Chapter 14 Nervous System: Senses

Which of the following is an example of a simple sensory system?
A. Vision via the eye
B. Hearing via the cochlea
C. Itch sensed by a receptor in the skin
D. Balance detected by the vestibular system

C. Itch sensed by a receptor in the skin

Which of the following is a characteristic of complex sensory systems?
A. They involve only a single neuron
B. They detect pain and temperature
C. They rely on multicellular sense organs
D. They operate only through proprioceptors

C. They rely on multicellular sense organs

Which of the following is an example of a simple sensory system?
A. Vision via the eye
B. Hearing via the cochlea
C. Itch sensed by a receptor in the skin
D. Balance detected by the vestibular system

C. Itch sensed by a receptor in the skin

Which of the following is a characteristic of complex sensory systems?
A. They involve only a single neuron
B. They detect pain and temperature
C. They rely on multicellular sense organs
D. They operate only through proprioceptors

C. They rely on multicellular sense organs

Which of the following is not a somatic sense?
A. Proprioception
B. Itch
C. Temperature
D. Hearing

D. Hearing

Which of the following senses is considered a special sense?
A. Pain
B. Smell
C. Touch
D. Temperature

B. Smell

What do proprioceptors primarily detect?
A. Light
B. Body position and movement
C. Sound vibrations
D. Surface temperature

B. Body position and movement

Which of the following best describes the role of a sensory receptor in the sensory pathway?
A. It amplifies the action potential once it reaches the CNS
B. It transports neurotransmitters to the cerebral cortex
C. It acts as a transducer, converting physical stimuli into intracellular signals
D. It prevents graded potentials from reaching threshold

C. It acts as a transducer, converting physical stimuli into intracellular signals

What typically triggers the generation of an action potential in a sensory neuron?
A. Integration at the cerebral cortex
B. The threshold level of a graded potential is reached
C. Inhibition of neurotransmitter release
D. Direct stimulation of the spinal cord

B. The threshold level of a graded potential is reached

Which sequence correctly represents the flow of information in a typical sensory pathway?
A. CNS → Action Potential → Stimulus → Receptor
B. Stimulus → Sensory Receptor → CNS → Graded Potential
C. Stimulus → Sensory Receptor → Graded Potential → Threshold → Action Potential → CNS
D. Receptor → Stimulus → CNS → Action Potential

Graded Potential
C. Stimulus → Sensory Receptor → Graded Potential → Threshold → Action Potential → CNS

Where does integration of sensory input typically occur?
A. Only in the spinal cord
B. Only in the thalamus
C. At the sensory receptor
D. In the CNS, either subconsciously or in the cerebral cortex

D. In the CNS, either subconsciously or in the cerebral cortex

What is the typical result of a stimulus that does NOT reach threshold?
A. It causes an immediate muscle contraction
B. It results in a failed action potential
C. It triggers neurotransmitter release at the CNS
D. It results in a graded potential without an action potential

D. It results in a graded potential without an action potential

Which of the following is true about simple neural receptors?
A. They are associated with special senses only
B. They have naked (free) nerve endings
C. They always contain connective tissue capsules
D. They are exclusively myelinated

B. They have naked (free) nerve endings

Complex neural receptors differ from simple neural receptors in that they:
A. Are always found in the cerebral cortex
B. Are nonneural and associated with hair cells
C. Are enclosed in connective tissue capsules
D. Cannot transmit action potentials

C. Are enclosed in connective tissue capsules

Which of the following is a feature of nonneural receptors associated with the special senses?
A. They do not interact with sensory neurons
B. They generate action potentials themselves
C. They release chemical signals to activate a nearby sensory neuron
D. They are found only in the skin and muscles

C. They release chemical signals to activate a nearby sensory neuron

Which of the following statements best describes the function of myelination in sensory neurons?
A. It inhibits the action potential from forming
B. It ensures that graded potentials do not occur
C. It increases the speed of action potential conduction
D. It decreases the strength of the stimulus

C. It increases the speed of action potential conduction

Mechanoreceptors are responsible for detecting which of the following stimuli?
A. Light and temperature
B. Sound and pressure
C. Heat and cold
D. Chemical gradients

B. Sound and pressure

Which of the following is considered an accessory structure in the visual system?
A. Retina
B. Iris
C. Cornea
D. Optic nerve

C. Cornea

Hairs on the skin help somatosensory receptors primarily by:
A. Producing neurotransmitters for sensory neurons
B. Increasing skin temperature
C. Enhancing the detection of movement in the air
D. Absorbing light for photoreception

C. Enhancing the detection of movement in the air

A nurse is educating a patient with peripheral neuropathy about why they might not perceive pain in their extremities. Which explanation best reflects the underlying sensory physiology?
A. "Your complex neural receptors are overly active, and they suppress the transmission of pain signals before they reach your brain."
B. "Damage to your proprioceptors prevents the conduction of mechanical signals, leading to deficits in pain detection."
C. "The free nerve endings, which are simple neural receptors responsible for pain, may be damaged or unable to transduce mechanical or chemical stimuli into graded potentials."
D. "Your photoreceptors, which normally modulate pain in the extremities, have lost their ability to initiate action potentials in associated sensory neurons."

