Question 1
Question
Attached are the solute concentrations for a normal mammalian cell under resting conditions. Which value will be closest to the resting membrane potential of this cell?
Answer
-
100 mV
-
4 mV
-
-80 mV
-
-183 mV
-
-22 mV
Question 2
Question
The attached figure shows data obtained by measuring the uptake of L-alanine into a mammalian cell from an isotonic salt solution made without (“Without Na+”) versus with (“With Na+”) sodium. Sodium was replaced on a mole-per-mole basis with choline in the “Without Na+” isotonic saline solution. Which of the following statements about L-alanine uptake into this cell is most correct?
Answer
-
L-alanine moves into the cell via an antiporter for Na+
-
In the absence of Na+, L-alanine moves into the cell via a uniporter with a Km for L-alanine of 50
microM
-
At 500 microM L-alanine in the extracellular solution, the majority of L-alanine uptake is through a
Na+-dependent process
-
ATP depletion would not affect the rate of L-alanine uptake into the cell
-
Increasing the extracellular isotonic saline solution K+ concentration will decrease the Na+-dependent component of L-alanine uptake into the cell
Question 3
Question
You are examining the uptake into cells of a proposed peptide growth factor, Gribel. You show there are no membrane transporters that mediate the movement of Gribel across the plasma membrane. You measure the internalization of Gribel into neuronal cells after you add Gribel to the extracellular solution. You also measure the uptake of a fluid phase marker, a soluble compound that quantitates the rate of fluid uptake, in the absence and presence of Gribel. The data are attached. Based on the presented data, which of the following statements about Gribel is most correct?
Answer
-
Gribel is internalized in vesicles that are greater than 250 nm in size
-
Gribel is not internalized in coated pits
-
Gribel internalization is not energy-dependent
-
Gribel is internalized via a mechanism other than endocytosis
-
Gribel is not internalized by receptor-mediated endocytosis
Question 4
Question
Spectrin is an integral part in which of the following intracellular structure(s)?
Answer
-
Intermediate filaments
-
Centrosome
-
Basal body
-
Desmosome
-
Cell cortex
Question 5
Question
Which protein is necessary to create the forces that result in the bending movements of cilia and flagella?
Answer
-
Myosin
-
Dynein
-
Actin
-
Kinesin
-
Keratin
Question 6
Question
Which intracellular process would be primarily disrupted by inhibition of Arp2/3 complexes?
Answer
-
Microtubule nucleation
-
Dynamic instability
-
Microfilament nucleation
-
Treadmilling
-
Intracilliary transport
Question 7
Question
Which type of the anchoring contact is used by the migrating (crawling) fibroblasts?
Answer
-
Desmosome
-
Adherence junction
-
Hemidesmosome
-
Tight junctions
-
Focal adhesion
Question 8
Question
What is the primary function of tissue fibronectin?
Question 9
Question
Which of the following extracellular matrix components assembles proteoglycans into the gigantic complexes called proteoglycan aggregates?
Answer
-
Collagen type I
-
Hyalumnan
-
Heparan sulfate
-
Fibronectin
-
Laminin
Question 10
Question
Which type of gene mutations confer a selective growth advantage in cancers?
Answer
-
Passenger mutations
-
Frameshift mutations
-
Driver mutations
-
Deletions
-
Insertions
Question 11
Question
Ninety-five percent of the mutations in tumors are:
Question 12
Question
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?
Question 13
Question
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?
Question 14
Question
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?
Answer
-
Vitamin C
-
Folic acid
-
Thiamine
-
Vitamin B6 (pyridoxine)
-
Vitamin B12
Question 15
Question
Which vitamin is involved in collagen synthesis?
Answer
-
Folic acid
-
Niacin
-
Vitamin B12
-
Vitamin C
-
Vitamin D
Question 16
Question
The attached image depicts a histological image of the human mammary gland stained with H&E. What type of connective tissue is most abundant immediately around the glands (arrows)?
Answer
-
Dense irregular
-
Dense regular
-
Embryonic
-
Loose connective
-
Wharton's jelly
Question 17
Question
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?
Answer
-
Amylase
-
DNase
-
Lipase
-
Proteinase
-
RNase
Question 18
Question
Which of the following antigens is the most immunogenic?
Answer
-
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
Question 19
Question
Which multilobed lymphatic organ serves as the place for T cell maturation?
Answer
-
Spleen
-
Trachea
-
Thymus
-
Bone marrow
-
Salivary gland
Question 20
Question
The term redundancy of cytokines means that:
Answer
-
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
Question 21
Question
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?
Answer
-
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
Question 22
Question
Compared to a secondary response, a primary response is:
Answer
-
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
Question 23
Question
Which is the most accurate description of the type of organism that a laboratory would try to isolate on MacConkey agar?
Question 24
Question
The designated purpose of the “A” (bacitracin)-disc is to distinguish:
Answer
-
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
Question 25
Question
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:
Question 26
Question
What type of epithelial tissue is normally keratinized?
Answer
-
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
Question 27
Question
The inner lining of this blood vessel allows for passive diffusion and filtration. It is best classified as what type of epithelium? (Please see attachment)
Answer
-
Pseudostratified
-
Simple squamous
-
Cuboidal
-
Simple columnar
-
Transitional
Question 28
Question
Which of the tissues/organs listed below is most likely to be lined by transitional epithelium?
Answer
-
Bladder
-
Large intestine
-
Skin
-
Esophagus
-
Uterus
Question 29
Question
Which of the following features does cardiac muscle have in common with skeletal muscle?
Question 30
Question
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?
Question 31
Question
The accompanying photo represents a microscopic section of an unidentified organ with an area of necrosis which shows preserved cellular architecture with loss of nuclei, resulting from loss of blood supply. What does this most likely represent? (Please see attachment)
Answer
-
A kidney infarct
-
Acute pancreatitis
-
Pulmonary tuberculosis
-
Brain abscess
-
Vascuilitis
Question 32
Question
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:
Question 33
Question
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?
Answer
-
Complement C3b
-
Selectins
-
Integrins
-
NADPH oxidase
-
Leukotrienes
Question 34
Question
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:
Question 35
Question
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?
Answer
-
Infection
-
Malnutrition
-
Foreign body
-
Dehiscence
-
Contracture
Question 36
Question
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:
Answer
-
Neutrophils
-
Collagen
-
Granulomas
-
Keloid
-
Granulation tissue
Question 37
Question
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:
Answer
-
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
Question 38
Question
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:
Answer
-
Benign
-
Well-differentiated
-
Slow-growing
-
High grade
-
Well-circumscribed
Question 39
Question
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?
