Neural Control and Coordination — Practice Questions with Answers

Q1.

The basic structural unit of the nervous system is the:

• A Neuroglia
• B Axon
• C Neuron
• D Synapse

Q2.

The axon transmits impulses:

• A Toward the cell body
• B Away from the cell body
• C In both directions
• D Only to other neurons

Q3.

Myelin sheath is formed by:

• A Astrocytes, which regulate the blood-brain barrier
• B Schwann cells (in PNS) alone, with no CNS counterpart
• C Neurons themselves, by folding their own membrane
• D Oligodendrocytes (in CNS) or Schwann cells (in PNS)

Q4.

A reflex arc involves:

• A The brain alone, processing input before any response
• B Spinal cord (and sometimes brain) without conscious thought
• C Conscious decision-making in the cerebral cortex
• D Only motor neurons, with no sensory input required

Q5.

The largest part of the human brain is the:

• A Cerebellum
• B Medulla oblongata
• C Cerebrum
• D Pons

Q6.

The cerebellum controls:

• A Hunger and thirst
• B Breathing and heart rate
• C Balance and coordination
• D Vision and hearing only

Q7.

Synapse is the:

• A Cell body of a neuron
• B Junction between two neurons
• C Type of brain cell
• D Part of spinal cord

Q8.

The resting potential of a neuron is approximately:

• A +70 mV
• B -70 mV
• C 0 mV
• D 120 mV

Q9.

Acetylcholine and noradrenaline are examples of:

• A Hormones, secreted into the bloodstream by glands
• B Enzymes, which catalyze specific biochemical reactions
• C Neurotransmitters
• D Vitamins, obtained only through dietary intake

Q10.

The medulla oblongata controls:

• A Voluntary movement initiated by the motor cortex
• B Learning and memory consolidation in the hippocampus
• C Heartbeat and breathing (vital centers)
• D Balance and posture via the cerebellum

Q11.

Sensory neurons carry signals from:

• A Brain to muscles
• B Muscles to brain
• C Sense organs to CNS
• D CNS to sense organs

Q12.

Motor neurons carry signals from:

• A CNS to muscles/glands (effectors)
• B Muscles directly back to the brain for processing
• C Sensory organs toward the brain for interpretation
• D Signals confined only within the spinal cord itself

Q13.

The autonomic nervous system controls:

• A Voluntary muscle movement via motor neurons
• B Involuntary body functions (heart, digestion)
• C Conscious thought processed in the cerebrum
• D Only the eyes and ears through cranial nerves

Q14.

Sympathetic nervous system is activated during:

• A Sleep
• B Digestion after a meal
• C Fight-or-flight response
• D Rest and recovery

Q15.

Parasympathetic nervous system is active during:

• A Fight-or-flight responses during acute danger
• B Sudden emergency responses to perceived threats
• C Rest and digest (calms the body)
• D Extreme physical exercise and exertion

Q16.

Knee-jerk reflex is an example of:

• A A conditioned reflex learned through repeated practice
• B Unconditioned (inborn) spinal reflex
• C A response primarily mediated through higher brain centers
• D Behavior shaped mainly through repeated learning experience

Q17.

The hypothalamus controls:

• A Balance and fine motor coordination of all skeletal muscle movement
• B Vital breathing and heart rate functions through the brainstem and medulla
• C Homeostasis, hunger, thirst, body temperature, and pituitary hormones
• D All voluntary movement initiation via the cerebral motor cortex

Q18.

The spinal cord is protected by:

• A Meninges and vertebral column
• B Skull bone alone, with no other covering
• C The brain, positioned directly above it
• D Rib cage surrounding the thoracic cavity

Q19.

Depolarization of a neuron occurs when:

• A K+ rushes into the cell
• B Na+ rushes into the cell
• C Cl- rushes out
• D K+ rushes out

Q20.

Brain and spinal cord together form the:

• A Peripheral nervous system
• B Central nervous system
• C Autonomic nervous system
• D Somatic nervous system

Q21.

Saltatory conduction occurs in:

• A Unmyelinated neurons that conduct impulses continuously
• B Myelinated neurons (impulse jumps between nodes of Ranvier)
• C Mainly sensory neurons carrying afferent signals to the CNS
• D Mainly motor neurons carrying efferent signals to muscles

Q22.

Nodes of Ranvier are gaps in the:

• A Axon itself, where the cytoplasm is interrupted
• B Myelin sheath exposing the axon membrane
• C Cell body, where the nucleus and organelles are located
• D Dendrites, where incoming signals are received

Q23.

The all-or-nothing principle of nerve impulses means:

• A All neurons throughout the body fire simultaneously together
• B An impulse is either at full strength or does not occur at all
• C Impulses can vary continuously in strength depending on stimulus size
• D Only motor neurons obey this principle, unlike sensory neurons

Q24.

