Lecture 26- Mechnoreception and electroreception

Question 1

define mechanoreception:

Answer 1

is the mechanical stimuli including sound and pressure that bends or pulls on a receptor (the hair cells). used in sensing touch, hearing, and the detection of water pressure and water currents.

Question 2

the anatomy/functions of the acoustico-lateralis system include:

Answer 2

1. semicircular canals which detect gravity and acceleration
2. hearing organs which detects sound
3. the lateral line which detects water displacement

Question 3

all of the acoustico- lateralis is based on the same receptor which is?

Answer 3

the vertebrate hair cell

Question 4

each cell has a set of projections ———- and ———- that bend in response to mechanical stimuli

Answer 4

stereocilia and kinocilium

Question 5

fish flesh has a density near that of water thus pressure is felt via structures with a density that differs from water including:

Answer 5

1. bones: specifically the inner ear bones otliths

2. gas space (swimbladders) which is often connected to the ear

Question 6

why is the semi-circular canal important?

Answer 6

important for maintenance of normal orientation and in the coordination of movements by detecting gravity and changes in acceleration.

Question 7

there are three semi circular canals to manage movement/gravity in all three plans. the three directions are called what?

Answer 7

pitch: up and down
yah: side to side
Roll: rolling back and forth

Question 8

why are lamprey and hafish not as spacially aware?

Answer 8

lamprey only have 2 canals and hafish only have 1

Question 9

while fish are able to detect many of the same frequencies as other vertebrates their hearing systems gives poor directional sensitivity, why?

Answer 9

due to the high speed sound of water.

Question 10

describe the lateral line:

Answer 10

the lateral line detects pressure and low freqeuncy sounds. the arrangement of the pores in the lateral line gives great directional sensitivty. their vertebrate hair cells are on the lateral line that detect sound/pressure

Question 11

why are fish in a good position to use electric information?

Answer 11

1. water is a good condutor of electricity

2. all living things produce electrical currents

Question 12

electroreception is almost universal among what kind of fish?

Answer 12

primitive

Question 13

electroreceptors are categorized differently:

Answer 13

1. ampullary receptors (ex. ampullae of lernzini). all non-teleost electroreceptors fall into this category, have the same set up. They are tuned to low frequency signals and are used primarily in orientation and food location.
2. tuberous receptors account for most of the teleost receptors and may be tuned to high frequencies and used for social interactions.

Question 14

what are the two kinds of tuberous receptors?

Answer 14

1. knollenorgan: allows for communication between species

2. mormyromast cells: much less sensitive and try to sense prey or predators.

Question 15

electric abilities can be further divided into two types:

Answer 15

1. passive electrorception: occurs when fish have specialized sense organs to detect electric currents hut do not produce enhanced electric currents of their own.
2. active electroreception: occurs when fish produce enhanced electrical currents from electric organs and detect distortions in the electric field. Has more to do with electro creation then reception. The knife fish is a good example!

Question 16

the strength of the electric signals produced by fishes fall into 2 categories:

Answer 16

1. weak electric organs are used in orientation and for social communication
   ex. ) fish with transimission at the same frequency may fight over a specific wave length with the winner gaining dominance in social hierarchy. knifefish
2. strong electric organs produce currents strong enough to deter predators and stun prey. pacific electric ray is the most electric fish on the planet and stuns fish.