All Questions: 301-330
301. When motor signals are sent from the motor cortex to control movements of the head and face, which pathway do they primarily follow?
- A. Corticospinal tract
- B. Spinocerebellar tract
- C. Vestibulospinal tract
- D. Corticobulbar tract
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Correct answer: D
The corticobulbar tract carries motor commands from the cerebral cortex to the motor nuclei of cranial nerves in the brainstem, which control muscles of the head and face. In essence, it does for the head and face what the corticospinal tract does for the rest of the body.
302. About one-third of people with migraines experience neurological symptoms just before or during the onset of a headache. This is known as a/an:
- A. prodrome
- B. postdrome
- C. aura
- D. trigeminal activation
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Correct answer: C
A migraine aura consists of neurological symptoms such as visual disturbances, tingling, or speech changes that occur immediately before or during the onset of a migraine headache.
303. In a thrombotic stroke (i.e., a stroke caused by a thrombus), a blood clot:
- A. forms in a distant site and then travels to the brain
- B. forms in a cerebral vein and blocks venous blood outflow from the brain
- C. forms locally in an artery in the brain or an artery that supplies the brain
- D. forms only in the blood supply to the peripheral nervous system
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Correct answer: C
When a blood clot forms in same area where the blockage occurs, it is known as a thrombus. When a blood clot forms at a distant site and then travels to another part of the body or the brain to block a blood vessel, it is known as an embolus. A thrombotic stroke involves a blood clot that forms in the brain or in an artery that directly supplies the brain.
304. Type 1 narcolepsy is a sleep disorder characterized by excessive daytime sleepiness and sudden muscle weakness (cataplexy). It is most directly associated with a deficiency of which of the following neurochemicals?
- A. dopamine
- B. serotonin
- C. acetylcholine
- D. orexin (hypocretin)
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Correct answer: D
Narcolepsy is a chronic condition that causes excessive daytime sleepiness and leads to an increased tendency to fall asleep during daytime activities. Narcolepsy type 1 is linked to a loss of orexin-producing neurons in the hypothalamus, leading to low orexin levels. Orexin neurons have an excitatory effect on several regions of the brain that are involved in promoting wakefulness and suppressing REM sleep.
305. Which of the following accurately describes the function of the sodium-potassium (Na⁺/K⁺) pump?
- A. It allows Na and K ions to passively diffuse along their concentration gradients
- B. It uses ATP to move 3 Na ions out and 2 K ions into the cell per cycle
- C. It uses ATP to move 3 Na ions in and 2 K ions out of the cell per cycle
- D. It creates an equal distribution of Na and K ions across the cell membrane
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Correct answer: B
The main function of the Na⁺/K⁺ pump is to transport sodium ions out of the cell and potassium ions into the cell. It uses ATP to accomplish this, and each cycle of the pump causes 3 sodium ions to move out of the cell and 2 potassium ions to move into the cell.
306. This extension of the pia mater stretches from the caudal end of the spinal cord to the coccyx (tailbone) and helps to anchor the spinal cord in place:
- A. conus medullaris
- B. cauda equina
- C. filum terminale
- D. denticulate ligament
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Correct answer: C
The filum terminale is a thin, thread-like extension of the pia mater that extends downward from the end of the spinal cord to the coccyx. It helps to anchor the spinal cord in place.
307. Which substance is produced as a byproduct of ATP usage and accumulates in the brain during waking states, contributing to feelings of tiredness over time?
- A. acetylcholine
- B. dopamine
- C. serotonin
- D. adenosine
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Correct answer: D
As neurons use ATP for energy, adenosine accumulates in the brain. Adenosine inhibits wake-promoting neurons and contributes to the feeling of tiredness. During sleep, adenosine levels fall, restoring alertness.
308. Which of the following correctly characterizes serotonin?
- A. amino acid neurotransmitter
- B. catecholamine neurotransmitter
- C. monoamine neurotransmitter
- D. peptide neurotransmitter
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Correct answer: C
Serotonin is a monoamine neurotransmitter, a term that refers to its chemical structure and the fact that it is derived from an amino acid.
309. After a car accident, a patient suffers substantial damage to the right side of the cervical spinal cord. Her corticospinal tract fibers on the right are severely damaged. What motor deficit would you expect to see?
- A. weakness or paralysis on the right side of the body below the damage
- B. weakness or paralysis on the right side of the body above the damage
- C. weakness or paralysis on the left side of the body below the damage
- D. weakness or paralysis on the left side of the body above the damage
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Correct answer: A
Damage to the right corticospinal tract in the spinal cord causes weakness or paralysis on the same side (ipsilateral) of the body below the lesion/damage.
