Ch 50 Sensory System Flashcards
What transmits pain signals?
Free nerve endings
What stimulates a pain signal?
1) Thermal stimuli
2) Mechanical stimuli
3) Molecules released by injured cells
What two things are related in most animals?
1) Hearing
2) Perception of body equilibrium
Mechanoreceptors
Detect particles or moving fluids for hearing and perception of body equilibrium
Hair cells
Receptors with mechanically-gated ion channels that open in response to displacement
Hair cells are the receptors of what?
1) Hearing
2) Equilibrium
3) Electroreceptive
Are all hair cells of similar structure?
Yes
Functions of vertebrate ear function
1) Sound reception
2) Balance
Three structures through which vibrations from sounds are transmitted (in order)
1) Tympanic membrane
3) Three middle ear bones
3) Cochlea
How is volume detected?
By the number of hair cells stimulated
How is pitch detected?
By the position of the stimulated cells along the cochlea
In invertebrates, movement and position relative to gravity is detected by:
Statolith-containing organs
In vertebrates, movement and position relative to gravity is detected by:
The inner ear
What is the later line system of aquatic vertebrates used for?
To detect vibrations and currents in water
Chemoreception
The oldest and most universal sensory modality
Six things chemoreception is important in identiying
1) Food
2) Mates
3) Predators
4) Noxious chemicals
5) CO2
6) H2O
Olfactory cells
The receptors of smell
Olfactory cells detect signals that:
1) Are distant from their source
2) Are at low threshold
3) Originate from volatile/soluble substances
Phereomones
Chemicals used for communication among members of the same species
How many different odorant receptors are possessed by mammals?
Over 1000
Gustatory cells
The receptors of taste
Gustatory receptors detect signals that
1) Come from contact with the chemical (especially contact with mouth parts)
2) Are food-related
3) Are water-soluble
4) Are in high concentrations
In humans, how are receptor cells for taste organized?
As taste buds
Individual taste cells of humans express what?
One receptor type
Individual taste cells detect what?
One of the five tastes
Five tastes
1) Sweet
2) Salty
3) Sour
4) Bitter
5) Umami
Electroreceptors
Detect the electric field produced by the muscle activity of living organisms
Electroreception is widely distributed among what group of organisms?
Aquatic chordates
Photoreceptors
Receptors that respond to light
The compound eyes of arthropods are comprised of many what?
Adjacent photoreceptors
Each with their own protective cornea and focusing lens
Each photoreceptor of the arthropod compound eye contributes what?
A “pixel” to the image
Single-lens eye of vertebrates
Focuses light on photoreceptors in the retina
Rhodospins
Pigments that change configuration in response to light
Rhodospins trigger what?
A reaction that stimulates nerves
Rod photoreceptors
Sensitive to low light
Cone photoreceptors
Sensitive to specific frequencies of light
Cone photoreceptors are used for what kind of vision?
Color vision
What results from interaction among neurons of the retina?
1) Lateral inhibition
2) Enhanced contrast in the image
Pit organ
Detect infrared radiation
Function in thermal imaging
Pit organs are possessed by what?
Some vipers
