Neuro-4

Question 1

What sensors reinforce the pattern of swimming seen in the lamprey?

Answer 1

There is a pattern of stretch receptors which provide sensory feedback as to how the muscle is acting
And promote the alternations of contractions seen in the swimming lamprey

Question 2

What is the difference between sensations and perceptions?

Answer 2

Sensations are action potentials carried away from the sense organ to the brain
Perceptions are the brains awareness of sensations

Question 3

What are mechanoreceptors?

Answer 3

Cells which have cilia on the top of them which will respond to movement in a way which can generate an action potential

Question 4

What are chemoreceptors?

Answer 4

These are receptors that respond to chemicals and function in things like smell
They are exposed and have channels which bind molecules and send signals to the CNS

Question 5

What are electromagnetic receptors involved in?

Answer 5

Vision

Question 6

What did all our sensory cells evolve from?

Answer 6

Ciliated cells which have modified their cilia to detect different stimuli

Question 7

What are the different components of sensory systems?

Answer 7

Filter which is a structure which channels energy to a receptor
Reception which is the ability of the system to absorb energy
Transduction which is conversion of stimulus to receptor potential
Amplification
Transmission (action potentials in sensory neuron)
Integration which occurs from the level of the receptor through all levels of the brain

Question 8

What was the behavioural observation made that allowed determination of stimuli that the sharks electrosensory mechanism responded to?

Answer 8

The shark was able to find buried prey (flounder)
It was determined it was able to do this through an electro-sensory mechanism through the elimination of all other potential mechanisms
Odour was removed through the placement of an agar shield and could not detect the flounder if it was wrapped in electrical insulator the shark would not be able to find the flounder
The shark would find and look for buried electrodes

Question 9

Where was electroreception lost?

Answer 9

In the development of the bony fish

However it has been reinvented by both the south American and south African knite fish

Question 10

What are the features of the electroreception?

Answer 10

There is very little filter
The transduction is electrical
Transmission is through an afferent sensory nerve
There is an adaptive filter and integration/analysis

Question 11

What are non-shark examples of electromagnetic receptors?

Answer 11

There is infrared imaging performed by both rattlesnakes and fire beetles