Exam 5: Lecture 76: Neurophysiology 2

Question 1

Which proprioceptive receptor is primarily responsible for detecting muscle stretch?
A. Golgi tendon organ
B. Muscle spindle
C. Ruffini’s corpuscle
D. Pacinian corpuscle

Answer 1

B

Question 2

The primary pathway for conscious proprioception in animals is:
A. Anterolateral system
B. Dorsal Column-Medial Lemniscal (DCML) system
C. Spinocerebellar tract
D. Corticospinal tract

Answer 2

B

Question 3

What clinical sign would indicate a general proprioceptive deficit in a dog?
A. Knuckling of the paw
B. Paralysis
C. Hyperalgesia
D. Shortened stride

Answer 3

A

Question 4

The functional difference between Pacinian corpuscles and Merkel discs is:
A. Pacinian corpuscles sense deep pressure, while Merkel discs sense fine touch.
B. Pacinian corpuscles detect stretch, while Merkel discs detect temperature.
C. Both detect vibration but in different frequency ranges.
D. Pacinian corpuscles are non-adaptive, while Merkel discs are rapidly adaptive.

Answer 4

A

Question 5

The sensation of deep pain is best assessed by:
A. Hemiwalking test
B. Response to a pinprick
C. Flexion withdrawal reflex
D. Application of deep pressure to the limb

Answer 5

D

Question 6

Which type of receptor mediates thermal pain in response to extreme heat?
A. TRPV1 channels
B. TRPM8 channels
C. Ruffini endings
D. Mechanoreceptors

Answer 6

A

Question 7

Allodynia refers to:
A. An exaggerated response to a painful stimulus.
B. Pain in response to a non-painful stimulus.
C. Reduced sensitivity to a painful stimulus.
D. Pain resulting from nerve damage.

Answer 7

B

Question 8

Hyperalgesia is caused by:
A. Increased central sensitization to pain.
B. Diminished receptor sensitivity to noxious stimuli.
C. Inhibition of nociceptive pathways.
D. Reduced synaptic activity in the thalamus.

Answer 8

A

Question 9

Proprioceptive placing can be tested by:
A. Observing the animal’s gait on a leash.
B. Gently lifting a paw and observing correction.
C. Using a pinprick on the distal limb.
D. Performing a hemiwalking test.

Answer 9

B

Question 10

In the case of a unilateral lesion affecting the DCML pathway in the spinal cord, you would expect:
A. Ipsilateral loss of proprioception.
B. Contralateral loss of proprioception.
C. Ipsilateral loss of pain and temperature sensation.
D. Contralateral loss of pain and temperature sensation.

Answer 10

A

Question 11

The spinocerebellar tracts primarily carry:
A. Conscious proprioceptive signals.
B. Subconscious proprioceptive signals.
C. Pain and temperature signals.
D. Tactile signals for fine touch.

Answer 11

B

Question 12

Which tract primarily carries nociceptive signals to the brain?
A. Dorsal column-medial lemniscus
B. Spinothalamic tract
C. Spinocerebellar tract
D. Vestibulospinal tract

Answer 12

B

Question 13

Endogenous opioids modulate pain by:
A. Blocking the activity of substance P.
B. Enhancing excitatory neurotransmission.
C. Directly hyperpolarizing nociceptive neurons.
D. Attenuating the effect of prostaglandins.

Answer 13

A

Question 14

The term “knuckling” in veterinary neurology refers to:
A. Loss of postural control in the distal limb.
B. Hyperextension of the metacarpophalangeal joints.
C. Failure to flex the carpal joint.
D. Muscle spasticity in the forelimb.

Answer 14

A

Question 15

Nociceptive signals are modulated in the spinal cord by:
A. Presynaptic inhibition in the dorsal horn.
B. Cortical input to motor neurons.
C. Excitatory interneurons in the ventral horn.
D. Thalamic relay neurons.

Answer 15

A

Question 16

Ataxia associated with proprioceptive deficits results from dysfunction in:
A. Upper motor neurons.
B. Sensory pathways detecting limb position.
C. Golgi tendon organ signals.
D. Corticospinal motor tracts.

Answer 16

B

Question 17

Hypermetria, as seen in cerebellar dysfunction, is best described as:
A. Overreaching movements.
B. Lack of coordination in limb placement.
C. Reduced stride length.
D. Loss of fine motor control.

Answer 17

A

Question 18

In animals, tactile placing requires the functional integration of:
A. Muscle spindles and descending motor pathways.
B. Mechanoreceptors and proprioceptive pathways.
C. Visual input and vestibular signals.
D. Nociceptive and motor tracts.

