General Principles of Sensory Processing (Kapitel 8)

Question 1

A ‘sensory receptor organ’ can be defined as?

Answer 1

An organ (such as the eye or ear) specialized to receive particular stimuli.

Question 2

A ‘recepter cell’ is?

Answer 2

A specialzed cell that responds to a particular energy or substance in the internal or external environment and converts this energy into a change in the electrical potential across its membrane.

Question 3

Can you name 4 types of different sensory systems?

Answer 3

Mechanical (touch, pain, hearing), Visual (seeing), Chemical (smell, taste) and Electrical (electroreception).

Question 4

The brain recognizes the different kinds of sensation as separate and distinct because each modality sends its action potentials along separate nerve tracts. This concept is called?

Answer 4

Labeled Lines.

Question 5

What is meant by ‘sensory transduction’?

hint; its a sort of conversion process

Answer 5

It is the process by which a receptor cell converts the energy in a stimulus into a change in the electrical potential across its membrane.

Question 6

What is meant by ‘receptor potential’?

Answer 6

Also called; generator potential. A local change in the resting potential of a receptor cell that mediates between the impact of stimuli and the initiation of nerve impulses.

Question 7

What is a Pacinian Corpuscle?

hint: it appears close to the skin. In the Hypodermis

Answer 7

Also called, lamellated corpuscle. A skin receptor cell type that detects vibration. (p. 227).

Question 8

The pacinian corpuscle, that is known to detect vibration, have an efferent axon that leads to the spinal cord. But where in the spinal cord?

Answer 8

The axon travels through Dorsal root ganglion, and into the dorsal part of the spinal cord. That is because sensory information towards the brain “gets in” through the dorsal part, whereas motorsignals from the brain is “sent out” through the ventral part of the spinal cord.

Question 9

Hvilken amerikansk forfatter, har skrevet et essay med titlen:” A supposedly funny thing i will properbly never do again” ?

Answer 9

David Foster Wallace. yo.

Question 10

When someone is referring to something as ‘somatosensory’ what are they referring to?

Answer 10

The person would be referring to body sensation, particularly touch or pain sensation.

Question 11

Explain the difference between a ‘tonic receptor’ and a ‘phasic receptor’.

Answer 11

In a tonic receptor, the frequency of action potentials declines slowly or not at all as stimulation is maintained, whereas a phasic receptors action potentials, drops rapidly as stimulation is maintained.

(This way, they both have to do with ‘adaptation’. Tonic receptors are the ones, that show very little adaptation).

Question 12

Where is the thalamus located?

Answer 12

At the top of the brainstem. Trading information with the cortex.

Question 13

Sensory cranial nerves, is first and foremost connected to? And sensory peripheral nerves, are connected to?

Answer 13

Sensory cranial nerves, are connected to the brainstem, whereas the sensory peripheral nerves are connected to the spinal cord (leading to the brainstem).

Question 14

Decribe what the primary sensory cortex does?

Answer 14

For a given sensory modality, it is the region of cortex that receives most of the information about modality from the thalamus or, in the case of olfaction, directly from the secondary sensory neurons.

Question 15

Primary somatosensory Cortex (S1) is located just X to the central sulcus. What is X?

Answer 15

Posterior.

Question 16

S2 is?

Answer 16

Secondary Somatosensory Cortex.

Question 17

What is the name of the sulcus, laying just anterior to the postcentral sulcus?

Answer 17

Central Sulcus.

Question 18

Cingulate Cortex lies.. ?

Answer 18

Is a region of medial cerebral cortex that lies dorsal to the corpus callosum. (p. 234).

Question 19

What is meant by ‘polymodal’?

Answer 19

That something is involving several sensory modalities.

Question 20

What is ‘synesthesia’?

Answer 20

A condition in which stimuli in one modality evoke the involuntary experience of an additional sensation in another modality.

Question 21

Can you differentiate between the dermis, the hypodermis and the epidermis? Which comes first, so to speak..

(ps. i have mixed them up, in the question).

Answer 21

The epidermis is the outermost layer of skin, over der dermis. “Furthest in” is the innermost layer, the hypodermis.

Question 22

Hvilken musiker har hen mod slutningen på en koncert sagt:” I have so many hits for you tonight. We are gonna play hits, until you cry.” ?

Answer 22

Prince. yo.

Question 23

In our human hands, there are four different highly sensitive receptors. Can you name them? And maybe what they ‘do’ as well?

