- Transection of the anterolateral tract results in which of the following?
- Loss of proprioception
- Spastic paralysis
- Flaccid paralysis
- Loss of pain and temperature sensation
- Areflexia(Answer D. B140 & 142: Somatosensory I & II)
- Which of the following special senses conducts its generated action potential over the longest distance?
- Hearing
- Photoreception
- Gustation
- Touch
- Olfaction(Answer E. Options A, B, and C all use short axons to conduct their generated action potentials. B140 & 142: Somatosensory I & II)
- Menthol gel is recommended to relieve minor aches and pains associated with simple backache, arthritis, and strains. Which of the following best explains the mechanism for how this product works?
- Activates TRPM8
- Activates TRPV1
- Activates TRPV5
- Activates TRPM6
- Activates TRPM5(Answer A. B143 & 145: Neurophysiology: Intro to sensory system & Pain Physiology)
- Which of the following is considered to be a phasic receptor?
- Joint receptor
- Muscle Spindles
- Baroreceptors
- Golgi tendon organs
- Pacinian corpuscles(Answer E. Phasic receptors are those that are fast adapting and usually encompass tactile receptors.. Proprioceptors, baroreceptors, chemoreceptors, etc are usually considered tonic because they are slow or non-adapting. B143 & 145: Neurophysiology: Intro to sensory system & Pain Physiology.)
- Which growth factor drives scar formation?
- VEGF
- PDGF
- HGF
- TGF-B
- FGF(Answer D. B141 & 144: Tissue Repair & Renewal I & II.)
- A 72 year old patient presents to the Emergency Department via ambulance following a motor vehicle accident. The patient states that he is in renal failure and has been getting dialysis two days a week for the last 3 months. He was in a car accident attempting to get to the dialysis center and is currently in a substantial amount of pain from windshield glass that became lodged in his shoulder. Blood chemistry analysis reveals that the patient is in metabolic acidosis, most likely due to his renal failure. The attending physician instructs you to use a shot of Lidocaine (a local anesthetic) to numb his shoulder and remove the glass, while he attempts to correct the acidosis. Which of the following should you expect from the patient?
- Decreased response to the lidocaine due to the metabolic acidosis and inability for the drug to enter the neurons
- Increased response to the lidocaine due to the metabolic acidosis and inability for the drug to enter the neurons
- Increased response to the lidocaine due to the metabolic acidosis and increased ability for the drug to enter the neurons
- Decreased response to the lidocaine due to the metabolic acidosis and increased ability for the drug to enter the neurons
- No change in response to the lidocaine(Answer A. B145: Pain.)
- Capsaicin is an active component of chili peppers and an irritant for mammals, including humans. It produces a sensation of burning in any tissue with which it comes into contact. Capsaicin activates which of the following receptors?
- TRPM8
- TRPV5
- TRPV1
- TRPM6
- TRPM5(Answer C. Other activators for TRPV1 include H+, adenosine, bradykinin, piperine, camphor, some venoms and jellyfish extract. TRPV1 is upregulated in Crohn’s disease and ulcerative colitis. Capsaicin can also work as a topical analgesic (overactivation can shut down pain receptors). B145: Pain.)
- Angel S. is undergoing massage therapy following a crossfit injury to her erector spinae muscles after trying to deadlift 300 lbs. While the injury is painful, the massage helps substantially. Which of the following best explains the mechanisms for how massage can relieve pain?
- It stimulates Aα fibers, causing suppression of pain signals
- It stimulates Aβ fibers, causing suppression of pain signals
- It stimulates Aγ fibers, causing suppression of pain signals
- It stimulates Aδ fibers, causing suppression of pain signals
- It stimulates C-polymodal fibers, causing suppression of pain signals(Answer B. Stimulation of Aβ fibers from tactile receptors can lead to suppression of pain signals. This explains the effect of massage and acupuncture. B145: Pain.)
- An older male in your clinic states they have been having severe diarrhea and red, itchy skin for several weeks. The patient’s daughter is present for the visit and states that he has been increasingly forgetful lately, and she is worried he has started drinking again. What is a likely vitamin deficiency that could lead to his specific symptoms?
- B1
- B2
- B3
- B6
- B9(Answer C. This patient is presenting with the “three D’s of pellagra: dermatitis, diarrhea, and dementia. This is caused by a severe niacin (B3) deficiency. Niacin deficiency is often associated with alcoholism, but this is more a correlation with alcoholics having a poorly balanced diet low in B3, rather than a direct effect of the alcohol. B146: Nutritional Disorder.)
- Which of the following is the leading cause of blindness, worldwide?
