Ascending sensory pathways I

Question 1

What is spinothalamic responsible for?

Answer 1

Pain, temp, some touch and pressure

Question 2

What is dorsal column pathway responsible for?

Answer 2

Touch, vibration and position

Question 3

Three ways of knowing where we are in space

Answer 3

Vestibulocochlear system
Muscle spindles
Visual

Question 4

Spinothalamic pathway have what type of fibres

Answer 4

Thin, poorly myelinated or unmyelinated fibres

Slow conduction

Question 5

Dorsal column pathway have what type of pathways and why

Answer 5

Large diameter, heavily myelinated
Fast conduction
For higher perception e.g. 2-point discrimination and vibration and proprioception

Question 6

Where is primary sensory cortex?

Answer 6

Post central gyrus

Question 7

First order neuron for spinothalamic and dorsal column

Answer 7

DRG

Pseudounipolar cell body outside of CNS
Sensory receptor to CNS
Note does not synapse! just gives off cell body

Question 8

Second order neuron for spinothalamic and dorsal column

Answer 8

Always synapses upon immediately entering the spinal cord - ipsilateral grey matter

These are the neurons that cross the midline but at different points

Question 9

Third order neuron for spinothalamic and dorsal column

Answer 9

Thalamus - posterior ventral nucleus

Goes on to terminate at primary sensory cortex in post central gyrus

Question 10

Dorsal column is…

Answer 10

Ipsilateral

Question 11

Spinothalamic is…

Answer 11

Contralateral

Question 12

Lateral corticospinal is…

Answer 12

Ipsilateral

Question 13

Ventral corticospinal is…

Answer 13

Contralateral

Question 14

Spinothalamic second order neuron crosses midline where

Answer 14

Ventral white commisure

Ventral to central to central canal

Question 15

Past the medulla the spinothalamic tract becomes

Answer 15

The spinal lemniscus

Question 16

Where does primary neuron run in dorsal column?

Answer 16

Primary neuron runs up the spinal cord to important nuclei of gracile and cuneate

Question 17

Where does gracile fasicle run?

Answer 17

Whole length of spinal cord medially

graceful ballerina

Question 18

Where does cuneate fascicle run?

Answer 18

Above T6 lateral

Question 19

Where do the primary neurons of dorsal column pathway synapse?

Answer 19

SAME SIDE

Then decussate through internal arcuate fibres to form medial lemniscus which ascends contralateral brainstem to VPL

Question 20

Dorsal column second neuron distribution in medial lemniscus from dorsal to ventral at closed medulla

Answer 20

Arm -> trunk -> leg

To clarify, arm is most dorsal

Question 21

Second order neuron of dorsal column synapse where to become third

Answer 21

Posterior limb of internal capsule

Question 22

Second order spinothalamic synapses where to become third

Answer 22

Post. limb of internal capsule