C. "The free nerve endings, which are simple neural receptors responsible for pain, may be damaged or unable to transduce mechanical or chemical stimuli into graded potentials."

Which of the following best describes the key distinction between sensory pathways involved in somatic senses and those involved in special senses?
A. Somatic sensory pathways involve nonneural receptors, while special senses involve direct CNS integration.
B. Somatic senses rely on free nerve endings exclusively, while special senses involve myelinated motor neurons.
C. Somatic senses often utilize simple or complex neural receptors embedded in skin and muscle, while special senses are processed through multicellular organs with nonneural receptors that chemically activate associated sensory neurons.
D. Special senses transmit signals via spinal interneurons only, whereas somatic senses transmit through cranial nerves.

C. Somatic senses often utilize simple or complex neural receptors embedded in skin and muscle, while special senses are processed through multicellular organs with nonneural receptors that chemically activate associated sensory neurons.

A 70-year-old male patient reports a gradual loss of balance and an increased number of falls over the past six months. His hearing seems unaffected. Neurological exam is unremarkable, but Romberg test is positive. Which of the following best explains the likely physiological cause?
A. Degeneration of proprioceptors in the muscles and joints is preventing the CNS from receiving adequate input on limb positioning, causing loss of balance even with visual compensation.
B. A lesion in the cerebellum has impaired voluntary muscle movement and disrupted the function of chemoreceptors required for balance regulation.
C. The hair cells in the cochlea have lost their ability to fire action potentials, eliminating the auditory cues essential for proprioception.
D. Thermoreceptors in the semicircular canals have stopped detecting spatial changes in head temperature, leading to equilibrium disturbances.

A. Degeneration of proprioceptors in the muscles and joints is preventing the CNS from receiving adequate input on limb positioning, causing loss of balance even with visual compensation.

4. A patient in the ICU is on high-dose antibiotics and begins to show signs of vestibular toxicity, including dizziness and disorientation. The nurse understands that the medication may be affecting which of the following?
A. The complex neural receptors in the retina, leading to blurred vision and misjudged spatial orientation
B. The thermoreceptors in the inner ear, leading to poor regulation of body temperature and perceived vertigo
C. The hair cells in the vestibular apparatus of the inner ear, which are nonneural receptors that release neurotransmitters to initiate action potentials related to balance
D. The proprioceptors located in the cerebral cortex, leading to poor integration of balance cues with visual stimuli

C. The hair cells in the vestibular apparatus of the inner ear, which are nonneural receptors that release neurotransmitters to initiate action potentials related to balance

A trauma patient presents with an inability to feel pain and temperature on the left side of the body below the waist but still perceives touch and proprioception. MRI reveals damage to the right lateral spinothalamic tract in the spinal cord. What is the most accurate explanation of this finding?
A. The patient's thermoreceptors and mechanoreceptors on the left side are destroyed, resulting in loss of all sensory modalities.
B. The right spinothalamic tract transmits pain and temperature from the contralateral (left) side, while touch and proprioception travel via different, spared pathways.
C. Damage to the right anterior corticospinal tract impairs motor function but not sensory function, explaining the sensory dissociation.
D. Photoreceptors in the spinal cord fail to modulate nociceptive input, resulting in selective sensory loss.

B. The right spinothalamic tract transmits pain and temperature from the contralateral (left) side, while touch and proprioception travel via different, spared pathways.

What is meant by the term adequate stimulus in the context of sensory receptors?
A. The stimulus that activates the brain most rapidly
B. The minimum strength of any stimulus that reaches the spinal cord
C. The type of energy to which a sensory receptor is most sensitive
D. Any form of stimulus that causes immediate conscious perception

C. The type of energy to which a sensory receptor is most sensitive

Which of the following examples best illustrates a receptor responding to a non-adequate stimulus due to high intensity?
A. Hair cells in the cochlea responding to high-pitched sounds
B. Photoreceptors in the retina detecting bright light
C. Mechanoreceptors in the skin detecting vibration
D. Photoreceptors being activated by pressure when you rub your eyes and "see" light

D. Photoreceptors being activated by pressure when you rub your eyes and "see" light

What is the best definition of threshold in relation to sensory receptors?
A. The point at which pain becomes unbearable
B. The minimal stimulus intensity required to activate a receptor and start signal transduction
C. The average amount of neurotransmitter needed to excite a sensory neuron
D. The voltage needed to open voltage-gated sodium channels in any axon