- Age related macular degeneration
- Diabetic Retinopathy
- Cataracts
- Glaucoma
- Trauma(Answer C. B147-8: Visual System I & II)
- A patient presents to the clinic complaining of reduced vision. Upon examination, you realize that the patient has reduced vision in the left visual field of the left eye and the right visual field of the right eye. Which of the following locations is the most probable location of a lesion that would result in these visual deficits?
- Optic chiasm
- Optic tract
- Lateral geniculate nucleus
- Geniculocalcarine tract
- Visual cortex of the cerebrum(Answer A. Options B – E are all distal to the optic chiasm, and lead to homonymous visual defects. B147-8: Visual System I & II.)
- A patient has a lesion affecting the upper portion of the right visual cortex. Which of the following explains how this person’s vision is likely to be altered?
- The patient would have reduced vision in the lower right field in both eyes
- The patient would have reduced vision in the lower left field in both eyes
- The patient would have reduced vision in the upper right field in both eyes
- The patient would have reduced vision in the lower right field in the left eye but the lower left field of the right eye
- The patient would have reduced vision in the upper left field in both eyes(Answer B. B147-8: Visual System I & II)
- Which of the following correctly lists the path of light through the eye?
- Cornea → Aqueous Humor → Lens → Vitreous Humor → Retina
- Cornea → Vitreous Humor → Lens → Aqueous Humor → Retina
- Lens → Aqueous Humor → Cornea → Vitreous Humor → Retina
- Lens → Vitreous Humor → Cornea → Aqueous Humor → Retina
- Sclera → Aqueous Humor → Lens → Vitreous Humor → Retina(Answer A. B149-50: Special Sense I Vision.)
- The majority of light refraction involved in vision is performed by which of the following structures?
- Sclera
- Lens
- Cornea
- Retina
- Aqueous Humor(Answer C. Hef mentioned this 3+ times so I would know it! 🙂 B149-50: Special Sense I Vision.)
- Atropine is a medication used to treat certain types of nerve agent and pesticide poisonings. It works by blocking ACh and preventing parasympathetic activation. Which of the following is a potential side effect of Atropine?
- Cycloplegia
- Bradycardia
- Presbyopia
- Miosis
- Ptosis(Answer A. Cycloplegia is the loss of accommodation due to the paralysis of the ciliary muscle. All components of the accommodation reflex are parasympathetically innervated. Hef mentioned this in class.B149-50: Special Sense I Vision.)
- Which of the following structures is responsible for secretion of aqueous humor?
- Ciliary body
- Iris
- Lens
- Cornea
- Canal of schlemm(Answer A. B147-8: Visual System I & II.)
- Which of the following extraocular muscles is involved in the accommodation reflex?
- Lateral rectus
- Medial rectus
- Inferior rectus
- Superior rectus
- Superior oblique(Answer B. Components of the accomodation reflex include ocular convergence (medial rectus), pupillary constriction (constrictor pupillae) and contraction of the ciliary muscle (causing lens thickening by relaxing the zonular/suspensory ligament). B147-8: Visual System I & II.)
- You are visiting family during your much needed summer break when your family decides to go out to eat. However, your grandfather forgot his reading glasses and now can’t read the menu. Which of the following conditions is most likely preventing your grandfather from reading the menu without reading glasses?
- Myopia
- Hypermetropia
- Astigmatism
- Presbyopia
- Cycloplegia(Answer D. B147-8: Visual System I & II.)
- You are shadowing an opthamologist when a patient presents complaining that she is specifically having trouble driving at night. She mentions that her vision doesn’t seem to be as bad during the day. Which of the following explains this phenomenon?
- Dilation of the pupil during the day reduces distortion of the light and allows for higher visual acuity
- Constriction of the pupil during the day reduces distortion of the light and allows for higher visual acuity
- Constriction of the pupil at night increases distortion of the light, decreasing visual acuity
- This patient most likely has closed-angle glaucoma
- This patient most likely has open-angle glaucoma(Answer B. B147-8: Visual System I & II.)
- Inability to read in dim light is due to which of the following?
- High amount of convergence at the fovea centralis
- Lack of rods at the temporal and nasal portions of the retina
- Lack of cones at the fovea centralis
- Lack of rods at the fovea centralis
- Lack of cones at the temporal and nasal portions of the retina(Answer D. B147-8: Visual System I & II.)
- Which of the following explains blindness as a potential side effect of Viagra?
- Viagra inhibits PDE5, preventing hyperpolarization of the cones
- Viagra inhibits PDE5, prevenging depolarization of the cones
- Viagra inhibits PDE5, preventing hyperpolarization of the rods
- Viagra inhibits PDE5, prevenging depolarization of the rods
- Viagra inhibits transducin(Answer C. B147-8: Visual System I & II.)
- Rods are sensitive to all colors, EXCEPT which of the following?
- Blue
- Green
- Yellow
- Purple
- Red(Answer E. B147-8: Visual System I & II.)
