formation of the neural tube?

• Accumulation of folic acid in neuroectoderm

• Closure of the rostral neuropore

• Production of bone morphogenetic proteins (BMPs) by neural crest cells

• Release of alpha-fetoprotein (AFP) by neuroectoderm

• Release of the signaling protein sonic hedgehod (SHH) notochord cells

What defect, most commonly observed in infants, will most likely result from excessive cerebrospinal fluid?

• Anencephaly

• Arnolad-Chiari malformation

• Hydrocephalus

• Meroanencephaly

• Spina bifida with meningomyelocele

How can genetic defects that specifically affect central and peripheral nervous system cells also affect skin pigmentation?

• Because certain pigment forming cells are of neural crest origin

• Because melanocytes are of mesodermal origin

• Because of a direct innervation of pigment forming cells

• Because of the involvement of Schwann cells in skin pigmentation

• Because pigment forming chromaffin cells are of neuroectodermal origin

What distinguishes microglia from all other major resident cell types found in the central nervous system?

• Microglia are derived from mesoderm

• Microglia are derived from neural crest cell

• Microglia are non-phagocytic

• Microglia form processes that wrap around brain endothelial capillaries

• Microglia have the ability to differentiate into macroglia

Neural signals mediating touch and proprioception are carried by the:

• Corticospinal pathway which decussates in the midbrain

• Corticospinal pathway which decussates in the medulla

• Pyramidal tract which decussates in the midbrain

• Spinothalamic tract which is medially located throughout the length of the brainstem

• Dorsal column-medial lemniscus pathway which decussates in the medulla

The inferior olivary complex of nuclei:

• Project axons across the midline to the red nuclei

• Control eye movements

• Are anterior to the pyramids in the brainstem

• Are located in the midbrain

• Project axons across the midline to the cerebellum

A patient has pain and temperature loss on the right side of the body, but unaffected movement control. A possible location of the lesion in the brainstem is in:

• The left ventral pons

• The left medial pontine tegmentum

• The right medial medulla

• The right ventral midbrain

• A lateral part of the tegmentum

Of the following, you most suspect that a patient with a localized brainstem injury who complains of loud noise would also:

• Be able to blink both eyes

• Have difficulty sticking out his tongue symmetrically

• Have hemiparisis

• Have impaired ocular elevation

• Have impaired lateral gaze

The medial rectus muscle:

• Depresses the eye

• Elevates the eye

• Extorts the eye

• Intorts the eye

• Participates in conjugate eye movements

A patient has muscle weakness and intact sensation on the left side of the body. To rule out medial medullary syndrome you test:

• Contralateral facial pain

• Facial paralysis

• Lateral gaze

• Upward gaze

• Tongue movement

An absent bilateral corneal reflex may be due to unilateral injury of:

• CN II

• CN III

• CN VI

• CN VII

• CN V

A lesion in the midbrain will most likely affect:

• Pain and temperature sense on the face

• Blink reflex

• Swallowing

• Touch and proprioception on the face

• Chewing

Each CN XI projects to the:

• Bilateral sternocleidomastoids and the contralateral trapezius

• Contralateral sternocleidomastoid and the contralateral trapezius

• Contralateral sternocleidomastoid and the ipsilateral trapezius

• Ipsilateral sternocleidomastoid and the contralateral trapezius

• Ipsilateral sternocleidomastoid and the ipsilateral trapezius

CN IX affects:

• Somatosensation, blood pressure feedback, lacrimation, and salivation

• Trapezius control, taste, blood pressure feedback, and salivation

• Somatosensation, taste, blood pressure feedback, lacrimation, and swallowing

• Somatosensation, taste, blood pressure feedback, mastication, and swallowing

• Somatosensation, taste, blood pressure feedback, salivation, and swallowing

Including facial expression, CN VII also affects:

• Somatosensation, taste, and blood pressure feedback

• Somatosensation, taste, blood pressure feedback, and salivation

• Somatosensation, taste, blood pressure feedback, and swallowing

• Taste, salivation, and swallowing

• Somatosensation, taste, salivation, and hearing

Cranial nerves involved with muscular control of swallowing include:

• V, VII, IX, X

• V, X, XII

• VII, X, XII

• VIII, IX, X

• IX, X

The number of cranial nerves projecting directly to each eye is:

• 3

• 4

• 10

• 8

• 5

Cranial nerve VII is involved with:

• The gag reflex

• Parotid gland secretion

• Proprioception from the posterior part of the tongue

• Taste from the posterior part of the tongue

• Controlling the stapedius

Cranial nerve IX is involved with:

• Controlling facial expression muscles

• Producing tears and saliva

• Skin sense from the back of the ear

• Taste from the anterior part of the tongue

• Regulating blood pressure

The pyramidal decussation:

