Overview of Sensory Systems and Receptors Flashcards
What are Aδ fibers?
- 1-5 micrometers in diameter
- 4-30 m/sec
- sharp pain, cold temperature
Name the fiber type:
- small, unmyelinated axons
- 1 micrometer in diameter
- average conduction velocity of 0.4-2 m/s
- info about warm temperature, burning pain, itch, crude touch
C fibers
Some receptors, such as hair cells of the auditory system, respond to stimulation with ______.
an oscillatory change
What do muscle mechanoreceptors fire in response to?
stretch
Give 2 examples of a long sensory receptor.
- the somatosensory receptor cell
- skin mechanoreceptors
Name the fiber type:
- 5-10 micrometers in diameter
- 30-60 m/sec
- mechanoreceptors of the skin
Aβ fibers
Give 6 examples of sensory modalities.
- vision
- hearing
- smell
- taste
- touch
- thermoreception
What are C fibers?
- small, unmyelinated axons
- 1 micrometer in diameter
- average conduction velocity of 0.4-2 m/s
- info about warm temperature, burning pain, itch, crude touch
What are the 5 attributes of a stimulus that sensory systems convey?
- modality
- intensity
- quality
- duration/frequency
- location
Auditory information is relayed through the _____ to the auditory cortex in the temporal lobe.
medial geniculate nucleus (MGN)
What is the role of the sensory receptor cell?
to convert one type of physical energy into a change in membrane potential and to transmit this information to a 2nd order nerve cell
Cells that hyperpolarize in response to stimulation have resting potentials that lie btw ____ and ____, generally _____.
0 and -70mV; typically -30 to -40 mV
What are the 3 main functions of sensory information?
- conscious sensation
- control of mvmt
- maintaining arousal
In receptor cells that respond to stimuli by hyperpolarization, increased stimuli intensity will cause the cell to _____.
become more hyperpolarized
Visual information is relayed through the lateral geniculate nucleus (LGN) of the thalamus to the _____.
visual cortex in the occipital lobe
Conscious appreciation of sensory modalities is determined by specific neuronal connections from sensory organs through the ____ to the _____.
thalamus; cerebral cortex
What kind of protein is rhodopsin?
a GPCR (7 transmembrane segments)
In ______ receptor cells (less than 0.1mm to 100 micrometers in length), the receptor potential spreads to the synaptic end of the cell by passive electronic transmission.
short sensory
What is the concept of labeled lines?
conscious appreciation of a sensory modality is determined by the specific neuronal connections from sensory organs through the thalamus to the cerebral cortex
Increased conductance in the receptor causes the membrane potential to ____.
move towards 0mV
What does metarhodopsin do?
it activates transducin
Receptors that depolarize do so as a result of _____.
an increase in nonspecific cation conductance in the receptive area membrane
Light causes rhodopsin to change into _____.
metarhodopsin
Receptor potential increases in magnitude as the ______ of the stimulus increases.
intensity
The selectivity of a receptor lies at the _____ level.
molecular
What does transducin do?
it activates a cGMP phosphodiesterase enzyme leading to the breakdown of cGMP to guanosine
In long sensory receptors (_____ in length), regenerative action potentials must be employed to carry info from the receptive ending to the synaptic release site.
greater than 0.1mm
Visual information is relayed through the______ of the thalamus to the visual cortex in the occipital lobe.
lateral geniculate nucleus (LGN)
Receptor potential _____ in magnitude as the intensity of the stimulus ______.
increases; increases
What is transduction?
the process of sensory input and transformation of info into a change in neuronal action potential
What are Aβ fibers?
- 5-10 micrometers in diameter
- 30-60 m/sec
- mechanoreceptors of the skin
Give 2 examples of short sensory receptors.
- photoreceptor cells
- auditory hair cells
In short sensory receptor cells (_____ in length), the receptor potential spreads to the synaptic end of the cell by passive electronic transmission.
less than 0.1mm to 100 micrometers
_____ information is relayed through the lateral geniculate nucleus (LGN) of the thalamus to the visual cortex in the occipital lobe.
Visual
In short sensory receptor cells (less than 0.1mm to 100 micrometers in length), the receptor potential spreads to the synaptic end of the cell by _____.
passive electronic transmission
What is the receptor protein in rod photoreceptors?
rhodopsin
Name the fiber type:
- 1-5 micrometers in diameter
- 4-30 m/sec
- sharp pain, cold temperature
Aδ
What does decreased cGMP in the eye receptor do?
hyperpolarizes the photoreceptor cell –> NT release
Which sensory system is an exception in that it does not have to travel through the thalamus on the way to its brain destination?
the olfactory system
In ______ receptors (greater than 0.1mm in length), regenerative action potentials must be employed to carry info from the receptive ending to the synaptic release site.
long sensory
______ information is relayed through the medial geniculate nucleus (MGN) to the auditory cortex in the temporal lobe.
Auditory
Give an example of a receptor that hyperpolarizes upon stimulation.
rod photoreceptors
In long sensory receptors (greater than 0.1mm in length), ______ must be employed to carry info from the receptive ending to the synaptic release site.
regenerative action potentials
______ increases in magnitude as the intensity of the stimulus increases.
Receptor potential
Auditory information is relayed through the medial geniculate nucleus (MGN) to the ______.
auditory cortex in the temporal lobe