Answer
-
Leiomyosarcoma
-
Melanoma
-
Fibroadenoma
-
Papiloma
-
Adenocarcinoma
Question 40
Question
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?
Answer
-
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
Question 41
Question
Which of the following is a signal that mammalian cells use to communicate between themselves?
Answer
-
Light
-
Sound
-
Smell
-
Heat
-
Gas
Question 42
Question
Beta 2 adrenergic receptor has a Kd of 10-10 M for epinephrine and 10-8 for norepinephrine. This means that:
Answer
-
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
Question 43
Question
Which of the following statements is true regarding Cholera toxin and Pertussis toxin?
Answer
-
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
Question 44
Question
Which of the following statements is true regarding the second messenger cAMP?
Answer
-
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
Question 45
Question
Which of the following statements is true regarding PIP2 (Phosphatidylinositol 4,5-bisphosphate) and PIP3 (Phosphatidylinositol 3,4,5-trisphosphate)?
Answer
-
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
Question 46
Question
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?
Question 47
Question
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?
Answer
-
Down syndrome
-
Edwards syndrome
-
DiGeorge syndrome
-
Patau syndrome
-
Turner syndrome
Question 48
Question
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:
Answer
-
Carbamazepine
-
Erythromycin
-
Itraconazole
-
Probenecid
-
Ritonavir
Question 49
Question
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:
Answer
-
Dose dependent toxicity
-
Gentoxicity
-
Idiosyncratic toxicity
-
Supra-additive toxcitiy
-
Unpredictable toxicity
Question 50
Question
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:
Answer
-
Apoptosis
-
Fibrosis
-
Mutagenesis
-
Necrosis
-
Teratogenesis
Question 51
Question
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:
Answer
-
Allosteric antagonism
-
Chemical antagonism
-
Partial antagonism
-
Physiologic antagonism
-
Receptor antagonism
Question 52
Question
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:
Answer
-
Efficacy
-
Half-life
-
Potency
-
Selectivity
-
Spectrum
Question 53
Question
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?
Answer
-
EC50 right shift
-
Emax decrease
-
Peak/MIC
-
T>MIC
-
24h-AUC/MIC
Question 54
Question
Which of the following provide glutamatergic input to granule cells?
Answer
-
Stellate cells
-
Purkinje cells
-
Climbing fibers
-
Mossy fibers
-
Parallel fibers
Question 55
Question
Cerebellar efferents destined for the right red nucleus exit through which peduncle?
Answer
-
Left inferior peduncle
-
Left middle peduncle
-
Left superior peduncle
-
Right inferior peduncle
-
Right superior peduncle
Question 56
Question
Striatal neurons possessing D1 receptors:
Answer
-
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
Question 57
Question
This basal ganglia disorder has a strong genetic component:
Question 58
Question
Which of the following basal ganglia nuclei receive direct input from the cerebral cortex?
Question 59
Question
The presence of these neuron-embedded protein aggregations are a hallmark of Parkinson’s disease:
Answer
-
Amyloid plaques
-
Lewy bodies
-
Melanin
-
MPTP
-
Neurofibrillary tangles
Question 60
Question
The cell bodies of which neurons are found in the middle layer of the cerebellar cortex?
Answer
-
Climbing fibers
-
Deep cerebellar nuclei
-
Granule cells
-
Inhibitory interneurons
-
Purkinje cells
Question 61
Question
Primary somatosensory cortex receives direct input from which nuclei?
Answer
-
Gracile and cuneate nuclei
-
Medial dorsal nuclei (MD)
-
Mesencephalic trigeminal nucleus
-
Reticular formation
-
Ventral posterior lateral nuclei (VPL)
Question 62
Question
A lesion to this neural substrate would blunt the sensation of light touch along the left forehead:
Answer
-
Left spinal trigeminal nucleus
-
Left pontine trigeminal nucleus
-
Left mesencephalic trigeminal nucleus
-
Left ventral posterior medial nucleus
-
Right ventral posterior lateral nucleus
Question 63
Question
Which sensation would be least affected by blocking the activity of myelinated afferent fibers?
Answer
-
Limb position
-
Muscle force
-
Sharp pain
-
Vibration
-
Warmth
Question 64
Question
Accurate two-point discrimination is dependent on which sensory organ?
Answer
-
Joint receptors
-
Merkel disks
-
Muscle spindles
-
Pacinian corpuscles
-
Ruffini corpuscles
Question 65
Question
Neurons of the corticobulbar tract:
Answer
-
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
Question 66
Question
What percentage of pyramidal tract fibers form the ventral corticospinal tract?
Question 67
Question
Which of the following is characteristic of a lower motor neuron lesion?
Answer
-
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
Question 68
Question
What is the lateral-medial representation within primary motor cortex?
Answer
-
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
Question 69
Question
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?
Answer
-
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
Question 70
Question
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):
Answer
-
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
Question 71
Question
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?
Question 72
Question
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?
Answer
-
Raymond's syndrome
-
Wallenberg's syndrome
-
Millard-Guebler syndrome
-
Weber's syndrome
-
Foville's syndrome
Question 73
Question
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?
Question 74
Question
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?
Question 75
Question
Neurons in the neocortex with pyramidal morphology and dendritic spines release which of the following neurotransmitters?
Answer
-
Acetylcholine
-
Gamma amino-butyric acid
-
Glutamate
-
Norepinephrine
-
Serotonin
Question 76
Question
Genetic mutations affecting this cellular process have been implicated in microcephaly?
Answer
-
Neurotransmitter release
-
Dendritic growth
-
Cell division
-
Axonal sprouting
-
Neuronal excitability
Question 77
Question
Which of the following best describes the developmental sequence for neocortical layer IV?
Answer
-
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
Question 78
Question
Which of the following best describes the function of the massa intermedia?
Answer
-
Constitutes the speech-language pathway
-
Connects the cerebral hemispheres
-
Connects the thalamic hemispheres
-
Connects the thalamus and cortex
-
Connects the mammillary bodies and thalamus
Question 79
Question
Which of the following constitutes the axonal pathway connecting the thalamus and neocortex?
Answer
-
Arcuate fasciculus
-
Corpus callosum
-
Internal capsule
-
Massa intermedia
-
Mammilothalamic tract
Question 80
Question
Neurons in the primary auditory cortex project to which of the following thalamic nuclei?
