Sensory System

Question 1

two main functions

Answer 1

1. Detection of the signal

2. Quantitative features

Question 2

detection of the signal

Answer 2

• can occur without the animal being away
• discrimination power of sensory input
• estimation = quality needs to be determined (modality) what it is

Question 3

Quantitative features

Answer 3

• intensity of the signal
• brain will assess if the individual needs to be aware
• duration and frequency determined
• spatial location

Question 4

How do you get a response

Answer 4

signal gets converted into an action potential

- it is interpreted in the brain based on the stimulation from the signal

Question 5

what are the classifications of receptors based on location

Answer 5

• telereceptors ( hearing and sight )
• exteroreceptors ( external changes like temp and pressure)
• interoceptors ( internal changes )

Question 6

sensory coding

Answer 6

• receptor conveys type of info it is sending
• conveys intensity of the stimulus ( more stronger signals = more frequent APs)
• send info about the location and receptive field characteristic of the receptor

Question 7

will all stimulus give signals?

Answer 7

no - if it doesnt pass the threshold it is not seen as there

Question 8

Chemoreceptors

Answer 8

chemical signals ( taste and smell)

• sweet and salty have different receptors
• internal variables : pH, blood oxygen

Question 9

mechanoreceptors

Answer 9

touch, hearing, balance, and figures body position and blood pressure

Question 10

Photoreceptors

Answer 10

light

vision

Question 11

thermoreceptors

Answer 11

temperature and changes

Question 12

Polymodal receptors

Answer 12

sharks: ampullae of lorenzini

touch and temperature

Question 13

nociceptors

Answer 13

temperature pression, chemical products, perception of pain (humans)

Question 14

primary reception structures

Answer 14

• perceived by terminal end
• afferent level ( out goes in)
  nociceptors
  thermoreceptors
  photoreceptors
  mechanoreceptors
  touch receptors
  chemoreceptors

Question 15

secondary reception structure

Answer 15

mechanoreceptors used for balance and audition

they have cilia and chemoreceptors end of neuro synapse with non nervous sensitive cells

Question 16

can aquatic animals sense smell

Answer 16

no

Question 17

how does smelling occur

Answer 17

• chemicals dissolve in the mucus layer
• change into AP for brain to understand
• axons send the AP
• transductions arrive at the terminal end of the dendrites
• activated g olf protein moves through membrane and activates adelhynate cuclase which converts ATP to cAMP
• G protein changes to become active and energetic
• cAMP is now secondary messenger it goes into sodium channel and activates it
• sodium causes depolarization to open sodium and calcium channels
• cAMP changes to cAM

Question 18

Pheromones

Answer 18

• take in air to sample molecules
• little circle in palette where air is sucked into (also helps detect gender)
• can affect behaviour of organisms

Question 19

photoreceptor layout

Answer 19

• rods: elongated cilium and between 600-900 receptors (better for nocturnal animals)
• cones: center of cornea and 200-300 receptors

Question 20

Rods

Answer 20

more photopigment
slow response
high amplification
saturating response 
non directionally selective
highly convergent retinal pathways
high sensitivity
low acuity
achromatic: one type of pigment

Question 21

cones

Answer 21

less photopigment
fast response
less amplification
non saturating response
directionally selective
highly convergent retinal pathways
lower absolute sensitivity
high actuity
chromatic: three types of pigment

Question 22

different mechanoreceptors

Answer 22

proprioceptors
baroreceptors
osmoreceptors

Question 23

proprioceptors

Answer 23

body ability to sense change ( self movement and body position)

Question 24

Baroreceptors

Answer 24

changes in pressure

sense for internal and external environment

Question 25

osmoreceptors

Answer 25

changes in osmolarity

Question 26

tactile receptors

Answer 26

merkel: braille reading - paccini: sensitive to pressure and found deep within the skin and some organs - Ruffini: located in skin and joints. work together with proprioceptors to maintain balance and change body positions - root hair plexus

Question 27

primary mechanoreceptors

Answer 27

dendritic extensions of afferent neurons bipolar spiral wound around the muscle fiber, spindles

Question 28

what is the junction between muscle and tendon

Answer 28

golgi tendon organ

Question 29

secondary mechano receptors

Answer 29

hair cell receptors involved in the sense of hearing and equilibrium

Question 30

magnetoreception

Answer 30

field used by different species can be followed N/S but they dont know which is which - used for homing -maghemite gives direction

Question 31

electroreceptors

Answer 31

- mainly present in most fish and amphibians - ability to percieve natural electric signals or stimuli - almost exclusively in aquatic/amphibian animals

Question 32

what are electroreceptors used for

Answer 32

- electrolocation | - electrocommunication

Question 33

why do sharks rely on electric field

Answer 33

- used to determine what their prey is - most electric sensitive - ampullae of lorezini - may use it to navigate ocean

Question 34

active electroreception

Answer 34

- animal senses its surrounding environment by generating electric fields and detecting distortion in the fields using electroreceptor organs - different categories - different muscles - can count for up to 30% of the energy production

Question 35

passive electroreception

Answer 35

- animal senses the weak bioelectric fields generated by other animals and use it to locate them - sharks use this and some fish have it in the gill membrane - solely by ampullary electroreceptors can also be found in the lateral line in fish

Question 36

what part of the fish body emits the signal/sound

Answer 36

the tail

Question 37

what kind of change do pit organs sense in snakes and how sensitive

Answer 37

temperature | very sensitive - 1/100th

Question 38

what are some transient receptor potential (TRP)

Answer 38

``` TRPV 2 (~50ºC) TRPV 3/4 (between 22 - 40 ºC) TRPM 8 (below 22ºC) ```