• Accounts for the cortical activity related to sensation of contralateral proprioception

• Accounts for the cortical activity related to sensation of contralateral bodily pain

• Is dorsal to the inferior cerebellar peduncles

• Is where all corticospinal fibers cross the midline

• Accounts for the cortical control of contralateral movement

Which of the following is responsible for the transition between the action potential undershoot and the return of the membrane potential back to rest:

• Opening of voltage-gated K+ channels

• Activation of glutamate receptors

• Opening of voltage-gated Na+ channels

• Closing of voltage-gated K+ channels

• Opening of voltage-gated Ca+ channels

Opening of voltage-gated K+ channels during the action potential is responsible for which of the following?

• Only the falling phase

• Only the rising phase

• Only the undershoot

• The overshoot and the falling phase

• The falling phase and the undershoot

Which of the following cell types make contact with the brain vasculature?

• Purkinje cells

• Oligodendrocytes

• Schwann cells

• Astrocytes

• Satellite cells

Which of the following cell types produce myelin insulating axons of the PNS?

• Oligodendrocytes

• Satellite cells

• Schwann cells

• Choroid plexus cells

• Microglial cells

Which of the following is an active mechanism that contributes to a hyperpolarized resting membrane potential in neurons?

• Leak K+ channels

• Glutamate receptors

• Na-K+ pump

• Voltage-gated Na+ channels

• Voltage-gated K+ channels

Which of the following clinical conditions is often associated with the breakdown of the blood-brain barrier?

• Grave's disease

• Autism spectrum disorder (ASD)

• Multiple sclerosis (MS)

• Serotonin syndrome

• Metabolic syndrome (e.g. clinical obesity)

Which of the following brain sites lacks a blood-brain-barrier?

• The area postrema

• The cerebellum

• The falx cerebri

• The hippocampus

• The Virchow-Robin space

Significant amounts of serotonin (5-HT)-containing neurons are found in the upper brain stem, particularly in the pons and medulla, areas that are collectively called the:

• Paraventricular nucleus (PVN) of the hypothalamus

• Ventral tegmental area (VTA)

• Meso-striatal pathways

• Raphe nuclei

• Supraoptic nucleus

Which of the following physiological conditions is modulated by the actions of substance P?

• Nociceptive transmission

• Cognitive processes

• Metabolic signaling cascades

• Feeding signals

• Spinal reflexes

Which of the following receptors can modulate the release of neurotransmitters from the same nerve ending?

• Inositol trisphosphate receptors/channels

• Auto-receptors

• Metabotropic receptors

• Intra-cellular receptors

• Post-synaptic receptors

Which of the following structural brain deficits have been repeatedly reported in patients with schizophrenia?

• Expansion of the ventricular system

• Expansion of the Virchow-Robin space

• Selective atrophy of the hippocampus

• Degeneration of the frontal cortex

• Malformations of the cerebellum

An expansion of the ventricles due to tissue loss, as in the case of Alzheimer’s disease, is termed:

• Hydrocephalus ex vacuo

• Focal cerebral ischemia

• Cytotoxic cerebral edema

• Traumatic brain injury

• Epidural hematoma

Which modification of histones is associated with a decrease in transcription?

• Phosphorylation

• Methylation

• Acetylation

• Glycosylation

• Addition of a coenzyme

In an experimental polymerase chain reaction (PCR), 12 out of 25 total cycles have been completed. During the 13th cycle, immediately after a DNA polymerase synthesizes the target DNA sequence on all available DNA templates, which one of the following will occur next?

• The samples will be cooled down

• Additional reactants will be added

• The flanking primers hybridize to their complementary DNA sequences

• The double -stranded DNA will be denatured by heating

• Taq polymerase will catalyze DNA synthesis

During DNA replication:

• Addition of nucleotides occurs at the 5' end of a new strand

• The double helix is unwound by SSB protein

• RNA primers are removed by DNA polymerase

• Multiple primers are added to the leading strand

• Okazaki fragments are joined by DNA ligase

Antibiotics in the quinolone family:

• Disrupt the initiation step of bacterial protein synthesis

• Block the action of bacterial RNA polymerase

• Act as inhibitors of bacterial DNA topoisomerases

• Are incorporated into new DNA and stop replication of the AIDS virus

• Degrade bacterial DNA

The toxin of the Amanita phalloides mushroom:

• Binds to eukaryotic RNA polymerase and blocks transcription

• Acts to prematurely remove the new mRNA from its DNA template

• Inhibits the splicing process in eukaryotes

• Stops the post-transcriptional processing of mRNA

• Blocks the action of topoisomerases

What is the definition of an intron?