Answer
-
Only the medial geniculate
-
Only the reticular nucleus
-
Medial geniculate and reticular nucleus
-
Medial dorsal and reticular nucleus
-
Medial geniculate and medial dorsal
Question 81
Question
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?
Question 82
Question
Which of the following hypothalamic nuclei is the feeding center of the brain?
Answer
-
Lateral nucleus
-
Medial preoptic nucleus
-
Arcuate nucleus
-
Ventromedial nucleus
-
Mammillary nucleus
Question 83
Question
Which of the following hormones participates in the short-term control of pre-meal hunger and meal initiation?
Question 84
Question
Which of the following hypothalamic nuclei is the satiety center of the brain?
Answer
-
Lateral nucleus
-
Suprachiasmatic nucleus
-
Supraoptic nucleus
-
Paraventricular nucleus
-
Ventromedial nucleus
Question 85
Question
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:
Answer
-
Hypothalamus
-
Brown adipose tissue
-
Pituitary
-
Duodenum
-
Proximal small intestine
Question 86
Question
Stringing together unrelated or inappropriate facts, as often seen in patients with chronic alcohol consumption, is known as:
Answer
-
Confabulation
-
Diplopia
-
Vertigo
-
Hyperorality
-
Hyperphagia
Question 87
Question
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?
Question 88
Question
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?
Question 89
Question
Which of the following nuclei is associated with the neural control of micturition?
Answer
-
Supraoptic nucleus
-
Raphe nucleus
-
Barrington's nucleus
-
Edinger-Westphal nucleus
-
Nucleus of Maynert
Question 90
Question
Which of the following conditions is a common side effect of opioid medication?
Answer
-
Hemorrhoids
-
Constipation
-
Ascites
-
Proctorrhea
-
Diarrhea
Question 91
Question
Which of the following brain regions modulates the phenomenon of stimulus-induced analgesia?
Question 92
Question
Which of the following brain waves best represents stage 3-4 of the sleep-wake cycle? (Please see attachment)
Question 93
Question
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?
Question 94
Question
Which of the following physical exam findings are clinical features of narcolepsy?
Question 95
Question
Which of the following neuropeptides plays an essential role in maintaining wakefulness and regulating transitions between sleep and wake cycles?
Answer
-
Orexins
-
Melanocortins
-
Indoleamines
-
Cannabinoids
-
Endorphins
Question 96
Question
At what vertebral level can one most easily introduce a needle into the dural sac without piercing the spinal cord?
Answer
-
C5/6
-
L3/4
-
S3/4
-
T4/5
-
T8/L1
Question 97
Question
Which neural structure is located on the ventral medulla?
Answer
-
Gracile tubercle
-
Inferior olive
-
Mammillary bodies
-
Medial eminence
-
Superior colliculus
Question 98
Question
What neural structure is immediately inferior to the inferior colliculus?
Answer
-
Gracile tubercle
-
Inferior olive
-
Pyramidal decussation
-
Superior colliculus
-
Trochlear nerve
Question 99
Question
The tonsils belong to what part of the cerebellum?
Answer
-
Anterior lobe
-
Floculonodular lobe
-
Inferior vermis
-
Posterior lobe
-
Uvula
Question 100
Question
Impaired temperature and pain sensation from the right leg would result from a lesion to which white matter tract of the spinal cord?
Question 101
Question
Which is the largest descending tract of the spinal cord?
Question 102
Question
Which portion of the spinal cord is involved in processing pain information?
Answer
-
Onuf's nucleus
-
Phrenic nucleus
-
Nucleus dorsalis
-
Spinal accessory nucleus
-
Substantia gelatinosa
Question 103
Question
Damage to which of the cerebral lobes is likely responsible for the majority of expressive aphasia cases?
Question 104
Question
Which cortical invagination divides the primary motor cortex from the primary sensory cortex?
Answer
-
Central sulcus
-
Lateral fissure
-
Longitudinal fissure
-
Pre-occipital notch
-
Sylvian fissure
Question 105
Question
Which cerebral lobe controls primary motor movement on the right side of the body?
Answer
-
Left frontal lobe
-
Left parietal lobe
-
Left temporal lobe
-
Right frontal lobe
-
Right parietal lobe
Question 106
Question
Which of the following general statements applies to the human brain?
Answer
-
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
Question 107
Question
Which process/event initiates the invagination of neuroectodermal tissue and is thereby responsible for the formation of the neural tube?
Answer
-
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
Question 108
Question
What defect, most commonly observed in infants, will most likely result from excessive cerebrospinal fluid?
Question 109
Question
How can genetic defects that specifically affect central and peripheral nervous system cells also affect skin pigmentation?
Answer
-
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
Question 110
Question
What distinguishes microglia from all other major resident cell types found in the central nervous system?
Answer
-
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
Question 111
Question
Neural signals mediating touch and proprioception are carried by the:
Answer
-
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
Question 112
Question
The inferior olivary complex of nuclei:
Answer
-
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
Question 113
Question
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:
Answer
-
The left ventral pons
-
The left medial pontine tegmentum
-
The right medial medulla
-
The right ventral midbrain
-
A lateral part of the tegmentum
Question 114
Question
Of the following, you most suspect that a patient with a localized brainstem injury who complains of loud noise would also:
Answer
-
Be able to blink both eyes
-
Have difficulty sticking out his tongue symmetrically
-
Have hemiparisis
-
Have impaired ocular elevation
-
Have impaired lateral gaze
Question 115
Question
The medial rectus muscle:
Question 116
Question
A patient has muscle weakness and intact sensation on the left side of the body. To rule out medial medullary syndrome you test:
Question 117
Question
An absent bilateral corneal reflex may be due to unilateral injury of:
Answer
-
CN II
-
CN III
-
CN VI
-
CN VII
-
CN V
Question 118
Question
A lesion in the midbrain will most likely affect:
Question 119
Question
Each CN XI projects to the:
Answer
-
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
Question 120
Answer
-
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
Question 121
Question
Including facial expression, CN VII also affects:
Answer
-
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
Question 122
Question
Cranial nerves involved with muscular control of swallowing include:
Answer
-
V, VII, IX, X
-
V, X, XII
-
VII, X, XII
-
VIII, IX, X
-
IX, X
Question 123
Question
The number of cranial nerves projecting directly to each eye is:
Question 124
Question
Cranial nerve VII is involved with:
Answer
-
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
Question 125
Question
Cranial nerve IX is involved with:
Answer
-
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
Question 126
Question
The pyramidal decussation:
Answer
-
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
Question 127
Question
Which of the following is responsible for the transition between the action potential undershoot and the return of the membrane potential back to rest:
Answer
-
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
Question 128
Question
Opening of voltage-gated K+ channels during the action potential is responsible for which of the following?
