2. Senses

Question 1

4 types of ion channels

Answer 1

Voltage gated
Intracellular ligand gated
Extracellular ligand gated
Stress-activated

Question 2

Vision sensors

Answer 2

Light changes protein configuration = polarization in rods/cones through
intracellular ligand channels

Question 3

Audition Sensors

Answer 3

Sound vibrates cochlear membranes, shakes hair cells pulls open
stress-activated channels

Question 4

Taste Sensors

Answer 4

Chemicals bind to ion channels that open
Extracellular ligand gated

Question 5

Olfaction Sensors

Answer 5

Chemicals bind to ion channels to open
Extracellular ligand gated

Question 6

Somatosensation Sensors

Answer 6

Physical force opens stress-acitvated channels for touch
Chemicals from tissue damage bind to extracellular ligand channels for pain/itch

Question 7

Path to Cortex Vision

Answer 7

RVF = LF, nasals retina cross at optic chiasm
to LGN in thalamus
to V1 (in medial occipital lobe)
(superior colliculus does blind sight and orient)

Question 8

Path to Cortex Audition

Answer 8

Crossing at every level to compare for location-finding
Auditory nerve -> Cochlear nuclei -> Sup. olive nucleus -> Inferior colliculus -> MGN of thal -> A1 (in STG)

Question 9

Path to Cortex Taste

Answer 9

Taste receptors -> Cranial Nerve -> Solitary tract -> M VPN (VPMN) Thal -> Taste cortex

Question 10

Path to Cortex Somatosensation

Answer 10

Touch receptors -> DRG -> Gracilen/Cuneate medulla -> (cross medial lemniscus) to Thal (VPLN for body, VPMN for head)-> S1

Question 11

Where is olfaction cortex and where is taste cortex

Answer 11

Olfactory bulb to Primary olfaction cortex in medial frontal and temporal lobes, and limbic (smell/memory), also orbito-frontal cortex

Taste cortex in insula (lateral to putamen)

Question 12

Sensory Maps

Answer 12

Retinotopic Map in Vision in S1 (upside down and backward, superior is inferior field, and LVF = RH), foveal magnification

Tonotopic Map for hearing in A1 (goes up in Hz, matches cochlea, low freq rostral, high caudal)

Sensory homonculus for touch in S1

Prob no maps for olfaction/taste, too complex variables

Question 13

Top Down Control for senses and what is

Answer 13

Sensing not passive, processing and response properties can be controlled
Vision - gaze control/pupil dilation
Audition - cocktail party effect, change cochlea stiffness
Taste - expectations guide, blind tasting
Olfaction - sniff, habituation
Somatosensation - rub away pain, habituate away things, pain CBT therapy, reappraisal