• It connects the codon to the anticodon

• It codes for a nonfunctional part of a protein

• It is part of the final protein

• It is a mutation in the DNA

• It is one type of a promoter

A 32-year-old man with AIDS (CD4 count is 21/mm3) presents with shortness of breath. Despite treatment with piperacillin-tazobactam, he has progressive respiratory failure and is intubated. Chest radiographs show a diffuse interstitial pneumonia. Silver staining of sputum reveals the presence of irregularly shaped 5 micron organisms that do not grow in the laboratory. This disease is most likely caused by which of the following fungi?

• Pneumocystis jirovecii

• Aspergillus niger

• Candida albicans

• Sporothrix schenckii

• Coccidioides immmitis

Which of the following diseases is orally acquired and spreads to the central nervous system causing flaccid paralysis mostly in children?

• Infectious mononucleosis

• Measles

• Polio

• Herpes simplex virus

• Chicken pox

e reverse transcriptase of HIV:

• Transcribes viral DNA to cell DNA

• Transcribes viral RNA to DNA

• Transcribes cellular DNA to viral DNA

• Is attached to the viral DNA

• Translate viral RNA to DNA

Which is the correct sequence (first to last) of events in viral replication?

• Penetration, uncoating, synthesis, adsorption, assembly, release

• Uncoating, penetration, synthesis, assembly, absorption, release

• Adsorption, penetration, uncoating, synthesis, assembly, release

• Assembly, synthesis, uncoating, release, penetration, adsorption

• Synthesis, uncoating, release, penetration, adsorption, assembly

Which is the protein shell around the nucleic acid core of a virus?

• Capsid

• Spike

• Envelope

• Monolayer

• Canon

A 53-year-old man with a renal transplant develops shortness of breath and fevers. His chest radiograph reveals a dense left upper lobe infiltrate. A bronchoscopy with biopsy is performed. The pathologist calls to inform you that encapsulated yeast cells ~5 micrometer (μm) in diameter are present in the biopsy specimen. Which of the following is the cause of this patient’s disease?

• Histoplasma capsulatum

• Aspergillus fumigatus


• Cryptococcus neoformans

• Blastomyces dermatitidis

• Candida albicans

Outbreaks of systemic mycoses have been associated with:

• Urban areas

• Summer season

• Cold weather

• Regions over sea level

• Disturbances of the environment in endemic regions

Which of the following combination of characteristics apply only to fungi?

• Eukaryotic, autotrophic, rigid cell wall

• Eukaryotic, heterotrophic, rigid cell wall

• Eukaryotic, heterotrophic, no cell wall

• Eukaryotic, autotrophic, no cell wall

• Prokaryotic, heterotrophic, rigid cell wall

Viruses are distinguishable from both bacteria and protozoan parasites because viruses have:

• Flagella

• DNA or RNA genomes and not both

• Chromosomal DNA

• Intracellular organelles

• Ribosomes that assist in RNA synthesis

The Rickettsia microbe is a good example of a type of pathogen that:

• Is a frequent cause of gastroenteritis

• Causes a condition known as oral thrush

• Grows and divides inside various host cells

• Produces spores under harsh conditions

• Has a cell similar to yeast-like fungi

Which of the following is an accurate description for the pathogen that can cause encephalitis in immunocompromised patients and congenital abnormalities, and can be acquired from contact with infected cat feces?

• Protozoan parasite

• Acid-fast bacillus

• Gram negative bacillus

• Gram positive coccus

• Dimorphic fungus

A widespread infection or disease with high attack rates that includes either high morbidity or mortality rates and occurs worldwide or in a particular region is known as a/an:

• Endemic situation

• Epidemic situation

• Pandemic situation

• Incubation period

• Prolonged carrier state

Your patient is a 54-year-old man who presents with a fever, cough and chest pain. A sputum sample reveals numerous neutrophils and extracellular gram-positive diplococci. The likely etiologic agent is

• Chlamydophila pneumoniae

• Haemophilus influenzae


• Mycoplasma pneumoniae

• Streptococcus pneumoniae

• Klebsiella pneumoniae

A 3-year-old girl presents to the emergency department in severe respiratory distress. She has a fever and difficulty breathing. A gram-negative pathogen is isolated from a respiratory sample which is only culturable on chocolate agar. This clinical scenario could have been prevented if the patient had been immunized with:

• The BCG vaccine

• Pneumovax

• Lipopolysaccharide

• Serotype b vaccine

• Acelluar pertussis vaccine

Your patient is a 9-year-old boy who presents with a fever and a severe sore throat. A rapid test for Group A streptococcal antigen is done using a throat swab and it comes back positive. Which of the following tests would confirm the likely diagnosis?