Somatosensory Systems & Long Tracts

Stereognosis

What category of input does the ability to use touch & proprioception info to identify object fall under? … (happens at the cortical level) dealing w /sensation and aids in multitasking

Receptors

What structure are modified versions of a cell, capable of producing neurotransmitters /sending a AP?

Gamma motor neurons

What type of receptor help your muscles stay calibrated, to preform accordingly?

2nd Order Neuron

Which order neuron synapses in spinal cord, starts in the dorsal horn and goes up to the thalamus (in most tracts)?

Proprioceptive and movement

Tracts that travel in the Anterior Lateral Pathway transmit information related information what to the cerebellum? (accurate but subconscious) → adjustments to movement and posture.

Cuneocerebellar

Which high fidelity pathway transmits info from the arms and upper half of the body regarding information of muscle for movement planning?

Afferents

What type of fibers are classified according to axon diameter: 1a, 1b, 2 or A (beta), A (gamma), C?

Chemoreceptors

Which type of receptor responds to substances released by cells, including damaged cells after injury or infection?

Dorsal Column Medial lemniscal

Which ascending tract transmits discriminative touch, proprioception, vibration, 2 pt discrimination to consciousness?

touch, pressure, vibration

Cutaneous receptors respond to _______, ______ , ________, stretch, noxious stimuli, pain and temperature.

Unconscious Relay Tract

What category of tracts adjusts movements in size strength by utilizing sensory info & proprioception?

Spinocerebellar

Which ascending tract relays information about muscle tension, limb position …planning for movements?

1a ( A-alpha)

Which type of afferent fiber is the largest and heavily myelinated, prevalent in areas that need quick reactions…maximum speed= milliseconds (ex: mechanoreceptors)?

Nociceptors

Which type of receptor (subset of somatosensory receptors) does stimulation results in the sensation of pain…activated when cell damage /death might occur?

High fidelity transmission

What is is the characteristic of tract that provides accurate details regarding location of stimulation?

Phasic Receptors

Which type of sensory receptor ADAPTS to the stimulus, meaning that after a while the stimulus will still be there but not as apparent to the you?

Muscle spindles

Which type of muscle receptor responds to quick and prolonged stretches…more about time, aids in stretching and passive movement?

spinal cord

Proximal axon: project the message from the cell body into the ________ /brainstem.

Somatosensation

What is the processing of sensory information from the skin and information from the musculoskeletal systems?

Sensory

What is it when it is categorized as when looking at the impulses generated from the original stimuli?

Tonic Receptors

What type of sensory receptors DO NOT adapt to the stimulus?

Tonic Receptor

What type of sensory receptor is a a photoreceptor, mechanoreceptor, chemoreception (can me overridden, just turn on/off)?

Phasic Receptors

What type of sensory receptor ADAPTS to the stimulus, meaning that after a while the stimulus will still be there but not as apparent to the you?

Mechanoreceptors

What type of receptor responds to touch, pressure, stretch or vibration (goes into the Dorsal Column/Medial Lemniscus pathway)?

Chemoreceptors

What type of receptor responds to substances released by cells, including damaged cells after injury or infection?

Thermoreceptors

What type of receptor responds to a change in temperature, hot or cold?

Nociceptors

What type of receptor is a subset of somatosensory receptors, and stimulation results in the sensation of pain…activated when cell damage/death might occur?

Mechanoreceptors & Nociceptors

___________ are stimulated by stubbing a toe due to the change in pressure..the sensation of pain is stimulated by _______

Sensation

What is it when it is categorized as when looking at ones awareness of the stimuli based on the senses?

Distal & Proximal

Somatosensory Peripheral Neurons have 2 types of axons...

Distal

Which type of Somatosensory Peripheral Neurons conducts messages from the receptor to the cell body?

Proximal

Which type of Somatosensory Peripheral Neurons projects the message from the cell body into the spinal cord/brainstem?

axon diameter

Afferents are classified according to.....

1b (A-beta)

Which is the 2nd largest afferent fiber found in retina cells?

C fibers

Which afferent fiber is the smallest and slowest transmitting axon?

Somatic Afferents

Which type of fibers innervate at the Cutaneous layer?

Meissners & Pacinians corpuscle

Which 2 cutaneous receptors are detect changes in pressure?

Free endings

Which cutaneous receptor is unmyelinated and has a slow transmission of signals?

Pain

Free nerve endings specifically nociceptors detect what?

Temperature

Free nerve endings specifically thermoreceptors detect what?

Belly of the muscle

Somatic Afferents start where

1A fibers

Which afferent fiber is responsible feeling how the muscle is moving?

Intrafusal fibers

Which specialized muscle fiber contract at the ends, the center region does NOT contract?

Primary endings

Which sensory fiber ending wraps around the central region of each intrafusal fiber … detect a quick sense of change b/c they are wrapped around the fiber?

Secondary endings

Which sensory fiber ending is mainly on nuclear chain fibers adjacent to the primary endings?

Muscle spindles

Which muscle receptor responds to quick and prolonged stretches…more about time, aids in stretching and passive movement?

Tendon organs

Which muscle receptor signals the force generated by the muscle contraction or by passive stretch of the tendon…more about amplitude, adjusts muscle tension (quick jump)?

Joint Receptors

Which muscle receptor responds to mechanical deformation of joint capsule…"where you are in space"?