B. The minimal stimulus intensity required to activate a receptor and start signal transduction

A thermoreceptor primarily detects changes in temperature, but under intense mechanical pressure it may still produce a sensation. This response is possible because:
A. All receptors are mechanoreceptors by default
B. Receptors can adapt to any type of energy with repeated exposure
C. High-intensity stimuli can activate receptors even if it’s not their adequate stimulus
D. The spinal cord overrides receptor specificity in emergency situations

C. High-intensity stimuli can activate receptors even if it’s not their adequate stimulus

What is the process called that converts physical stimuli into graded potentials?
A. Amplification
B. Transmission
C. Sensory Transduction
D. Integration

C. Sensory Transduction

What type of potential is generated in a sensory receptor in response to a stimulus?
A. Action potential
B. Resting potential
C. Receptor potential
D. Synaptic potential

C. Receptor potential

Receptor potentials are most similar to which of the following?
A. Action potentials
B. Graded potentials
C. Hyperpolarizations
D. EPSPs only

B. Graded potentials

How do sensory receptors convert stimulus energy into electrical signals?
A. Through ATP hydrolysis
B. By opening or closing ion channels
C. By firing continuous action potentials
D. By increasing neurotransmitter synthesis

B. By opening or closing ion channels

What can a receptor potential directly lead to?
A. Release of hormones into the bloodstream
B. A change in DNA transcription
C. An action potential or neurotransmitter release
D. Muscle fiber contraction

C. An action potential or neurotransmitter release

In some sensory receptors, how is information passed on to a sensory neuron?
A. Through gap junctions
B. By releasing neurotransmitters
C. By phagocytosis
D. By hormone signaling

B. By releasing neurotransmitters

Which of the following best explains the concept of an "adequate stimulus" in relation to a sensory receptor such as a photoreceptor or thermoreceptor?
A. An adequate stimulus refers to the most energy-efficient stimulus that can bypass synaptic transmission and directly trigger an action potential in a primary sensory neuron, regardless of receptor type.
B. An adequate stimulus is the lowest intensity of any stimulus that is capable of depolarizing a sensory receptor to the point of neurotransmitter release.
C. An adequate stimulus is the form of energy a particular receptor is most sensitive to, even though it may respond to other forms if the stimulus intensity exceeds threshold levels.
D. An adequate stimulus is any physical or chemical change that produces an action potential when the receptor potential summates to threshold, regardless of receptor specificity.

C. An adequate stimulus is the form of energy a particular receptor is most sensitive to, even though it may respond to other forms if the stimulus intensity exceeds threshold levels.

A patient presents to the emergency room after being struck in the eye. They report seeing flashes of light despite the room being dimly lit. As a nurse, you understand this occurs because:
A. The mechanical pressure damaged photoreceptor synapses, triggering the optic nerve directly via retrograde conduction.
B. Pressure applied to photoreceptors in the retina caused them to fire, as receptors can respond to strong non-adequate stimuli, mimicking a light-induced receptor potential.
C. Mechanical deformation of the lens distorted the refraction of light, increasing visual field stimulation and triggering cortical perception of light flashes.
D. Blunt trauma led to increased cerebrospinal fluid pressure, which indirectly stimulated the optic tract and produced visual artifacts.

B. Pressure applied to photoreceptors in the retina caused them to fire, as receptors can respond to strong non-adequate stimuli, mimicking a light-induced receptor potential.

Which of the following best describes the relationship between threshold and the conversion of a physical stimulus into a neural signal during sensory transduction?
A. A stimulus reaching threshold ensures the graded receptor potential fully depolarizes the membrane, producing repetitive action potentials in all adjacent neurons to amplify the signal.
B. When a stimulus exceeds the receptor’s threshold, it opens or closes ion channels, changing membrane potential; if strong enough, this may lead to an action potential or neurotransmitter release, depending on the receptor type.
C. Threshold is the same for all sensory receptors and is determined by the number of action potentials needed to activate second-order neurons in the CNS.
D. Once the threshold is exceeded, sensory receptors bypass graded potentials and initiate a direct chemical signal to the central nervous system, independent of ion channel activity.

B. When a stimulus exceeds the receptor’s threshold, it opens or closes ion channels, changing membrane potential; if strong enough, this may lead to an action potential or neurotransmitter release, depending on the receptor type.

You are caring for a burn patient who is unable to sense temperature changes in the affected area. Which explanation best accounts for the sensory deficit, based on your understanding of thermoreceptor function?
A. The injury has likely destroyed voltage-gated sodium channels, preventing thermoreceptor synaptic activity in the dorsal root ganglia.
B. The loss of sensory function indicates that the threshold for thermoreceptors has been permanently raised beyond the ability of environmental temperature to generate a receptor potential.
C. The burn may have damaged thermoreceptor membranes, impairing ion channel function required for transducing temperature into electrical signals.
D. Thermal injury causes disruption of cerebral temperature integration centers, meaning the receptors still function, but the brain can no longer perceive the input correctly.