Answer 18

B

Question 19

Which of the following gait abnormalities is characteristic of cerebellar ataxia?
A. Shortened stride
B. Hypermetria
C. Knuckling
D. Circling

Answer 19

B

Question 20

Proprioceptive deficits are most effectively assessed using:
A. Wheelbarrow test
B. Pain withdrawal reflex
C. Deep tendon reflexes
D. Visual observation of the gait alone

Answer 20

A

Question 21

A dog presents with a hemistand deficit and exaggerated proprioceptive placing on the left side. The lesion is most likely located in:
A. The left cerebellum
B. The right cerebral cortex
C. The left cervical spinal cord
D. The right lumbar spinal cord

Answer 21

C

Question 22

Which of the following best describes the mechanism of allodynia?
A. Activation of TRPV1 channels by normal temperature stimuli
B. Altered central processing of non-noxious stimuli as painful
C. Enhanced activity of peripheral nociceptors due to inflammation
D. Increased threshold for activation of sensory neurons

Answer 22

B

Question 23

Hyperalgesia develops primarily due to:
A. Peripheral sensitization of nociceptors
B. Reduced conduction velocity in A-delta fibers
C. Loss of inhibitory interneurons in the spinal cord
D. Decreased endogenous opioid activity

Answer 23

A

Question 24

The flexor withdrawal reflex primarily involves:
A. Descending motor control pathways
B. Polysynaptic circuits in the spinal cord
C. Proprioceptive feedback to the cerebellum
D. Corticospinal tract inhibition

Answer 24

B

Question 25

Which of the following is NOT a characteristic of deep pain sensation?
A. It is mediated by unmyelinated C fibers.
B. Loss of deep pain indicates severe spinal cord injury.
C. It can be tested using gentle tactile stimulation.
D. It involves connections to the limbic system for emotional response.

Answer 25

C

Question 26

Lesions affecting the rubrospinal tract would primarily result in:
A. Loss of postural reflexes in the hind limbs.
B. Deficits in voluntary movement of distal limbs.
C. Hyperextension of the forelimbs.
D. Loss of pain and temperature sensation.

Answer 26

B

Question 27

The corticospinal tract contributes most significantly to:
A. Fine motor control of the limbs.
B. Postural adjustments via reflex pathways.
C. Subconscious proprioceptive feedback.
D. Integration of visceral sensory signals

Answer 27

A

Question 28

Which descending pathway is most critical for maintaining upright posture?
A. Corticospinal tract
B. Vestibulospinal tract
C. Spinothalamic tract
D. Rubrospinal tract

Answer 28

B

Question 29

A dog displays contralateral loss of pain sensation and ipsilateral proprioceptive deficits. This suggests a lesion in the:
A. Brainstem
B. Cerebral cortex
C. Spinal cord
D. Thalamus

Answer 29

C

Question 30

The primary sign of a lesion in the medial lemniscus is:
A. Contralateral loss of fine touch and proprioception
B. Ipsilateral loss of pain and temperature sensation
C. Contralateral loss of motor control
D. Bilateral loss of autonomic reflexes

Answer 30

A

Question 31

An animal with damage to the vestibulocochlear nerve may display:
A. Inability to maintain posture during head movement
B. Proprioceptive deficits in the hind limbs
C. Hyperalgesia and allodynia
D. Absence of nociceptive reflexes

Answer 31

A

Question 32

The thalamus is crucial for:
A. Generating motor reflexes
B. Filtering and relaying sensory information to the cortex
C. Modulating spinal reflex arcs
D. Initiating voluntary movements

Answer 32

B

Question 33

Which statement best explains the function of the spinothalamic tract?
A. It carries proprioceptive information to the cerebellum.
B. It transmits nociceptive and thermal signals to the thalamus.
C. It mediates fine touch and vibration sensation.
D. It integrates sensory and motor feedback.

Answer 33

B

Question 34

Ipsilateral deficits in proprioception and contralateral loss of pain sensation are consistent with a lesion in:
A. The cerebellum
B. The spinothalamic and dorsal column pathways of the spinal cord
C. The medial longitudinal fasciculus
D. The corticospinal tracts

Answer 34

B

Question 35

Which proprioceptive test specifically evaluates tactile placing?
A. Observing limb correction after misplacement
B. Wheelbarrow test with blindfold
C. Spinal reflex testing
D. Extensor thrust during a hop

Answer 35

A