Chapter 16 (smell and taste) Flashcards
two divisions of chemoreception
A) Olfaction (smell)
B) Gustation (taste)
Olfaction
results from stimulation of sensory receptor cells in the olfactory organs, innervated by the olfactory nerve. smells.
Gustation
mediated by taste buds, innervated by the facial, glossopharyngeal, vagus nerves.
where are taste buds found?
mouth cavity, gill cavity, gill arges, external surfaces of the body (barbels, skin)
olfactory organs
aka nares, paired bilateral structures consisting of olfactory chambers, folds of olfactory epithelia called lamellae
what do lamellae do?
dramatically increase the surface area of the olfactory chambers
how is water pushed thru nares?
- branchial pump (sharks, rays)
- swimming
2 Olfactory sensitivities:
1- perception of v. low odors
2- discrimination of 2 or more odors in a mix
why is gustation important?
location and identification of possible food sources.
reproductive behaviour and chemoreception
play a role in courtship behavior, parental behaviour, aggressive behaviour.
what is an example of olfaction in predator avoidance?
schreckstoff or alarm substance. prey recognition
innate avoidance behavior
detect prey, stop migration, reverse direction, show fright behaviour
Acoustico laterlis system
includes the sound receptive and equilibrium centers of the inner ear and the free and connected neuromasts of the cephalic and lateral line system
how much faster does sound travel in water than air?
4.8x
what are the three liquid filled sac containing an otolith?
utriculus, sacculus, lagena
three otoliths are called what?
lapillus, sagitta, asteriscus
what are the two sensory modalities that fish posses to detect underwater vibrations?
inner ear, lateral line system
the lateral line system consists of several series of cennected or unconnected…
neuromasts.
where are neuromasts located?
running over the course of the head and body
what are neuromasts?
encapsulated hair cells that produce nervous impulses when bent in one of two directions.
are neruomasts far or near field receptors? what do they react to?
near. the dispacement of water particles and not pressure waves alone. (inner ear can do both)
in what manners can neuromasts be presented?
free neuromasts lying on the surface of skin or within pits, or canals and grooves on the head and body.
the neuromast canals are filled with what?
endolymphic fluid (mucous) passes vibrations to the neuromasts.
the more active the fish, the faster the water flows, how does this affect the lateral lines? why?
the greater the propensity that the system to be contained with canals. reduces the extraneous noise of outside environment
how are the lateral lines positioned according to lifestyle and form?
form follows function (on top for flat fish, below for surface, arch above pec fins)
functions of lateral line and inner ear in the detection of moving objects:
1: near the source
2: farther from the source
3: at large distances from the source
1: hydrodynamic detection
2: near field hearing
3: far field hearing
(slide 47)
