Sensory systems 1

Question 1

what are the 4 qualities of sensory input

Answer 1

Modality (type)
Intensity
Duration
Location

Question 2

what are 1st, 2nd, 3rd order neurons

Answer 2

1st- specialized type of physical energy for each receptor

2nd- More complex analysis (ex basic shape of object)

3rd.- most advanded processing

Question 3

difference bw 2 types of blind sight

Answer 3

retinal blindness- light can enter eyes but once it makes it to retina there is no processing

Cortical blindness- optic nerves/tracts work fine but prob in visual cortex. Can sense vision to some degree.

Question 4

what does the topographic organization of the sensory input refer to

Answer 4

Neighboring regions in the periphery are maintained in the CNS (neighboring mechanoreceptors are neighboring in the cns)

Question 5

how do PSP get activated in receptors (ex mechanotransductor)

Answer 5

mechanoreceptors sensitive to pressure

-when there is a change in pressure it causes sodium channels to open which depolarizes cell

Question 6

what is activity code

Answer 6

ex. light touch will only cause a couple channels to open where harder touchwill cause an increased number to open (population code)

Question 7

How quick do pancian corpuscles adapt and methods on how they do

Answer 7

• very quick
• ion channels open/close quickly
• Pancian corpusle damped by tissue (will move corpuscle to side)

Question 8

what is labled line code

Answer 8

certain types of sensory input is carried on specific lines (tracts)
ex. friendly touch vs noxious touch

Question 9

what is pattern code(and ex)

Answer 9

• taste

- spectrum of flavour of something

Question 10

what are nociceptors and how do they get into heighted states

Answer 10

Responds directly to tissue damage or stim that has potential to damage tissues

when cells are dammaged chem mediators release chems that sensitize nociceptors

Question 11

What temps do thermoreceptors detect and how does the info travel

Answer 11

cold- bw -20 is
hot- up to 45

travel on specific labeled line tracts

Question 12

what receptors for touch found on smooth skin

Answer 12

Meissners

merkels

Question 13

what doe joint capsul mechanoreceptors detect

Answer 13

sheering
bending
muscle pulls
deep ressure

Question 14

What do muscle spindles detect and when do they cause mm to fire

Answer 14

Sensitive to strethc

-when there is no stretch detected will cause gamma fibes to cause contraction

Question 15

what do cone and rod cells detect

Answer 15

cones- color

rods- b+ww

Question 16

when there is light what happens in the light cells (and what does it cause to the channels in the end; general)

Answer 16

1. light breaks down rhodopsin to retinal + opsin
2. retinal activates G pro
3. G pro activates c GMP phosphodieterase which decreases cGMP which causes sod channels to close

Question 17

what happens when light is there in 1st and 2nd order neurons

Answer 17

retinal- rhodopsin brocken down. Causes decreased cGMP, so na channels closed and no glutamate release.

Bipolar- no NT allow cGMP to build up on bipolar which opens sod channels on ON receptor which releases glutamate to ganglion cell

Question 18

What happens when there is no light in 1st and 2nd order neurons

Answer 18

retinal- no rhodopsin released so cAMP increases allowsing sod channels to open and glutamate release

Bipolar
ON- cGMP decreased closes sod channels

OFF- cGMP thrives allowing sod channels to open and releases NT to ganglion.

Question 19

What do horizontal cells do

Answer 19

Ensure there is no incorrect activaion (off cells are off in presence of light)
-enhances contrast

Question 20

what is a low tolerance to hot foods associated w

Answer 20

increased nociceptors on the tongue

Question 21

salts and acis activate this type of channel whereas Carbs lead to this type of channel

Answer 21

Salts + acids activate ionotropic channels

Carbs- activate g protiens

Question 22

What 2 tastes have cross over in high conc

Answer 22

High conc of sour substances may cross over and acttivate salt receptor

Question 23

what is the CNS refelx for hearing

Answer 23

Tightens mm attached to ossicles to dampen sound

Question 24

What happens when there is an unexpected loud sound in the inner ear

Answer 24

Causes spastic type of mm contraction that causes ringing in ear due to vibration of ossicle

Question 25

where are high and low frquencies heard in the chochlea

Answer 25

basilar end for high frequencies (shorter hair follicles)

Apical end for low frequeincies

Question 26

what is the longest hair cell called and which way of bending causes depolarization and hyperpolarization

Answer 26

largest is kinocillim

Bending towards= depolarization
Bending away= hyperpolarization

Question 27

What happens with ppl w R sided Strabismus

Answer 27

R eye might have down and out

May start to tilt head to R to compoensate

Question 28

How do we localize sound (2)

Answer 28

interneural intensity dif- difference in intensity bw ears

Itraoral time dif- time dif bw two ears

Question 29

Where is interneural and intraoral time diff processed

Answer 29

Interneural intensity- Lat sup olivary nucleus

Intraoral- Medial sup olivary dif

Question 30

max delay of tiem dif ears can detect and what frequencies are better localized

Answer 30

800usec

> 1000Hz