Sensory pathways 2 Flashcards
what is the neospinothalamic pathway
discriminating part of the spinothalamic tract of the anterolateral system
what is the paliospinothalamic tract
non discriminating part of the spinothalamic tract of the anterolateral system
what is the spinomesencephalic tract
spinal cord to midbrain part of anterolateral system
what is the spinoreticular pathway
spinal cord to the reticulum part of the anterolateral system
what is the function of the midbrain (mesencephalon)
reflexes associated with hearing and vision
fine control of skeletal movement through the red nucleus
habituation and motivation via dopaminergic centers
ascending and descending information
can modulate pain
function of the thalamus
input from the cortex
gatekeeper to the cortex
controls arousal and somnolence of the cortex
the reticulum
carries information between different areas of the brainstem
can modulate pain
modulates the cortex via the thalamus
where does the neospinothalamic tract teminate
VPL nucleus
A delta fibres
where does the paliospinothalamic tract terminate
dorsomedial and intralaminar areas (not somatotopic)
composed of c fibres
why is the neospinothalamic tract able to discriminate pain
terminates in the VPL which is somatotopic
what part of the brain does the anterolateral system use to form a memory circuit
hippocampus and amygdala
how does the anterolateral system increase arousal
synapses with brainstem nuclei
pain prevents sleep
how does pain make you sweat and feel sick
stimulates hypothalamic autonomic circuitry
what causes the emotional component of pain
association with the limbic system
describe a cordotomy for terminal disease pain
lesions in the lateral spinothalamic tract cause decreased perception of pain and temperature on the contralateral side of the body one or two dermatomes below the level of the lesion
surgical procedure but only lasts for a year
can paresthesia result from spinothalamic tract lesion
not usually, may cause searing or shooting or burning pain
how do sensations travel from the head to the brain
trigeminal nerve branches
what are the three divisions of the trigeminal system
mesencephalic, main sensory pathway and the spinal pathway
what are the three divisions of the trigmenial nerve
opthalmic, maxillary and mandibular
what is the function of the trigeminal mesecephalic nucleus
proprioception from the mouth and jaw
wha tis the function of the trigeminal pontine sensory nucleus
discriminating touch, vibration and conscious proprioception from the face
what is the function of the trigeminal motor nucleus
controls muscles of mastication
what is the function of the trigeminal spinal nucleus
pain and temperature sensation from face back of tongue, pharynx, larynx and ear
what are the two pathways from the principle trigeminal nucleus
- touch and vibration from the face via the trigmenial lemniscus to the contralateral VPM. projects somatopically to the somatosensory cortex
- carries touch and vibration via the ipsilateral posterior trigeminothalamic tract to the thalamus, from the mouth
where does information go from the mesencephalic nucleus
unconscious proprioceptive information is passed to the cerebellum for processing
what is the spinal trigeminal pathway
a homolog of the anterolateral system
A delta and C fibres which enter the brainstem at the midpontine level
describe the features of the spinal trigeminal pathway
deep/crude touch, pain, and temperature from the ipsilateral face.
carries pain information from 7, 9, 10 as well as 5
what can trigeminal nerve lesions cause
loss of sensory or motor function depending on site of lesion
what is trigeminal neuralgia
intense shooting sharp pain in the areas supplied by the trigeminal nerve in response to light touch
may be associated with de myelination of the nerve
can be treated with phenytoin
what is the function of the cerebellum
gathers information about the body movements and compares them with planned movements of the body
then issues real time correctional information to acheive smooth movements
what are the two types of information fed to the cerebellum
joint proprioception, cutaneous muscle spindle and golgi tendon organ information
all of the above but integrated with descending modulatory and reflex arc messages which provides information about how the CNS is moving
describe the non integrated proprioceptive information pathway
information enters the cerebellum at the inferior peduncle via two ipsilateral pathways
- the posterior spinocerebellar tract
- the cuneocerebellar tract
what is the posterior spinocerebellar tract
sensory axons from the lower limbs enter the dorsal horn and synapse in the vertical column known as Clarkes column.
post synaptic neurons in clarks column ascend to the cerebellum as the posterior spinocerebellar tract and enteres via the infeiror peduncle
what is the cuneocerebellar tract
proprioceptive information form the upper limbs and neck to the cerebellum
what are the two types of integrated proprioceptive and motor information
anterior spinocerebellar tract
rostral spinocerebellar
what is the anterior spinocerebellar tract
proprioceptive information to the cerebellum
double crosses
what is the rostral spinocerebellar tract
transmits information from the golgi tendon organs of the cranial half of the body to the cerebellum.
what is freidreich’s ataxia
inherited disease where the spinocerebellar tract becomes increasingly ineffective
caused by frataxin repeats involved in iron metabolism
what are the symptoms of freidrichs ataxia
uncoordinated arm and leg movements
reeling gait
intention tremor
what is the cuneate nucleus
carries fine touch and proprioception from the upper body, part of the posterior column–medial lemniscus pathway,
found in the medulla
