lecture 16 - somatic sensation

Question 1

What is somatic sensation?

Answer 1

Pain, touch from the body that you can ‘feel’

Question 2

What is visceral sensation?

Answer 2

Sensory information from internal organs

Question 3

What is discriminative sensation?

Answer 3

deep/superficial touch, vibration, joint position sense/proprioception

Question 4

What is affective/non-discriminative sensation?

Answer 4

Sensations from potentially damaging stimuli: pain, heat/cold

Question 5

What are receptive fields?

Answer 5

Areas where a number of receptors are associated with one sensory neuron

Question 6

What are the 2 major pathways/tracts carrying sensory information to the brain?

Answer 6

Dorsal column medial leminscus, Spinothalamic/anterolateral

Question 7

What type of sensory information does the dorsal column medial lensiscus pathway carry?

Answer 7

Discriminative sensation - pressure, vibration, light touch, proprioception

Question 8

Where are the first order neurons located in the dorsal column medial lensiscus pathway ?

Answer 8

Travel from periphery to the dorsal root and travel ipsilaterally up the spinal cord to the gracile and cuneate nuclei where they synapse with the second order nuclei.

Question 9

Where are the second order neurons located in the dorsal column medial lensiscus pathway?

Answer 9

starting at the cuneate/gracile nuclei, then decussate at the medulla and ascend to the thalamus where they synapse with third order neurons

Question 10

What is the location of the third order neurons in the dorsal column medial lensiscus pathway?

Answer 10

Start at the thalamus and relay to the sensory cortex in the post central gyrus

Question 11

What is the medial leminscus?

Answer 11

Bundle of discriminative fibres in the brain stem after they have decussated in the medulla

Question 12

What is the sensory pathway for unconscious proprioception?

Answer 12

The spinocerebellar tract

Question 13

What is the function of the spinothalamic pathway?

Answer 13

transmission of non-discriminative sensation (pain, temperature, crude touch) to the brain

Question 14

Where are the first order neurons located in the spinothalamic pathway?

Answer 14

Sensory neurons enter the spinal cord at the dorsal root and immediately synapse with the second order nruon

Question 15

Where are the second order neurons located in the spinothalamic pathway?

Answer 15

after synapsing with the first order neuron as it enters the spinal cord, immediately decussates at this level then ascends until it synapses at the thalamus

Question 16

Where are the third order neurons located in the spinothalamic pathway?

Answer 16

Begin at the thalamus then project to the sensory cortex

Question 17

Where is the spinothalamic tract located in the spinal cord?

Answer 17

Anterior and laterally