General Sensory Mechanisms-4 Flashcards
Merkels’s discs are best characterized as what type of receptor?
- mechanoreceptors with expanded tip endings (free endings)
The Meissner’s and Kraus’ corpuscle are best described as what type of mechanoreceptors?
- encapsulated endings. Still receives skin tactile senses
What are the free and encapsulated endings that are located within deep tissue, mechanoreceptors?
- Ruffini’s corpuscle are free expanded tip
- pacinian corpuscles are encapsulated
What roles can mechanoreceptors play in sensations?
- hearing
- equilibrium
- arterial pressure
Nocireceptors respond to what type of stimulus?
- free nerve ending that respond to pain
What is unique to the receptors in general?
- specific sensitivity: high sensitivity to one stimulus and nonresponsive to others.
- modality (refer to principal type of sensation)
- labeled line principle: specificity of nerve fiber for transmitting only one modality of sensation
What is the adaptation of receptors refer to?
- adaptation of receptors to a constant stimulus after a period of time.
What is a tonic receptors and how does it work?
- slow adapting receptor
- relay continuous stimulus strength
- transmit impulse while stimulus is present
What is a phasic receptor and how does it operate?
- rapid adaptation
- no continuous signal transmitted
- only stimulated when the strength of the stimulus changes
How many type A nerve fiber types are there?
- alpha
- beta
- gamma
- delta
- these are large to medium sized myelinated fibers
What are type C nerve fibers?
- small unmyelinated
- more than half the sensory fibers in the peripheral nerves and postganglionic autonomic fibers
What are type A alpha fibers? (Group 1a)
-fibers from annulospiral ending of muscle spindle
The type A alpha (Group 1b) fibers are where?
- fibers that are from golgi tendons
What are type Abeta, gamma fibers (Group II)?
Conduct from cutaneous tactile receptors and flower-spray
What information do type Agamma fibers (Group III) generally conduct?
-temperature, crude touch, and pricking pain.