Repolarization of the axon during action potential involves:

• A Na+ flowing in, depolarizing the membrane further
• B K+ flowing out restoring negative inside
• C Ca2+ entering through voltage-gated channels at the terminal
• D Cl- flowing in, hyperpolarizing the resting membrane

Q25.

Inhibitory postsynaptic potentials (IPSPs) involve:

• A Na+ influx causing rapid membrane depolarization
• B Cl- influx or K+ efflux causing hyperpolarization
• C Mainly acetylcholine release at the synaptic cleft
• D Neurotransmitter uptake occurring back from the synapse

Q26.

The blood-brain barrier is formed by:

• A Neurons themselves, by forming an insulating layer around capillaries
• B Tight junctions between brain capillary endothelial cells (and astrocytes)
• C The bony skull enclosing and protecting the brain
• D Cerebrospinal fluid alone, cushioning the brain tissue

Q27.

Long-term potentiation (LTP) is associated with:

• A Forgetting, through gradual weakening of synaptic connections over time under usual circumstances
• B The cellular mechanism of memory formation (strengthening of synaptic connections)
• C Relaxation of skeletal muscle following a period of sustained contraction according to most researchers
• D Release of hormones specifically from the anterior pituitary gland in the majority of cases studied

Q28.

Cerebrospinal fluid (CSF) is produced in:

• A The cerebral cortex, by neurons lining its outer surface
• B Choroid plexus inside the ventricles
• C The cerebellum, through its dense layer of granule cells
• D The spinal cord, by glial cells lining the central canal

Q29.

Dopamine deficiency is associated with which disease?

• A Alzheimer disease
• B Parkinson disease
• C Multiple sclerosis
• D Myasthenia gravis

Q30.

The sympathetic nervous system uses which neurotransmitter at target organs?

• A Acetylcholine, released at the neuromuscular junction
• B Noradrenaline (norepinephrine)
• C Dopamine, acting mainly within reward pathways of the brain
• D Serotonin, regulating mood within central synapses

Q31.

GABA is the main _____ neurotransmitter in the CNS:

• A Excitatory
• B Inhibitory
• C Neither excitatory nor inhibitory
• D Only in peripheral nervous system

Q32.

The corpus callosum connects:

• A Brain to spinal cord via the brainstem pathway
• B Left and right cerebral hemispheres
• C Cerebrum to cerebellum through the pons region
• D Thalamus to hypothalamus within the diencephalon

Q33.

Myasthenia gravis is caused by:

• A Dopamine deficiency in the substantia nigra region of the midbrain
• B Autoimmune attack on acetylcholine receptors at neuromuscular junction
• C Progressive loss of the myelin sheath surrounding central nervous system axons
• D Excess GABA accumulation occurring at inhibitory central nervous synapses

Q34.

Broca's area in the left frontal lobe controls:

• A Vision processing, relayed from the occipital lobe
• B Speech production (motor speech)
• C Hearing, processed primarily in the temporal lobe
• D Memory only, consolidated in the hippocampus

Q35.

Spinal cord injury above C4 affects:

• A Mainly leg movement, leaving the arms and trunk unaffected
• B Breathing and all limbs (may require ventilator)
• C Mainly arm movement, sparing the lower limbs largely
• D Mainly bladder control, with limb function largely preserved

Q36.

Glutamate is the main _____ neurotransmitter in the CNS:

• A Inhibitory, hyperpolarizing postsynaptic neurons via GABA receptors
• B Excitatory (NMDA, AMPA receptor activation)
• C Modulatory mainly, acting through slow second-messenger pathways
• D Peripheral mainly, restricted to neuromuscular junctions

Q37.

Pavlov's conditioning is an example of:

• A Innate behavior present from birth, occurring without any prior learning involved
• B Classical conditioning (associating a neutral stimulus with an unconditioned stimulus)
• C Habituation, a decreased response that develops to a repeated harmless stimulus
• D Operant conditioning, where behavior is gradually shaped by reward or punishment

Q38.

The thalamus acts as:

• A A long-term memory storage center within the limbic system
• B Relay station for sensory information to cerebral cortex
• C A motor coordination center fine-tuning voluntary movement
• D A hormone production center regulating the endocrine system

Q39.

The term for the minimum voltage that must be reached to trigger an action potential is:

• A Resting potential
• B Threshold potential
• C Graded potential
• D Absolute refractory period

Q40.

Multiple sclerosis results from:

• A Dopamine deficiency in midbrain dopaminergic neurons
• B Autoimmune destruction of myelin sheath in CNS
• C Progressive degeneration and loss of spinal motor neurons
• D Overproduction of acetylcholine at the neuromuscular junction

Q41.