Joint Receptors

Which muscle receptor signals can be override by cognitive function and utilizing other input?

Pathways to the Brain

Tracts are ....

Dorsal Column (aka Medial Lemniscus)

Which tract is responsible for transmitting fine touch, vibration & proprioception (travels ipsilateral)?

Anterolateral (aka Spinothalamic)

Which tract is responsible for transmitting pain, temperature, and pressure (travels contralateral)?

Anterior and Posterior Spinocerebellar

Which tract is responsible for transmitting muscle tension & limb position…plans for movement (travels contralateral)?

1st order neuron

Which order neuron is the sensory cell picks up the signal, interacts with with environment? …ex free nerve ending, muscle spindle fiber

Divergent Pathways

What type of pathway is it when info is transmitted to many location in brainstem and cerebrum, affects a variety of neurons?

Diffuse response & low fidelity

Aching pain is an example of what?

Spinothalamic

Which tract is important in transmitting pain, temp and pressure…poor localization?

Dorsal Column/Medial lemniscal

Which tract is important in transmitting discriminative touch, proprioception, vibration, 2 pt discrimination to consciousness

Spinocerebellar

Which tract is important in transmitting relay information about muscle tension, limb position …planning for movements?

Gracilis region

Which portion of the Dorsal Column tract sends info from the lower limbs & runs centrally?

Cuneatus region

Which portion of the Dorsal Column tract sends info from the upper limbs & run laterally?

Discriminative Touch

____________: Localization of touch & vibration, discriminate b/w 2 closely spaced points touching the skin (conscious path provides input...)

Conscious Proprioception

___________: movements and relative position of body parts (conscious path provides input...)

Stereognosis

__________: ability to use touch & proprioception info to identify object…( happens at the cortical level ) dealing w/ sensation and aids in multitasking (conscious path provides input...)

Primary sensory cortex

In which cortex do we find discrimination among size, texture or shape of object?

Somatosensory association area

In which cortex do we find analyze info from the primary sensory area & thalamus?

1st order neuron

In the Anterior Lateral Pathway which order neuron brings info into the dorsal horn (synapsing immediately = allows for a quick response)?

2nd order neuron

In the Anterior Lateral Pathway which order neuron crosses at the midline and goes from the spinal to the thalamus?

3rd order neuron

In the Anterior Lateral Pathway which order neuron thalamus to cerebral cortex?

Anterior Spinocerebellar pathway

Which tract transmits limb movement/tension/positions info from the legs and lower half of the body?

1st order neuron

Which order neuron would transmit info from the thoracic and upper lumbar spinal cord in the Posterior Spinocerebellar pathway?

2nd order neuron

Which order neuron would transmit info from the (specific) cell body = Nucleus dorsalis and the axon ascends as the Spinocerebellar tract?

Cuneocerebellar pathway

Which tract transmits high fidelity info from the arms and upper half of the body?

Anterior spinocerebellar tract

Which tract transmits info from the thoracolumbar spinal cord?

Rostro-spinocerebellar tract

Which tract transmits info from the cervical spinal cord to the cerebellum (same side)?

Mechanoreceptors, Chemoreceptors, Thermoreceptors, Nociceptors

What are the 4 types of receptors that respond to specific stimuli?

Tonic, do not adapt to stimulus & Phasic, adapts to the stimulus

What are the 2 categories of sensory receptors & what is their specific characteristic?

Proximal region, less innervation

Where do we expect to see a large receptive field & why?

Distal regions, densely packed receptors

Where do we expect to see a small receptive field & why?

Our perception of pain/feeling

Damage to these receptors alter...

Meissner's & Pacinian's

Which 2 cutaneous receptors detect pressure?

Muscle fibers, Sensory fibers & Motor endings

What are the 3 sensory organs in the Muscle Belly?

Nuclear Bag

Which intrafusal fiber is a clump of nuclei and helps sense end range?

Nuclear Chain

Which intrafusal fiber are the nuclei arranged in a single file line and helps sense velocity of change?

tension in the tendons

The Golgi tendon organ is sensitive to ...

1b afferent fibers

What type of axonal fiber is found in the Golgi tendon?

Ligament receptors, Ruffini endings, Paciniform endings, Free nerve endings

What are the 4 types of joint receptors?

Type 2 afferents, extreme joint movements & they prevent from reaching end range

What do Ruffini's endings detect and what type of fiber are they?

Type 1b afferents, sense tension

What do ligament receptors detect and what type of fiber are they?

Type 2 afferents, sense pressure and vibration

What do Paciniform corpuscles/endings detect and what type of fiber are they?

quick and prolonged stretches

Muscle spindles respond to ....

the force generated by the muscle

Tendon organs signal...

mechanical deformation of joint capsule

Joint receptors respond to...

High level and detailed recall

In conscious relay pathways high input leads to

Midbrain, postural response

Spinomesencephalic travels to the... & causes what kind of response

Carries nociceptive information, Controls head posture and activates descending pain tracts

Spinomesencephalic carries? controls? activates?

Reticular Formation, postural response

Spinoreticular travels to the... and causes what response?

Arousal, Attention & Sleep cycle...increases attention and postural responses

Spinoreticular modulates? increases ones _______ & _________

Limbic formation, emotional response

Spinolimbic travels to...and causes what response?

Emotional response to pain & aids in automatic movement

Spinolimbic control? and aid in?