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WorksheetsTouch and Proprioception
Total questions: 15
Worksheet time: 8mins
A 20-year-old male presented to the neurology clinic with a progressive gait disturbance, limb coordination difficulties, and muscle weakness. His medical history revealed a family history of similar symptoms, suggesting a genetic etiology. Neurological examination demonstrated signs of cerebellar dysfunction, including dysarthria and impaired coordination of voluntary movements. Genetic testing confirmed the diagnosis of Friedreich's ataxia. What is the dysfunctional mechanism of this patient's condition at the cellular level?
Increased frataxin protein levels causing dysfunction in DNA transcription
Trinucleotide repeat expansion in the FXN gene resulting in dysfunction of the endoplasmic reticulum
Reduced frataxin protein levels causing mitochondrial dysfunction
Upper and lower motor neuron lesions due to autoimmune destruction of neurons
Improved coordination of voluntary movements due to enhanced frataxin gene expression
Where would the cell body of a sensory neuron that transmits touch information from the cheek to the central nervous system be located?
Ganglion alongside the brainstem
Nucleus inside the brainstem
Ganglion alongside the spinal cord
Nucleus inside the spinal cord
Ganglion immediately underneath the skin of the cheek
Afferent fibers that lack specialized receptors at their terminals detect which type of stimuli?
Touch
Vibration
Pressure
Pain
Stretch
Which type of somatosensory afferents transmit information from touch mechanoreceptors to the central nervous system?
Aβ
Aδ
C
D
On which body part would the two-point discrimination threshold be shortest?
Thigh
Foot
Arm
Thumb
Ear
A dermatome is an area innervated by:
fibers of the cells from a single dorsal root ganglion.
the axon of a single neuron.
fibers with similar properties.
fibers of the cells from a single nucleus in the brain stem.
Which afferents have the highest spatial resolution?
Meissner
Pacinian
Merkel
Ruffini
Pain
Merkel afferent fibers convey information about which variable(s)?
Motion detection
Temperature
Proprioception
Shape and texture
Subtle vibrations
The axons of the medial lemniscus synapse with neurons of the
primary sensory cortex
thalamus
gracile nucleus
cuneate nucleus
dorsal root ganglion
Which feature is characteristic of the pseudounipolar neurons of the somatosensory system?
Central and peripheral components of the fibers are of a similar length
Thick fibers that enables fast signal transduction
Fibers with particularly high myelin content
Continuous fibers, with the cell body attached by a single process
Multiple dendrites
Which component of the musculoskeletal system is responsible for force-production?
Muscle spindle
Intrafusal muscle fiber
Extrafusal muscle fiber
Sensory afferents
Connective tissue capsule
Which role do γ motor neurons play in the function of a muscle spindle?
They improve the accuracy of the reported sensory information by innervating extrafusal fibers.
They improve the accuracy of the reported sensory information by innervating intrafusal fibers.
They enhance the force of muscle contraction by innervating extrafusal fibers.
They enhance the force of muscle contraction by innervating intrafusal fibers.
They coordinate the contraction of extrafusal and intrafusal fibers.
Tactile information from the face to the central nervous system follows which pathway?
Cutaneous receptors, trigeminal ganglion, pons, VPL of thalamus, ipsilateral cortex
Cutaneous receptors, trigeminal ganglion, trigeminal brainstem complex, VPL of thalamus, contralateral cortex
Cutaneous receptors, cranial nerve V, trigeminal brainstem complex, VPM of thalamus, contralateral cortex
Cutaneous receptors, dorsal root ganglion, trigeminal brainstem complex, VPM of thalamus, ipsilateral cortex
Cutaneous receptors, dorsal root ganglion, dorsal column nuclei, VPM of thalamus, cortex
Functional reorganization in the brain
occurs at all ages, all of the time.
occurs after nerve damage, amputation, and skill training.
results in a temporary loss of sensory input.
occurs only during the first ten years of life.
occurs only in the cortex.
A 6-year-old boy was brought to the pediatric clinic by his parents due to concerns about his social interaction and communication skills. The child exhibited repetitive behaviors, such as hand flapping and rocking, and had difficulty maintaining eye contact with others. Clinical evaluation revealed delays in speech and language development, along with sensory sensitivities to certain stimuli. What is this patient's likely diagnosis?
