The beggining

Question 1

4 main functions of sensory information

Answer 1

Perception
Control of Movement
Regulation of the function of internal organs
Maintenance of arousal

Question 2

Perception

Answer 2

The brain’s construction of the world using certain rules
Also means that out sensory experiences actually feel like something that can only be understood when you experience it

Question 3

Common Properties of sensation

Answer 3

1. Modality ( quality, e,g, somatic/vision/audition/olfaction)
   - Submodality(e.g fine touch, warmth, heat)
2. Intensity
3. Duration
4. Location

Question 4

Dorsal Column-medial lemniscal pathway

Answer 4

Fine touch (sensitive touch at fingertips and vibration)
Proprioception (Sensory feedback from muscles and joints)

Question 5

Anterolateral pathway

Answer 5

Pain
Temperature
These two are more involved in monitoring body states

Question 6

Primary sensory afferents of DCMLP

Answer 6

1) A-alpha and A-beta fibers enter the spinal cord from the periphery and remain ipsilateral
2) They travel up to the brainstem and then FIRST SYNAPSE in this pathway

Question 7

Differences between the DCMLP and ALP

Answer 7

ALP makes a synaose right as it enters the spinal cord and ipsilaterally make a synapse which then goes to the other side of spinal cord

Question 8

Anterolateral pathway fibers?

Answer 8

A-delta and C fibers

Question 9

Dorsal column-medial lemniscal pathway fibers?

Answer 9

A-alpha
A-beta

Question 10

Primary Somatic Sensory Afferent Description

Answer 10

One long axon
No dendrites
Cell body off to the side before reaching the spinal cord
Equivalent to dendrites is the specialized ending (sensory receptor)
Transduction baby!!!!!

Question 11

Sensory Transuction

Answer 11

First step of sensory processing
Sensory information from the external(or internal) environment into opening (or closing) of ion channels in receptor cells.

Question 12

Low-threshold mechanoreceptors

Answer 12

Stretch-activated ion channels
Ending gets depolarized which causes an action potential

Question 13

Primary Sensory Fiber

Answer 13

Pressure on the skin is encoded as action potentials in primary sensory fibers

Question 14

Action potential encoding

Answer 14

When AP starts stimulus starts
When AP ends stimulus ends
As pressure increases, frequency of action potentials increases

Question 15

Sensory receptors

Answer 15

Act as filters, extracting specific forms of sensory information and ignoring others

Question 16

Types of primary somatic sensory fiber endings

Answer 16

Slowly Adapting
Rapidly Adapting
Free nerve endings

Question 17

Slowly Adapting

Answer 17

They fire action potentials as long as there is pressure on the skin, firing rate however starts to fade out over time.
Merkel and Ruffini have endings that are specialized to maintain depolarization throughout the pressure pulse so neuron keeps firing throughout the pressure pulse
Almost all sensory transduction processes fade out over time

Question 18

Rapidly Adapting

Answer 18

Fire at the beginning and in the end
Meissner and Pacinian

Question 19

SA1

Answer 19

Merkel Cell
Light touch

Question 20

SA2

Answer 20

Ruffini ending
Stretch

Question 21

RA1

Answer 21

Meissner Corpuscles
- Detect vibration
- really high frequency vibration like hundreds of hertz
- Detect texture

Question 22

RA2

Answer 22

Pacinian Corpuscles
- Detect vibration
- low frequency vibration
- Detect texture

Question 23

Free nerve endings

Answer 23

• Transducing pain and temperature

Question 24

Perception has to do with which labeled line is activated

Answer 24

Specific subset of neurons have to be activated e.g neurons over 50 degrees Celsisus
Capsacian activate labeled line of heat
Mint activates cool

Question 25

Combinatorial Processing

Answer 25

Perceived

Question 26

Fast pain - Stove

Answer 26

a-delta

Question 27

Slow pain - Stove

Answer 27

C fibers

Question 28

Receptive field

Answer 28

The primary somatic sensory neurons Innervate a specific region of the body surface. Stimulus within receptive field excites the cell

Question 29

Anterolateral Pathway

Answer 29

A-delta and C fibers Cross to contralateral side in anterolateral column, continue to brainstem and then cortex

Question 30

DCMLP

Answer 30

A-alpha and A-beta Stay on ipsilateral side, until brainstem synapse where they cross to contralateral side

Question 31

Length and diameter of spinal cord

Answer 31

42 to 45cm long <= 1cm in diameter

Question 32

31 segments of spinal cord

Answer 32

8 cervical 12 thoracic 5 lumbar 5saccrial 1 coccygeal Each corresponds to the entry point of a pair of spinal nerves

Question 33

Cervical and lumbar enlargements

Answer 33

Correspond to the segments that innervate the limbs

Question 34

Lumbar cistern

Answer 34

Cord is shorter then verterbral canal, ending at the 1st lumbar vertebra Below this spinal nerves project down towards the lumbar cistern Vertebra form this space Exit at the appropriate vertebrae forming the CAUDA EQUINA (horse's tail)

Question 35

Cauda Equina

Answer 35

The sack of nerve roots (nerves that leave the spinal cord between spaces in the bones of the spine to connect to other parts of the body) at the lower end of the spinal cord. These nerve roots provide the ability to move and feel sensation in the legs and the bladder.

Question 36

Foramen Magnum

Answer 36

Where cord enters skull to form the medulla

Question 37

What is the most caudal region of the brainstem?

Answer 37

medulla

Question 38

First pain

Answer 38

A-delta

Question 39

Second pain

Answer 39

C-fiber