L71. Senses and Perception 2

Question 1

Neurons with the same function are grouped into ________________.

Answer 1

Bundles / pathways

Question 2

Where do neural pathways terminate?

Answer 2

Specific areas of the brain known as primary receiving areas.

Question 3

What types of axons do peripheral nerves contain?

Answer 3

Either sensory axons only, or sensory and motor axons.

Question 4

What substance surrounds the peripheral nerves?

Answer 4

Epineurium

Question 5

What substance are peripheral nerves encapsulated by?

Answer 5

Perineurium

Question 6

Do peripheral nerve bundles contain blood vessels?

Answer 6

Yes.

Question 7

Name the above axons in relation to the following :
largest diameter Smallest diameter
slowest signal Fastest signal

Answer 7

A alpha
A beta
A delta
C

Question 8

A alpha axons respond to what kind of stimulus?

Answer 8

Skeletal muscle

Question 9

A beta axons respond to what kind of stimulus?

Answer 9

mechanoreceptors on skin

Question 10

A delta axons respond to what kind of stimulus?

Answer 10

pain, temperature

Question 11

C axons respond to what kind of stimulus?

Answer 11

Pain, temperature, itch

Question 12

Give the name for the 31 pairs of structures which sit either side of the spinal cord (31 pairs).

Answer 12

Dorsal root ganglions

Question 13

What type of neurons take a sensory signal from the stimulus to the dorsal horn?

Answer 13

Sensory afferents

Question 14

What type of neurons take a motor signal from the ventral horn to the effector?

Answer 14

Motor efferents

Question 15

For the 3 branches of the trigeminal nerve, name the type(s) of nerves.

Answer 15

Branch 1 (ophthalmic) - sensory
Branch 2 (maxillary) - Sensory
Branch 3 (mandibular) - sensory and motor

Question 16

Do touch and pain have the same pathways?

Answer 16

No, they have separate pathways.

Question 17

Give a vague region as to where each of the following neurons can be found:

1. Primary sensory neuron
2. Secondary sensory neuron
3. Tertiary sensory neuron

Answer 17

1. Periphery
2. Spinal cord/brainstem
3. Thalamus

Question 18

What type of stimulus does the medial lemniscal pathway occur for?

Answer 18

Mechanoreception

Question 19

Give the route of the medial lemniscal pathway.

Answer 19

1. Afferent nerve fibre from stimulus
2. Brainstem nucleus
3. Thalamus
4. Sensory cortex

Question 20

What kind of receptor is the posterior dorsal trigeminothalamic tract used for?

Answer 20

Mechanoreception

Question 21

Give the route of the posterior dorsal trigeminothalamic tract.

Answer 21

1. Trigeminal ganglion
2. brainstem nucleus
3. thalamus
4. sensory cortex

Question 22

What kind of receptor is the spinothalamic pathway used for?

Answer 22

Nociception

Question 23

Give the route of the spinothalamic pathway.

Answer 23

1. Afferent nerve
2. Spinal cord
3. Thalamus
4. Sensory cortex

Question 24

What stimulus is the anterior ventral trigeminothalamic tract used for?

Answer 24

Nociception

Question 25

Give the route of the anterior ventral trigeminothalamic tract.

Answer 25

1. Trigeminal ganglion
2. spinal nucleus
3. thalamus
4. sensory cortex

Question 26

Why is the sensory homunculus image distorted?

Answer 26

The more sensory neurons that supply the area, the more “brain space” allocated in the cortex. ie. Areas of high density receptors (small receptive fields) are more represented in the cortex.

Question 27

What is stereognosis?

Answer 27

The ability to recognise objects by touch alone.

Question 28

What is proprioception?

Answer 28

Having knowledge of the positions of the body eg. balance from the inner ear.