1 (15) Special Senses Flashcards
(128 cards)
In general, how do all sensory receptors work?
neurons are stimulated, info is sent to brain, cerebral cortex integrates info, forms perception
What is the difference between sensation and perception?
sensation - awareness of the stimuli
perception - interpreting the stimuli
How do we form perceptions?
neurons are stimulated, info is sent to brain, cerebral cortex integrates info, forms perception
What is the largest sense organ of the body?
skin
What do we mean by a threshold? Do receptors respond to only one stimulus?
- with enough stimulation the nerve fires
* receptors can respond to multiple stimuli
What are exteroceptive senses?
respond to stimuli arising outside the body
What are interoceptive senses?
respond to stimuli arising in internal viscera and blood vessels
What are proprioceptive senses?
respond to stretch in skeletal muscles, tendons, joints, ligaments, and CT coverings of bones and muscles (informs brain of one’s movement)
What do we mean when we speak of simple receptors?
- modified dendritic endings of sensory neurons
* found throughout body and monitor most types of general sensory info
Is the cerebral cortex the only place where information is processed?
no
How is information processed?
3 levels:
1) receptor level (sensory receptors)
2) circuit level (processing in ascending pathways)
3) perceptual level (processing in cortical sensory areas)
What is meant by a graded potential or receptor potential?
- graded potential: a ligand opens a ligand-gated channel in the dendrites, allowing ions to enter (or exit) the cell
- receptor (generator) potential: a type of graded potential, is the transmembrane potential difference produced by activation of a sensory receptor
What is transduction?
the conversion of a sensory stimulus from one form to another
What are generator potentials?
stationary depolarization of a receptor that occurs in response to a stimulus and is graded according to its intensity and that results in an action potential when the appropriate threshold is reached
What is sensory adaptation?
reduction in sensitivity to a stimulus after constant exposure to it
What is the difference between phasic and tonic receptors?
phasic - fast adapting (mainly to report changes)
tonic - sustained response w/ little or no adaptation
How is information processed at the perceptual level? What is frequency encoding?
information is processed in cerebral cortex // means by which the central nervous system, limited by the all-or-none properties of nerve impulse conduction, is able to convey information about varying intensity of signals
What sense organs help us feel touch and pressure? What are their receptor cells?
skin // mechanoreceptors
How do we sense different temperatures?
thermoreceptors in skin
What are the receptors for pain? What stimuli can cause pain?
nociceptors detect damage from mechanical, electrical, thermal, or chemical energy
What is substance P?
neurotransmitter involved in the synaptic transmission of pain and other nerve impulses
Do pain receptors adapt? Why is this good?
pain receptors adapt little, if at all (if adapted, protection from pain would be lost and would become useless)
What is the difference between pain threshold and pain tolerance?
all people have the same threshold (perceived pain at the same stimulus intensity), not all people have the same tolerance (how well you handle pain)
What can change a person’s pain tolerance?
age, chronic pain, cultural/psychological factors