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?
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?
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
At 500 microM L-alanine in the extracellular solution, the majority of L-alanine uptake is through a
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
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?
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
Spectrin is an integral part in which of the following intracellular structure(s)?
Which protein is necessary to create the forces that result in the bending movements of cilia and flagella?
Which intracellular process would be primarily disrupted by inhibition of Arp2/3 complexes?
Which type of the anchoring contact is used by the migrating (crawling) fibroblasts?
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
Which type of gene mutations confer a selective growth advantage in cancers?
Ninety-five percent of the mutations in tumors are:
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?
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?
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 B6 (pyridoxine)
Which vitamin is involved in collagen synthesis?
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)?
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?
Which of the following antigens is the most immunogenic?
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?
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-negative enteric bacillus
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:
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
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)
Which of the tissues/organs listed below is most likely to be lined by transitional epithelium?
Which of the following features does cardiac muscle have in common with skeletal muscle?
Peripheral, multiple nuclei
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?
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)
A kidney infarct
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 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?
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
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?
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:
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:
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?
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?
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
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?
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?
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:
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
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:
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:
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:
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
Which of the following provide glutamatergic input to granule cells?
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:
Idiopathic Parkinson'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
The presence of these neuron-embedded protein aggregations are a hallmark of Parkinson’s disease:
The cell bodies of which neurons are found in the middle layer of the cerebellar cortex?
Deep cerebellar nuclei
Primary somatosensory cortex receives direct input from which nuclei?
Gracile and cuneate nuclei
Medial dorsal nuclei (MD)
Mesencephalic trigeminal nucleus
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?
Accurate two-point discrimination is dependent on which sensory organ?
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?
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?
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?
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?
Middle cerebellar peduncle
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
Neurons in the neocortex with pyramidal morphology and dendritic spines release which of the following neurotransmitters?
Gamma amino-butyric acid
Genetic mutations affecting this cellular process have been implicated in microcephaly?
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?
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
Which of the following hypothalamic nuclei is the feeding center of the brain?
Medial preoptic nucleus
Which of the following hormones participates in the short-term control of pre-meal hunger and meal initiation?
Corticotropin-releasing factor (CRF)
Which of the following hypothalamic nuclei is the satiety center of the brain?
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:
Brown adipose tissue
Proximal small intestine
Stringing together unrelated or inappropriate facts, as often seen in patients with chronic alcohol consumption, is known as:
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?
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?
Which of the following nuclei is associated with the neural control of micturition?
Nucleus of Maynert
Which of the following conditions is a common side effect of opioid medication?
Which of the following brain regions modulates the phenomenon of stimulus-induced analgesia?
Ventral tegmental area
Suprachiasmatic nucleus of the hypothalamus
Periaqueductal gray area
Which of the following brain waves best represents stage 3-4 of the sleep-wake cycle? (Please see attachment)
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
Which of the following physical exam findings are clinical features of narcolepsy?
Which of the following neuropeptides plays an essential role in maintaining wakefulness and regulating transitions between sleep and wake cycles?
At what vertebral level can one most easily introduce a needle into the dural sac without piercing the spinal cord?
Which neural structure is located on the ventral medulla?
What neural structure is immediately inferior to the inferior colliculus?
The tonsils belong to what part of the cerebellum?
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?
Lateral corticospinal tract
Ventral corticospinal tract
Which portion of the spinal cord is involved in processing pain information?
Spinal accessory nucleus
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?
Which cerebral lobe controls primary motor movement on the right side of the body?
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?
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 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
An absent bilateral corneal reflex may be due to unilateral injury of:
A lesion in the midbrain will most likely affect:
Pain and temperature sense on the face
Touch and proprioception on the face
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
The number of cranial nerves projecting directly to each eye is:
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?
Which of the following cell types are stained black in the attached photomicrograph? (Please see attachment)
Which of the following cell types produce myelin insulating axons of the PNS?
Choroid plexus cells
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?
Which of the following is an active mechanism that contributes to a hyperpolarized resting membrane potential in neurons?
Leak K+ channels
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?
Autism spectrum disorder (ASD)
Multiple sclerosis (MS)
Metabolic syndrome (e.g. clinical obesity)
Which of the following brain sites lacks a blood-brain-barrier?
The area postrema
The falx cerebri
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)
Which of the following physiological conditions is modulated by the actions of substance P?
Metabolic signaling cascades
Which of the following receptors can modulate the release of neurotransmitters from the same nerve ending?
Inositol trisphosphate receptors/channels
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
Which modification of histones is associated with a decrease in transcription?
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?
Which of the following diseases is orally acquired and spreads to the central nervous system causing flaccid paralysis mostly in children?
Herpes simplex virus
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?
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?
Outbreaks of systemic mycoses have been associated with:
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:
DNA or RNA genomes and not both
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?
Gram negative bacillus
Gram positive coccus
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:
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
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
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?
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
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:
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:
Magnitude of effect
Variability in drug serum levels
Fluconazole has an oral bioavailability factor of 1. What percentage of an oral dose reaches the systemic circulation?
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:
Concentration of drug in plasma (Cp)
Hepatic blood flow (Qhepatic)
Maximum rate of drug metabolism (Vmax)
Volume of distribution (Vd)
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?
1- (CL / Q)
(CL X Css) / F
Dose / AUC
(t1⁄2 x CL) / 0.693
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?
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:
Hepatic blood flow
First-order elimination kinetics
Time to steady state
Variation of effect between subjects
The ability of a drug bound to its receptor to activate downstream effector mechanisms defines the drug’s:
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:
Cytochrome P450 enzymes
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?
Phase 1 metabolism
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:
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?
Pain on injection
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?