- Which of the following substances is important in establishing circadian rhythm?
- Rhodopsin
- Melanopsin
- Photopsin
- Lumirhodopsin
- Metarhodopsin II(Answer B. Some ganglion cells are sensitive to light and have melanopsin which is important for circadian rhythm regulation by stimulating the suprachiasmatic nucleus. B147-8: Visual System I & II.)
- [Part 1 of 2] A medical student smells pizza in a nearby room where a meeting for a club he has never heard of is getting underway. Naturally, he ducks into the room and grabs a few slices of pizza. He wastes no time and bites into the hot pie, burning his tongue. Which set of papillae, if burned, would leave his sense of taste diminished?
- Circumvallate
- Fungiform
- Filiform
- A & B
- A & C(Answer D. B151: Olfaction and Taste.)
- [Part 2 of 2] If the pizza burns were isolated to the tip of the tongue, the papillae effected would lose their ability to send gustatory afferent information to the brain via which nerve?
- CN V
- CN VII
- CN IX
- CN X
- CN XI(Answer B. The lingual branch of the trigeminal nerve, A, sends tactile information from the anterior 2/3 of the tongue. The facial nerve CN VII sends gustatory information from the anterior 2/3 of the tongue. B151: Olfaction and Taste.)
- It’s been a rough week, and you decide to let loose with a couple friends at The Residents. You have a few drinks, and begin spinning in a chair mid-conversation. You begin to feel dizzy and upon stopping, it takes a few seconds for the room to stop spinning. Which structure contributes to this feeling?
- Uterus
- Ciliary body
- Cupula
- Utricle’s macula
- Saccule’s macula(Answer C. The semicircular ducts contain the cupula, which detect angular or rotational acceleration of the head. The utricle’s macula, whose stereocilia point superiorly, detect linear acceleration from side to side. The saccule’s macula, whose stereocilia point laterally, detect linear acceleration of the head vertically. B152 & 156: Auditory & Vestibular Systems I & II.)
- A patient arrives with the complaint of becoming car sick. Upon further history taking, the patient tells you this happens mostly when the car is accelerating forward. Upon physical exam, the patient does not have complications with rotating their head or moving up and down in a chair. Which structure is responsible for the patient’s presentation?
- Uterus
- Ciliary body
- Cupula
- Utricle’s macula
- Saccule’s macula(Answer D. Although the utricle is described as detecting side-to-side acceleration, this includes anterior and posterior displacement as well. The accelerating car scenario is a red herring. B152 & 156: Auditory & Vestibular Systems I & II.)
- You are performing a Romberg’s test on a patient following a complaint of altered gait. The patient stands, but even with their eyes open, they are not able to stand steady. Which part of the CNS would you expect to find a lesion?
- Vestibulocerebellum
- Dorsal column medial lemniscal tract
- Medial vestibulospinal tract
- Spinothalamic tract
- Medial longitudinal fasciculus(Answer A. Cerebellar dysfunction leads to the inability to stand still even with the eyes open. B152 & 156: Auditory & Vestibular Systems I & II.)
- Low dose daily aspirin therapy is recommended for people over the age of 50 to prevent heart attack and stroke due to the ability of NSAIDs to inhibit platelet aggregation. Aspirin inhibits which of the following in order to inhibit platelet aggregation?
- Prostacyclin (PGI2)
- Thromboxane A2
- Prostaglandin E2 (PGE2)
- A & B
- A, B C(Answer B. B154-5: Clotting & Disruption to blood flow I & II.)
- Which of the following coagulation factors is involved in the intrinsic pathway, but not the extrinsic pathway?
- X
- V
- XII
- VII
- TF(Answer C. B154-5: Clotting & Disruption to blood flow I & II.)
- Which of the following is associated with platelet aggregation?
- ADP
- Extonucleotidase
- Adenosine
- Tissue Factor Pathway inhibitor
- Heparan Sulfate(Answer A. B154-5: Clotting & Disruption to blood flow I & II.)
- Which of the following is TRUE regarding glycoprotein receptors located on the surface of platelets?
- GP-1b-V-VI binds to free vWF
- GP-1a/IIa binds to collagen via vWF
- GPIIb/IIIa binds to free fibrinogen
- GPIIb/IIIa binds to collagen via vWF
- GPIIb/IIIa binds to collagen directly (Answer C. B154-5: Clotting & Disruption to blood flow I & II.
- The dampening of sounds can be accomplished through all of the following structures EXCEPT:
- Outer hair cells
- Inner hair cells
- Tensor tympani
- Stapedius (Answer B. B157:Special Sense II Hearing.)
- A patient complains with hearing loss that has gotten progressively worse over the past few months. She began working a night shift in the hospital approximately 9 months ago. You perform blood tests, and you find that she has low Vitamin D and she is hypocalcemic. How do you explain to your patient how this could be a contributing factor to her hearing loss?
