Peripheral nerves and peripheral sensory receptors

Question 1

What structure are motor neurones?

Answer 1

Multipolar

1 axon and lots of dendrites

Question 2

Where is the cell body of motor neurones?

Answer 2

In the CNS

Question 3

Where do fibres from motor neurones go?

Answer 3

To the periphery

Question 4

What structure are sensory neurones?

Answer 4

Unipolar

1 axon and 1 dendrite from same fibre

Question 5

Where is the cell body of sensory neurones?

Answer 5

Dorsal root ganglion (outside CNS)

Question 6

What does 1a sensory fibre correspond to in terms of letter system?

Answer 6

A alpha

Question 7

What does 1b sensory fibre correspond to in terms of letter system?

Answer 7

A alpha

Question 8

What does A beta sensory fibre correspond to in terms of Roman numeral system?

Answer 8

II

Question 9

What does A delta sensory neurone correspond to in terms of Roman numeral system?

Answer 9

III

Question 10

What does C sensory neurones correspond to in terms of letter system?

Answer 10

IV

Question 11

What sensory fibres carry pain fibres?

Answer 11

III, IV

A delta, C

Question 12

What do 1a sensory fibres transmit?

Answer 12

A alpha

Muscle spindle primary endings

Question 13

What do 1b sensory fibres transmit?

Answer 13

A alpha

Golgi tendon organ

Question 14

What do A beta sensory fibres transmit?

Answer 14

II

Touch, kinaesthesia, muscle spindle secondary endings

Question 15

What do III sensory fibres transmit?

Answer 15

Alpha delta

Pain and cold receptors

Question 16

What do IV sensory fibres transmit?

Answer 16

C

Pain and temperature

Question 17

What is the only neurone classification system that describes motor neurones?

Answer 17

Letter system

Question 18

What are the motor fibres?

Answer 18

B (preganglionic)
C (postganglionic)
A alpha (skeletal muscle)
A gamma (muscle spindle)

Question 19

What does the dorsal column transmit information about?

Answer 19

Fien touch, pressure, vibration, proprioception

Question 20

Describe the route of the dorsal column

Answer 20

Ascends to dorsal column ipsilatteraly.
Terminates at the cuneate or gracile nucleus (depending on where sensory information comes from)
Decussates to the contralateral side in the medulla.
Ascends to synapse in the thalamus via medial lemniscus.
Synpases in the ventral posterolateral nucleus in the thalamus.
Ascends to the sensory cortex in postcentral gyrus

Question 21

What does the anterolateral (spinothalamic) tract transmit information about?

Answer 21

Anterior spinothalamic - crude touch and pressure

Lateral spinothalamic - pain temperature

Question 22

Describe the route of anterolateral system?

Answer 22

Synpases in spinal cord, decussate to contralateral side in spinal cord.
Ascends to thalamus via the spinothalamic tract and synapses in ventral posterior lateral nucleus in thalamus.
Ascends to sensory cortex in the post central gyrus

Question 23

What does the trigeminothalamic pathway transmit?

Answer 23

Sensation from the face

Question 24

Describe the route of trigeminothalmic pathway?

Answer 24

Sensory neurones enter pons through trigeminal ganglion, synapse in trigeminal nucleus.
Decussates to the contralateral side in the pons.
Ascend to the ventral posterior medial nucleus in the thalamus.
Ascends to the sensory cortex in the post central gyrus

Question 25

Describe the route of the pain and temperature system?

Answer 25

Sensory euroens ener the pons throguh trigeminal ganglion.
Synapse int he trigeminal nucleus.
Fibres descend via the spinotrigmeinal tract and terminate in the spinotrigeminal complex in the medulla.
decussate in the medulla and ascend to the thalamus (ventral posterior medial nucleus)
Ascend to the sensory cortex in the post central gyrus