Sensory Systems 1

Question 1

What are the 4 types of mechanoreceptor on the skin?

Answer 1

1. Messiner’s Corpuscle
2. Penician Corpuscle
3. Merckel disk
4. Ruffini Corpuscle

Question 2

What type of input is the Messiner’s Corpuscle responsible for reading?

Answer 2

Skin Motion

Question 3

What type of input is the Pacinian Corpuscle responsible for reading?

Answer 3

Vibration perception

Question 4

What type of input is the Merckel disk responsible for reading?

Answer 4

texture perception

Question 5

What type of input is the Ruffini Corpuscle responsible for reading?

Answer 5

Stretch perception

Question 6

What are PIEZO1 and PIEZO2?

Answer 6

They are pressure detectors

Question 7

What is TRPM8?

Answer 7

Temperature receptors

Question 8

What are the 4 types of axon in order from thickest to smallest?

Answer 8

1. A-alpha
2. A-Beta
3. A-Delta
4. C

Question 9

What do receptors differ in?

Answer 9

Spatial Precision

Question 10

What are the two ways that Receptive field can differ spatially?

Answer 10

RF’s can overlap, or they can depend on stimulus intensity

Question 11

What axon type innervates the 4 important mechanoreceptors?

Answer 11

A-beta

Question 12

What axon type innervates D-hair follicles for a light brush feeling?

Answer 12

A-delta

Question 13

What sensations are associated with A-delta axons?

Answer 13

Pain & temperature

Question 14

What sensations are associated with C fibers

Answer 14

temperature, pain & itch

Question 15

Which receptors have rapid adaptation?

Answer 15

Meissners & Pacinian corpuscle

Question 16

What is adaptation?

Answer 16

the opening and closing of ion channels

Question 17

What receptors have slow adaptation?

Answer 17

Merkel’s disk & Ruffini’s ending

Question 18

Which types of receptors have large receptive field size?

Answer 18

Pacinian corpuscle & Ruffini’s ending (deep in skin)

Question 19

Which types of receptors have small receptive field size?

Answer 19

Meissner’s corpuscle & Merkel’s disk

Question 20

What is two-point discrimination?

Answer 20

the ability to perceive two separate touch stimuli as distinct

Question 21

What neural pathway involves the dorsal root ganglion and sensory reception?

Answer 21

The dorsal column-medial lemniscal pathway

Question 22

How can we describe axons in the sensory system?

Answer 22

Unipolar

Question 23

After touch afferents go through the dorsal column nuclei, where does the signal terminate?

Answer 23

In the contralateral thalamus

Question 24

After somatosensory information goes to the thalamus, where is it sent to?

Answer 24

The somatosensory cortex

Question 25

What is the mechanism for a reflex?

Answer 25

The somatosensory information connects to motor neurons directly at every stage

Question 26

What is the term for brain organization that resembles body parts

Answer 26

Homunculus somatotopic mapping

Question 27

What is a much larger feature of the somatotopic map in rodents?

Answer 27

The vibrissae

Question 28

What is an example of plasticity of somatotopic mapping?

Answer 28

phantom limb

Question 29

What 3 stimuli do nociceptors respond to?

Answer 29

mechanical, thermal, chemical

Question 30

What are the two described chemical stimuli

Answer 30

Bradykinin - stimulates heat-activated channels Substance P - nociceptors cause vasodilators/histamine release

Question 31

What thermoreceptor did Capsaicin identify? (hot)

Answer 31

Trpv1

Question 32

What thermoreceptor did Menthol identify? (cold)

Answer 32

Trpm8

Question 33

At what temperature does the pain channel respond?

Answer 33

43*C

Question 34

What is thermal hyperalgesia? What substance causes this?

Answer 34

Over-sensitivity to heat; capsaicin opens channels at lower temperatures

Question 35

Whats the difference between the touch spinothalamic pathway and the pain/temperature spinothalamic pathway?

Answer 35

Touch crosses at the medulla Pain & temperature cross at the spinal cord

Question 36

What sensations are the spinothalamic pathways responsible for?

Answer 36

Pain & temperature

Question 37

What does PAG stand for?

Answer 37

Periaqueductal Gray matter

Question 38

Whats the role of the PAG?

Answer 38

Modulating pain sensation based on emotion