Term
| What are the 4 somatosensation perceptual modalities? |
|
Definition
tactile (fine touch, texture)
proprioception
thermal
pain |
|
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Term
| What receptor is tactile or cutaneous receptors? |
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Definition
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Term
| What is the main anatomical pathway for touch and proprioception? |
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Definition
|
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Term
| What is the main anatomical pathway for pain and temperature? |
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Definition
|
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Term
| Does the trigeminothalamic tract go with the STT, DC, or both? |
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Definition
both
These (STT/DC) are the face and arms, and the TTT is head; but there are components of both of these in the TTT. |
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Term
| What determines how well you discriminate between 2 areas of skin in touch, spatial resolution. |
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Definition
density of receptors/innervation
size of receptive field |
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Term
True or false:
The amount of cortex devoted to each part of the skin will vary, and will vary indirectly proportionately to density of innervation. |
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Definition
False
the amount of cortex devoted to each part of the skin will vary, and will vary DIRECTLY proportionately to density of innervation.
(the smaller the receptive fields are and the larger the density of innervation: those areas are going to have bigger representation in the = concept of homunculus) |
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Term
| What is the receptor mechanism of all our sensory systems? |
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Definition
| Transduction - takes physical property stimulus and translates it into electrical signal |
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Term
| What are the afferents in the somatosensory system? |
|
Definition
DC and STT (synapse in spinal cord with cell bodies in DRG)
TTT (CN innervation-CNV coming into CNV nucleus) |
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Term
| Does somatosensation have a nucleus in the brainstem? |
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Definition
|
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Term
| What part of the brainstem do the primary afferents from TTT end up in the DC? |
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Definition
|
|
Term
Where does the head part of the somatossensory end up in the thalamus?
body? |
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Definition
|
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Term
| Where is the primary somatosensory cortex? |
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Definition
|
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Term
| When mechanoreceptors respond to stretch or pressure, opening the channels will lead to ___________. |
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Definition
|
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Term
| What is neurotransmitter that is released onto the primary afferent? |
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Definition
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Term
| Will the superficial or deep receptors have a larger receptive field? |
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Definition
| deep (more tissues for stimulus to travel through) |
|
|
Term
| What are the 2 superficial receptors for touch? |
|
Definition
merkel's and meissner's
(both M's, earlier in alphabet) |
|
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Term
| What are the 2 deep receptors for touch? |
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Definition
|
|
Term
| How many cutaneous receptors are there? |
|
Definition
| 4 (2 superficial, 2 deep) |
|
|
Term
Rapid-adapting or slow-adapting:
Fires an action potential and then stops (signal becomes desensitized and then fades away) |
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Definition
|
|
Term
Rapid-adapting or slow-adapting:
Receptor stays on all the time |
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Definition
|
|
Term
Is the Meissner's corpuscle a superficial or deep receptor?
Is it rapid-adapting or slow-adapting? |
|
Definition
superficial
rapid-adapting |
|
|
Term
Is the Merkel cell a superficial or deep receptor?
Is it rapid-adapting or slow-adapting? |
|
Definition
|
|
Term
Is the Pacinian corpuscle a superficial or deep receptor?
Is it rapid-adapting or slow-adapting? |
|
Definition
|
|
Term
Is the ruffini ending a superficial or deep receptor?
Is it rapid-adapting or slow-adapting? |
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Definition
|
|
Term
| What is a particular area in periphery where application of adequate stimulus will cause cell to respond? |
|
Definition
|
|
Term
True or false:
For touch, a portion of skin is directly innervated by receptor terminals |
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Definition
|
|
Term
True or false:
Most sensitive areas of skin have smallest density of receptors and greatest RFs |
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Definition
False
Most sensitive areas of skin have greatest density of receptors and smallest RFs |
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|
Term
| Will the fingertips have more or less area of cortex devoted to them when compared to the back for sensitivity? |
|
Definition
|
|
Term
True or false:
Most sensory receptors are maximally sensitive to multiple stimulus energies. |
|
Definition
False
Most sensory receptors are maximally sensitive a single stimulus energy |
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|
Term
True or false:
Axons of receptors function as modality-specific line of communication between the periphery and the brain |
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Definition
|
|
Term
| What are the 2 things that proprioception monitors? |
|
Definition
| stationary body position and movement (kinesthesia-how fast we're going) |
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Term
| What are the 2 receptors in proprioception that respond to muscle stretch and tension? |
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Definition
Muscle spindles respond to muscle being stretched, elongated.
Golgi tendon organs (intrafusal fibers) responding to tension, respond when muscles contracting. |
|
|
Term
| Are the muscle spindles parallel or perpendicular to normal muscle fibers? |
|
Definition
parallel
(as muscles stretch in this direction, spindle will get stretched and will pull open mechanosenstive channels and you will get signaling) |
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|
Term
Where do the ascending touch and proprioception fibers synapse?