Question 129
Question
Which of the following cell types make contact with the brain vasculature?
Answer
-
Purkinje cells
-
Oligodendrocytes
-
Schwann cells
-
Astrocytes
-
Satellite cells
Question 130
Question
Which of the following cell types are stained black in the attached photomicrograph? (Please see attachment)
Answer
-
Schwann cells
-
Satellite cells
-
Purkinje cells
-
Astrocytes
-
Microglial cells
Question 131
Question
Which of the following cell types produce myelin insulating axons of the PNS?
Answer
-
Oligodendrocytes
-
Satellite cells
-
Schwann cells
-
Choroid plexus cells
-
Microglial cells
Question 132
Question
Which of the following values would be the resting membrane potential of a neuron given the ionic conditions, permeability values, and reversal potentials shown in the attached table?
Answer
-
+62 mV
-
0 mV
-
-80 mV
-
+123 mV
-
-72 mV
Question 133
Question
Which of the following is an active mechanism that contributes to a hyperpolarized resting membrane potential in neurons?
Question 134
Question
Which of the following clinical conditions is often associated with the breakdown of the blood-brain barrier?
Question 135
Question
Which of the following brain sites lacks a blood-brain-barrier?
Answer
-
The area postrema
-
The cerebellum
-
The falx cerebri
-
The hippocampus
-
The Virchow-Robin space
Question 136
Question
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:
Question 137
Question
Which of the following physiological conditions is modulated by the actions of substance P?
Question 138
Question
Which of the following receptors can modulate the release of neurotransmitters from the same nerve ending?
Question 139
Question
Which of the following structural brain deficits have been repeatedly reported in patients with schizophrenia?
Answer
-
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
Question 140
Question
An expansion of the ventricles due to tissue loss, as in the case of Alzheimer’s disease, is termed:
Answer
-
Hydrocephalus ex vacuo
-
Focal cerebral ischemia
-
Cytotoxic cerebral edema
-
Traumatic brain injury
-
Epidural hematoma
Question 141
Question
Which modification of histones is associated with a decrease in transcription?
Answer
-
Phosphorylation
-
Methylation
-
Acetylation
-
Glycosylation
-
Addition of a coenzyme
Question 142
Question
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?
Answer
-
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
Question 143
Question
During DNA replication:
Answer
-
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
Question 144
Question
Antibiotics in the quinolone family:
Answer
-
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
Question 145
Question
The toxin of the Amanita phalloides mushroom:
Answer
-
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
Question 146
Question
What is the definition of an intron?
Answer
-
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
Question 147
Question
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?
Answer
-
Pneumocystis jirovecii
-
Aspergillus niger
-
Candida albicans
-
Sporothrix schenckii
-
Coccidioides immmitis
Question 148
Question
Which of the following diseases is orally acquired and spreads to the central nervous system causing flaccid paralysis mostly in children?
Answer
-
Infectious mononucleosis
-
Measles
-
Polio
-
Herpes simplex virus
-
Chicken pox
Question 149
Question
e reverse transcriptase of HIV:
Answer
-
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
Question 150
Question
Which is the correct sequence (first to last) of events in viral replication?
Answer
-
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
Question 151
Question
Which is the protein shell around the nucleic acid core of a virus?
Answer
-
Capsid
-
Spike
-
Envelope
-
Monolayer
-
Canon
Question 152
Question
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?
Answer
-
Histoplasma capsulatum
-
Aspergillus fumigatus
-
Cryptococcus neoformans
-
Blastomyces dermatitidis
-
Candida albicans
Question 153
Question
Outbreaks of systemic mycoses have been associated with:
Question 154
Question
Which of the following combination of characteristics apply only to fungi?
Answer
-
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
Question 155
Question
Viruses are distinguishable from both bacteria and protozoan parasites because viruses have:
Question 156
Question
The Rickettsia microbe is a good example of a type of pathogen that:
Answer
-
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
Question 157
Question
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?
Answer
-
Protozoan parasite
-
Acid-fast bacillus
-
Gram negative bacillus
-
Gram positive coccus
-
Dimorphic fungus
Question 158
Question
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:
Answer
-
Endemic situation
-
Epidemic situation
-
Pandemic situation
-
Incubation period
-
Prolonged carrier state
Question 159
Question
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
Answer
-
Chlamydophila pneumoniae
-
Haemophilus influenzae
-
Mycoplasma pneumoniae
-
Streptococcus pneumoniae
-
Klebsiella pneumoniae
Question 160
Question
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:
Question 161
Question
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?
Answer
-
Giemsa stain of a patient sample
-
Growth on MacConkey agar
-
Presence of a peptidoglycan capsule
-
Alpha hemolysis on a blood agar plate
-
Inhibition of a growth by bacitracin
Question 162
Question
A 64-year-old homeless man presents to the emergency department complaining of fever, chills and night sweats. He also has a productive cough and a sputum sample reveals acid-fast bacilli. A PPD skin test is done and 48 hours later the area of induration measures 10 mm. The likely diagnosis is:
Answer
-
Psittacosis
-
Tuberculosis
-
Pneumococcal pneumonia
-
Influenza
-
Legionnaires disease
Question 163
Question
An experimental drug is found to produce its maximum effect at concentrations in which all of its targeted receptors are bound by the drug. This example describes the relationship between drug dose, receptor occupancy, and:
Question 164
Question
Fluconazole has an oral bioavailability factor of 1. What percentage of an oral dose reaches the systemic circulation?
Question 165
Question
A hospitalized hypotensive patient is started on a continuous intravenous infusion of a drug that raises blood pressure. The serum concentration of the drug reaches steady state when the dosing rate equals the clearance multiplied by:
Answer
-
Concentration of drug in plasma (Cp)
-
Half-life (t1⁄2)
-
Hepatic blood flow (Qhepatic)
-
Maximum rate of drug metabolism (Vmax)
-
Volume of distribution (Vd)
Question 166
Question
A hospitalized patient stabilized on an intravenous medication is being switched to the oral form of the same drug. Which of the following equations is used to calculate the maintenance dose?
