Sensory Mechanisms Flashcards
What are the two sensory outputs of star-nosed moles and their respective motor outputs
food absent, move on
food present, bite
what are sensations
sensory stimuli trigger receptors and travel to brain as APs via sensory pathways
what are the three steps of sensations
concerting stimulus energy into a neuronal signal
encoding information about stimulus
interpretation of information
what are two key points about the nervous system
rapid communication and information processing
what are three steps of information processing
sensory input, integration, motor output
what is sensory input
external and internal information from sensory receptors
what is integration
interpretation of input, association of input with responses
what is motor output
signals from integration centre to effector cells
pathway of afferent neurons
periphery to CNS (sensory)
efferent neuron pathway
CNS to periphery (motor)
how is stimulus energy converted into a neuronal signal
transduction and transmission
what is the pathway of transduction
stimulus, sensory receptors, change in receptor membrane permeability, receptor potential (graded change in membrane potential)
what is amplification
activation of a cascade
what is sensory adaptation
when continued stimulation decreases responsiveness
what is transmission (2 cases)
if receptor = sensory neuron, conducts APs to CNS
if receptor does not = sensory neuron, sensory neuron generates APs
what happens when the taste receptor recognizes the presence of ligant
changes shape and activates, initiating a cascade —> G protein activated
What do G proteins do
activate enzymes
what is a cascade
amplification, receptor and G protein stay activated and enzymes function as long as there is substrate available
What happens if the receptor is an afferent neuron
receptor is capable of generating a AP on its own
what happens if the receptor regulates an afferent neuron
receptor detects stimulus, generates stimulus, releases neurotransmitter which acts on an afferent neuron that generates the action potential
what are the four types of information that is encoded about a stimulus
type of stimulus, intensity, location, duration
what does the type of stimulus depend on
the type of activated receptor
what does the intensity of a stimulus depend on
number of activated receptors and frequency of action potentials
what does the location of a stimulus depend on
location of receptors and timing (for sound and smell)
what does the duration of a stimulus depend on
the pattern of action potentials
what are the five types of receptors
chemoreceptors
mechanoreceptors
thermoreceptors
nociceptors
electromagnetic receptors
what senses are related to chemoreceptors
smell and taste
what senses are related to mechanoreceptors
sound and touch (pressure)
what do thermoreceptors detect
temperature
what do nociceptors detect
tissue damage
what sense is related to electromagnetic receptors
sight
what is the difference between action potential and receptor potential
action = all or none
receptor = stronger stimulus = more neurotransmitter
what does increased stimulus strength do to action potentials
increases their frequency
what are two characteristics of sensory reception via hair cells
spontaneously active
direction of bending conveys information (toward longest cilia = more neurotransmitter, away = less neurotransmitter)
where does interpretation of information start and culminate
process and integrate information starting in the sensory pathways and culminating in the brain
what are the two types of processing information
hierarchical and parallel
how are different perceptions processed
by different parts of the brain
where is information incorporated
from different modalities in higher association centres
what is perception
ability to discriminate various aspects of the stimulus, meaningful interpretation of sensory data
what two senses are interrelated
chemoreception = taste and smell
