4 L1 Special Senses: The Somatosensory System

Question 1

Other name for sensory neurons

Answer 1

Primary afferent neurons

Question 2

Where is the cell body of sensory neurons located

Answer 2

In dorsal root ganglia or cranial root ganglia

Question 3

Define the receptive field

Answer 3

Area over which the dendrites form branches- region whose stimulation affects the activity of the neuron

Question 4

2 structural types of nerve endings

Answer 4

Free or encapsulated

Question 5

4 features of stimulus that are coded

Answer 5

Modality
Intensity
Location
Duration

Question 6

Describe modality

Answer 6

Receptor specificity e.g. type of receptor

Question 7

Describe intensity

Answer 7

The frequency of AP firing in a sensory axon and the intensity (strength) of the stimulus

Question 8

Describe location of a stimulus

Answer 8

Mapping of receptors in specific areas allows location of stimulus to be known in somatosensory cortex

Question 9

Describe duration of stimulus

Answer 9

The beginning/end and pattern of AP firing can encode start/end of stimulus

Question 10

What determines the location and shape of the receptive field

Answer 10

The neurons sensory apparatus

Question 11

Ascending somatosensory pathways 1

Answer 11

Dorsal columns- Fine touch and vibration

Question 12

Ascending somatosensory pathways 2

Answer 12

Spinothalamic (Anterolateral) tract - Pain, temperature, crude (non-discriminative) touch

Question 13

Ascending somatosensory pathways 3

Answer 13

Spinocerebellar tracts- Proprioception