Answer
-
1- (CL / Q)
-
(CL X Css) / F
-
Dose / AUC
-
(t1⁄2 x CL) / 0.693
-
(Vd xCss)/F
Question 167
Question
A particular receptor agonist is given to a patient for pain management. The patient is directed to take the medicine once daily at the same time of day. After a couple of weeks, the patient notices that the drug is not controlling the pain as well as it did when she first started taking it, even though she is taking it exactly as directed. She does not smoke or take any other drugs or alcohol. Which one of the following best describes the receptor-related mechanism for the reduced efficacy of this drug?
Answer
-
Constitutive activity
-
Desensitization
-
Reduced affinity
-
Saturation
-
Upregulation
Question 168
Question
A series of increasing doses of an experimental drug in preclinical development is administered to a group of experimental animals. The therapeutic index of this drug in this population is found to be large. This parameter is indicative of:
Question 169
Question
The ability of a drug bound to its receptor to activate downstream effector mechanisms defines the drug’s:
Question 170
Question
A particular drug undergoes significant first-pass effect by diffusing into the lipid bilayer of the endoplasmic reticulum in hepatocytes where it undergoes an oxidation reaction. The enzymes involved in the metabolism of this drug are most likely:
Answer
-
Cytochrome P450 enzymes
-
Isomerases
-
Glucuronosyltransferases
-
Metalloproteinases
-
Oxidoreductases
Question 171
Question
A pharmacologic hormone undergoes hepatic glucuronidation and biliary secretion. Intestinal bacterial flora cleave the glucuronic acid from the therapeutic molecule, which is then reabsorbed. Which one of the following best fits this description?
Question 172
Question
A pharmaceutical company develops a second-generation version of an antihistamine that prevents seasonal allergy symptoms (sneezing, itchy, runny nose and watery eyes). The advantage of the new version is that, unlike the first-generation drug, it does not cause central nervous system side effects, such as sedation and dizziness. Both drugs are taken orally. Compared to the older antihistamine, the second-generation agent has a low degree of:
Answer
-
Absorption
-
CYP metabolism
-
Effectiveness
-
Ionization
-
Lipid solubility
Question 173
Question
A woman experiencing menopausal symptoms is given a prescription for estrogen in a drug delivery system that allows for gradual diffusion of the hormone across the skin and dermal layers and into the venous circulation. Which one of the following is a disadvantage of this route of administration?
Answer
-
Frequent administration
-
First-pass metabolism
-
Gastric hyperacidity
-
Pain on injection
-
Skin irritation
Question 174
Question
A weak acid, HA, has a pK of 5.75. A solution is made by dissolving HA in water to a final concentration of 10 mM. The pH of this solution is adjusted to 7.75. Which of the following statements about this solution is true?
Answer
-
The concentration of the conjugate base (A-) in the solution is less than 5 mM
-
The solution strongly resists changes to its pH
-
All HA is dissociated into H+ and A-
-
The concentration of A- is greater than the concentration of HA
-
The pH of the solution was adjusted to 7.75 by adding HCl
Question 175
Question
Which of the following will be the most effective buffer pair for a solution that is adjusted to pH 6.80?
Question 176
Question
A test subject hyperventilates (breathes deeply and much faster than usual) for 3 minutes. Which of the following statements will be true of this test subject at the end of this 3 minute period?
Answer
-
The test subject’s [HCO3-]plasma will be decreased
-
The test subject’s [HCO3-]plasma will be increased
-
The test subject’s pHplasma will be below 7.20
-
The test subject’s pHplasma will be above 7.40
-
The test subject’s [CO2]plasma will be increased
Question 177
Question
Living cells are placed in a solution of 300 mM sucrose. The intracellular environment contains 140 mM NaCl and 5 mM KCl. These compounds have the following reflection coefficients:
σsucrose =1,σNa =0.8,σK =1,σCl =1.
Which of the following statements about this experiment is true?
Answer
-
The cells will swell
-
Sucrose will move into the cells
-
K+ will move out of the cells
-
The cells will shrink
-
Cl- will move into the cells
Question 178
Question
In early July, a 28-year-old woman is brought to the emergency department complaining of profuse diarrhea, weight loss, weakness, and dizziness for the past three days. She says she weighed 55 kg the morning her diarrhea began. Her weight upon admission is 50 kg. Lab tests of the diarrheal fluid indicate it has an osmolarity of 147 mOsm. Which Darrow-Yannet diagram reflects what has occurred in this patient during her diarrhea period?
Answer
-
Diagram A
-
Diagram B
-
Diagram C
-
Diagram D
-
Diagram E
Question 179
Question
A patient has lost a significant amount (1-2 L) of blood through hemorrhage. In the emergency department, a new resident administers 2 L of hypertonic saline solution by IV. Which diagram shows what would be the correct treatment for this patient to restore their blood volume? (Please see attachment)
Answer
-
Diagram A
-
Diagram B
-
Diagram C
-
Diagram D
-
Diagram E
Question 180
Question
Which of the following situation would produce a Hill plot with nH<1.0:
Answer
-
The protein has multiple subunits, each with a single ligand-binding site. Binding of ligand to one site increases the binding affinity of other sites for the ligand
-
The protein is a single polypeptide with two ligand binding sites, each having a different affinity for the ligand
-
The protein is single polypeptide with a single ligand-binding site. As purified, the protein preparation is heterogeneous, containing some protein molecules that partially denatured and thus have a lower affinity for the ligand
-
The protein has two different subunits. Only one subunit has a binding site for the ligand
-
The protein has multiple subunits, each with a single ligand-binding site. Binding of ligand to one site decreases the binding affinity of other sites for the ligand
Question 181
Question
Which of following is the allosteric regulator of hemoglobin oxygen binding?
