General Properties Of Sensory Systems Flashcards
What are the 4 types of sensory receptors? Give examples of stimuli for each one.
Explain how photoreceptors work.
Top left picture: Light goes through hole (pupil) into eye, then hits back of eye where the sensory receptors are located.
Bottom left and right picture: The sensory receptors (rods and cones)
Pacinian corpuscles, hair cells, and tension receptor organ are examples of what type of sensory receptor?
Mechanoreceptors.
Pacinian corpuscles: found right below skin: feel vibration
Hair cells: found in cochlea (ear) : involved in transduction of sound wave energy into auditory signal.
Tension organ (receptors): found between muscle fibers and tendons in our skeletal muscles.
What are free nerve endings?
They are nerves that don’t have a specialized receptor/ accessory structure associated with them. Just naked axons with receptors that respond to tissue damage. They are used for pain and temperature!
General properties of Sensory Receptors
Define adequate stimulus. Why is it adequate?
The stimulus that activates the receptor at low threshold. (Which is why sensory receptors usually only respond to their specialized adequate stimuli).
It’s adequate because other stimuli can come from other sources and create an action potential as well, but it take a much stronger stimuli.
Ex. Getting a concussion and hearing ringing in your ears.
Define what a labeled line is. What can it tell do?
Labeled line: The series of neurons that are connected by synapses from the sensory receptor to secondary sensory and third order sensory neurons in the nervous system.
Do: enable the brain to distinguish and process information about different types of physical stimuli.
Define ONLY the special senses that are usually conscious.
Define ONLY the somatic senses that are usually conscious.
Define only the somatic stimuli that is usually subconscious.
Define ONLY visceral stimuli that is subconscious.
What differentiates simple, complex, and nonneural sensory receptors(special senses receptors)?
Simple: free nerve endings, may/may not have myelin.
Complex: nerve ending enclosed in connective tissue capsules. They have myelin.
Special senses: specialized receptors are cells, but no axons, no action potential. Instead activate a transmitter that activates a primary neuron that is connected intimately with that receptor.
- Why does the original hump go away?
- Does anything about the action potential change from picture 2 to picture 3?
- The hump is the receptor potential (graded potential)
- No, there are the same amount of action potentials at the same strength/frequency.
Explain how we (think we) know how action potentials work?
Graph A (question slide) has money axon impulses vs strength of stimuli. And it correlates with how human respond to touch (graph b). This is an inference!
This graph (on answer slide): replication of money experiment on humans confirming theory!
When do receptors adapt?
When there is a sustained stimulus.
What are the two main receptor adaptation types? Which one is fast? Slow?
Tonic receptors: the receptor potential is sustained, but decreased slightly. It is sustained for as long as the stimulus is held in place and generates action potentials. Responsible for giving a steady report. Ex. How much light is in a room, how much pressure is on us from sitting.)
Phasic receptors: Not sustained receptors. Only tell us when something has changed. Ex. You smell something bad, eventually you forget about the smell even while in the same room.
Explain to somatic pathway, the eye pathway, tongue pathway. Sound pathway, nose pathway, Equilibrium pathway?
Explain the neural pathway of pain and temperature receptors.
Know this:
Rate confidence or make individual flash cards if needed.
Summary test:
Rate your confidence. Can you answer them all?