C. The burn may have damaged thermoreceptor membranes, impairing ion channel function required for transducing temperature into electrical signals.

A student reports that pressing on their closed eyelid causes them to see colors or flashes of light. As their nurse educator, how would you best explain this phenomenon?
A. "That’s a visual illusion created by pressure on the cornea, which alters blood flow in the retina and tricks the brain into interpreting it as light."
B. "When you apply mechanical pressure to the eye, you stretch the optic nerve and cause depolarization of its axons, which generates visual sensations."
C. "Photoreceptors in your eye are specialized to respond to light, but strong mechanical pressure can also stimulate them because receptors can respond to other forms of energy if they exceed threshold."
D. "Your brain is misinterpreting motor activity in the muscles around your eye as visual input due to crossover of sensory signals in the midbrain."

C. "Photoreceptors in your eye are specialized to respond to light, but strong mechanical pressure can also stimulate them because receptors can respond to other forms of energy if they exceed threshold."

What is a receptive field?
A. The synapse between two motor neurons
B. The region of the brain that interprets sensory input
C. The physical area where a sensory neuron responds to a stimulus
D. The pathway of blood vessels surrounding a sensory organ

C. The physical area where a sensory neuron responds to a stimulus

What happens when multiple primary sensory neurons converge onto a single secondary sensory neuron?
A. The sensitivity of the receptive field decreases
B. A larger receptive field is formed
C. The number of action potentials decreases
D. The receptive field becomes more specific

B. A larger receptive field is formed

Which of the following best explains why receptive fields often overlap?
A. To reduce the number of neurons needed
B. To prevent overstimulation of one neuron
C. To allow neurons to work together for more accurate perception
D. To allow better sleep-wake cycles

C. To allow neurons to work together for more accurate perception

Which structure is responsible for directly detecting the stimulus in a receptive field?
A. Secondary sensory neuron
B. Brainstem nucleus
C. Primary sensory neuron
D. Interneuron in the spinal cord

C. Primary sensory neuron

A touch neuron in the skin responds to pressure in a specific location. This is an example of:
A. A secondary sensory input
B. Referred pain
C. A receptive field
D. An inhibitory reflex

C. A receptive field

What does convergence in sensory neurons refer to?
A. One postsynaptic neuron sending signals to many presynaptic neurons
B. Many presynaptic neurons synapsing onto fewer postsynaptic neurons
C. Sensory input being blocked at the spinal cord
D. Motor neurons stimulating sensory receptors

B. Many presynaptic neurons synapsing onto fewer postsynaptic neurons

What is the result of increased convergence in a sensory pathway?
A. A smaller receptive field with precise localization
B. Reduced sensitivity to touch
C. A larger receptive field with decreased stimulus localization
D. Complete loss of sensory function

C. A larger receptive field with decreased stimulus localization

Why does convergence reduce the ability to precisely localize a stimulus?
A. The brain cannot detect signals from large areas
B. The signals cancel each other out
C. Multiple signals are combined into one, losing spatial specificity
D. Primary neurons stop firing

C. Multiple signals are combined into one, losing spatial specificity

Which of the following best describes the relationship between receptive field size and sensory discrimination?
A. Larger receptive fields increase sensitivity and precision
B. Smaller receptive fields allow better discrimination between stimuli
C. Receptive field size does not affect stimulus detection
D. Larger receptive fields detect weaker stimuli more accurately

B. Smaller receptive fields allow better discrimination between stimuli

A nurse is performing a neurological assessment on a patient who reports decreased sensitivity in the left forearm following a laceration injury. During the two-point discrimination test, the nurse notes that the patient can only distinguish two separate points when they are at least 45 mm apart. What is the most accurate explanation of this result?

A. The injury likely caused damage to secondary sensory neurons, reducing convergence and increasing the size of receptive fields in the forearm.
B. This area of the skin has smaller receptive fields due to high sensory innervation, which explains the poor discrimination ability.
C. The forearm normally has large receptive fields and fewer sensory neurons, so high convergence results in poor spatial resolution.
D. The ability to distinguish two points 45 mm apart indicates hyperesthesia, suggesting increased sensory sensitivity due to reduced convergence.

C. The forearm normally has large receptive fields and fewer sensory neurons, so high convergence results in poor spatial resolution.

A primary sensory neuron in the fingertip has a small receptive field and synapses onto a secondary sensory neuron with minimal convergence. What is the functional significance of this arrangement for the perception of touch?

A. This arrangement minimizes the overlap of receptive fields, making the area less sensitive to subtle changes in stimulus intensity.
B. The limited convergence results in larger receptive fields, which enhances the brain's ability to interpret vague or diffuse stimuli.
C. Small receptive fields with minimal convergence enhance spatial resolution, allowing the brain to distinguish between closely spaced tactile stimuli.
D. Because the secondary sensory neuron integrates signals from multiple large receptive fields, this area can detect light touch over a broad surface.

