sensory organization

Question 1

receptors

Answer 1

filter and transduce energy
photoreceptors: light –> chemical energy
hair cells: air waves –> mechanical energy

Question 2

visual perception cell organization

Answer 2

ganglion cells –> amacrine cells –> bipolar cells –> horizontal cells –> photoreceptors

Question 3

visual path: retina to V1

Answer 3

temporal and nasal aspects of each eye are both processing aspects from opposite sides

Question 4

2 pathways from visual system

Answer 4

1. geniculostriate: what are we looking at? - shape, color

2. tectopulvinar: where is the object? - guides head to observe, localization of object

Question 5

auditory system stimulus

Answer 5

sound waves- movement of molecules in air causing vibrations

Question 6

function of outer ear

Answer 6

funnel information from environment

Question 7

function of middle ear

Answer 7

amplify sound

Question 8

function of inner ear

Answer 8

cochlea- localize and transduce sound information

Question 9

place theory

Answer 9

depending on localization of stimulation on basilar membrane you will have high or low frequencies

• base is HIGH frequnecy
• apex is LOW frequency

Question 10

auditory system pathway

Answer 10

decussates in medulla
- some info passes ipsilaterally
synapse in medial geniculate nucleus

Question 11

auditory cortex

Answer 11

maintains tonotopic organization of cochela

Question 12

2 somatosensory pathways

Answer 12

temperature and pain - contralateral - antereolateral
touch and proprioception- ipsilateral - posterior columns
motor- contralateral- lateral corticospinal tract

Question 13

posterior column medial lemniscal pathway

Answer 13

conveys proprioception, vibration and fine touch
- up through dorsal column (sensory)
- arms: gracilis, legs: cuneates
- decussates in caudal medulla
- up to VPL of thalamus (sensory)
- up to somatosensory cortex
primary cells are large, myelinated

Question 14

antereolateral pathways

Answer 14

convey pain, temperature sense and crude touch
- up through dorsal (sensory)
- decussates in cervical spinal cord 
- up to VPL (sensory) 
- somatosensory cortex
primary cells are small, unmyelinated

Question 15

thalamus

Answer 15

relays sensory info from periphery, motor inputs from cerebellum and basal ganglia

Question 16

lesion: S1 and thalamus are gone in left side

Answer 16

loss os sensation from right side and proprioception (unsure)

Question 17

lesion: lateral pons and lateral medullla

Answer 17

lesion of antereolateral pathway: loss of pain and temp sensation on contralateral side of body and ipsilateral side of face

Question 18

lesion: medial medulla

Answer 18

lesion of medial leminiscal pathway: loss of vibration and joint position sense in contra lateral side of body

Question 19

lesion: nerve roots or peripheral nerves

Answer 19

peripheral nerves of posterior and column medial lemniscla and antereolateral systems
- distal symmetrical polyneuropathies cause glove and stocking distribution