Exam 2 - Other Sensory Systems

Question 1

Somatosenses

Answer 1

body or mechanical senses. provide info about what is happening on the SURFACE of our body and INSIDE it

Question 2

cutaneous senses

Answer 2

info from SURFACE of body

Question 3

proprioception

Answer 3

info about location of body in space Ex. kick ball without seeing

Question 4

kinesthesia

Answer 4

info about the MOVEMENT of the body through space Ex. running

Question 5

organic senses

Answer 5

info from in and around internal ORGANS Ex. feeling nauseous

Question 6

cutaneous receptor info

Answer 6

stimuli: pressure, vibration, heating, cooling, tissue damage.
Skin (outmost part of body). protects the body from dirt & bacteria. Can be Hairy or hairless (aka glabrous). contains our mechanoreceptors.
2 Layers: 1-epidermis 2- dermis (has subcutaneous fat & connective tissue).

Question 7

Mechanoreceptors

Answer 7

in skin, blood vessels, joints, organs. have unmyelinated axon fibers, which contain sodium ion channels that respond to stretching or tension. When the ion channel opens, causes changes in membrane potential (leads to signal transduction). 2 types of mechanoreceptors

Question 8

2 types of mechanoreceptors

Answer 8

Encapsulated: axon fibers surrounded by capsule of connective tissue. QUICK adapting responses. Feel stimulus when present and then when it leaves.

Nonencapsulated: SLOW adapting responses. Constantly feeling stimulus.

Question 9

2 types of encapsulated mechanoreceptors

Answer 9

Meissner’s corpuscles –> feather touch, fingertips
Pacinian corpuscles –> vibration

Question 10

2 types of nonencapsulated mechanoreceptors

Answer 10

Merkel’s disks –> detection of form and roughness ex. finger poking you, fingertips
Ruffini’s endings –> skin stretching

Question 11

features of mechanoreceptors

Answer 11

1. size of receptive field: area of skin or tissue that provides info to a particular receptor. Smaller receptive field –-> can identify borders of smaller stimuli
2. Rate of adaptation: length of time the mechanoreceptors will continue to respond/be active to unchanging stimuli Ex. feel something the entire time you make contact
3. Quality of stimulus processed –> (pressure, vibration, stretch)

Question 12

Pain

Answer 12

An unpleasant sensory and emotional experience associated with actual or potential tissue damage or described in terms of such damage (according to International Association for the Study of Pain)

Question 13

3 types/components of pain

Answer 13

1. Sensory-discriminative (quality, duration of physical pain)
2. Motivational-affective (emotional)
3. Overall Cognitive evaluation/long-term (thinking back to painful experience and how we felt)

Question 14

How does pain help us?

Answer 14

1. Short-lasting pain causes us to withdraw from the source (reflexes), preventing further damage
2. Long-lasting pain promotes behaviors (sleep, rest/inactivity, feeding, drinking) that speed recovery. Ex. being sick
3. Serves as social signal to other animals. Elicits caregiving behavior from others. Warns others of danger or potential harm

Question 15

4 phases of Nociception

Answer 15

1. transduction
2. transmission
3. perception
4. modulation

Question 15

Nociception

Answer 15

Nociceptors - free nerve endings that respond to pain
Nociception - Neural encodings of impending or actual tissue damage (by way of noxious stimulation). Noxious stimuli can be 1) mechanical 2) chemical or 3) Thermal (heat).

Question 16

Transduction (touch)

Answer 16

Initial tissue injury (bumping your arm on a table) that triggers the release of chemicals within the body, which excite the nociceptive nerve fibers.

