Somatosensation 1

Question 1

A-alpha afferents (also called Ia)

Answer 1

Axons associated with muscle spindles, sensory structures within voluntary muscles, important for reflex control of movement. Also give us our sense of limb position.

Question 2

A-beta afferents

Answer 2

Axons associated with cutaneous receptors, which give us our sense of fine touch, as well as pressure and vibration.

Question 3

A-delta afferents

Answer 3

Axons associated with free nerve endings in the skin. May be mechanosensory in function (responsible for crude, poorly localized touch). May also be sensitive to temperature (painful and non-painful) and noxious (potentially damaging, painful) stimuli.

Question 4

C-fibres

Answer 4

Thin, unmyelinated axons associated with free nerve endings in the skin. Slow conducting. Sensitive to a variety of noxious and non-noxious stimuli (chemosensory, mechanosensory, temperature, multimodal).

Question 5

Dorsal root ganglia

Answer 5

Ganglia located along spinal nerves, just outside the spinal cord. Contain the cell bodies of primary afferents of the somatosensory system.