Question 182
Question
Vitamin C deficiency may cause the following collagen related disease:
Answer
-
Osteogenesis imperfecta
-
Ehlers Danlos syndrome
-
Scurvy
-
Sticker syndrome
-
Marfan syndrome
Question 183
Question
Collagens are the major components of:
Answer
-
Mitchondria matrix
-
Endoplasmic reticulum
-
Nuclear matrix
-
Extracellular matrix
-
Golgi
Question 184
Question
A patient of yours has elevated levels of Alanine aminotransferase (ALT). The patient most likely has a problem with his:
Answer
-
Liver
-
Eyes
-
Heart
-
Bones
-
Pancreas
Question 185
Question
A patient of yours has been admitted to the cardiac care unit after having a myocardial infarction (heart attack). You are monitoring his recovery by measuring serum enzymes. Over the next two days, you find that his CK-MB levels are decreasing towards normal. On the third day, you see a sudden increase in CK-MB levels. This suggests that the patient:
Answer
-
Is recovering from the myocardial infarction (heart attack) and ready to go home
-
Is recovering from the myocardial infarction (heart attack) but is having a liver damage
-
Had another recent myocardial infarction (heart attack)
-
Is recovering from the myocardial infarction (heart attack) but is having some other muscle damage
-
Never had a myocardial infarction (heart attack); the diagnosis was wrong
Question 186
Question
Rotenone, a chemical derived from some roots, kills fish when added to ponds and is often used to kill non-native invasive species. Rotenone seems to affect the mitochondria by inhibiting complex I enzymes. When mitochondria are inhibited by rotenone, the:
Answer
-
Rate of respiration will increase
-
Rate of ATP synthesis will increase
-
Rate of NADH oxidation by the electron transport chain will decrease
-
Rate of succinate oxidation by the electron transport chain will decrease
-
Extent of reduction of Coenzyme Q in mitochondria will increase
Question 187
Question
In the rare Luft disease, patients show some microscopic disorder in mitochondrial structures. Mitochondrial respiratory chain complexes show normal levels of activities. When patients with Luft disease complain of feeling hot, have high rates of oxygen consumption and elevated heart rate, this may indicate:
Answer
-
Defective tricarboxylic acid cycle (TCA cycle) enzymes
-
Inhibition of complex III enzymes
-
Lack of Coenzyme Q
-
Uncoupling of the mitochondria electron transfer chain
-
Defective electron shuttles into the mitochondria
Question 188
Question
The glycerol phosphate dehydrogenase shuttle is not as good as the malate-aspartate shuttle because the glycerol phosphate dehydrogenase shuttle:
Answer
-
Brings electrons in at the NADH level
-
Produces less ATP than the malate-aspartate shuttle electrons
-
Can also transport ADP
-
Does not depend on the proton gradient
-
Is unidirectional
Question 189
Question
A new drug that you are studying has the unfortunate side effect of inhibiting cytochrome c oxidoreductase (complex III). This suggests that the drug will:
Answer
-
Decrease the reduction levels of complex II but not complex I
-
Decrease the reduction levels of complex I but not complex II
-
Increase the proton gradients
-
Decrease the reduction level of complex IV
-
Increase respiration
Question 190
Question
What are the effects of an increase in the plasma glucagon level on the activity of the tandem enzyme and the level of fructose 2,6-bisphosphate?
Answer
-
Increase in tandem enzyme kinase activity and an increase in the cellular level of fructose 2,6-bisphosphate
-
Decrease in tandem enzyme kinase activity and an increase in the cellular level of fructose 2,6-bisphosphate
-
Increase in tandem enzyme phosphatase activity and a decrease in the cellular level of fructose 2,6-bisphosphate
-
Decrease in tandem enzyme phosphatase activity and an increase in the cellular level of fructose 2,6-bisphosphate
-
No effect on tandem enzyme and no change in cellular level of fructose 2,6-bisphosphate
Question 191
Question
In red blood cells, the reduction of pyruvate produces:
Answer
-
Acetaldehyde, CO2, and NAD
-
Propionyl CoA, and FADH2
-
Ethanol and NADH + H+
-
Lactate and NAD
-
Acetyl CoA, CO2, and NADH + H+
Question 192
Question
The irreversible reaction(s) of glycolysis is(are) catalyzed by:
Answer
-
Hexokinase, phosphofructokinase, and pyruvate kinase
-
Glyceraldehyde 3-phosphate dehydrogenase
-
Phosphoglucisomerase, and triose phosphate isomerase
-
Phosphoglycerate kinase, enolase, and pyruvate kinase
-
Aldolase
Question 193
Question
Sulfate groups are most likely to be components of:
Answer
-
Monosaccharides
-
Disaccharides
-
Heteropolysaccharides
-
Homopolysaccharides
-
Oligosaccharides
Question 194
Question
The correct feature of glycosylaminoglycans is that they:
Answer
-
Contain a phosphate group on every fourth sugar residue
-
Are composed of repeating disaccharide units
-
Are a storage form of glucose in invertebrates
-
Contain codes for molecular targeting
-
Are chains of 50-100 fructosamine residues
Question 195
Question
The correct statement about the anomeric carbon of a sugar molecule is that it:
Answer
-
Is formed from an optically active carbon
-
Contains a carboxylic acid group formed in the creation of a hemiacetal
-
Can be any carbon in a sugar with an OH attached to it
-
Contains an OH group formed from a carbonyl group during the creation of a hemiacetal
-
Is the terminal carbon in a monosaccharide containing an H2COH group
Question 196
Question
In regard to main catabolism, the goal of the citric acid cycle is to form:
Answer
-
CO2 to maintain the normal plasma pCO2 level
-
Water to aid in water balance
-
Reducing equivalents for use by the electron transport chain
-
Nucleotide triphosphates by substrate level phosphorylation
-
CO2 by breakdown of acetyl groups (from acetyl-CoA) to regulate cellular levels of metabolites
Question 197
Question
Decarboxylation reactions during the TCA cycle are catalyzed by:
Answer
-
Citrate synthetase and glyceraldehye 3-phosphate dehydrogenase
-
Malate dehydrogenase and fumerase
-
Isocitrate dehydrogenase and alpha-ketoglutrate dehydrogenase
-
Succinate dehydrogenase and pyruvate carboxylase
-
Lactate dehydrogenase and malate dehydrogenase
Question 198
Question
During the conversion of pyruvate to acetyl-CoA catalyzed by the pyruvate dehydrogenase complex (PDH), the reaction that utilizes thiamine pyrophosphate (TPP) as the coenzyme is:
Answer
-
Oxidative phosphorylation of glyceraldehyde 3-phosphate
-
Shift of a hydroxyl group in the conversion of citrate to isocitrate
