Neuro - Week 1 Flashcards Preview

Block 5 > Neuro - Week 1 > Flashcards

Flashcards in Neuro - Week 1 Deck (176)
Loading flashcards...
1

What types of Stimulus do general sensory receptors encode? (4)

1) Quality: brush, pressure, vibration, temperature, pain
2) Intensity: light stroke vs. intense pressure
3) Duration:
4) Location:

2

What is a Receptive Field?

Area in periphery (ex. skin) where an adequate stimulus causes a response in a neuron.

3

How does a sensory neuron encode intensity? (2)

Rate Code: Frequency of AP's firing per neuron. The more action potentials firing, the higher the intensity

Spatial Summation Code: Number of neurons firing. The more neurons firing, the higher the intensity

4

What factors influence conduction velocity? (2)

1) AXON DIAMETER (higher = faster)

2) MYELINATION (thicker = faster)

5

Which fibers have the LARGEST myelin and FASTEST conduction? (2)

1) A alpha fibers: muscle spindle
2) A beta fibers: light touch, vibration, pressure

6

Which fibers have THIN myelin and MEDIUM conduction? (1)

A delta fibers: Nociceptors (fast pain), cooling receptors

7

Which fibers are UNMYELINAED and have the SLOWEST conduction? (1)

Nociceptors (slow pain) and warm receptors

8

What is a Remap Bundle?

a bundle of Nociceptors

9

What would a Compound AP from a nerve look like if there was a loss of access to a particular nerve fiber?

The magnitude of the peak corresponding to the fiber that has damage would be reduced.

10

What would a Compound AP from a nerve look like if there was a decrease in the conduction velocity of a fiber?

The peak corresponding to the fiber that has damage would shift to the right.

11

What would most likely cause a decrease in conduction velocity of a nerve?

De-myelination. Diseases that cause this include Diabetes, Herpes Zoster. and Guillian-Barre

12

What are the CHARACTERISTICS and PURPOSE of a SLOWLY ADAPTING response?

Characteristics: Fires throughout stimulus: Sustained, unchanging stimulus

Purpose: Pressure and the Shape of Objects

13

What are the CHARACTERISTICS and PURPOSE of a RAPIDLY ADAPTING response?

Characteristics: Fires only when stimulus changes: Fires at the beginning and end of stimulus

Purpose: Impact, motion of objects, on/off stimuli

14

What does SPATIAL RESOLUTION depend on? (2)

1) Receptive field size (smaller = more sensitive and higher spatial resolution)

2) Innervation Density

15

What is a 2-point discrimination threshold?

Minimum distance between two detectable stimuli

16

What are the characteristics of MECHANORECEPTORS? (4)

1) Very sensitive to force (low threshold)
2) Doesn't respond to painful stmiuli
3) Silent without stimulation (doesn't fire without stimulation)
4) Myelinated axons (fast conduction velocity)

17

What are 5 types of mechanoreceptors?

1) Merkel Disks
2) Meisnner's corpuscles
3) Ruffini corpuscles
4) Pacinian Corpuscles
5) Hair follicle receptors

18

What are the following characteristics of MERKEL DISKS?

Type of information encoded?

Fine touch, 2 point discrimination, resolution of texture (bumpy vs smooth)

19

What are the following characteristics of MERKEL DISKS?

Receptive field characteristics (size, number, name)?

Several small, sensitive spots called "Touch Domes"

20

What are the following characteristics of MERKEL DISKS?

Location and skin level?

superficial, high density in finger tips, lips and mouth

21

What are the following characteristics of MERKEL DISKS?

Adaption Response?

Slowly adapting response and the number of action potentials indicates indentation force

22

What are the following characteristics of MERKEL DISKS?

Axon characteristics?

Myelinated, several disks are innervated by a single axon

23

What are the following characteristics of MEISSNER'S CORPUSCLES?

Type of information encoded?

Type of information encoded: Fine touch, 2-point discrimination, senses abrupt changes in edges, bumps, corners of objects

24

What are the following characteristics of MEISSNER'S CORPUSCLES?

Receptive field characteristics (size, number, name)?

single spot

25

What are the following characteristics of MEISSNER'S CORPUSCLES?

Location?

superficial, glabrous skin only, high density in finger tips, lips, mouth

26

What are the following characteristics of MEISSNER'S CORPUSCLES?

Adaption Response?

Rapidly adapting response. Number of action potentials fired indicates the number of times the skin is indented

27

What are the following characteristics of MEISSNER'S CORPUSCLES?

Axon characteristics?

Myelinated, terminal fiber wraps around epithelium so force is easily sensed

28

What are the following characteristics of RUFFINI CORPUSCLES?

Type of information encoded?

Type of information encoded: Stretch of skin, sense gravity force against skin

29

What are the following characteristics of RUFFINI CORPUSCLES?

Receptive field characteristics (size, number, name)?

Receptive field: Large and diffuse

30

What are the following characteristics of RUFFINI CORPUSCLES?

Location?

Location: superficial, Deep in the dermis