- Low calcium is known to cause hypertonic muscles. The stapedius and tensor tympani are staying contracted, leading to diminished conduction in the ossicles.
- Calcium is required for the activation of special proteins, called prestin, which aid in hearing.
- Low calcium is causing the membrane potential to be decreased, so the action potentials required for hearing are diminished.
- Vitamin D is responsible for the production of proteins that amplify the vibrations on the outer hair cells to the inner hair cell.
- Calcium is required for the depolarization of the vagus nerve, which is important in bone conduction in the inner ear.(Answer B. B157: Special Sense II Hearing.)
- Aminoglycosides (AGs) are widely used antibiotics because of their low cost and high efficacy against gram-negative bacterial infection. However, AGs are ototoxic, and can lead to deafness when used extensively. Which of the following structures do these drugs damage to cause this effect?
- Auditory nerve
- Inner hair cells
- Outer hair cells
- Prestin
- Tympanic membrane (Answer C. B157: Special Sense II Hearing.)
- Which of the following best explains the function of the stria vascularis?
- Maintains K+ levels in the endolymph to allow for fast depolarization
- Maintains Na+ levels in the endolymph to decrease speed of depolarization
- Maintains Na+ levels in the perilymph to decrease speed of depolarization
- Maintains K+ levels in the perilymph to allow for fast depolarization
- Maintains K+ levels in the endolymph to decrease speed of depolarization(Answer A. B157: Special Sense II Hearing.)
- You are shadowing a neurologist when a 36 year old male patient presents to the clinic following a diagnosis of MS by his primary care doctor. He says that he is able to hear but is having trouble localizing where sounds are coming from. Which structure is most likely involved in this symptom?
- Dorsal cochlear nucleus
- Posteroventral cochlear nucleus
- Medial Geniculate
- Auditory cortex
- Superior olivary complex (Answer E. The medial/lateral superior olive and are responsible for locating sound sources in space. B157: Special Sense II Hearing.)
- Which of the following correctly describes how olfactory neurons are stimulated?
- Odorants bind GPCRs which leads to opening of voltage gated channels, causing an influx of Na+/Ca2+
- Odorants bind to a GPCR which leads to opening of cyclic nucleotide gated channels, causing an outflux of Na+/Ca2+
- Odorants bind GPCRs which leads to opening of voltage gated channels, causing an outflux of Na+/Ca2+
- Odorants bind to a GPCR which leads to opening of cyclic nucleotide gated channels, causing an influx of Na+/Ca2+
- Odorants bind to GPCRs which leads to closing of cyclic nucleotide gated channels, preventing the outflux of Na+/Ca2+(Answer D. B158: Special Sense III Taste & Olfaction.)
- Which of the following are means by which odor fatigue can occur?
- Internalization of receptors
- Ca++ inhibition of adenylate cyclase & cyclic nucleotide gated channels
- Synaptic inhibition by GABA
- A & B
- A, B, & C(Answer E. Just a factoid. B158: Special Sense III Taste & Olfaction.)
- Monosodium glutamate (MSG) is used in the food industry as a flavor enhancer. Which of the following taste sensations is elicited by this substance?
- Sweet
- Salt
- Umami
- Sour
- Bitter(Answer C. B158: Special Sense III Taste & Olfaction.)
- Which of the following taste sensations is NOT associated with a GPCR?
- Sweet
- Umami
- Sour
- Bitter(Answer C. Salt and sour response to ions and do not depend on a G-protein coupled receptor. B158: Special Sense III Taste & Olfaction.)
- A patient presents with pelvic pain. She has had bladder stones before, and she believes this is the same presentation. Her pelvic pain has been progressing over the course of 3 days. Which nerves are responsible for the transmission of her pelvic pain to the CNS?
- Splanchnic nerves
- Pudendal nerves
- Cardiac nerves
- Inferior hypogastric plexus
- Renal nerves(Answer A. The afferent fibers responsible for conveying nociceptive information from the abdominal and pelvic viscera are the splanchnic nerves. B159: Viscerosensory Regulation.)
- Many chemoreceptors are responsible for relaying information to the CNS to maintain the composition of your arterial blood. Where are these found in the body?
- Smooth muscle layer of pulmonary airway
- Joint capsule
- Epithelia of pulmonary airways
- Carotid body
- Carotid sinus(Answer D. Chemoreceptors are found in the carotid bodies and aortic body (within the aortic arch). Baroreceptors are found in the aortic arch and carotid sinus. B159: Viscerosensory Regulation.)
- Which cortical area is primarily responsible for viscerosensory information?