-
Decarboxylation of pyruvate
-
Hydrolysis of succinyl-CoA
-
Phosphorylation and decarboxylation of oxaloacetate
Question 199
Question
The correct statement about ketone bodies is:
Answer
-
They are used by liver when plasma glucose is low
-
Acetone is the major intermediate in ketone body synthesis
-
Excess acetyl-CoA is the starting material for ketone body synthesis
-
They do not contain ionizable H+ ions
-
Tissues that use ketone bodies convert them to pyruvate
Question 200
Question
The purpose of transferring a fatty acid to carnitine to form acyl-carnitine is:
Answer
-
Carnitine is the acyl group carrier used in fatty acid synthesis
-
In the circulation, carnitine is the carrier of fatty acids destined for breakdown in the liver
-
Carnitine is the coenzyme required for formation of a carbon-carbon double bond in a fatty acid
chain during synthesis
-
Acyl-carnitine can be transported across the inner mitochondrial membrane
-
Carnitine is the acyl group carrier used during lipolysis
Question 201
Question
The reaction at the main control point for fatty acid breakdown is:
Answer
-
Lipolysis
-
Thiolysis
-
Oxidation
-
Hydration
-
Reduction
Question 202
Question
The correct sequence of reactions in fatty acid synthesis is:
Answer
-
Condensation -> oxidation -> hydration -> oxidation
-
Oxidation -> hydration -> reduction -> condensation
-
Condensation -> reduction -> dehydration -> reduction
-
Reduction -> condensation -> carboxylation -> reduction
-
Condensation -> carboxylation -> dehydration -> reduction
Question 203
Question
The main control point for fatty acid synthesis is:
Answer
-
Carboxylation of acetyl-CoA
-
Transfer of acetyl and malonyl groups to acyl carrier protein
-
Condensation reaction of fatty acid synthesis
-
Elongation reaction
-
Formation of triacylglycerol
Question 204
Question
The role of the malonyl group in fatty acid metabolism is to:
Answer
-
Aid in the transport of acetyl groups across the inner mitochondrial membrane
-
Supply energy through decarboxylation for reactions in fatty acid synthesis
-
Supply three carbon groups for synthesis of fatty acids with odd numbers of carbons
-
React with acetyl-CoA to form 3-hydroxy-3-methylglutaryl CoA
-
Supply reducing equivalents for use in fatty acid synthesis
Question 205
Question
If a cell requires both reducing equivalents and five carbon sugars for use in biosynthesis reactions, the products of the pentose phosphate pathway will be:
Answer
-
Ribulose 5'-phosphate and FADH2
-
Fructose 6'-phosphate and glyceraldehyde 3-phosphate
-
Ribose 5'-phosphate and NADPH+H+
-
Xyulose 5'-phosphate, erythrose 4-phosphate and NADPH+H+
-
Ribose 5'-phosphate and NADH+H+
Question 206
Question
The enzyme that can be used to replenish the levels of citric acid cycle intermediates through its anaplerotic function is:
Answer
-
Pyruvate carboxylase
-
Aconitase
-
Pyruvate dehydrogenase
-
Citrate synthetase
-
Phosphopentose epimerase
Question 207
Question
Compounds that can enter gluconeogenesis include:
Answer
-
Acetyl-CoA, succinyl-CoA, and acetoacetate
-
Fatty acids and acetyl-CoA
-
Fatty acids, glycerol, and beta-hydroxybutyrate
-
Lactate and glycerol
-
Hydroxymethylglutaryl-CoA, acetone, and lactate
Question 208
Question
The effects of insulin on hepatic glycogen metabolism are:
Answer
-
Activation of glycogen synthesis and inactivation of glycogen breakdown through activation of phosphatase I
-
Activation of glycogen synthesis and inactivation of glycogen breakdown through phosphorylation and inactivation of cAMP-dependent protein kinase
-
Activation of glycogen synthesis and inactivation of glycogen breakdown by causing glucagon to dissociate from its receptor
-
Activation of glycogen breakdown and inactivation of glycogen synthesis through inactivation of phosphodiesterase
-
Activation of glycogen breakdown and inactivation of glycogen synthesis through activation of adenylate cyclase
Question 209
Question
During a period of starvation all glycogen reserves in a patient’s body have been consumed. Following treatment with glucose, synthesis of new glycogen will be initiated by:
Question 210
Question
Pyridoxal phosphate is used as a prosthetic group by:
Question 211
Question
A McDonald's McCafé Frappé Mocha has 18 grams of fat, 65 grams of sugar and 7 grams of proteins. Approximately how many Kcalories is that?
Question 212
Question
Right after a big and heavy lunch:
Answer
-
Blood glucose is high and fat breakdown is high
-
Blood glucose is low and fat synthesis is high
-
Blood glucose is high and insulin is high
-
Fat synthesis is high and glycogen breakdown is high
-
Fat breakdown is high and insulin is high
Question 213
Question
When a man has not eaten for 20 hours, it is likely that his blood sugar levels are maintained by:
Question 214
Question
A phosphate group is a component of:
Answer
-
Sphingomylein
-
Ceramide
-
Globoside
-
Sulfatide
-
Ganglioside
Question 215
Question
In the CDP-diacylglycerol branch of phosphoglyceride synthesis, CDP-diacylglycerol can react with:
Answer
-
CDP-choline
-
Acyl-CoA
-
Inositol
-
Phosphatidate
-
S-adenosylmethionine
Question 216
Question
The starting materials for synthesis of sphingosine are:
Answer
-
Phosphatidate and glycine
-
Palmitoyl-CoA and serine
-
Glycerol 3-phosphate and acyl-CoA
-
Cerebroside and UDP-glucose
-
Arachidonate and CMP-N-acetylneuraminate
Question 217
Question
You have isolated a new enzyme that catalyzes the attached reaction. This enzyme would be classified as a/an: (Please see attachment)
Answer
-
Oxidoreductase
-
Transferase
-
Hydrolase
-
Lyase
-
Isomerase
Question 218
Question
Many drugs are competitive inhibitors of the target enzymes. Such competitive inhibitors will:
Answer
-
Increase the apparent Km of the target enzymes
-
Decrease the apparent Km of the target enzymes
-
Decrease the Vmax of the target enzymes
-
Increase the Vmax of the target enzymes
-
Not affect the Vmax of Km of the target enzymes
Question 219
Question
You are developing a new drug to treat a new disease by stabilizing the native form of a protein. You believe that phosphorylation of a particular amino acid in the protein will stabilize the protein. Your target is likely to be a/an:
Question 220
Question
A new enzyme you have isolated is activated only when a very nonpolar small effector molecule binds to a control site; you have also found that a single mutation at the control site abolishes the binding of the effector molecule to the enzyme. Which of the following mutations is the most likely candidate?
