The Somatosensory System (Lecture 1-Dr. Smith)

Question 1

Transduction

Answer 1

Sensory receptor converts energy into a grade potential

Question 2

What is the termination point for sensory info?

Answer 2

The somatosensory cortex

Question 3

Where does the somatosensory cortex receive info from?

Answer 3

The opposite side of the body (contralateral)

Question 4

What is the cortical homunculus?

Answer 4

“little man”
That funny pic in the textbook that is essentially saying that there is a large range of receptor density in the body, There are a lot more receptors in the face than in the lower back

Question 5

Mechanoreceptors. Stimuli and two types?

Answer 5

mechanical stimuli
hapsis- touch, pressure, vibration
proprioceptors - position, rate of movement

Question 6

hapsis

Answer 6

touch, pressure, vibration

Question 7

Proprioceptors

Answer 7

position and rate of movement

Question 8

Skin mechanoreceptors. There are lots of recpetors for hepsis. what are the 4?

Answer 8

Meissner corpuscle
Hair root plexus
Merkel disk
Ruffini corpuscle

Question 9

Two receptors for pressure?

Answer 9

Merkel disc
Ruffini corpuscle

Question 10

Receptors for vibration

Answer 10

Pacinian corpuscle
Meissner corpuscle

Question 11

Receptors for itch

Answer 11

free nerve endings

Question 12

What do proprioceptors sense?

Answer 12

position and rate of movement

Question 13

Where does transduction occur?

Answer 13

At the receptor endings. At the stimulus

Question 14

Explain the events that take place in order for sensation to occur.

Answer 14

1. Sensory Receptors
2. Transduction
   sensory receptor converts energy into a GP
3. AP
   if the GP reaches threshold it creates a AP and is propogated to the CNS
4. Integration
   processed. If it reaches the cerebral cortex it is concious

Question 15

2 types of sensory receptors

Answer 15

1. Peripheral endings (encapsulated or not)
2. Separate cells

Question 16

Where does integration occur?

Answer 16

at each synapse

Question 17

Decussation

Answer 17

crossing over (contralateral)

Question 18

Where does the somatosensory pathway terminate?

Answer 18

somatosensory cortex

Question 19

Where are thermoreceptors?

Answer 19

Skin, hypothalamus, and spinal cord

Question 20

What are the 3 types of nociceptors?

Answer 20

1. Mech (pinch, puncture)
2. Thermal (extreme temps)
3. Polymodal (various stimuli like chemical (bee sting))

Question 21

Visceral pain

Answer 21

Referred pain (from a different site)
Ex Myocardial infration ppl hold their arms

Question 22

Neuropathic pain

Answer 22

No stimulus - phantom pain

Question 23

Deferred or endogenous analgesia

Answer 23

Sensed later - like an athlete who rolls their ankle mid race

Question 24

What are the 5 types of pain?

Answer 24

Somatic - fast (pin prick)
Somatic - slow (toothache)
Visceral
Neuropathic
Deffered

Question 25

Why is understanding referred pain important?

Answer 25

for clincal diagnoses

Question 26

What are the 3 types of nociceptors?

Answer 26

mechanical
thermal
polymodal

Question 27

Are there nociceptors in the brain?

Answer 27

no

Question 28

Where are nociceptors less dense?

Answer 28

Internal organs

Question 29

What is the result of lower density of nociceptors in internal organs?

Answer 29

Reffered pain

Question 30

Somesthesia

Answer 30

The perception of more than one sensation at once

Question 31

What are the components of the somatosensory system?

Question 32

How does referred pain occur?

Answer 32

Both somatic and visceral sensory neurons converge on second-order neurons of the same ascending pathway