chapter 7 (study guide and powerpoint)

interoceptors respond to…

internal stimuli

Exteroceptors respond to….

external stimuli

what are polymodal receptors, and give an example

sensory receptors cells that can detect more than one type of stimulus

example, nociceptors

explain the process of transduction

chemoreceptors protein binds chemical to initiate signal transduction pathway → change in membrane shape elicits signal transduction by mechanoreceptors → light activates photoreceptor protein to activate signal transduction pathway

what are receptor potentials

for some senses, sensory receptor cell synapses with a sensory neuron. In this case, graded potential is referred to as a receptor potential

what are generator potentials

for some senses, sensory neurons function as sensory receptors. In this case, graded potential is referred to as a generator potential

what are graded potentials

change in membrane potential of a cell that varies in magnitude with the stimulus intensity; results from the opening and closing of ion channels

lateral inhibition increases the ….

contrast between the signals from neurons at the center of the stimulus and neurons on the edge, allowing finer discrimination

lateral inhibition is the process by which…

a sensory stimulus at one location inhibits the activity of adjacent neurons

lateral inhibition enhances…

 contrast and improves edge detection in sensory systems

phasic receptors produces APs…

only during part of the stimulus (usually at stimulus onset and removal)

tonic receptors fires action potentials …

as long as the stimulus continues and thus can convey information about how long the stimulus lasts

in terms of olfaction, chemicals sensed in …

air

in terms of gustation, chemicals sensed in …

solution

what are the 3 structural criteria for distinguishing between olfaction and gustation

1. different sense organs

2. different transduction pathways

3. different integrating centers

in vertebrates, explain the receptors associated with olfaction

binding of odorant to the receptor is linked to G-protein, causes formation of cAMP and opens ion channels. VNO organ.

in vertebrates, explain the receptors associated with gustation

taste receptors, clustered in groups are called taste buds (bipolar neurons, g-protein coupled and express only 1 receptor protein)

in invertebrates, explain the receptors associated with gustation

taste receptors, clustered in groups are called taste buds (bipolar neurons, g-protein coupled and express only 1 receptor protein)

in invertebrates, explain the receptors associated with olfaction

Jacobson's organ is the replacement to VNO in reptiles. Sensilla, hair-like projection of the cuticle and contains odorant receptors.

what is the VNO

vertebrate sense organ adjacent to the mouth and nasal cavities that is involved in detecting pheromones

what are pheromones

chemicals that elicit changes in behavior and physiology of conspecifics

what are the 5 basic vertebrate tastings

1. Salty (detection of sugars, proteins, and ions)

2. Sweet (detection of sugars, proteins, and ions)

3. Unami (savory) (detection of sugars, proteins, and ions)

4. Bitter (detection of potentially toxic substances)

5. Sour (detection of potentially toxic substances)

what are sensilla

Hair like projection of cuticle

Contain odorant receptor 

Function like those of vertebrates (G-protein coupled)

they are found… inside and outside of mouth, along wing margin, and ends of legs

receptor in sensilla are… neurons and are … (2)

bipolar

G-protein coupled

express only 1 receptor protein

where are taste receptors located in terrestrial species

located on tongue, soft palate, and in larynx, lungs and GI tract

where are taste receptors located in aquatic species

located in oral cavity and at external body surface to allow detection of food in the environment