NMDA receptors are special among ionotropic receptors because:

• A They respond mainly to GABA, the principal inhibitory neurotransmitter found within the central nervous system as generally observed
• B They require both ligand binding (glutamate) AND membrane depolarization to remove Mg2+ block (coincidence detectors for LTP)
• C They are found mainly within the peripheral nervous system and rarely occur centrally in the brain in typical laboratory settings
• D They signal mainly through a slow G-protein coupled second-messenger cascade rather than a channel directly under usual circumstances

Q42.

Calcium/calmodulin-dependent kinase II (CaMKII) is important in LTP because:

• A It is reported to inhibit presynaptic glutamate release, thereby reducing the overall strength of synaptic transmission at that particular synapse according to most researchers
• B It is persistently activated after brief Ca2+ entry (via NMDA) and phosphorylates AMPA receptors, increasing their conductance, and recruits more AMPA to synapse
• C It is said to enzymatically degrade neurotransmitter molecules that remain within the synaptic cleft after their initial release event in the majority of cases studied
• D It is reported to physically form the entire structural scaffold of the postsynaptic density largely on its own, mostly unaided as widely reported in standard practice

Q43.

The absolute refractory period of a neuron is due to:

• A Potassium channels remaining continuously open, thereby preventing any further membrane depolarization event under most conditions encountered
• B Na+ channels being inactivated (h gate closed) -- no matter how strong the stimulus, no action potential can be generated
• C Continuous chloride efflux that hyperpolarizes the neuronal membrane indefinitely without any recovery period as frequently observed in practice
• D A temporary, complete absence of ATP needed to power the sodium-potassium exchange pump mechanism in many documented cases

Q44.

Quantal neurotransmitter release at the synapse means:

• A Transmitter release scales smoothly and continuously in direct proportion to action potential firing frequency according to conventional understanding
• B Transmitter is released in discrete, all-or-nothing packages (quanta = synaptic vesicles) each containing ~5,000 molecules
• C The total amount of transmitter released varies continuously along an unbroken smooth gradient curve in routine practice
• D Exactly one single transmitter molecule is released from the presynaptic terminal at any given time overall in most cases

Q45.

The postsynaptic density (PSD) at excitatory synapses contains:

• A Voltage-gated Na+ channels that are mainly responsible for the rising phase of the action potential itself under typical conditions
• B Scaffold proteins (PSD-95), AMPA and NMDA receptors, signaling enzymes (CaMKII) -- organizing the postsynaptic signaling complex
• C Mainly nicotinic acetylcholine receptors, with very few glutamate receptors present overall according to standard textbooks
• D Mainly inhibitory GABA-A receptors that are clustered tightly at the postsynaptic membrane surface region in general practice

Q46.

Vesicle docking and fusion at the presynaptic terminal requires:

• A Calcium ions alone, requiring little additional dedicated protein fusion machinery at the presynaptic membrane region as frequently described
• B SNARE proteins (synaptobrevin on vesicle, syntaxin and SNAP-25 on plasma membrane) forming a complex when Ca2+ triggers synaptotagmin
• C ATP hydrolysis alone, occurring largely independent of any incoming calcium signal at the synaptic terminal in most textbook accounts
• D Calmodulin protein acting largely alone, without much involvement of a SNARE protein complex at the membrane during normal conditions

Q47.

Tetrodotoxin (TTX) blocks action potentials by:

• A Blocking voltage-gated K+ channels, thereby preventing normal repolarization of the cell membrane afterward as generally observed in typical laboratory settings
• B Specifically blocking voltage-gated Na+ channels from outside, preventing depolarization (used in research and is the puffer fish toxin)
• C Inhibiting voltage-gated Ca2+ channels located at the presynaptic nerve terminal region specifically under usual circumstances according to most researchers
• D Blocking postsynaptic NMDA receptors, thereby preventing glutamate-induced membrane depolarization events in the majority of cases studied

Q48.

Benzodiazepines (like diazepam) act by:

• A Directly and competitively blocking GABA-A receptors, thereby reducing inhibitory chloride conductance levels as widely reported
• B Acting as positive allosteric modulators of GABA-A receptors, increasing frequency of Cl- channel opening in response to GABA
• C Mimicking the action of glutamate at excitatory NMDA and AMPA receptor binding sites directly in standard practice under most conditions encountered
• D Blocking voltage-gated sodium channels distributed along the entire length of the axon membrane as frequently observed in practice

Q49.

Neurogenesis in adult brain primarily occurs in:

• A All regions of the adult brain equally, with little regional specificity
• B Subventricular zone (SVZ) and subgranular zone of hippocampal dentate gyrus
• C Mainly within the granule cell layer of the cerebellum
• D Mainly within nuclei located in the brainstem

Q50.

Synaptic scaling (homeostatic plasticity) occurs when:

• A Individual synapses are selectively and permanently strengthened through long-term potentiation alone repeatedly in many documented cases
• B Neurons globally scale all synaptic strengths up or down to maintain stable activity levels (compensating for prolonged changes in activity)
• C Mainly inhibitory GABAergic synapses undergo any measurable change in synaptic strength over time according to conventional understanding
• D Synapses are permanently and irreversibly eliminated, with little compensatory scaling response occurring afterward in routine practice

Q51.

The cerebellum predicts and corrects motor movements using:

• A Direct motor commands transmitted straight from the cerebellum to skeletal muscle fibres, largely bypassing the spinal cord pathway overall
• B Internal forward models: comparing efference copy (predicted movement) with sensory feedback to compute error signals, adjusting motor output
• C Long-term storage of most movement sequence the organism has ever previously learned throughout its entire lifetime span in most cases under typical conditions
• D Visual input alone, largely without much use of any proprioceptive or vestibular motor feedback signal present according to standard textbooks

Q52.

The Hodgkin-Huxley model of the action potential uses which equation?

• A Mainly a simple, fixed-threshold equation that includes few voltage-dependent gating variables present in general practice
• B Differential equations with m, h (Na+ channel gating) and n (K+ channel gating) variables derived from voltage-clamp experiments
• C Ohm's law alone, relating membrane current directly to voltage and a fixed resistance term value as frequently described in most textbook accounts
• D The Nernst equation alone, describing mainly the equilibrium potential of a single permeant ion species during normal conditions

Q53.

BDNF (brain-derived neurotrophic factor) promotes neuronal survival and LTP by:

• A Blocking glutamate receptors largely, thereby reducing overall excitatory synaptic transmission activity as generally observed in typical laboratory settings
• B Activating TrkB receptors, stimulating MAPK and PI3K signaling, promoting survival gene expression, and modulating synaptic protein synthesis
• C Blocking apoptosis through a single, narrowly defined caspase-dependent signaling pathway mainly under usual circumstances according to most researchers
• D Inactivating synapses that are determined to be no longer needed within current neural circuit pathways in the majority of cases studied

Q54.

The dorsal root ganglion contains:

• A Cell bodies of motor neurons that directly control the contraction of skeletal muscle fibres themselves as widely reported
• B Cell bodies of primary sensory (afferent) neurons that transmit pain, temperature, and touch to the spinal cord
• C Cell bodies of autonomic neurons that regulate involuntary visceral organ function broadly in standard practice
• D Mainly the cell bodies of interneurons confined largely within the grey matter of the spinal cord under most conditions encountered

Q55.

Pain perception (nociception) involves which key receptor?

• A AMPA receptors, which mainly mediate fast excitatory transmission at central glutamatergic synapses broadly as frequently observed in practice
• B TRPV1 (transient receptor potential vanilloid 1) channels activated by heat (>43C), acid, and capsaicin, initiating pain signals
• C Mainly NMDA receptors, which generally require coincident membrane depolarization in order to open in many documented cases
• D Voltage-gated potassium channels that generally repolarize the neuronal membrane after each firing event according to conventional understanding

Q56.

Demyelinating disease slows nerve conduction because:

• A It directly destroys the entire neuron cell body along with its nucleus and cellular organelles in routine practice
• B Loss of myelin sheath converts saltatory conduction to slow continuous conduction; threshold may not be reached at nodes
• C It pharmacologically blocks voltage-gated sodium channels distributed along the entire axon membrane overall in most cases
• D It substantially increases resting membrane permeability specifically to potassium ions present under typical conditions

Q57.

The enteric nervous system is called the second brain because:

• A It is sometimes mistakenly thought to control all conscious thought processes largely independent of the cerebral cortex itself
• B It contains ~500 million neurons and can control digestion independently of CNS (two nerve plexuses: myenteric and submucosal)
• C It is reported to store the majority of an organism's long-term declarative memories permanently
• D It is simply located anatomically very close in proximity to the brain structure itself

Q58.

Mirror neurons, first discovered in macaques, fire when:

• A An animal generally detects a sudden change in ambient light intensity within its visual field of view according to standard textbooks
• B An animal performs an action AND when it observes another performing the same action (proposed role in imitation, empathy)
• C Mainly during slow-wave or REM sleep stages, rarely during ordinary waking activity periods in general practice as frequently described
• D Mainly in direct response to acute nociceptive pain stimulation applied to the skin surface in most textbook accounts

Q59.

In pain wind-up, repeated C-fiber stimulation causes:

• A A steady, progressive decrease in perceived pain intensity over repeated identical stimulation events during normal conditions
• B Progressive increase in dorsal horn neuron response due to NMDA receptor activation and substance P release (central sensitization)
• C Little measurable change in dorsal horn neuron firing rate observed over an extended period of time as generally observed in typical laboratory settings
• D Sensitization restricted mainly to peripheral nociceptor nerve terminals, rarely reaching the spinal cord region under usual circumstances