Lecture 3 Flashcards
What are the characteristics of receptors? (4)
Differential sensitivity (receptor detects only specific stimuli)
Modality (types of sensation)
Labeled line principle (transmit only 1 kind of stimuli)
Adaptation of receptors (all adapt to sensation over time; some adapt faster)
What are the sensory receptor types? What is an example of each?
- Mechanoreceptors (free and encapsulated endings; Meissner’s Kraus’ and Pacinian corpuscles)
- Thermoreceptors - cold/warm
- Nocireceptors - pain
- Electromagnetic receptors - rods/cones (eyes)
- Chemoreceptors - taste, smell, O2 and CO2
What are ways you can stimulate receptors?
Mechanical deformation - stretch memb. / open ion channels
Apply chemical to membrane - opens ion channels
Temperature change = changes the permeability of the memb.
Electromagnetic radiation = light indirectly/directly opens ion channels
When comparing tonic and phasic receptors, which are faster to adapt?
Phasic receptors
Which receptor transmits only if stimuli is present for a long time? (tonic or phasic)
Tonic
Which receptor detects continuous stimuli? (tonic or phasic)
Tonic
Which receptor is stimulated only when there is a change in strength and transmits info about the rate of that change? (tonic or phasic)
Phasic
Muscle spindles, Golgi tendon organs, macula & vestibule receptors, baroreceptors, and chemoreceptors are what type of receptors?
Tonic receptors
What are the two main nerve fiber types?
A & C
Which nerve fiber type is large and myelinated?
A
Which nerve fiber type has low velocity signal transduction, and makes up 1/2 of the PNS sensory fibers and all of the post ganglionic autonomic fibers.
type C (small and unmyelinated)
What are the four sub-types of type A nerve fiber?
Ia (A alpha) - muscle spindle
Ib (A alpha) - golgi-tendon
II (A beta,gamma) - cutaneous tactile
III (A delta) - temp, crude, pricking pain
What is the sub-type of type C nerve fiber?
IV (C) - itch, pain, temp, crude touch
What are the two types of summation?
Spatial and Temporal
A cluster of nerve endings creating a big local potential, describes what type of summation?
Spatial; More fibers = more strength
Which type of summation is described as increased strength in potential due to an increase in frequency?
Temporal
A functional group of neurons that process and integrate information, describes what?
Neuronal Pool
What is a stimulatory field?
An area within the neuronal pool stimulated by an incoming fiber
The output fibers stimulated by the incoming fiber in a neuronal pool are in what zone? But, if they are not excited by the incoming fiber then they are in which zone?
Discharge; facilitated
An amplified signal that spreads, would be which kind of pathway?
Diverging pathway
True/False: An inhibitory circuit is one fiber that splits and can be either inhibited or excited.
True
This circuit is oscillatory, uses positive feedback and may discharge repetitively for a long time, which circuit is this?
Reverbatory Circuit
What is a converging pathway?
Multiple fibers –> 1
Single/multiple sources