C. Small receptive fields with minimal convergence enhance spatial resolution, allowing the brain to distinguish between closely spaced tactile stimuli.

A patient recovering from peripheral nerve damage in the left hand is enrolled in sensory re-education therapy. The nurse is helping the patient improve two-point discrimination. Based on your knowledge of receptive fields and neural convergence, which of the following interventions would be most appropriate to enhance tactile resolution?

A. Encourage the patient to use the entire hand to explore textured objects, focusing on activating larger receptive fields through broader surface contact.
B. Limit sensory stimulation to a single area of the palm to promote convergence and increase the sensitivity of secondary sensory neurons.
C. Incorporate activities that stimulate small, localized receptive fields such as picking up small beads with fingertips to improve cortical representation.
D. Emphasize the use of firm, continuous pressure over wide areas of the skin to reinforce integration of tactile input through synaptic summation.

C. Incorporate activities that stimulate small, localized receptive fields such as picking up small beads with fingertips to improve cortical representation.

Which of the following is TRUE regarding how sensory information reaches the brain?
A. All sensory information must pass through the spinal cord before reaching the brain.
B. Sensory information never travels through cranial nerves.
C. Sensory information can enter the spinal cord and ascend to the brain.
D. Only motor information travels to the brain via ascending pathways.

C. Sensory information can enter the spinal cord and ascend to the brain.

Which of the following structures allows some sensory information to bypass the spinal cord and go directly to the brain?
A. Cerebellum
B. Cranial nerves
C. Ascending tracts
D. Autonomic ganglia

B. Cranial nerves

Sensory information that initiates autonomic reflexes is often processed at which level of the nervous system?
A. Cerebral cortex
B. Hippocampus
C. Brain stem or spinal cord
D. Basal ganglia

C. Brain stem or spinal cord

Why do some autonomic reflexes not reach conscious perception?
A. They are too weak to be detected by the nervous system.
B. They are integrated and processed at a subconscious level.
C. They involve only the muscles, not sensory receptors.
D. They are blocked by the blood-brain barrier.

B. They are integrated and processed at a subconscious level.

Regulation of blood pressure is an example of which of the following?
A. Voluntary somatic reflex
B. Conscious sensory processing
C. Autonomic reflex processed in the brain stem
D. Reflex involving only the cerebral cortex

C. Autonomic reflex processed in the brain stem

Which part of the brain receives visual information?
A. Medulla
B. Thalamus
C. Midbrain
D. Cerebellum

C. Midbrain

The medulla is responsible for receiving which types of sensory information?
A. Balance and touch
B. Sound and taste
C. Vision and smell
D. Pain and temperature

B. Sound and taste

Sensory information about balance and equilibrium is processed by the:
A. Medulla
B. Cerebrum
C. Midbrain
D. Cerebellum

D. Cerebellum

Which sensory pathway bypasses the thalamus and projects directly to the cerebrum?
A. Auditory
B. Visual
C. Gustatory
D. Olfactory

D. Olfactory

What is the main role of the thalamus in sensory processing?
A. Initiating motor responses
B. Filtering blood to the brain
C. Relaying and processing sensory information before it reaches the cerebrum
D. Controlling autonomic reflexes like breathing

C. Relaying and processing sensory information before it reaches the cerebrum

What is the perceptual threshold?
A. The minimum number of neurons required to detect a stimulus
B. The amount of time it takes to respond to a stimulus
C. The level of stimulus required to become consciously aware of a sensation
D. The maximum strength of a stimulus before it causes pain

C. The level of stimulus required to become consciously aware of a sensation

Which of the following is an example of adjusting your perceptual threshold?
A. Flinching at a sudden loud sound
B. Not noticing the feeling of your clothes on your skin after a while
C. Crying in response to pain
D. Detecting a change in light intensity immediately

B. Not noticing the feeling of your clothes on your skin after a while

The brain's ability to ignore irrelevant or repetitive stimuli is known as:
A. Amplification
B. Habituation
C. Sensitization
D. Integration

B. Habituation

Habituation occurs through inhibitory modulation primarily in which neurons?
A. Primary sensory neurons
B. Secondary and higher-order neurons in the sensory pathway
C. Motor neurons
D. Interneurons of the spinal cord

B. Secondary and higher-order neurons in the sensory pathway

What happens to sensory stimuli that fall below the perceptual threshold due to habituation?
A. They are processed more quickly
B. They are amplified in the thalamus
C. They are ignored and do not reach conscious awareness
D. They trigger reflexes without brain involvement

C. They are ignored and do not reach conscious awareness

A 45-year-old male patient is admitted after experiencing sudden dizziness, imbalance, and vomiting. Neurological assessment shows intact hearing and vision, but poor coordination and difficulty maintaining posture. No loss of consciousness is noted. Based on this presentation and your understanding of sensory integration in the CNS, which brain structure is MOST likely affected and why?