Where do reflex responses synapse? |
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Definition
DC nuclei in medulla
spinal cord |
|
|
Term
| What neuron is needed in order to complete a muscle stretch reflex? |
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Definition
|
|
Term
| What is the main pathway to the cortex for fine touch and proprioception? |
|
Definition
|
|
Term
| What is the main pathway to the cortex for pain and temperature? |
|
Definition
| AL (anterolateral- STT is part of it because there are other pathways that travel here) |
|
|
Term
| What are the projections to cerebellum (SCT) also known as? |
|
Definition
unconscious proprioception pathways
(Taking that information, not to conscious somatosensory cortex but directly to cerebellum.) |
|
|
Term
| Where are the primary neuron's cell body located? |
|
Definition
|
|
Term
| Is the DC/ML or STT fast? |
|
Definition
DC/ML is fast, STT is slow.
pain and temperature not as fast.
Fastest fibres are proprioceptive |
|
|
Term
Are there small or large fibers in pain and temperature sensation?
Are there small or large fibers in proprioception and touch? |
|
Definition
|
|
Term
| What are the 2 ways to classify fibers? |
|
Definition
| speed of action potential propagation and diameter |
|
|
Term
| What are the 2 ways to name fastest to slowest fibers? |
|
Definition
A to C
I to IV (I and II are fastest) |
|
|
Term
| What are proprioceptive fibers categorized from I to IV? |
|
Definition
|
|
Term
| What are pain fibers called from A to C? |
|
Definition
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|
Term
Where does touch and proprioception cross?
Where does pain temp cross? |
|
Definition
touch and proprioception (DC) stay ipsilateral until they get to the medulla and then cross over
pain and temp (STT) cross over in the spinal cord |
|
|
Term
The dorsal column is (ipsilateral or contralateral) below the medulla?
When it crosses over it forms the __________. |
|
Definition
ipsilateral
medial leminscus |
|
|
Term
| Is the gracile or cuneate fascicle involved with lower limb and trunk innervation? |
|
Definition
|
|
Term
| Is the gracile or cuneate fascicle involved with upper limb and neck? |
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Definition
|
|
Term
Where is the primary synapse for DC/ML and STT pathways?
Where is the secondary synapse? |
|
Definition
primary: DC/ML- medulla; STT-spinal cord
secondary: both in thalamus |
|
|
Term
| Where is the point of entry for the trigeminal nerve? |
|
Definition
|
|
Term
In TTT, where does touch and proprioception come in and synapse?
Where does CN V primary afferent synapse? |
|
Definition
trigeminal ganglion (equivalent to DRG)
main sensory or chief sensory nucleus of trigeminal system |
|
|
Term
| Where does pain and temperature synapse in TTT? |
|
Definition
| Fibres come in, descend and synapse in different locations within another nucleus that runs all the way into the spinal cord; nucleus is called spinal nucleus of five |
|
|
Term
| Where do we get unconscious proprioception from the jaw (keep jaw position accurate) in TTT? |
|
Definition
| mesencephalic nucleus of trigeminal system in midbrain |
|
|
Term
| In the TTT, where does STT and DC/ML come together? |
|
Definition
| pons - pontine fibers push sensory system out of the way |
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|
Term
The pathway for input from head and face:
Trigeminal input goes to main trigeminal nucleus (touch) in _____ and SN of V (pain & temp) in _________/________.
2nd order neurons’ axons cross and ascend in_______________ to Ventroposterior Medialis (VPM).
VPM projects to ____________. |
|
Definition
Trigeminal input goes to main trigeminal nucleus (touch) in pons and SN of V (pain & temp) in medulla/spinal cord
2nd order neurons’ axons cross and ascend in medial lemniscus to Ventroposterior Medialis (VPM)
VPM projects to somatosensory cortex |
|
|
Term
If you have damage to 1 side of the spinal cord, will you have deficits in touch (ipsilaterally or contra laterally)?
Is deficit in pain (ipsilateral or contralateral)? |
|
Definition
| Deficits in touch ipsilaterally, pain contralaterally |
|
|
Term
If you have damage to 1 side of the medulla, will you have deficits in touch (ipsilaterally or contra laterally)?
Is deficit in pain (ipsilateral or contralateral)? |
|
Definition
| Deficits in touch and pain both contralaterally |
|
|
Term
The VPM is to the head or legs/arms?
The VPL is to the head or legs/arms? |
|
Definition
VPM-head
VPL-legs and arms |
|
|
Term
| In primary somatosensory cortex (post central gyrus), where are the legs, body, arms? |
|
Definition
Legs buried in midline.
Body and arms and head follow laterally on the top surface |
|
|
Term
| What are cortical columns produced by? |
|
Definition
| intracortical synaptic connectivity |
|
|
Term
| What are responsible for for input and output to cortex as well as cortico-cortical connections? |
|
Definition
| different cortical layers (within a column, information type is the same) |
|
|
Term
| What are two changes that show that there is human brain plasticity at the level of the cortex? |
|
Definition
Changes due to arm amputation (Ramachandran)
-Cortical face area expanded into arm area
-Phantom limb, pain?
Changes due to increased use
e.g., increased cortical representation of fingers of stringed instrument players |
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