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
Which of the following will be the most effective buffer pair for a solution that is adjusted to pH 6.80?
H2A- H+ + HA-2, pK = 5.45
H2B H+ + HB-, pK = 6.70
HB- H+ +B-2,pK=9.1
HA-2 H+ + A-3, pK = 7.20
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?
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
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?
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
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?
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)
Which of the following situation would produce a Hill plot with nH<1.0:
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
Which of following is the allosteric regulator of hemoglobin oxygen binding?
Vitamin C deficiency may cause the following collagen related disease:
Ehlers Danlos syndrome
Collagens are the major components of:
A patient of yours has elevated levels of Alanine aminotransferase (ALT). The patient most likely has a problem with his:
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:
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
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:
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
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:
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
The glycerol phosphate dehydrogenase shuttle is not as good as the malate-aspartate shuttle because the glycerol phosphate dehydrogenase shuttle:
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
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:
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
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?
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
In red blood cells, the reduction of pyruvate produces:
Acetaldehyde, CO2, and NAD
Propionyl CoA, and FADH2
Ethanol and NADH + H+
Lactate and NAD
Acetyl CoA, CO2, and NADH + H+
The irreversible reaction(s) of glycolysis is(are) catalyzed by:
Hexokinase, phosphofructokinase, and pyruvate kinase
Glyceraldehyde 3-phosphate dehydrogenase
Phosphoglucisomerase, and triose phosphate isomerase
Phosphoglycerate kinase, enolase, and pyruvate kinase
Sulfate groups are most likely to be components of:
The correct feature of glycosylaminoglycans is that they:
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
The correct statement about the anomeric carbon of a sugar molecule is that it:
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
In regard to main catabolism, the goal of the citric acid cycle is to form:
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
Decarboxylation reactions during the TCA cycle are catalyzed by:
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
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:
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
The correct statement about ketone bodies is:
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
The purpose of transferring a fatty acid to carnitine to form acyl-carnitine is:
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
The reaction at the main control point for fatty acid breakdown is:
The correct sequence of reactions in fatty acid synthesis is:
Condensation -> oxidation -> hydration -> oxidation
Oxidation -> hydration -> reduction -> condensation
Condensation -> reduction -> dehydration -> reduction
Reduction -> condensation -> carboxylation -> reduction
Condensation -> carboxylation -> dehydration -> reduction
The main control point for fatty acid synthesis is:
Carboxylation of acetyl-CoA
Transfer of acetyl and malonyl groups to acyl carrier protein
Condensation reaction of fatty acid synthesis
Formation of triacylglycerol
The role of the malonyl group in fatty acid metabolism is to:
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
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:
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+
The enzyme that can be used to replenish the levels of citric acid cycle intermediates through its anaplerotic function is:
Compounds that can enter gluconeogenesis include:
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
The effects of insulin on hepatic glycogen metabolism are:
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
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:
Pyridoxal phosphate is used as a prosthetic group by:
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?
Right after a big and heavy lunch:
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
When a man has not eaten for 20 hours, it is likely that his blood sugar levels are maintained by:
Glucose synthesis from acetyl-CoA
A phosphate group is a component of:
In the CDP-diacylglycerol branch of phosphoglyceride synthesis, CDP-diacylglycerol can react with:
The starting materials for synthesis of sphingosine are:
Phosphatidate and glycine
Palmitoyl-CoA and serine
Glycerol 3-phosphate and acyl-CoA
Cerebroside and UDP-glucose
Arachidonate and CMP-N-acetylneuraminate
You have isolated a new enzyme that catalyzes the attached reaction. This enzyme would be classified as a/an: (Please see attachment)
Many drugs are competitive inhibitors of the target enzymes. Such competitive inhibitors will:
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
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:
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?
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
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:
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
Ammonia is transported in a nontoxic form in the blood primarily as:
A patient with cystinuria cannot properly:
Transport arginine and cystine
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?
Carbamoyl phosphate synthetase I
Patients with a defect in the degradation of which amino acid should not consume aspartame?
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?
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
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:
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
In what genetic disorder is there a deficiency in a canalicular protein that transports bilirubin glucuronides into bile?
Crigler-Najjar syndrome type II
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)
Which of the following brain areas receive olfactory sensory information prior to thalamic relay and must be considered primary olfactory cortex?
Ventromedial prefrontal cortex
What would a patient with a partial bilateral lesion of taste fibers projecting to the geniculate ganglion most likely present with?
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"
What is the primary function of sustentacular cells found in the olfactory epithelium?
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
Irrigating the ear of a healthy patient with cold water causes:
Nystagmus toward the irrigated ear
Nystagmus away from the irrigated ear
Torsional ocular counter-roll
Vertical ocular counter-roll
Horizontal ocular counter-roll
Changing visual fixation to different external places is achieved by:
Smooth pursuit eye movement
Saccadic eye movement
The membranous labyrinth of the inner ear is filled with:
Closed angle glaucoma
Open angle glaucoma
Beta-blockers and/or cholinergic medication treats:
How is pupil size increased?
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
Myopic vision is due to the inability to:
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
Retinal detachment occurs directly between the:
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
Which of the following best describes the anatomical organization of the ossicles from the tympanic membrane to the round window?
Uncus, malleus, stapes
Malleus, stapes, uncus
Malleus, uncus, stapes
Stapes, malleus, uncus
Uncus, stapes, malleus
Which of the following would cause hearing deficits due to middle ear dysfunction?
Hair cell degeneration
Cranial nerve VIII leison
Which of the following best describes the fluid found in the scala vestibule?
Is high in potassium
Is different from the fluid in the scala tympani
Is low in potassium
Contains leukocytes and erythrocytes
Contains only leukocytes