310. What is the significance of the neuromuscular junction?
- A. It is the site where sensory neurons transmit pain signals to the spinal cord
- B. It is the location where two motor neurons connect
- C. It is the area where nutrients are exchanged between blood and muscle
- D. It is the region where a motor neuron communicates with muscle to cause movement
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Correct answer: D
The neuromuscular junction (NMJ) is a specialized synapse between a motor neuron and a skeletal muscle fiber. At the NMJ, acetylcholine released from the neuron binds to receptors on the muscle membrane, initiating an action potential that leads to muscle contraction.
311. Which cranial nerve is primarily responsible for controlling the muscles of mastication (chewing)?
- A. facial nerve (CN VII)
- B. trigeminal nerve (CN V)
- C. glossopharyngeal nerve (CN IX)
- D. hypoglossal nerve (CN XII)
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Correct answer: B
The mandibular branch of the trigeminal nerve innervates the muscles that move the jaw for chewing.
312. Drugs that increase activity at GABA-A receptors often reduce anxiety. Compounds known as beta-carbolines bind to the GABA-A receptor and decrease its activity below baseline, producing anxiety. What type of mechanism best describes the action of beta-carbolines?
- A. full agonism
- B. partial agonism
- C. allosteric modulation
- D. inverse agonism
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Correct answer: D
When a substance binds to a receptor and causes a decrease in signaling below baseline at the receptor, it can produce effects that are opposite to those of a full agonist. These substances are called inverse agonists, and beta-carbolines are a good example of them.
313. What is the name of the deep groove that separates the brain into two cerebral hemispheres?
- A. central sulcus
- B. Sylvian fissure
- C. longitudinal fissure
- D. parieto-occipital sulcus
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Correct answer: C
The longitudinal fissure is the deep groove that separates the left and right cerebral hemispheres. It runs along the midline of the brain.
314. The primary mechanism of serotonin-norepinephrine reuptake inhibitors (SNRIs) involves (in the answer choices, 5-HT = serotonin and NE = norepinephrine):
- A. increasing the activity of a protein that removes 5-HT and NE from the synapse
- B. decreasing the activity of a protein that removes 5-HT and NE from the synapse
- C. causing increased release of 5-HT and NE from presynaptic neurons
- D. causing decreased release of 5-HT and NE from presynaptic neurons
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Correct answer: B
SNRIs work primarily by inhibiting a mechanism called reuptake. In reuptake, a protein called a transporter transports excess neurotransmitter molecules out of the synaptic cleft, typically back into the neuron that released them. SNRIs inhibit the reuptake of serotonin and norepinephrine, thereby decreasing the activity of a protein that removes serotonin and norepinephrine from the synapse.
315. Which basal ganglia pathway is primarily known for its role in facilitating voluntary movement?
- A. indirect pathway
- B. direct pathway
- C. corticospinal pathway
- D. vestibulospinal pathway
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Correct answer: B
The direct pathway of the basal ganglia facilitates movement by reducing inhibition of the thalamus, which increases excitatory input to the motor cortex.
316. The hormonal response of the HPA axis starts with the hypothalamus releasing this hormone:
- A. corticotropin-releasing hormone (CRH)
- B. adrenocorticotropic hormone (ACTH)
- C. cortisol
- D. norepinephrine
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Correct answer: A
When we experience something stressful, the hypothalamus releases a hormone called corticotropin-releasing hormone (or CRH). CRH signals the pituitary gland to secrete a hormone called adrenocorticotropic hormone, or ACTH, into the bloodstream. ACTH travels down to the adrenal glands where it prompts the release of a hormone called cortisol from the cortex, or outer layer, of the adrenal glands.
317. This is the thinnest and innermost meningeal layer; it adheres closely to the surface of the brain:
- A. dura mater
- B. arachnoid mater
- C. pia mater
- D. denticulate mater
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Correct answer: C
The pia mater is the thinnest and innermost layer of the meninges. It adheres to the surface of the brain, closely following all of the contours of the brain.
318. The suprachiasmatic nucleus (SCN) uses information from which pathway to reset the circadian clock in response to light?
- A. retinotectal pathway
- B. retinogeniculostriate pathway
- C. retinohypothalamic pathway
- D. nigrostriatal pathway
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Correct answer: C
Specialized photosensitive retinal ganglion cells send light information directly to the SCN through the retinohypothalamic tract. This input helps synchronize the body’s internal clock with the external light–dark cycle.
319. The causes of restless legs syndrome are not fully understood, but a deficiency of this mineral in the brain is a common neurological feature of the condition:
- A. calcium
- B. magnesium
- C. zinc
- D. iron
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Correct answer: D
The mechanisms underlying restless legs syndrome (RLS) are not well understood. Genetic factors play a large role in susceptibility, but it’s thought that in most patients environmental factors must interact with genetics to bring about the condition. The most commonly-identified environmental factor in RLS is iron deficiency, and iron deficiency in the brain is the best-known neurological feature of RLS.
320. The cerebral cortex is covered with a collection of grooves and ridges. What are the ridges called?
- A. gyri
- B. fissures
- C. sulci
- D. transversals
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Correct answer: A
The ridges that are formed from the folding of the cerebral cortex are called gyri (singular: gyrus). The grooves are called sulci (singular: sulcus).
