Sensory pathways

Question 1

what are 2 touch tracts

Answer 1

1. spinothalamic

2. dorsal columns

Question 2

what senses go through spinothalamic tracts (3)

Answer 2

1. nociception
2. temp
3. crude touch (pressure)

Question 3

what senses go through dorsal columns

Answer 3

1. fine touch
2. vibration
3. proprioception

Question 4

where are cortexes for each sense

Answer 4

1. touch - post-central gyrus
2. taste - inf. post-central gyrus
3. auditory - transverse temporal gyrus
4. visual - ctx inf and sup. to calcarine fissure
5. smell - uncus and amygdala

Question 5

what is basic sensory pathways

Answer 5

receptor>1 neuron>2nd>3rd>cortex

Question 6

what type of neuron is 1st and where is the cell body

Answer 6

pseudounipolar
body - dorsal root ganglion
face - trigeminal ganglion

Question 7

where is cell body of 2nd neuron

Answer 7

in brainstem or dorsal horn of cord

Question 8

where is cell body of 3rd

Answer 8

in thalamus and projects to cortex

Question 9

which neuron decussates

Answer 9

2nd

Question 10

what are 2 parts of the dorsal columns

Answer 10

1. fasiculatis cuneatus

2. fasiculatis gracilis

Question 11

what is path of neuron through spinothalmic tract

Answer 11

receptor>1st neuron (DRG in PNS)>dorsal root synapse>2nd neuron>dessucate>ascend up spinothalmic tract>becomes spinal lemniscus>3rd neuron > cell bodies in thlamus>projects to the cortex

Question 12

what is somatotopy in spinothalmic tract

Answer 12

as ascend we add neurons medially

Question 13

4 basic rules of somatosensory pathways

Answer 13

1. consists of 3 neuron chains
2. for 1st neuron , axon in peripheral nerve in body and cranial nerve in face
3. cell body of 2nd neuron in dorsal horn or brainstem nucleus and projects to contralateral thalamus
4. cell body of 3rd neuron in VP nucleus of thalamus and projects to cortex

Question 14

what is lower body touch pathway

Answer 14

DRG>ascend in ipsilateral fasciulatis graciclis>synapse on nucleasu gracislis of medulla>decussate to medial lemnisucus>thalamus>cortex

Question 15

what is upper body touch pathway

Answer 15

DRG>ascend in ipsilateral fasciulatis cuneatis>synapse on nucleasu cuneatus of medulla>decussate to medial lemnisucus>thalamus>cortex

Question 16

what are the 3 trigeminal nuclei and what do they receive from

Answer 16

1. mesencephalic - 1st sensroy neuron - proprioception from jaw
2. chief sensory - 2ndry neurons - touch and vibration (like DC)
3. spinal trigeminal - 2ndry neurons - noci, temp, pressure (like STT)