Exam 2-General Sensory Process

Question 1

sensation

Answer 1

refers to the actual stimulus received by the body

results in action potentials in afferent neurons

Question 2

perception

Answer 2

refers to brain’s understanding of the stimulus (even just being aware)
*shaped by brain processing, personality, experience, mood

Question 3

(Receptor Encoding)

Stimulus Modality

Answer 3

proprioception, temperature, vision, pressure, taste, osmolarity, hearing, olfaction, pain

• submodality
• principle of labeled lines: each receptor, when stimulated, gives rise to one sensation (each receptor sensitive to a modality and a modality with in modality)

Question 4

(Receptor Encoding)

Stimulus Intensity

Answer 4

-indicated by increase in number of action potentials
(increase firing by single neuron)
(increase number of neurons firing: recruitment)
(some neurons have differing thresholds)

Question 5

(Receptor Encoding)
Stimulus Temporality
(tonic)

Answer 5

tonic receptors: slow adapting; continue to generate AP throughout stimulus period; convey info about both intensity and duration (want info constantly)

Question 6

(Receptor Encoding)
Stimulus Temporality
(phasic)

Answer 6

phasic receptors: rapidly adapting; only generate AP at onset (maybe offset) of a stimulus; convey info about change in stimulus intensity

Question 7

(Receptor Encoding)

Stimulus Location

Answer 7

• exoreceptors: interested in world around us (contact vs. distance)
• interoceptors: internally interested (often subconsious)
• proprioceptors: how the body is in relationship to the world around us
• acuity: ability to discriminate between location of simultaneous stimuli
• receptive fields: region of receptor surface that corresponds to a single neuron

Question 8

(touch)

mechanoreceptors

Answer 8

stretch-activated ion channels

send info to primary somatic sensory cortex

Question 9

(touch receptors)

Meissner’s corpuscle

Answer 9

• phasic, superficial skin
• responds to light touch (beginning/end)
• constantly sending info when vibration

Question 10

(touch receptors)

merkle’s corpuscle

Answer 10

• tonic, superficial

- light touch

Question 11

(touch receptors)

pacinian corpuscle

Answer 11

• phasic, subcutaneous
• forceful pressure
• when pushed down, fluid moves, when released, fluid returns and exerts pressure on neurons within layers

Question 12

(touch receptors)

ruffini corpuscle

Answer 12

• tonic, subcutaneous

- strong stimuli

Question 13

(taste)

basal cell

Answer 13

stem cells

Question 14

(taste)

support cell

Answer 14

provides support

Question 15

(taste)

pore

Answer 15

saliva pools so we can see what chemicals are present

Question 16

(taste)

cilia

Answer 16

increase surface area

Question 17

(taste)

salty

Answer 17

sodium channels always open

depolarize when salt ion present (follow conc. gradient)

Question 18

(taste)

sour

Answer 18

H+ blocks K+ channels
depolarization; channels always open
*vit. C in acid needed by collagen

Question 19

(taste)

sweet

Answer 19

GPCR; second messenger system (want glucose)

• often gets glucose and other things that come with it
• changes metabolism of cells

Question 20

(taste)

bitter

Answer 20

to detect poisonous (alkaloids)

-sensation and perception (genetic)

Question 21

(taste)

umami

Answer 21

ability to detect amino acids

Question 22

(smell)

olfaction

Answer 22

• certain patterns of neurons vs. specific receptors for specific smells
• increased sensitivity and decreased specificity
• processed in limbic system (memory/emotion)

Question 23

(smell)

olfactory epithelium

Answer 23

superior concha (bone right above nasal cavity)

• supporting cells (structure)
• olfactory receptor cells (neurons with stem cells that are always being replaced-sheets)
• basal cells (stem cells)

Question 24

(smell)

anosmia

Answer 24

• loss (partial loss) of the sense of smell
• causes: traumatic injury to cribform plate, exposure to toxic chemicals, Zn deficiency, aging (decrease stem cell population)