Unit 2-1

Question 1

Sensory Modality: touch

Answer 1

Contact with body surface

Question 2

Sensory Modality: pain

Answer 2

Tissue damage

Question 3

Sensory Modality: hearing

Answer 3

Sound vibrations in air or water

Question 4

Sensory Modality: vestibular

Answer 4

Head movement and orientation

Question 5

Sensory Modality: joint

Answer 5

Position and Movement

Question 6

Sensory Modality: muscle

Answer 6

Tension

Question 7

Sensory Modality: vision

Answer 7

Photons, from light sources or reflected from surfaces

Question 8

Sensory Modality: cold

Answer 8

Decrease in skin temperature

Question 9

Sensory Modality: warmth

Answer 9

Increase in skin temperature

Question 10

Sensory Modality: smell

Answer 10

Odorant chemicals in air

Question 11

Sensory Modality: taste

Answer 11

Substances in contact with tongue or other taste receptors

Question 12

Sensory Modality: vomeronasal

Answer 12

Pheromones in air or water

Question 13

Sensory Modality: electroreception

Answer 13

Difference in density of electrical currents

Question 14

Sensory Modality: magnetoreceptors

Answer 14

Magnetic fields for orientation

Question 15

Sensing

Answer 15

physiological process of detecting stimuli

Question 16

Perceiving

Answer 16

the brain processing the information and us becoming aware of it

Question 17

What transduction pathways have in common

Answer 17

Mechanism of collecting info is generalized: receptors activate and generate electrical potentials

Question 18

How transduction pathways are different

Answer 18

Receptors that collect info and the pathways that transmit the info are different (depends on sensory modality)

Question 19

Sensory Transduction

Answer 19

Converting environmental stimuli to electrical signals our brain can understand

Question 20

Coding and processing

Answer 20

Sensory pathways limit and filter the info that actually makes it to the brain

Question 21

Intensity of stimulus encoded by

Answer 21

Frequency of action potentials

Question 22

How sense determine location

Answer 22

Receptive fields

Question 23

Pathway for relaying touch/ pain to the brain

Answer 23

Thalamus

Question 24

Pathway for relaying touch/ pain to the brain in order (6)

Answer 24

1. External stimulus sensed be receptors in the skin
2. Sensory neuron projects through dorsal root ganglion into the dorsal column system
3. Enters the dorsal horn of the spinal cord and the projection ascends to the medulla
4. Makes a synapse, postsynaptic neuron projects contralaterally
5. Medulla neuron projects to the thalamus
6. Thalamus sends the info to the primary somatosensory cortex

Question 25

Different regions of the body project sensory info to

Answer 25

different parts of the spinal cord

Question 26

Association cortex

Answer 26

Integrates sensory information; made up of dispersed areas of cortex that process and integrate data from multiple senses

Question 27

Polymodal neurons

Answer 27

Process info from more than one sense

Question 28

Synesthesia

Answer 28

Sensory modalities overlap more than normal (music has a flavor)

Question 29

Three dimensions of pain

Answer 29

1. Sensory discriminative dimension (throbbing, gnawing, shooting) 2. Motivational affective/ emotional dimension (tiring, sickening, fearful) 3. Cognitive-evaluation dimension (no pain, mild, excruciating)

Question 30

Nociceptors

Answer 30

Pain receptors (free nerve ending)

Question 31

What happens during injury (3)

Answer 31

1. Damaged cells release substances to tell neighboring cells and blood vessels they have been injured (K+, serotonin, prostaglandins and leukotrienes- inflammation causing lipid molecules) 2. Substances bind to nociceptors and generate AP 3. Reach spinal cord —> sends to brain, sends messages back to periphery (Substance P)

Question 32

Substance P

Answer 32

Mediates further responses to pain (blood vessel constriction, histamine release)

Question 33

Nerves fibers that convey pain info from periphery to brain (2)

Answer 33

1. A-delta: large, myelinated axons: fast (sharp and sudden) 2. C fibers: small, unmyelinated: slow (duller and throbbing)

Question 34

Ascending CNS pain pathways (4)

Answer 34

1. Pain brought from periphery to dorsal horn of spinal cord 2. Axons cross midline and a send through spinal cord 3. Info relayed to Brainstem and midbrain locations and mediate behaviors like focalization’s and withdrawal (periaqueductal gray, site of opioid receptors) 4. Reaches thalamus and sent to two primary places (somatosensory cortex-S1, cingulate cortex-part of Limbic system, triggers emotion and empathy)

Question 35

Analgesia

Answer 35

Pain relief

Question 36

Placebo

Answer 36

Substance given to patient with expectation it will control pain but it is actually inactive

Question 37

Placebo effect

Answer 37

Substance helps anyways

Question 38

TRP channels

Answer 38

Specialized ion channels to detect temperature (bind to ligands)

Question 39

TRPV1

Answer 39

Main sensor for painful heat (acid, spicy as well)

Question 40

TRPM8

Answer 40

Primary channel for sensing cold (menthol/minty and other cool ligands-icilin)

Question 41

Sensing itch

Answer 41

- Free nerve endings, sensitive to histamine - same pathway as pain, different fibers - slow C fibers

Question 42

Proprioception

Answer 42

Perception of the position and movement of the body (knowing where you are in space and how you are moving through it) Found in mechanosensory (movement sensitive)