The term general senses refers to sensitivity to all of the following, except
Taste
Which of the following is not one of the special senses?
Vibration
The general senses
Involve receptors that are relatively simple in a structure
Which of the following can contribute to receptor specificity?
The structure of the receptor cell, characteristics of the receptor cell membrane, accessory cells that function with the receptor, and accessory structures and tissues that shield the receptors from other stimuli
Sensory transduction can involve which of the following?
A stimulus altering the permeability of a receptor membrane, change in the flow of ions across the sensory membrane,the production f a receptor potential, and inhibition of neurotransmitter release
Central adaptation refers to
Inhibition of nuclei located along a sensory pathway
Our perception of our environment is imperfect for all of the following reasons, except that
Receptors respond in an all-or-nothing manner.
Which of the following is sometimes called “prickling pain”?
Fast pain
Endorphins can reduce perception of sensations initiated by
Nociceptors
Thermoreceptors
Are found within the dermis, are free nerve endings, and for “cold” are structurally indistinguishable from those for “warm”
A receptor that contains many mechanically gated ion channels would function best as a
Tactile receptor
A fast-adapting mechanoreceptor in the papillary layer of the dermis that responds to fine touch is a
Tactile (meissner) corpuscle
Receptors that monitor the position of joints belong to the category called
Proprioceptors
Mechanoreceptors that respond to changes in blood pressure are called
Baroreceptors
Tactile receptors composed of capsules that surround a core of collagen fibers intertwined with dendrites are called
Ruffini corpuscles
A tactile receptor composed of highly coiled dendrites that are surrounded by modified Schwann cells and a fibrous capsule is a
Tactile (Meissner) corpuscle
A very large, fast-adapting tactile receptor that is composed of a single dendrite enclosed by concentric layers of collagen is a
Lamellated corpuscle
A highly sensitive tactile receptor composed of dendritic processes of a single myelinated fiber that makes contact with specialized cells of the stratum germinativum is a
Tactile (merkel) disc
A fast-adapting tactile receptor that monitors movements across the body surface is a
Root hair plexus
Which of the following kinds of information do fine-touch and light-pressure mechanoreceptors provide?
Location, shape, texture, and movement of the stimulus
Which of the following is not a property of thermoreceptors?
Tonic response to temperature change
Chemoreceptors are located in all of the following, except
In the skin
Which ascending tract carries the sensations for fine touch and vibration?
Posterior (dorsal) column
The spinal tract that carries sensations from proprioceptors to the CNS is the
Spinocerebellar
The spinal tract that relays information concerning pain and temperature to the CNS is the
Lateral spinothalamic
The spinal tract that relays information concerning crude touch and pressure to the CNS is the
Anterior spinothalamic
Each of the following is an ascending tract in the spinal cord, except the
Reiculospinal tract
The afferent neuron that carries the sensation to the CNS is a ________ neuron.
First-order
Examples of sensory modalities include
Touch, warmth, smell, and vibration
Thalamic neurons that project to the primary sensory cortex are ________ neurons.
Third-order
Only about ________ percent of the information provided by afferent fibers reaches the cerebral cortex and our awareness.
1
Neurons from the nucleus gracilis
Decussate before entering the medial lemniscus.
We can localize sensations that originate in different areas of the body because
Sensory neurons from specific body regions project to specific cortical regions
The descending spinal tract that crosses to the opposite side of the body within the cord is the ________ tract
Anterior corticospinal
The descending spinal tract that crosses to the opposite side of the body within the medulla oblongata is the ________ tract.
Lateral corticospinal
The spinal tract that normally plays a minor role in the control of the distal muscles of the arms is the ________ tract
Rubrospinal
The spinal tract that unconsciously maintains balance and muscle tone is the ________ tract
Vestibulospinal
The medial pathway that controls involuntary movements of head, neck, and arm position in response to sudden visual and auditory stimuli is the ________ tract
Tectospinal
The pyramidal system provides
Voluntary control over skeletal muscles
The corticospinal system is often referred to as the
Pyramidal system
The area of the motor cortex that is devoted to a particular region of the body is proportional to the
Number of motor units in that region
Axons of the corticobulbar tract terminate in the
Motor nuclei of cranial nerves
Based on the motor homunculus, which of the following body regions has the largest motor units?
Back
The pyramids on the ventral surface of the medulla oblongata are formed by fibers of the ________ tracts
Corticospinal
Axons that decussate between the pyramids of the medulla oblongata belong to the ________ tracts.
Lateral corticospinal
The upper motor neurons of the medial pathway are located within any of the following, except the
Mamillary bodies
Tracts of the lateral and medial pathways include all of the following, except ________ tracts.
