Lecture Exam 5 - Sensory Pathways and the Somatic Nervous System

Which type of sensory receptor is primarily sensitive to temperature changes?

Thermoreceptors

Which sensory pathway is responsible for carrying sensations of fine touch and proprioception?

Posterior column pathways

Which category of general sensory receptors responds to changes in chemical concentrations?

Chemoreceptors

Which statement about thermoreceptor adaptation is most accurate?

Adapts quickly to stable, non dangerous temperatures.

How does the size of a receptive field influence the localization of a stimulus?

Large receptive fields make stimulus localization more difficult.

Which motor neuron's axon extends outside the CNS to directly innervate skeletal muscle?

Lower motor neuron

What is the primary function of sensory receptors in the nervous system?

convert stimuli into action potentials for the CNS

Which sensory receptors communicate with sensory neurons across chemical synapses?

Receptors for gustation, vision, equilibrium, and hearing.

Which type of sensory receptor monitors the internal environment of the body?

interoceptors, which is within the visceral organs.

Which motor pathway is primarily responsible for providing voluntary control over skeletal muscles?

The corticospinal pathway, starting in the primary motor cortex.

What is the underlying cause of the abnormal increase in general muscle tone seen in Parkinson's disease?

Low dopamine production, normally inhibits the basal nuclei.

What unique characteristic distinguishes the spinocerebellar pathway from other sensory pathways?

Its information does not reach conscious awareness in the cerebrum.

What is a key difference between fast pain and slow pain signals?

Fast pain is carried by type A fibers; slow pain by type C fibers.

Which statement accurately describes the characteristics of nociceptors?

free nerve endings with large receptive fields detecting pain.

What is the main role of the medial pathway in somatic motor control?

helps control subconscious movement and muscle tone of the trunk.

What phenomenon describes the reduction in stimulus perception when a stimulus is constant?

Sensory adaptation, decreasing receptor activity.

Which of the following is considered a general sense as opposed to a special sense?

Proprioception (monitors body position)

What is the primary function of the cerebellum in coordinating muscle movements?

it maintains equilibrium and inhibits motor outputs for precise movements.

What process converts an arriving stimulus into an electrical signal the brain can understand?

transduction, which creates an action potential.

What neurological condition is characterized by the degeneration of both upper and lower motor neurons?

ALS, causing muscle atrophy.

Where are thermoreceptors, responsible for detecting temperature changes, primarily located?

In the dermis, skeletal muscle, liver and hypothalamus.

What is the fundamental difference between sensation and perception in sensory pathways?

Sensation is information arriving at the CNS, perception is its own interpretation.

What type of mechanoreceptor detects pressure changes in blood vessels and organs?

Baroreceptors, responding to stretch and internal pressure.

Which of the following describes the function of mechanoreceptors?

They respond to physical stimuli that distort cell membranes.

What is the consequence of interneurons decussating in the spinothalamic pathway?

Sensations from one side of the body are perceived by the opposite brain side.

What characteristic of sensory receptors ensures they respond to a specific type of stimulus?

Their inherent and unique receptor specificity.

What is the primary function of the solitary nucleus in the medulla oblongata?

It processes and sorts visceral sensory information.

How do basal nuclei contribute to the coordination of muscle contractions?

They adjust and modify voluntary commands, setting rhythms.

Which phenomenon involves feeling pain in an uninjured body part when pain originates elsewhere?

Referred Pain