Answer
-
Asp is replaced by Glu
-
Glu is replaced by Asp
-
Ala is replaced by Val
-
Leu is replaced by Arg
-
Leu is replaced by Ile
Question 221
Question
A man presents with back pain. He also complains that his urine is sometimes dark-colored. His ear cartilage has a gray appearance. The most likely cause of his symptoms is:
Answer
-
Homocystinuria
-
Maple syrup urine disease
-
Deficient enzyme in the degradation of tyrosine
-
Deficient enzyme in the formation of heme
-
Deficiency of the branched-chain alpha-keto acid dehydrogenase
Question 222
Question
Ammonia is transported in a nontoxic form in the blood primarily as:
Answer
-
Glutamine
-
Glutamate
-
Urea
-
A diglucuronide
-
Aspartate
Question 223
Question
A patient with cystinuria cannot properly:
Question 224
Question
Two infants appeared normal at birth but developed hyperammonemia after 24 hours. Their laboratory data is attached. Both infants had above normal levels of blood ammonia. Which one of the following enzymes could be deficient and cause this abnormality in infant II?
Answer
-
Carbamoyl phosphate synthetase I
-
Ornithine transcarbamoylase
-
Argininosuccinate synthetase
-
Argininosuccinate lyase
-
Arginase
Question 225
Question
Patients with a defect in the degradation of which amino acid should not consume aspartame?
Answer
-
Tyrosine
-
Phenylalanine
-
Glutamate
-
Glutamine
-
Aspartate
Question 226
Question
A 23-year-old female is brought to the emergency department because she is having hallucinations and is very confused. She spent the day painting outside in bright sunlight. The patient has undergone two previous laparotomies (exploratory pelvic surgery) for acute abdominal pain, but no pathology was found. What is the most likely reason for her symptoms?
Answer
-
She has taken barbiturates
-
She has eaten a lot of aged cheese
-
She has Lesch-Nyhan syndrome
-
She has porphyria cutanea tarda
-
She has acute intermittent porphyria
Question 227
Question
A 52-year-old obese male comes to his family doctor complaining of severe pain in the first metatarsophalangeal joint that began after he ate and drank too much on Thanksgiving Day. He has a history of kidney stones. The patient:
Answer
-
Should be treated with allopurinol to decrease the activity of xanthine oxidase
-
Should be treated with allopurinol to increase the purine salvage pathway
-
Has a deficiency of adenosine deaminase
-
Has a deficiency in PRPP synthetase activity
-
Has an decrease in the purine salvage pathway
Question 228
Question
In what genetic disorder is there a deficiency in a canalicular protein that transports bilirubin glucuronides into bile?
Question 229
Question
Two infants appeared normal at birth but developed hyperammonemia after 24 hours. Their laboratory data is attached. Both infants had above normal levels of blood ammonia. Which one of the following enzymes would likely be abnormal in infant I? (Please see attachment)
Answer
-
Carbamoyl phosphate synthetase I
-
Ornithine transcarbamoylase
-
Glutamate dehydrogenase
-
Argininosuccinate synthetase
-
Arginase
Question 230
Question
Which of the following brain areas receive olfactory sensory information prior to thalamic relay and must be considered primary olfactory cortex?
Question 231
Question
What would a patient with a partial bilateral lesion of taste fibers projecting to the geniculate ganglion most likely present with?
Answer
-
A general reduction of taste sensitivity of the anterior 2/3 of the tongue
-
A general reduction of taste sensitivity on the entire tongue and epiglottis
-
A general reduction of taste sensitivity on the rear 1/3 of the tongue
-
A specific reduction of taste for "bitter"
-
A specific reduction of taste for "salty" and "sweet"
Question 232
Question
What is the primary function of sustentacular cells found in the olfactory epithelium?
Answer
-
They act as inhibitory interneurons in fine pitch and tuning
-
They cover axons with a layer of myelin
-
They form Bowman's olfactory gland
-
They provide structural support and mucous secretions
-
They transmit action potentials to the olfactory bulb
Question 233
Question
Irrigating the ear of a healthy patient with cold water causes:
Answer
-
Nystagmus toward the irrigated ear
-
Nystagmus away from the irrigated ear
-
Torsional ocular counter-roll
-
Vertical ocular counter-roll
-
Horizontal ocular counter-roll
Question 234
Question
Changing visual fixation to different external places is achieved by:
Question 235
Question
The membranous labyrinth of the inner ear is filled with:
Answer
-
Endolymph
-
Perilymph
-
Cerebrospinal fluid
-
Blood
-
Bile
Question 236
Question
Iridectomy treats:
Answer
-
Cataracts
-
Closed angle glaucoma
-
Open angle glaucoma
-
Retinal detachment
-
Macular degeneration
Question 237
Question
Beta-blockers and/or cholinergic medication treats:
Answer
-
Cataracts
-
Closed angle glaucoma
-
Open angle glaucoma
-
Retinal detachment
-
Macular degeneration
Question 238
Question
How is pupil size increased?
Answer
-
Parasympathetic innervation to the dilator pupillae muscle causing mydriasis
-
Parasympathetic innervation to the sphincter pupillae muscle causing miosis
-
Sympathetic innervation to the ciliary muscle causing miosis
-
Sympathetic innervation to the dilator pupillae muscle causing mydriasis
-
Sympathetic innervation to the sphincter pupillae muscle causing miosis
Question 239
Question
Myopic vision is due to the inability to:
Answer
-
Stretch the lens enough to accommodate far stimuli
-
Relax the lens enough to accommodate far stimuli
-
Stretch the lens enough to accommodate near stimuli
-
Relax the lens enough to accommodate near stimuli
-
Compensate for anterior-posterior elongation of the eye
Question 240
Question
Retinal detachment occurs directly between the:
Answer
-
Amacrine cell layer and the pigment epithelium
-
Ganglion cell layer and the choroid layer
-
Photoreceptor layer and the choroid layer
-
Photoreceptor layer and the pigment epithelium
-
Pigment epithelium and the choroid layer
Question 241
Question
Which of the following best describes the anatomical organization of the ossicles from the tympanic membrane to the round window?
Answer
-
Uncus, malleus, stapes
-
Malleus, stapes, uncus
-
Malleus, uncus, stapes
-
Stapes, malleus, uncus
-
Uncus, stapes, malleus
Question 242
Question
Which of the following would cause hearing deficits due to middle ear dysfunction?
Question 243
Question
Which of the following best describes the fluid found in the scala vestibule?