- Inferior ganglion of the glossopharyngeal and vagus nerve
- Superior ganglion of the vagus nerve
- Inferior ganglion of the accessory nerve
- Superior ganglion of the glossopharyngeal nerve
- Superior ganglion of the accessory nerve(Answer A. The inferior ganglion of CN IX and X contain cell bodies of primary viscerosensory neurons. B159: Viscerosensory Regulation.)
- Pictured below is a MRI from a 58-year-old male with a left anterior thalamic infarct involving the anterior nuclei. What findings would you expect to find upon your history and physical examination?
- Hyperactive
- Slurred speech
- Clonus
- Persistent coma
- Facial droop(Answer D. Vascular compromise of the anterior thalamus leads to disruption of the ascending reticular activating system. B159: Viscerosensory Regulation.)
- Following a bilateral vagotomy, which of these do you expect to be present?
- Peristaltic reflex
- Increased gastric emptying
- Increased motility
- Absent defecation reflex
- Absent peristalsis(Answer A. The enteric peristaltic reflex is independent of parasympathetic innervation by the vagus nerve. B160: Visceral Motor Pathways.)
- Orthostatic hypotension can be a side effect of certain antidepressants. What causes this phenomenon?
- Lesion of the nucleus ambiguus
- Failure of the baroreceptor reflex to detect change in blood pressure
- Hyperactivity of the mechanoreceptors
- Displaced otoconia
- Sudden systemic vasoconstriction caused by sympathetic stimulation(Answer B. B160: Visceral Motor Pathways.)
- Spinal cord injuries at T6 or above lead to an overall reduction in sympathetic activity initially, with progression to overactivation of sympathetic reflexes, or autonomic dysreflexia. What signs and symptoms do you expect to see in a patient late into this diagnosis?
- Orthostatic hypotension
- Bradycardia
- Hypotension
- Miosis
- Systemic vasoconstriction(Answer E. Autonomic dysreflexia causes overactive sympathetic responses. Orthostatic hypotension is seen with initial injury. Systemic vasoconstriction, and therefore uncontrolled hypertension, can be lethal in patients with upper spinal cord injuries.B160: Visceral Motor Pathways.)
- You are on an OB/GYN rotation and deliver your first newborn. The newborn fails to have a bowel movement within the first 48 hours. The attending explains to you a condition in which the newborn may have early cessation of nerve development in the bowel. What condition is he referring to?
- Huntington’s disease
- Hirschsprung disease
- Diverticulosis
- Crohn’s disease
- Inflammatory bowel disease(Answer B. B160: Visceral Motor Pathways.)
- Which of the following hypothalamic nuclei are involved in regulation of circadian rhythm?
- Arcuate nucleus
- Supraoptic nucleus
- Suprachiasmatic nucleus
- Ventromedial nucleus
- Medial preoptic nucleus(Answer C. B161: Hypothalamus & Neuroendocrine Systems.)
- Which of the following hypothalamic nuclei are involved in secretion of ADH?
- Arcuate nucleus
- Supraoptic nucleus
- Suprachiasmatic nucleus
- Ventromedial nucleus
- Medial preoptic nucleus(Answer B. B161: Hypothalamus & Neuroendocrine Systems.)
- Which of the following hypothalamic nuclei are located in the tuberal region of the periventricular zone?
- Arcuate nucleus
- Suprachiasmatic nucleus
- Dorsomedial nucleus
- Ventromedial nucleus
- Mammillary body
- The hypothalamus receives afferent input via the medial forebrain bundle (MFB) for all EXCEPT which of the following?
- Septal nuclei
- Ventral striatum
- Insula
- Orbitalfrontal cortex
- Retina(Answer E. B161: Hypothalamus & Neuroendocrine Systems.)
- Which of the following hypothalamic nuclei is responsible for satiety?
- Posterior nuclei
- Supraoptic nucleus
- Suprachiasmatic nucleus
- Ventromedial nucleus
- Medial preoptic nucleus(Answer D. B161: Hypothalamus & Neuroendocrine Systems.)
- Prader-Willi syndrome is caused by a deletion of chromosome 15 which impacts the development of the hypothalamus. Which of the following is a major symptom of this condition?
- Emaciation
- Hypertonia
- Tall stature
- Chronic hunger
- Insomnia(Answer D. B161: Hypothalamus & Neuroendocrine Systems.)
- A list of unknown drugs and their respective ED50 and LD50 are shown below. Which of the following drugs has the most favorable therapeutic window?
- Drug A
- Drug B
- Drug C
- Drug D
- Drug E(Answer E. The Therapeutic window is defined as the LD50/ED50. A more favorable therapeutic window would be larger. Thus, the best answer is drug E. B162: Foundations of Pharm.)
- Which of the following is TRUE regarding intravenous drug administration?