Answer 23

1. Pacinian corpuscle (vibration)
2. Meissner’s corpuscle (light touch)
3. Merkel’s discs (light touch)
4. Ruffini’s ending (stretching of the skin)

(explanation on p. 236)

Question 24

Explain what the dorsal column system is, and how it is of assistance?

Answer 24

It is a somatosensory system that delivers most touch stimuli via the dorsal columns of spinal white matter to the brain.

Question 25

Explain what dorsal column nuclei is, and where it is located?

Answer 25

It is a collection of neurons in the medulla that receive somatosensory information via the dorsal columns of the spinal cord. These neurons send their axons across the midline and to the thalamus.

Question 26

Can you, from prior vendespil (flipping game, memory game, turning game?) remember the 5 different parts of the spinal cord?

Answer 26

From the head down:

1. Cervical
2. Thoracic
3. Lumbar
4. Sacral
5. Coccygeal

(p. 239)

Question 27

What is a dermatome?

Answer 27

A strip of skin innervated by a particular spinal root.

well explained by figure on p. 239

Question 28

What is meant by ‘congenital’?

Answer 28

That someone is born with it. People with congenital insensitivity to pain, is for example born without the ability to perceive pain.

Question 29

What is meant by free nerve endings?

Answer 29

It is axons that terminates in the skin without any specialized cell associated with it and that detects pain and/or changes in temperature.

Question 30

What is capsaicin?

hint: you might have it in your kitchen

Answer 30

It is a compound synthesized by various plants to deter predators by mimicking the experience of burning. (Chili is an example of such compound).

Question 31

Transient receptor potential vanilloid type 1 (TRPV1) is?

Answer 31

A receptor that binds capsaicin to transmit the burning sensation from chili peppers and normally detects sudden increases in temperature.

Question 32

Transient receptor potential 2 (TRP2) is?

Answer 32

A receptor, found in some free nerve endings, that opens its channel in response to rising temperatures.
(p. 243)

Question 33

The TRP2 receptors, are found on A delta fibers. What is ‘A delta fibers’?

Answer 33

A moderately large, myelinated, and therefore fast-conducting axon, usually transmitting pain information.

Question 34

Compared to A delta fibers, what is ‘C fiber’?

Answer 34

C fiber is a small, unmyelinated axon that conducts pain information slowly and adapts slowly. These are the nerve fibers that contain TRPV1 receptors.

Question 35

So, to sum up: What kind of nerve fibers contain TRP2? And what kind of nerve fibers does TRPV1 receptors contain?

Answer 35

TRP2 = A delta fibers.
TRPV1 = C fibers

(p. 243 - 244)

Question 36

What receptor is describes as:” A sensory receptor, found in some free nerve endings, that opens an ion channel in response to a mild temperature drop or exposure to menthol” ?

Answer 36

Cool-menthol receptor 1 (CMR1).

Question 37

Gastrin-releasing peptide (GRP), which is linked to histamine, is a..?

Answer 37

Neuropeptide that stimulates neurons in the dorsal horn to provide the sensation of itch. (p. 244).

Question 38

Can you name the system, that carries most of the pain information from the body to the brain?

Answer 38

Anterolateral system or spinothalamic system.

Question 39

What kind of a thing is glutamate?

Answer 39

An amino acid transmitter, the most common excitatory transmitter.

Question 40

What kind of a thing is substance P?

Answer 40

A peptide transmitter implicated in pain transmission.

Question 41

Can you name three endogenous opioids?

if only two, that is also fine!

Answer 41

Endorphins, enkephalins, dynorphins.

Question 42

Ryan Adams (ikke at forveksle med Brian Adams) har lavet et cover album, kaldet 1989. Hvem har han lavet cover numre af?

Answer 42

Taylor Swift. yo.

Question 43

Can you explain what a opioid receptor is?

Answer 43

It is a recepter that responds to endogenous and/or exogenous opioids.

Question 44

Where is the periaqueductal gray area located, and what is it involved in?

Answer 44

It is the neuronal bodyrich region of the midbrain surrounding the cerebral aqueduct that connects the third and fourth ventricles. It is involved in pain perception.

Question 45

What is analgesia?

hint: It occurs when you electrically stimulate the periaqueductal gray area

Answer 45

Absence of or reduction in pain.

Question 46

Quick tip: See p. 248 for Ascending pain communication pathways / Descending pain modulation pathways. It is a quite nice figure.

Answer 46

.. And that was it.

https://www.youtube.com/watch?v=TIIAQME1Uhg