A. Midbrain, because it processes auditory and visual input that could contribute to vertigo and imbalance if disrupted.
B. Medulla oblongata, since it is involved in involuntary functions like taste and could explain vomiting due to gustatory dysfunction.
C. Cerebellum, as it receives input about balance and equilibrium, and its dysfunction often leads to ataxia and postural instability without affecting consciousness.
D. Thalamus, because it relays sensory information, and damage to it would broadly impair all sensory pathways, causing widespread symptoms.

C. Cerebellum, as it receives input about balance and equilibrium, and its dysfunction often leads to ataxia and postural instability without affecting consciousness.

Which of the following best describes the process and function of perceptual threshold modulation in the central nervous system?

A. The brain increases the frequency of action potentials in response to a strong stimulus to prevent adaptation and maintain awareness of danger.
B. Secondary and higher-order neurons in sensory pathways inhibit the transmission of repetitive or non-essential stimuli, allowing the brain to conserve energy and focus on novel inputs.
C. The spinal cord integrates all sensory information, raises the perceptual threshold, and prevents any information from reaching conscious awareness unless it is painful.
D. Sensory receptor cells adapt to external stimuli by permanently blocking neurotransmitter release, effectively preventing any further signaling to the brain.

B. Secondary and higher-order neurons in sensory pathways inhibit the transmission of repetitive or non-essential stimuli, allowing the brain to conserve energy and focus on novel inputs.

A nurse is monitoring a patient recovering from a hemorrhagic stroke in the brainstem. The patient’s blood pressure fluctuates wildly and shows delayed recovery after postural changes. Based on your knowledge of sensory processing and autonomic reflexes, what is the MOST likely reason for these symptoms?

A. The stroke affected the cerebellum, which modulates balance and posture, leading to difficulty with blood pressure stabilization due to impaired movement.
B. The stroke disrupted midbrain function, causing the thalamus to stop filtering cardiovascular stimuli and leading to an overload of sympathetic output.
C. The stroke impacted the brainstem, which directly integrates visceral sensory input and generates autonomic reflexes like baroreceptor responses that regulate blood pressure.
D. The stroke likely damaged the cerebral cortex, preventing the conscious perception of blood pressure changes and impairing the individual’s ability to respond to them

C. The stroke impacted the brainstem, which directly integrates visceral sensory input and generates autonomic reflexes like baroreceptor responses that regulate blood pressure.

What distinguishes the olfactory sensory pathway from most other sensory systems in terms of CNS integration and processing?

A. Olfactory signals bypass the thalamus and are instead processed in the medulla before reaching conscious awareness.
B. Olfactory sensory input is integrated directly in the cerebellum, which explains why smells often evoke emotional memories.
C. Unlike other sensory modalities, olfactory input bypasses the thalamus and is relayed directly to the olfactory cortex and limbic system for immediate emotional and behavioral response.
D. Olfactory stimuli are filtered through the reticular formation, allowing the CNS to modulate which smells are consciously perceived and which are ignored.

C. Unlike other sensory modalities, olfactory input bypasses the thalamus and is relayed directly to the olfactory cortex and limbic system for immediate emotional and behavioral response.

A nursing student is studying in a quiet library but becomes distracted by the persistent ticking of a nearby clock. After several minutes, they no longer notice the sound unless they focus on it directly. What neural mechanism best explains this change in perception?

A. The primary auditory cortex adapted to the stimulus by reducing action potential generation in response to mechanical input from the cochlea.
B. The medulla filtered out the repetitive stimulus as it is the main center for integrating auditory information and coordinating attention.
C. The auditory sensory neurons stopped releasing neurotransmitters after extended stimulation, resulting in complete signal suppression at the receptor level.
D. Inhibitory modulation in secondary sensory neurons led to habituation, decreasing perception of the constant auditory input by raising the perceptual threshold.

D. Inhibitory modulation in secondary sensory neurons led to habituation, decreasing perception of the constant auditory input by raising the perceptual threshold.

If all action potentials are identical in form, how does the CNS determine the modality of a stimulus?
A. By the number of action potentials generated
B. By the pathway the signal takes to the brain
C. By the shape of the action potential
D. By the duration of the stimulus

B. By the pathway the signal takes to the brain

Which of the following best describes how the CNS determines the location of a stimulus?
A. The strength of the receptor potential
B. The specific nerve fibers that are active
C. The number of receptors activated
D. The rate of neurotransmitter release

B. The specific nerve fibers that are active

The intensity of a stimulus is primarily coded by which of the following?
A. The size of the action potential
B. The frequency of action potentials and number of neurons activated
C. The neurotransmitter type released
D. The shape of the synapse

B. The frequency of action potentials and number of neurons activated

How does the CNS determine the duration of a stimulus?
A. By the length of the receptor's refractory period
B. By the frequency of neurotransmitter release
C. By the length of time action potentials are generated
D. By the speed of signal transmission

C. By the length of time action potentials are generated

Which term refers to the concept that a specific receptor is linked to a specific sensation, regardless of how it is stimulated?
A. Population coding
B. Frequency modulation
C. Labeled line coding
D. Spatial summation

C. Labeled line coding

Which of the following is TRUE about sensory receptors and modality?
A. All sensory receptors respond equally to all stimuli
B. Receptor type is not related to the modality it detects
C. Each receptor is most sensitive to a particular type of stimulus
D. The brain decodes modality based on the strength of the receptor potential only

C. Each receptor is most sensitive to a particular type of stimulus

A person perceives light when pressure is applied to their closed eye. This is best explained by which concept?
A. Population coding
B. Sensory adaptation
C. Labeled line coding
D. Receptor desensitization

C. Labeled line coding

The brain interprets a signal from a cold receptor as "cold" because:
A. The signal travels slower than other sensory signals
B. The receptor releases a specific neurotransmitter unique to cold
C. The cold receptor is linked to a specific brain region dedicated to cold perception
D. Cold receptors produce larger action potentials

C. The cold receptor is linked to a specific brain region dedicated to cold perception

How is the location of a sensory stimulus coded in the nervous system?
A. By the frequency of action potentials
B. By which receptive fields are activated
C. By the strength of the stimulus only
D. By the chemical properties of the stimulus

B. By which receptive fields are activated

Which part of the brain is highly organized according to incoming sensory signals?
A. Cerebellum
B. Brainstem
C. Sensory regions of the cerebrum
D. Occipital lobe only

C. Sensory regions of the cerebrum

What does “topographical organization” in sensory systems refer to?
A. Sensory information is stored in long-term memory
B. Neurons randomly fire to interpret the environment
C. Specific areas of the sensory cortex correspond to specific areas of the body
D. The brain ignores sensory input from small body parts

C. Specific areas of the sensory cortex correspond to specific areas of the body

Which example best illustrates the concept of a topographic map in the brain?
A. Hormone release based on blood glucose levels
B. Pain being perceived as more intense in deeper tissues
C. The somatosensory homunculus representing different body parts in specific regions of the cortex
D. Visual reflexes bypassing the cerebral cortex

C. The somatosensory homunculus representing different body parts in specific regions of the cortex

Auditory information is an exception to the general localization rule because:
A. The auditory cortex receives information from only one ear.
B. Sound stimuli do not require localization in the brain.
C. The brain uses timing differences rather than a spatial map.
D. Auditory receptors are located outside the central nervous system.

C. The brain uses timing differences rather than a spatial map.

How does the brain determine the location of a sound stimulus?
A. By identifying the pitch of the sound
B. By detecting the amplitude of the sound in one ear
C. By comparing the timing of the sound arriving at both ears
D. By the frequency of vibrations on the eardrum

C. By comparing the timing of the sound arriving at both ears

What is the primary purpose of lateral inhibition in sensory processing?

A. To increase the sensitivity of inactive neurons
B. To decrease the overall strength of the stimulus
C. To enhance contrast and improve localization of the stimulus
D. To activate all neurons near the stimulus

C. To enhance contrast and improve localization of the stimulus

When a pin presses on the skin and activates three primary sensory neurons, what happens in the secondary neurons during lateral inhibition?

A. The strongest secondary neuron activates all its neighbors
B. The secondary neuron farthest from the stimulus is most active
C. The secondary neuron closest to the stimulus suppresses the activity of its neighbors
D. All secondary neurons are equally inhibited

C. The secondary neuron closest to the stimulus suppresses the activity of its neighbors

Which of the following would most likely result if lateral inhibition did not occur?

A. More accurate perception of the stimulus location
B. Broader and less precise sensory signals
C. Decreased sensory input to the brain
D. Enhanced activation of only the most central neuron

B. Broader and less precise sensory signals

What is the main benefit of population coding in sensory processing?

A. It ensures that each stimulus activates only one receptor
B. It prevents overstimulation of sensory pathways
C. It allows multiple receptors to work together to provide richer information to the CNS
D. It reduces the number of signals sent to the brain

C. It allows multiple receptors to work together to provide richer information to the CNS

A patient with a lesion in the primary somatosensory cortex is experiencing difficulty localizing tactile stimuli on the left side of the body. Which of the following best explains why the patient has impaired stimulus localization?

A. The somatosensory cortex is organized in a topographical manner such that each cortical column processes inputs from multiple regions of the body, making it difficult to determine where the stimulus occurred without intact integration.
B. Localization of sensory stimuli relies on the brainstem’s generalized perception of spatial information, and lesions in the cortex do not influence tactile discrimination.
C. Each part of the body is mapped onto the somatosensory cortex in a predictable, organized fashion (somatotopy), and damage to a specific region impairs the brain’s ability to determine the origin of sensory input from that corresponding body part.
D. Receptive fields are randomly distributed across the cortex, and cortical lesions merely affect overall sensation intensity, not localization of stimulus.

C. Each part of the body is mapped onto the somatosensory cortex in a predictable, organized fashion (somatotopy), and damage to a specific region impairs the brain’s ability to determine the origin of sensory input from that corresponding body part.

A nurse is caring for a postoperative patient who reports sharp, localized pain at the incision site. The patient describes the pain as coming from "a single point." Which neural mechanism is most responsible for this sharp localization of pain?

A. Population coding, in which widespread receptor activation allows the brain to perceive the area affected by pain, especially when the pain stimulus is intense and activates multiple receptor fields simultaneously.
B. Convergent sensory pathways that integrate multiple sensory modalities at the spinal cord level, which enhances spatial resolution and allows the brain to filter out non-painful inputs.
C. Temporal summation in the primary sensory cortex, where the timing of action potentials determines stimulus location more accurately than receptor distribution.
D. Lateral inhibition, where the primary sensory neuron most directly stimulated by the pain suppresses neighboring secondary neurons, increasing contrast and enhancing precise stimulus localization.

D. Lateral inhibition, where the primary sensory neuron most directly stimulated by the pain suppresses neighboring secondary neurons, increasing contrast and enhancing precise stimulus localization.

A nurse is assessing a patient who suffered minor burns on their forearm. The patient is able to localize the affected area despite the sensory input coming from multiple closely spaced nociceptors. Which concept best explains the brain’s ability to process this information and pinpoint the stimulus?

A. Population coding, where multiple sensory receptors work together to provide the central nervous system with a detailed and spatially informative signal.
B. Tonic adaptation of nociceptors, which ensures continuous signaling to the cortex for spatial mapping based on constant activation.
C. Disinhibition of spinal interneurons that facilitates spatial summation of weaker stimuli to enhance area-specific detection.
D. Frequency coding, where the frequency of action potentials from a single receptor increases as a way to signal more intense or specific stimuli to the CNS.

A. Population coding, where multiple sensory receptors work together to provide the central nervous system with a detailed and spatially informative signal.

Which of the following best describes tonic receptors?
A. Rapidly adapting receptors that respond only at the beginning and end of a stimulus
B. Receptors that ignore all constant stimuli
C. Slowly adapting receptors that continue firing as long as the stimulus is present
D. Receptors that only respond to pain

C. Slowly adapting receptors that continue firing as long as the stimulus is present

An example of a tonic receptor is a:
A. Olfactory receptor
B. Baroreceptor sensing blood pressure
C. Pacinian corpuscle
D. Thermoreceptor detecting brief heat

B. Baroreceptor sensing blood pressure

What is the key characteristic of phasic receptors?
A. They fire continuously in response to a constant stimulus
B. They respond only to chemical stimuli
C. They adapt rapidly and stop firing if the stimulus remains constant
D. They are located only in the skin

C. They adapt rapidly and stop firing if the stimulus remains constant

Which of the following is an example of a sensory system that uses phasic receptors?
A. Baroreceptors in arteries
B. Thermoreceptors in skeletal muscle
C. Olfactory receptors in the nose
D. Nociceptors detecting pain

C. Olfactory receptors in the nose

Why are phasic receptors important in sensory processing?
A. They block all sensory input after a short time
B. They detect and maintain awareness of constant stimuli
C. They filter out unchanging stimuli to focus on new or essential information
D. They only respond to dangerous stimuli

C. They filter out unchanging stimuli to focus on new or essential information

Which type of neuron in the somatic sensory pathway has its cell body located in the spinal ganglion and is activated by receptors in the skin and viscera?

A. Primary sensory neuron
B. Secondary sensory neuron
C. Tertiary sensory neuron
D. Motor neuron

A. Primary sensory neuron

Where do nociception, temperature, and coarse touch pathways cross the midline of the body?

A. In the thalamus
B. In the spinal cord
C. In the cerebellum
D. In the medulla

B. In the spinal cord

What is the correct pathway for fine touch, vibration, and proprioception in terms of where the information crosses the midline?

A. Crosses in the spinal cord
B. Crosses in the medulla
C. Does not cross at all
D. Crosses in the cerebellum

B. Crosses in the medulla

The tertiary sensory neurons involved in somatic perception are located in which part of the brain?

A. Cerebellum
B. Thalamus
C. Medulla
D. Motor cortex

B. Thalamus

The organization of the somatosensory cortex is often represented by a:

A. Dermatomal map
B. Somatic reflex arc
C. Sensory homunculus
D. Corticospinal tract

C. Sensory homunculus