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A&P1 - Chapter 15
Sensory Pathways and The Somatic Nervous System
Question | Answer |
---|---|
Define general senses | temperature, pain, touch, pressure, vibration and proprioception NOT taste |
List the special senses | smell, taste, balance, hearing, vision, sensations provided by specialized receptor cells NOT pressure |
The ___ sense involve receptors that are relatively simple in structure | general |
In order for a sensation to become a perception, it must be received by | somatosensory cortex |
What things 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/tissues that shield receptors from other stimulus |
Examples of sensory stimuli include | touch, pain, vibration and warmth |
What is central adaptation? | inhibition of nuclei located along a sensory pathway |
Peripheral adaptation ____ the number of action potentials that reach the CNS | decreases |
A receptor that contains many mechanically-gated ion channels would function best as a | tactile receptor |
A mechanoreceptor in the papillary layer of the dermis that responds to fine touch is a | tactile (Meissner) corpuscle |
What is "prickling pain"? | fast pain |
Endorphins can reduce perception of sensations initiated by | nociceptors |
Describe thermoreceptors | found within dermis, free nerve endings, "cold" are structurally indistinguishable from "warm" and more numerous for cold |
Receptors that monitor the position of joints belong to the category called | proprioreceptors |
Mechanoreceptor 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 |
Sensations of burning or aching pain can cause a generalized activation of the ____ | reticular formation and the thalamus |
Bladder fullness is to ___ as blood pH is to ___ | baroreceptors, chemoreceptors |
A fast-adapting tactile receptor that monitors movements across the body surface is a | root hair plexus |
We are constantly bombarded by a variety of stimuli inside and outside of our bodies. Why are we not overwhelmed by sensory info? | a very tiny percentage of incoming sensory info is received by the cerebral cortex |
Mechanoreceptors might detect what kinds of sensations? | pressure, touch, vibration and muscle length |
Pain is to ____ as cold is to ____ | nociceptors, thermoreceptors |
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 | cold |
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 ____ pain | referred |
Use Figure 15-1 Spinothalamic Tracts Identify the neuron labeled "3" | second order neuron |
Use Figure 15-1 Spinothalamic Tracts Where in the spinal cord is the structure labeled "2" located? | anterior white column |
Use Figure 15-1 Spinothalamic Tracts Identify the neuron labeled "1" | first order neuron |
Use Figure 15-1 Spinothalamic Tracts Identify the structure labeled "5" | thalamus |
Use Figure 15-1 Spinothalamic Tracts Which of the following is TRUE regarding the structure labeled "6"? | #3 the third-order neuron projects to the primary sensory cortex and #4 the third-order neuron's axon is identified |
Use Figure 15-1 Spinothalamic Tracts Which structure conducts action potentials directly from a sensory receptor? | #1, first-order neuron |
Use Figure 15-1 Spinothalamic Tracts Which ascending tract carries the sensations for fine touch and vibration? | posterior (dorsal) column |
Use Figure 15-1 Spinothalamic Tracts Identify the type of info that travels along the structure labeled "2" | pressure and touch sensations |
The descending spinal tract that crosses to the opposite side of the body within the cord is the ____ tract | anterior cortispinal |
The spinal tract that normally plays a role in the subconscious regulation of the muscles of the arms is the _____ tract | rubrospinal |
Descending (motor) pathways always involve at least ____ motor neuron(s) | 2 |
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 ____ tract provides subconscious regulation of balance and muscle tone and is part of the ___ pathway | vestibulospinal, medial |
The ____ tract provides subconscious regulation of upper limb muscle tone and movement and is part of the ___ pathway | rubrospinal, lateral |
Describe the functions of the cerebellum | functions to maintain proper posture and equilibrium, receives input from the motor cortex and basal ganglia, compares intended movement to actual movement and if damage leads to uncoordinated and jerky movements |
Based on the motor homunculus, which of the following body regions has the FEWEST number of motor unites involved? | back trunk |
Complex motor activities such as riding a bicycle require | the coordinated activity of several regions of the brain |
A brain injury to a patients results in facial paralysis. Which descending tract is most likely affected? | corticobulbar tract |
Damage to the pyramidal cells of the cerebral cortex would directly affect | voluntary motor activity |
Motor neurons whose cell bodies are within the spinal cord are called ____ neurons | lower motor |
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 |
Use Figure 15-2 The Corticospinal Pathway Identify the origin of the axon labeled "2" | upper motor neuron |
Use Figure 15-2 The Corticospinal Pathway The axon labeled "2" synapses with which structure? | #5, spinal cord |
Use Figure 15-2 The Corticospinal Pathway Identify the structure labeled "5" | ventral root |
Use Figure 15-2 The Corticospinal Pathway What occurs in this neural pathway at label "3"? | decussation |
Use Figure 15-2 The Corticospinal Pathway Identify the structure labeled "1" | primary motor cortex |
Use Figure 15-2 The Corticospinal Pathway Identify the type of info that travels along the structure labeled "4" | motor commands to skeletal muscles |
The heart is a ___ effector | visceral |
Sensory info from all parts of the body is routed to | the somatosensory cortex |
The ___ is the area monitored by a single receptor cell | receptor field |
The conversion of a sensory input to a change in membrane potential in the receptor is known as | transduction |
Sensory neurons that adapt quickly are called ___ receptors | phasic |
A reduction in sensitivity in the presence of a constant stimulus is referred to as | adaptation |
Sensory neurons that are always active are called ___ receptors | tonic |
___ provides info about the intensity, duration, location and modality of a sensory stimulus | sensory coding |
Why is it that one CANNOT identify the location of internal organs, although joints and bone location CAN be identified? | the internal organs have no proprioceptors like joints, bones and muscles |
The sense of proprioception passes along the ___ pathway | spinocerebellar |
Feeling pain in the left arm during a heart attack is an example of ___ pain | referred |
In the spinothalamic pathway, the sensory neuron that synapses with a neuron in the cerebral cortex is called the ___ neuron | third order |
Ascending tracts in the spinal cord relay ___ info | sensory |
In the corticospinal pathway, the neuron that exits the spinal cord and enters the spinal nerve is called the ___ neuron | lower motor |