Introduction To Sensory Receptors And Sensory Neurones

Question 0

What are the three types of primary afferent fibres?

Answer 0

Exteroceptors- from outside world (sensors in and beneath skin)
Proprioceptors- about posture and movement (sensors in muscle and tendons)
Interoceptors- about the internal environment and organs (sensors in visceral organs and tissues

Question 1

What are the 5 sensory modalities?

Answer 1

Touch (mechanosensation)
Temperature (thermosensation)
Pain (nociception)
Body position (proprioception)

Question 2

What modality is the ventral root?

Answer 2

Motor

Question 3

What modality is the dorsal root?

Answer 3

Sensory

Question 4

Where does the dorsal root ganglion lie?

Answer 4

Between the vertebrae in the spinal column

Question 5

Where does the trigeminal (gasserion) ganglion project?

Answer 5

Projects centrally to the brainstem trigeminal nucleus

Question 6

Where do the nodose (inferior vagal) ganglia project?

Answer 6

Project centrally to the floor of the 4th ventricle.

Question 7

What are the 3 sensory modalities?

Answer 7

Mechanical, sensory and thermal

Question 8

What sensory receptors respond to low threshold stimuli?

Answer 8

Low threshold mechanoreceptors- touch, vibration, pressure

Low threshold thermoreceptors- cold, cool, indifferent warm and hot

Question 9

What type of sensory receptors respond to high threshold stimuli?

Answer 9

High threshold mechanoreceptors (mechanical nociceptors)- high threshold mechanical stimuli
Thermal nociceptors- extreme hot and cold
Chemical nociceptors- substances in tissue (e.g. Inflammatory mediators)
Polymodal nociceptors- respond to at least 2 of the above

Question 10

What type of sensory modality does the Meissners corpuscle recognise?

Answer 10

Light touch

Question 11

What type of sensory modality does the pacinian corpuscle recognise?

Answer 11

Vibration