Question 17

chemicals in transduction

Answer 17

prostaglandins – lipids/chemicals present when feeling pain)

Question 18

Transmission

Answer 18

“Pain message” moves from skin, toward the spine to the brain. There are 2 possible tracts –> spinothalamic tract (STT) or spinoreticular tract

Question 19

Spinothalamic tract (STT)

Answer 19

involved in transmission. main pathway pain takes. Goes from Dorsal horn to brain stem to thalamus and lastly cerebral cortex

Question 20

spinoreticular tract

Answer 20

some pain signals make pit stop in reticular formation. Emotional (motivational-affective) aspect of pain follows unique pathway

Question 21

Perception and Modulation

Answer 21

Brain interacts with nerves to modulate or alter the pain experience (i.e., moving away from the stimulus).
Pain signals are reduced by the release of Endorphins (hormone alleviates pain) and Serotonin (involved in wound healing and bone health)
(modulation bc reducing transmission activity by decreasing pain experience)

Question 22

Phantom Limb Pain

Answer 22

After a limb is amputated 70% of individuals report feeling like the limb still exists and often hurts. Limb is not there, but the rest of the pathway from the spinal cord to the brain exists

Question 23

Mirror Box therapy

Answer 23

treatment to phantom limb pain. put mirror in btwn legs, seeing reflection of intact limb moving, relax them and ease pain

Question 24

Pharmacological (medications)

Answer 24

Opiates –> Class of drugs derived from opium. Bind to opioid receptors in periaqueductal grey matter and spinal cord

Question 25

Placebo

Answer 25

External & internal cues. Being told a treatment will make you feel better. beliefs or expectancies about outcome. May activate endorphin-mediated pain control system

Question 26

Taste/Gustation

Answer 26

taste stimuli - Substances that can dissolve in our saliva and stimulate receptors on the tongue.
Flavors: gustation + olfaction (taste and smelling are related)

Question 27

6 ish basic tastes

Answer 27

Bitter
Salty
Sweet
Sour
Umami (savory; presence of proteins/meats)
Fat? – more of a texture than taste

Question 28

Taste receptors

Answer 28

papilla and tastebuds (which are found in papilla)

Question 29

Papilla

Answer 29

small bumps on surface of the tongue. Each contains 1 or more taste buds

Question 30

Taste buds

Answer 30

found in papilla, detect tastes. Each contain 50-150 taste receptor cells. Receptors for all 5 basic tastes found wherever there are taste buds. Taste cells/buds lifespan 10-14 days

Question 31

transduction (taste)

Answer 31

tasted molecule binds with taste receptor, which produces changes in membrane potentials. (activate AP, opening up diff ion channels)
The different tastes are detected by different receptors. –> Not as much info. Ex: Salty detected by presence of salt; receptor is a sodium channel

Question 32

Gustatory Pathway

Answer 32

Each taste cell transmits info to many fibers & many fibers receive info from many taste cells. Carried to the brain via 3 different cranial nerves.
1. brain stem (medulla)
2. thalamus
3. Primary gustatory cortex (detect what we’re tasting)
4. Secondary gustatory cortex (NOT association cortex, realize if taste is desirable or not)

Question 33

What areas are involved with taste?

Answer 33

Taste is represented ipsilaterally (same side, R processed in R) in the brain. “Taste map” in primary gustatory cortex. Tastes represented in distinct areas. Different for everyone; but stable across time

Question 34

smell/olfaction

Answer 34

olfactory stimuli - Molecules suspended in air (molecular weight of 15-300). Air taken up by nasal cavities connected to the nostrils.

Question 35

transduction - smell

Answer 35

Olfactory receptors (in olfactory epithelium) are in nostrils/nasal cavities. Olfactory receptors die and are replaced every 4-6 weeks. Have cilia (like auditory receptors). Odorant molecules (in air taken into cavities) bind, can cause ion channels to open.

Question 36

Olfactory Pathway

Answer 36

After ion channels open, APs are produced and project to olfactory build via the olfactory nerve. Olfactory bulbs (mitral nerves together) synapse with mitral cells. Travel to different areas of the brain (Ipsilateral forebrain or contralateral olfactory bulb)
–> Amygdala or Primary olfactory cortex (NOT sent to thalamus BEFORE amygdala)
–> hypothalamus & thalamus
–> orbitofrontal cortex aka secondary olfactory cortex

Question 37

Perception of odors

Answer 37

receptors can recognize up to 10,000 different odors, but only ~339 olfactory receptors. Theorized that different odorant molecules attach to different combos of receptor molecules. Creates a unique “code” or pattern (similar to hearing bc diff odors hit diff receptors)