321. Which two cranial nerves are primarily responsible for carrying taste sensations from the tongue to the brain?
- A. glossopharyngeal (CN IX) & hypoglossal (CN XII)
- B. facial (CN VII) & glossopharyngeal (CN IX)
- C. Vagus (CN X) & hypoglossal (CN XII)
- D. Accessory (CN XI) & hypoglossal (CN XII)
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Correct answer: B
Taste information from the anterior two-thirds of the tongue is carried by the facial nerve (CN VII), while the glossopharyngeal nerve (CN IX) carries taste from the posterior one-third of the tongue.
322. Which cranial nerve is primarily responsible for carrying visual information from the retina to the rest of the brain?
- A. CN II - optic nerve
- B. CN III - oculomotor nerve
- C. CN IV - trochlear nerve
- D. CN VI - abducens nerve
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Correct answer: A
The optic nerve is a sensory nerve responsible for transmitting information about vision to the brain.
323. Chronic traumatic encephalopathy (CTE) is a neurological condition linked primarily to:
- A. Autoimmune inflammation of the meninges
- B. Repeated head injuries and concussions
- C. Deficiency of dopamine in the basal ganglia
- D. Accumulation of beta-amyloid plaques in the cortex
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Correct answer: B
Chronic traumatic encephalopathy, or CTE, is a neurological condition linked primarily to repetitive head trauma. Most cases of CTE occur in those who play sports where head injuries are common, but anyone who has experienced repeated head trauma is at risk. CTE symptoms may include: memory deficits, abnormal behavior such as paranoia, aggression and impulsivity, and mood disturbances such as depression.
324. Nicotine's primary mechanism of action in the nervous system involves the direct stimulation of receptors for which neurotransmitter?
- A. acetylcholine
- B. serotonin
- C. norepinephrine
- D. histamine
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Correct answer: A
Nicotine primarily exerts its effects by activating, or acting as an agonist, at certain receptors for the neurotransmitter acetylcholine. These receptors, known as nicotinic acetylcholine receptors, are found throughout the central and peripheral nervous systems.
325. Which of the following best describes the primary mechanical event that causes a concussion?
- A. tearing of the meninges leads to cerebrospinal fluid leakage
- B. reduction in cerebral blood flow due to a blood clot
- C. head impact or sudden movement makes the brain move within the skull
- D. compression of cranial nerves by swelling of brain tissue
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Correct answer: C
A concussion is a type of traumatic brain injury that occurs when rapid movement of the head or an impact to the head causes the brain to move within the skull, potentially stretching axons and damaging cell membranes of neurons.
326. A patient reports having a deficit in his ability to perceive movement, where moving objects appear to “jump” from one position to another rather than moving smoothly. This condition, known as akinetopsia, is commonly linked to damage to what part of the brain?
- A. middle temporal visual area (V5)
- B. parahippocampal gyrus
- C. primary visual cortex (V1)
- D. fusiform gyrus
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Correct answer: A
Akinetopsia, or “motion blindness,” is typically linked to damage to the middle temporal visual area, also known as visual area 5 (V5).
327. You’re home alone watching a horror movie when a sudden jump scare startles you, causing your heart to race. Which division of the nervous system is responsible for this increase in heart rate?
- A. parasympathetic nervous system
- B. enteric nervous system
- C. sympathetic nervous system
- D. somatic nervous system
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Correct answer: C
The sympathetic division of the autonomic nervous system is responsible for increasing heart rate during a sudden fright. It prepares the body for “fight-or-flight” by accelerating the heartbeat, increasing respiration, and redirecting blood flow to the muscles.
328. Which part of the substantia nigra is heavily populated with dopamine neurons?
- A. substantia nigra pars compacta
- B. substantia nigra pars reticulata
- C. both regions have equal numbers of dopamine neurons
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Correct answer: A
The dopamine neurons in the substantia nigra are primarily found in the substantia nigra pars compacta. The substantia nigra pars reticulata is more heavily populated with GABA neurons.
329. When an action potential reaches the synaptic boutons, it triggers the influx of which ion that is essential for neurotransmitter release?
- A. Potassium
- B. Chloride
- C. Magnesium
- D. Calcium
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Correct answer: D
When an action potential reaches the axon terminal, it depolarizes the membrane and opens voltage-gated calcium channels. The resulting calcium influx helps mobilize synaptic vesicles, preparing them for neurotransmitter release.
330. The development of the nervous system begins when an area of the ectoderm thickens and forms what is known as the:
- A. notochord
- B. neural crest
- C. spinal sheath
- D. neural plate
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Correct answer: D
The development of the nervous system begins at around the third week of embryonic development, when an area of the ectoderm, or the outer tissue layer of the embryo, thickens and forms what is known as the neural plate.