Cortiospinal
A brain injury to a patient results in facial paralysis. Which descending tract is most likely affected?
Corticobublbar tract
The basal nuclei
Provide the background patterns of movement involved in voluntary motor activities
Complex motor activities such as riding a bicycle
Require the coordinated activity of several regions of the brain
Damage to the pyramidal cells of the cerebral cortex would directly affect
Voluntary motor activity
The cerebellum adjusts motor activity in response to all of the following, except
Touch sensations
Motor neurons whose cell bodies are within the spinal cord are called ________ neurons.
Lower motor
Which ascending tract carries the sensations for fine touch and vibration?
Posterior (dorsal) column
Some neurons within the basal nuclei are known to
Inhibit neurons with GABA and stimulate neurons with acetylcholine
Visceral sensory information enters the CNS on afferent fibers within
Cranial nerves V, VII, IX, and X, dorsal root T1 and L2, S2 to S4
Mechanoreceptors might detect which of the following sensations?
Pressure, touch, vibration, and muscle length
If a friend is talking about someone she knows who lost his special senses, you would correct her when you hear her mention ________, because it is not a special sense.
It must received by the somatosensory cortex
Gustatory receptors are sensitive to dissolved chemicals but insensitive to light. This is due to
Receptor specificity
A receptor potential may
Increase and decrease neurotransmitter release, and hyper polarization and depolarization
Sensory information that arrives at the CNS is routed according to the ________ of the stimulus
Modality and location
Pain is to ________ as cold is to ________.
Nociceptors; thermoreceptors
Peripheral adaptation ________ the number of action potentials that reach the CNS
Decreases
Tickle is to ________ as itch is to ________.
Touch; pain
Tactile discs are to ________ as tactile corpuscles are to ________.
Merkel;Meissner
________ are receptors in the aorta that monitor the blood pressure
Baroreptors
Your uncle was just diagnosed with a heart attack. One of his major symptoms is left arm pain. You are not surprised because you are familiar with the phenomenon of
Referred pain
Descending (motor) pathways always involve at least ________ motor neuron(s).
2
Conscious and subconscious motor commands control skeletal muscles by traveling over the
Corticospinal pathway, medial and lateral pathway
The medial and lateral motor pathways can modify, or direct, skeletal muscle contractions by ________ lower motor neurons.
Stimulating, facilitating, inhibiting
The cerebellum relies on information from
The eyes, the inner ear as movements are under way, proprioceptive sensations, and motor commands from upper motor neurons
________ is a rare condition in which the brain fails to develop at levels above the mesencephalon or inferior part of the diencephalon.
Anencephaly
The labeled line is
A link between a receptor and a cortical neuron
________ receptors are ________ times more numerous than ________ receptors
Cold; 3 or 4; warm
In relation to the medial and lateral pathways, the ________ pathway controls ________ movements of trunk and ________ limb muscles.
Medial; gross; proximal
In relation to the medial and lateral pathways, the ________ pathway controls ________ movements of ________ limb muscles.
Lateral; precise; distal
A sensory receptor characterized peripherally as a free nerve ending and centrally uses glutamate and/or substance P as neurotransmitters, would most likely be a
Nociceptor
Sensory encoding of the perceived location of a stimulus depends on
The specific location of the cortical neuron that is stimulated
Destruction of or damage to a lower motor neuron in the somatic nervous system produces
Flaccid paralysis of its muscle fibers (motor unit)
All of the following are true of a prickling pain sensation, except that they
Are fast adapting.
Sensations of burning or aching pain
Cause a generalized activation of the reticular formation and the thalamus.
What loss would result from cutting through the medial lemniscus on the right side?
Loss of fine touch sensation on the left side of the body
Stimulation of a neuron that terminates in the superior region of the left postcentral gyrus would produce
A sensation in the right leg
Upper motor neurons are located in the
Precentral gyrus and spinal cord
Somatic sensory axons enter the ventral root and usually ascend directly to the thalamus
Both parts of the statements are false
Which of the following is true about the relation between stimulus intensity and its neural representation
Strong stimuli produce large generator potentials in sensory potentials and high frequency of action potentials in sensory afferents
Damage to the tectospinal tracts would interfere with the
Ability to make reflex responses of the head and neck in response to sudden movements or loud noises
Bladder fullness is to ________ as blood pH is to ________.
Baroreceptors; chemoreceptors
If the primary motor cortex is destroyed, fine control of movement will be lost, but movement may not be lost completely because the medial and lateral pathways can still provide coarse motor control.
Both parts are true