- It is most suitable for poorly soluble substances
- It is the 2nd fastest administration route, behind that of inhalation
- The bioavailability of IV drugs are 100%
- It is usually more safe than other routes of administration
- The majority of drug administered in this manner will undergo first pass metabolism(Answer C. B162: Foundations of Pharm.)
- Which of the following is TRUE regarding the Volume of distribution (Vd )?
- A low Vd usually correlates with a long half life
- A low Vd means that the drug is mostly located in the peripheral compartment
- It is the measure of a body’s efficiency in eliminating a drug from the systemic circulation
- A high Vd means that the drug is mostly located in the central compartment
- It relates the amount of drug in the body to the concentration of drug in the plasma(Answer E. B162: Foundations of Pharm.)
- Allopurinol is a medication used to prevent gout. It specifically works to reduce uric acid levels by competitively inhibiting the enzyme, Xanthine Oxidase. Which of the following correctly describes its drug-receptor interaction?
- Agonist
- Antagonist
- Allosteric activator
- Allosteric inhibitor
- Non-competitive inhibitor
- (Answer B. B162: Foundations of Pharm.)
- An alcohol enema, also known colloquially as butt-chugging, is the act of introducing alcohol into the rectum via the anus (don’t try this at home, kids). This method of alcohol consumption can be dangerous and even deadly because it leads to faster intoxication. Which of the following best explains why this method of alcohol consumption can be more dangerous to an individual?
- Rectal administration is associated with a lesser degree of first pass metabolism
- Rectal administration is associated with a lower bioavailability than oral administration
- Oral administration increases bioavailability making it less toxic
- Stomach acid neutralizes alcohol into a less active form
- Rectal administration is associated with a higher degree of first pass metabolism(Answer A. B163: Pharmacokinetics (Absorption & Distribution).)
- Your patient has a lesion in the left anterior corticospinal tract at the medullary pyramid. Which of the following do you expect to find in your physical exam?
- Left sided trunk weakness
- Right sided trunk weakness
- Left sided arm weakness
- Left sided leg weakness
- Right sided leg weakness(Answer B. The anterior corticospinal tract decussates at the level of the spinal cord and is also responsible for trunk and axial muscles. The lateral corticospinal tract decussates at the pyramids and is responsible for the limbs and digits.)
- Which would you expect to have the fewest muscle fibers per motor unit?
- Sternocleidomastoid
- Medial rectus muscle
- Quadriceps femoris
- Soleus
- Biceps(Answer B. Finely controlled muscles contain very few muscle fibers. Those involving less finely controlled muscles have more muscle fibers. The lateral compartment of the leg (containing the fibular muscles) has more fine control than the medial compartment, therefore, the lateral compartment has fewer muscle fibers. B164-5: Upper & Lower Motor Neurons I & II.)
- What presentation would you find in a patient that has damage to one side of the corticobulbar tract?
- Facial muscles would still work bilaterally. There is bilateral innervation.
- One side of the face would have signs of weakness due to unilateral innervation by CN XII.
- The lower portion of the face would show signs of weakness due to unilateral innervation by CN VII.
- One of the lower quadrants of the face would show signs of weakness due to unilateral innervation by CN VII.
- Facial sensation would be diminished on one side of the face due to unilateral innervation by CN V.(Answer C. If the corticobulbar tract is damaged on only one side, then only the lower face will be affected. B164-5: Upper & Lower Motor Neurons I & II.)
- The inability to voluntarily chew comes from damage to which tract and cranial nerve?
- Anterior corticospinal tract – CN VII
- Lateral Corticospinal tract – CN IX, X
- Corticobulbar tract – CN V
- Lateral corticospinal tract – CN V
- Corticobulbar tract – CN V(Answer E. B164-5: Upper & Lower Motor Neurons I & II.)
- Which response best describes the effect of stimulating golgi tendon organs after active contraction?
- Activation of agonist muscles and inhibition of antagonist muscles via Ib afferent signaling
- Inhibition of agonist muscles and activation of antagonist muscles via Ib afferent signaling
- Activation of agonist muscles and inhibition of antagonist muscles via Ia afferent signaling
- Inhibition of agonist muscles and activation of antagonist muscles via Ia afferent signaling
- Activation of type II interneurons for controlled, delayed response(Answer B. B166-7: Motor Control I & II.)
- In order to maintain tone in response to stretch, muscle spindles must continuously resensitize via the action of which class of neurons?
- Ia
- Ib
- II
- α
- γ(Answer E. B166-7: Motor Control I & II.)
- If a patient is specifically having difficulty copying the movements of others, quickly reacting to external stimuli, and executing pre-determined unilateral and bilateral movements, they most likely have diminished function of which area of the brain?
