General Sensory Mechanisms-4 Flashcards Preview

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Flashcards in General Sensory Mechanisms-4 Deck (22)
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1
Q

Merkels’s discs are best characterized as what type of receptor?

A
  • mechanoreceptors with expanded tip endings (free endings)
2
Q

The Meissner’s and Kraus’ corpuscle are best described as what type of mechanoreceptors?

A
  • encapsulated endings. Still receives skin tactile senses
3
Q

What are the free and encapsulated endings that are located within deep tissue, mechanoreceptors?

A
  • Ruffini’s corpuscle are free expanded tip

- pacinian corpuscles are encapsulated

4
Q

What roles can mechanoreceptors play in sensations?

A
  • hearing
  • equilibrium
  • arterial pressure
5
Q

Nocireceptors respond to what type of stimulus?

A
  • free nerve ending that respond to pain
6
Q

What is unique to the receptors in general?

A
  • 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
7
Q

What is the adaptation of receptors refer to?

A
  • adaptation of receptors to a constant stimulus after a period of time.
8
Q

What is a tonic receptors and how does it work?

A
  • slow adapting receptor
  • relay continuous stimulus strength
  • transmit impulse while stimulus is present
9
Q

What is a phasic receptor and how does it operate?

A
  • rapid adaptation
  • no continuous signal transmitted
  • only stimulated when the strength of the stimulus changes
10
Q

How many type A nerve fiber types are there?

A
  • alpha
  • beta
  • gamma
  • delta
  • these are large to medium sized myelinated fibers
11
Q

What are type C nerve fibers?

A
  • small unmyelinated

- more than half the sensory fibers in the peripheral nerves and postganglionic autonomic fibers

12
Q

What are type A alpha fibers? (Group 1a)

A

-fibers from annulospiral ending of muscle spindle

13
Q

The type A alpha (Group 1b) fibers are where?

A
  • fibers that are from golgi tendons
14
Q

What are type Abeta, gamma fibers (Group II)?

A

Conduct from cutaneous tactile receptors and flower-spray

15
Q

What information do type Agamma fibers (Group III) generally conduct?

A

-temperature, crude touch, and pricking pain.

16
Q

What sensations do group IV (Type C) fibers carry?

A
  • pain, itch, temperature, and crude touch.
17
Q

What is the best way to describe spatial summation?

A

-increase the signal strength being transmitted by progressively increasing the number of fibers.

18
Q

What is a common type of sensation that uses spatial summation and how does it work?

A
  • pain fibers
  • Large number of endings in the center of field, and dissipates as we move away from the center. Generates overlap of one pain fiber over others.
19
Q

How does temporal summation work?

A
  • relies on the increasing frequency of a nerve impulse to increase the signals strength
20
Q

Where is the stimulatory field of a neuronal pool located?

A
  • located in the area within the pool that is stimulated by each incoming nerve fiber.
21
Q

What is the difference of discharge and facilitated zones within a neuronal pool?

A
  • the discharge zone is the area of neuron firing.
  • the facilitated zone receives stimulus, but not strong enough to generate action potential, these zones can be either excitatory or inhibitory
22
Q

What are the five basic types of sensory receptors?

A
  • mechanoreceptors
  • thermoreceptors
  • nociceptors
  • electromagnetic receptors
  • chemoreceptors