Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

PHA 511 > 3. Sensory Overview > Flashcards

3. Sensory Overview Flashcards

1
Q

Afferent Nerve Fibers

A

Carry sensory info to CNS

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Afferent Neuron (components)

A

Peripheral process extending to sensory receptor

Centra process entering CNS through dorsal root/cranial nerve

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Sensory Transmission (steps)

A 
Sensory receptors
First order neuron
Second order neuron
Third order neuron
Fourth order neuron
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

First Order Neuron

A

Primary sensory afferent neuron

Cell body in dorsal root ganglion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Second Order Neuron

A

In spinal cord or brainstem

Interneurons can modify here (excitatory or inhibitory)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Third Order Neuron

A

Typically in thalamus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Fourth Order Neuron

A

Sensory cerebral Cortex

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Types of Sensory Receptors

A
  • Specialized peripheral ending of primary afferent neuron (free naked nerve ending)
  • Accessory sensory cell (transmits info to primary afferent neuron)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Adequate Stimulus

A

Form of stimulus energy that a receptor is most sensitive

Not absolute (can respond to other stimuli) (think eyes closed and pressure)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Classification of Sensory Receptors

A

Classified by:

  • the kind of stimulus they are sensitive to
  • location in body
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Mechanoreceptors

A

Respond to mechanical energy

Touch, pressure, vibration

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Thermoreceptors

A

Respond to temperature changes

Warm and cold receptors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Photoreceptors

A

Respond to light energy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Chemoreceptors

A

Respond to circulating or applied chemicals

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Exteroreceptors

A

Detect stimuli affecting external surface of the body

mechanoR, thermoR

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Interoreceptors

A

Lie inside the body

taste, olfaction, things that effect gut

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Proprioceptors

A

Located in internal mass of body

muscles, joints, tendons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Special Receptors

A

Vision, audition, taste, olfaction, balance

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Superficial Receptors

A

Touch, pressure, flutter, vibration, tickle, warmth, cold, pain, itch

20
Q

Deep Receptors

A

Position, kinesthesia, deep pressure, deep pain

21
Q

Visceral Receptors

A

Hunger, nausea, distention, visceral pain

22
Q

Nociceptors

A

Receptors associated with pain sensations

23
Q

Sensory Receptor (function)

A

Transduce/translate energy from one form to another

End result: train of impulses (APs) which carries info about the stimulus applied

24
Q

Sensory Trandsuction

A
  1. stimulus energy
  2. receptor
  3. receptor/generator potential
  4. action potentials
25
Q

Impulse Initiation

A
  1. Stimulus activates R
  2. Local, graded potentials occur across membrane (generator or receptor)
  3. In afferent nerve fiber, separate local potentials summed at first node of Ranvier
  4. AP generated when membrane reaches threshold
26
Q

Generator Potential

A

Graded potential

Receptor is modified afferent nerve ending

27
Q

Receptor Potential

A

Graded potential

Receptor is a separate cell

28
Q

Neural Encoding

A

Process by which information is transmitted from periphery to brain

29
Q

Sensory Information

A

Transmitted by sensory R

Coded as AP

  • Modality (quality/nature of sensation)
  • Location
  • Intensity
  • Duration
30
Q

Modality

A

Sensations that are referred to a single type of receptor

31
Q

Doctrine of Specific Nerve Energies

A

Sense organ is sensitive to many forms of energy

Sensation is always that of adequate stimulus - despite what form of energy was applied

32
Q

Labeled Lines

A

Modality of a sensation depends upon which particular cell, pathway, nucleus or lobe is activated by the stimulus

Pathways of sensory neurons dedicated to that modality

33
Q

Location

A

Ability to locate the side of stimulation and discriminate between two closely spaced stimuli

Encoded by receptive field of sensory neurons

34
Q

Receptive Fields

A

Area of the body that when stimulated results in a change in firing rate of sensory neuron

Areas supplied by different sensory units will overlap

More complex moving from primary to secondary etc neurons

35
Q

Receptive Fields: Increase in stimulus intensity …

A

Stimulus will spread

36
Q

The smaller the receptive field …

A

The greater the density of receptors - more precisely the sensation can be localized

37
Q

Two Point Discrimination Test

A

Minimal distance between two detectable stimuli

Better discrimination where receptive fields are very small and densely innervated

38
Q

Receptive Field: Secondary Neurons

A

Determined by:

  • summed inputs from primary neurons
  • input from interneurons
39
Q

Intensity

A

Methods of transmission:

  1. Frequency code
  2. Population code
  3. Intense stimuli activate different types of receptors
40
Q

Frequency Code

A

As stimulus intensity rises, firing frequencies of sensory neurons rise

More APs (number of AP per unit time)

41
Q

Population Code

A

Intense stimuli recruit greater numbers of nerve fibers to fire

Bigger stimulus - more neurons activated

42
Q

Duration

A

Encoded in the way sensory nerve fibers change their firing frequencies over time

Phasic vs. Tonic

43
Q

Phasic Receptors

A

Rapidly adapting

Signals only onset and cessation of stimulation

44
Q

Tonic Receptors

A

Slowly adapting

Continuously signal a persistent signal (fires as long as the stimulus is present)

45
Q

Sensory Dysfunction: Negative

A

Taking something away

Due to disruption of nerve activity

Numbness
Loss of cold or warmth
Blindness
Deafness

46
Q

Sensory Dysfunction: Positive

A

Gain sensation (in a way we don’t want)

Due to excitation or disinhibition

Pain
Paresthesias (tingling, pins and needles)
Visual sparkles
Tinnitus

PHA 511 (7 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions