Neuro: Quiz 6

Front 1

Sensory receptors are cells that detect __________ and produce ____________ __________.

Back 1

stimuli
receptor potentials

Front 2

What are the (5) classifications of sensory receptors?

Back 2

chemoreceptors
thermoreceptors
mechanoreceptors
photoreceptors
nociceptors

Front 3

What to chemoreceptors respond to?

Back 3

smell, taste, pH, metabolite concentrations

Front 4

What do thermoreceptors respond to?

Back 4

temperature and its changes

Front 5

What do mechanoreceptors respond to?

Back 5

physical deformation (ex: cutaneous receptors for touch, those that monitor muscle length and tension, auditory and vestibular receptors)

Front 6

What do photoreceptors respond to?

Back 6

visual information (of the retina)

Front 7

What do nociceptors respond to?

Back 7

pain (separate category)

Front 8

The _________ __________ system mediates the most diverse range of sensations.

Back 8

somatic sensory

Front 9

What does the somatic sensory system mediate (7)?

Back 9

fine touch, crude touch, pressure, proprioception, heat, cold, pain

Front 10

All sensations are transduced by specialized receptors in the _____ and conveys to specific _____ targets.

Back 10

PNS
CNS

Front 11

Neural pathways for the different systems are _____________ and __________ distinct.

Back 11

anatomically
functionally

Front 12

Somatic sensations arise from activity at the ends of _________ nerve fibers in ________ and _________.

Back 12

sensory
skin
muscle

Front 13

Where do cell bodies of body & facial sensory neurons reside? What are they called specifically?

Back 13

series of ganglia alongside the spinal cord and brainstem
dorsal root ganglia & cranial nerve ganglia

Front 14

How can you tell that a fiber is carrying touch information?

Back 14

It will get carried inside and go straight up without crossing over

Front 15

How can you tell that a fiber is carrying pain information?

Back 15

It gets carried inside and immediately crosses over

Front 16

Neurons are sensitive to specific stimuli via ___________ ___________.

Back 16

dendritic projections

Front 17

What is the name for Cranial Nerve 5?

Back 17

trigeminal

Front 18

Explain the steps of the 3-neuron pathway.

Back 18

1) Primary fiber goes up into the medulla and synapses with the secondary fiber.
2) Secondary fiber goes up to the thalamus. Thalamus connects with the tertiary fiber.
3)Tertiary fiber carries it to the somatosensory cortex.

Front 19

___________ is the conversion of one form of energy into another. It changes from a ________ stimulus to a(n) ________ signal.

Back 19

transduction
physical
electrical

Front 20

_____________ is the conversion of pressure, touch, heat, etc. into neural impulses.

Back 20

sensory transduction

Front 21

Explain the basic process of sensory transduction.

Back 21

-Stimulus alters permeability of cation channels in afferent nerve endings
-Depolarizing current is generated, called a receptor potential
-If threshold is reached, action potential is generated
-Rate of AP is proportional to depolarization magnitude
-Receptor potentials that directly cause changes in AP frequency are called generator potentials, which cause an increased frequency of APs in response to simulation.

Front 22

The rate of action potentials are proportional to __________ ___________.

Back 22

depolarization magnitude

Front 23

Receptor potentials that directly cause changes in AP frequency are called _________ ________. They all produce what (2) things?

Back 23

depolarizing receptor potentials
increased frequency of APs in response to simulation

Front 24

During perturbation, __________ open and _______ rushes in, generating a ___________ ________. A strong stimulus will reach the threshold and generate a(n) ___________ ___________.

Back 24

channels
sodium
depolarizing potential
action potential

Front 25

What are the different kinds of afferent fiber endings?

Back 25

mechanoreceptors
encapsulated
nonencapsulated

Front 26

__________ are specialized receptor cells that are found at peripheral endings.

Back 26

mechanoreceptors

Front 27

____________ fiber endings tune fiber to particular features of somatic stimulation. Afferents with specialized or encapsulated receptors are ________ adapting and generally have ________ thresholds for APs.

Back 27

encapsulated
rapidly
lower

Front 28

________________ fiber endings are also called _________ nerve endings. They are formed by branching terminations of sensory fibers in the skin with no obvious specialization around them other than partial ___________ by __________ cells found throughout the body.

Back 28

free

Front 29

Different __________ are most sensitive to particular types of sensation.

Back 29

mechanoreceptors

Front 30

Afferent fibers of different mechanoreceptors differ in _________ and _________. Therefore, _______ afferents supply sensory receptors in muscle. _________ diameter fibers mediate touch. ________________ and ________ are conveyed by the smallest fibers.

Back 30

diameter
myelination
largest
intermediate
temperature & pain

Front 31

_________ __________ is an area of skin over which stimulation results in a change in action potential rate. The size of this varies significantly over the _______ and _________ of receptor. Each of these responds to a single __________ ______. Generally, fine touch receptors have _________ fields because of fewer __________ and denser ___________.

Back 31

receptive field
body, type
afferent fiber
branches
innervation

Front 32

What is a significant area of research with nociceptors? What does "nocere" mean?

Back 32

understanding basic physiology, changes in disease, managing pain

to hurt

Front 33

Peripheral processes are called _____ _________ because they lack a receptor structure. They also may be relatively unspecialized. They are grouped according to _______ properties. They conduct ______ because of light or no _______________ and small __________. What are the (2) general types?

Back 33

free endings
axonal
slowly
myelination
diameter
Aδ and C fiber nociceptors

Front 34

Rapidly conducting ______ nociceptors respond to dangerously intense mechanical and/or thermal stimuli (____ pain/____ pain).

Back 34

Aδ
delta; first

Front 35

Unmyelinated ___ fibers are ___________ because they respond to thermal, mechanical, and chemical stimuli (____pain/_____ pain)

Back 35

C
polymodal
slow; aching

Front 36

What do Aδ nociceptors respond to?

Back 36

dangerously intense mechanical/thermal stimuli

Front 37

What do C nociceptors respond to?

Back 37

thermal, mechanical, and chemical stimuli

Front 38

What are the (3) general categories of nociceptors?

Back 38

Aδ mechanosensitive nociceptors
Aδ mechanothermal nociceptors
polymodal nociceptors

Front 39

Fine touch receptors or ___-_____________ thermal receptors do not discharge at a greater rate if pain is induced.

Back 39

non-nociceptive

Front 40

What are the (2) categories of thermal receptors?

Back 40

nociceptive thermoreceptors
non-nociceptive thermoreceptors

Front 41

____ nociceptors mediate the sharp first pain. ____ fibers mediate the second pain, which is delayed, diffuse, and longer-lasting.

Back 41

Aδ
C

Front 42

Pain pathways: After entering the ______ _______, processes run up and down several levels to provide multiple ________ contacts. _________ order neurons ____________ and ascend in the _______________ quadrant of the spinal cord. This is why it is called the __________ system, or the _____________ tract.

Back 42

spinal cord
synaptic
second
decussate
ventrolateral
anterolateral
spinothalmic tract

Front 43

Finer ____________ are present with cortical areas representing distinct clusters of responses.

Back 43

parcellations

Front 44

Explain the posterior (dorsal) column-medial lemniscus pathway.

Back 44

1) Primary afferents carrying tactile & proprioceptive info synapse in the posterior column nuclei of the ipsilateral medulla
2) Second-order neurons then cross the midline and form the medial lemniscus, ascend to the VPL (ventral posterolateral) nucleus of the thalamus
3) Third-order neurons then project to the somatosensory cortex of the postcentral gyrus.

Front 45

Explain the spinothalamic tract.

Back 45

1) Pain, temperature, and some touch and pressure afferents
2) at level of the SC, 2nd order fibers cross the midline, form the spinothalamic tract, ascend to the VPL nucleus of the thalamus
3) Thalamic cells project to the somatosensory cortex of the postcentral gyrus, insula, other cortical areas.

Front 46

Where does posterior (dorsal) column-medial lemniscus pathway a) synapse... b) decussate?

Back 46

a) in the posterior column nuceli of the ipsilateral medulla
b) secondary fiber decussates at the level of the medulla

Front 47

Where does the spinothalamic tract a) synapse b) decussate?

Back 47

a) at the level of the spinal cord
b) spinal cord

Front 48

What are the somatosensory areas?

Back 48

BA 1, 2, 3

Front 49

In posterior column-medial lemniscus pathway, where does the 2nd-order neuron synapse with the 3rd-order neuron?

Back 49

the thalamus

Front 50

What are (2) mysteries in pain?

Back 50

phantom limb pain & central pain