- Primary motor area
- Premotor area
- Supplementary motor area
- Sigulate motor area
- Superior motor area(Answer B. B is the best answer for this response because the premotor area contains mirror neurons, which act to turn imagined movements into planned sequential movements. The premotor area works together with the supplemental area to react quickly to external stimuli and plan movements, but SMA damage would likely also result in decreased muscle tone and lowered bimanual dexterity. B166-7: Motor Control I & II.)
- A student who has recently had a stroke has decreased movement of their lower facial muscles. They are frustrated that when they attempt to smile, they are unable to do so. However, when they listen to jokes from their hilarious Egyption professor’s recorded lectures, they show a perfect ability to smile. What is likely the cause of this discrepancy?
- Lower motor neuron lesion of ipsilateral CN VII
- Upper motor neuron lesion to contralateral primary motor cortex
- Upper motor neuron lesion to ipsilateral primary motor cortex
- Upper motor neuron lesion to contralateral cingulate motor cortex
- Upper motor neuron lesion to ipsilateral cingulate motor cortex(Answer D. The caudal cingulate cortex controls emotional response of facial muscles. A lower motor lesion would affect both voluntary and involuntary movements. B166-7: Motor Control I & II.)
- Which of the following is the least common drug-receptor bond?
- Hydrogen bonding
- Van der Waals Forces
- Hydrophobic bonds
- Covalent bonds
- Electrostatic forces (Answer D. If the bond is covalent, the drug receptor interaction is irreversible.B171: Pharmacodynamics (Receptor Theory).)
- A list of unknown drugs with their respective KD are listed below. Based on this information, which of the following drugs has the highest potency?
- A
- B
- C
- D
- E(Answer D. KD = 1/drug affinity. A low KD correlates to a high affinity and high potency. B171: Pharmacodynamics (Receptor Theory).)
- You are on rotations in the Emergency Department when a patient presents following a heroine overdose. The paramedics have administered Narcan (Naloxone) to completely reverse the effects of the overdose. When the patient comes around, they tell you that their near death experience has given them the push they need to stop using. Due to their extensive history of drug abuse, you decide to administer Buprenorphine to slowly wean them off of heroine. Which of the following best describes the effect of Buprenorphine?
- Full agonist
- Full antagonist
- Partial antagonist
- Partial agonist
- Inverse agonist (Answer D. In this question, Narcan would be working as a full antagonist. B171: Pharmacodynamics (Receptor Theory).)
- [Part 1 of 2] In the graph shown below, the purple line most likely represents which of the following?
- Full antagonist
- Partial agonist
- Full agonist
- Partial antagonist
- Reverse agonist (Answer B. B171: Pharmacodynamics (Receptor Theory).)
- [Part 2 of 2] Which line most likely represents a reverse agonist?
- A
- B
- C
- D
- None of the above (Answer D. B171: Pharmacodynamics (Receptor Theory).)
- Which of the following cells plays an inhibitory roles of the deep cerebellar nuclei?
- Stellate cells
- Purkinje cells
- Golgi cells
- Basket cells
- Granule cells(Answer B. B172: Cerebellum.)
- The image below shows a micro-pictograph of the cortex of a cerebellum. Which of the following layers correctly identifies the location of the axons and/or dendrites of cerebellar neurons?
- A
- B
- C
- The axons/dendrites of cerebellar nuclei are not located in the cerebellum(Answer A. B172: Cerebellum.)
- Which of the following are most important for cerebellar learning?
- Climbing fibers and their associated simple spike
- Mossy fibers and their associated simple spike
- Climbing fibers and their associated complex spike
- Mossy fibers and their associated complex spike
- None of the above(Answer C. B172: Cerebellum.)
- Which of the following arrows on the image below is pointing to the Dentate nucleus?
- Green
- Red
- Yellow
- Blue
- None of the above (Answer D. Green is Fastigial (Vermis). Red is Globose (Paravermal/Medial). Yellow is Emboliform (Paravermal/Medial). The dentate nucleus receives input from lateral hemisphere. Mnemonic:”Don’t Eat Greasy Foods.” B172: Cerebellum.)
- The medial cerebellar peduncle receives afferent information from which of the following?
- Anterior Spinocerebellar Tract
- Posterior Spinocerebellar Tract
- Olivocerebellar Tract
- Pontocerebellar Tract
- Dentothalamic Pathway(Answer D. B172: Cerebellum.)
- [Part 1 of 2] The black line on the graph below represents drug X, an agonist to a specific receptor. The y axis represents the effect of drug X and the x-axis represents the concentration of drug X. Which of the following lines represents the response when drug X is added with a noncompetitive antagonist?
- A
- B
- C
- D
- None of the above (Answer A. Noncompetitive antagonists (also called irreversible) cause the drug efficacy to decrease (potency stays the same). The red line best represents this. Line D represents drug X with a competitive antagonist. B174: Pharmacodynamics (Dose Response).)
- [Part 2 of 2] How did the addition of a noncompetitive antagonist change the EC50 and KD of drug X?
- Decreased EC50; Decreased KD
- Increased EC50; Increased KD
- No change EC50; Increased KD
- No change EC50; No change KD
- Increased EC50; Decreased KD(Answer D. Both the EC50 and KD are indicators of a drug’s potency. Since the potency remained constant, neither of these values would be affected. Line D is representing drug X with a competitive antagonist. In this case, the efficacy is constant, while the potency is decreased. A decreased potency would mean an increased KD and increased EC50. B174: Pharmacodynamics (Dose Response).)
- An experiment is performed with a drug labelled “A.” Drug A is combined with increasingly higher concentrations of a noncompetitive antagonist and the responses are shown below on the graph. A1 shows drug A with no antagonist present, and A5 represents drug A with the highest concentration of antagonist present. Which of the following best explains this phenomenon?
- Drug A can reach full response at a concentration that does not occupy all available receptors
- The noncompetitive antagonist must be partially competitive
- Drug A must occupy all available receptors to reach full effect
- The noncompetitive antagonist is a partial agonist
- This same effect would occur with a competitive antagonist (Answer A. The receptors that are not occupied by Drug A are known as “spare.” B174: Pharmacodynamics (Dose Response).)
- Glucocorticoids increase blood glucose levels, whereas insulin decreases blood glucose levels. Both drugs work through entirely different mechanisms (i.e. don’t use the same receptors). Which of the following terms best describes glucocorticoids interaction with insulin?
- Chemical antagonism
- Physiological (Functional) Antagonism
- Allosteric Modulation
- Partial agonist
- Full agonist (Answer B. B174: Pharmacodynamics (Dose Response).)
- In a recently concluded clinical study, Drug Y was tested for its effect on blood glucose levels (BGL) in diabetic rats. The rats received 10 mg/kg of body weight of undisclosed substance Z prior to the administration of Drug Y and the percent decreases in BGL were recorded (shown below). Substance Z is most likely acting on the receptors as which of the following?
- Competitive antagonist
- Non-competitive antagonist
- Partial agonist
- Inverse agonist
- Full agonist(Answer B. B174: Pharmacodynamics (Dose Response).)
- In a recently concluded clinical study, a new anesthetic drug was tested for ED50 and LD50. The results are shown in the chart below. Which of the following is closest to the therapeutic index (TI)?
- 0.86
- 0.07
- 1.17
- 0.06
- 1.56(Answer C. TI = (TD50 or LD50) / ED50. The LD50 in this question is 0.07 and the ED50 is 0.06. 0.07/0.06 = 1.17. B174: Pharmacodynamics (Dose Response).)
- Huntington’s Disease is associated with which of the following?
- Degeneration of the striatum
- Contralateral lesion to the STN
- Degeneration of the substantia nigra
- Decreased Dopamine levels
- Degeneration of the Globus pallidus(Answer A. Hemiballismus is associated with B. Parkinson’s is associated with C & D. B176: Basal Ganglia.)
- Tardive dyskinesia is a potential side-effect of prolonged use of dopamine antagonists. It causes stiff, jerky movements of your face and body that you can’t control. Which of the following explains the reasoning for this side-effect?
- Thalamic atrophy
- Thalamic hypertrophy
- Decreased receptor hypersensitivity
- Increased receptor hypersensitivity
- Atrophy of the Substantia Nigra(Answer D. B177: Basal ganglia.)
- A 18 year old male patient presents following blow to the head during football practice. He is having trouble remembering what happened the minutes leading up to his injury. Which of the following describes his presentation best?
- Anterograde Amnesia
- Retrograde Amnesia
- Procedural Amnesia
- Anterograde Paresthesia
- Retrograde Paresthesia(Answer B. B180: Cortical Function.)
- Which of the following best explains why alcohol intoxication can prevent long-term potentiation?
- It inhibits the NMDA
- It inhibits AMPA
- It inhibits TRPV1
- It decreases amount of GABA
- It prevents the release of Glutamate(Answer A. B180: Cortical Function.)
- A 57 year old male presents to the Emergency Department via ambulance following a complaint of angina characteristic of a myocardial infarction. The paramedics have given him sublingual Nitroglycerin and 324 mg of Aspirin. While his chest pain has subsided for now, you notice that he has extremely low blood pressure and is beginning to lose consciousness. You suspect drug interaction to be the cause of his hypotension. Which of the following drugs did this patient most likely have in addition to the Nitroglycerin given to him by the paramedics?
- Alcohol
- Aminoglycosides
- Propanolol
- Sildenafil(Answer E. Sildenafil (also known as Viagra) is a PDE inhibitor that causes synergistic effects and dangerously low blood pressure when paired with Nitro.)