Final Lecture 18: March 28

Question 1

what is considered our “sixth sense”?

Answer 1

vestibular system and our sense of equilibrium

Question 2

Modalities and qualities of spatial orientation

Answer 2

Sense of linear motion
Sense of angular motion
Sense of tilt

Question 3

what is Sense of linear motion :

Answer 3

the perceptual modality that senses translation.

Question 4

what is -> Sense of angular motion:

Answer 4

the perceptual modality that senses head rotation from side to side (as if to say “no”).

Question 5

what is -> Sense of tilt:

Answer 5

the perceptual modality that senses head inclination with respect to gravity.

Question 6

Sense of linear motion
Sense of angular motion
Sense of tilt
these are considered what

Answer 6

These are different considered senses (like audition and vision) and not different qualities of the same sense because they transduce different energies.

- > linear acceleration
- > angular acceleration
- > gravity

Question 7

The main peripheral component of the vestibular system is what

Answer 7

the labyrinth:

Question 8

what is the labyrinth:

Answer 8

an elaborate set of interconnected chambers.

Question 9

The labyrinth has many things in common with what

Answer 9

the cochlea (hair cells, endolymph, etc.).

Question 10

The labyrinth consists of what

Answer 10

two otolith organs, the utricule and saccule, and three semicircular canals

Question 11

Hair cells are located in the

what

Answer 11

utricule and saccule,

Question 12

tree ampullae located where

Answer 12

at the basis of the semi-circular canals.

Question 13

The two otilith organs are responsible for perception of: what

Answer 13

1) linear accelaration, and 2) gravity.

Question 14

The semicircular canals are responsible for perceiving what

Answer 14

of rotatation.

Question 15

what is th Principle of equivalence

Answer 15

Gravity and Linear accelaration are fundamentally the same thing

(you feel the same in space as you do free falling
you also feel the same on earth as you do in a rocket)

Question 16

go over the lecture for the vestibular system– cant do in flash cards

Answer 16

do it

Question 17

starting at sensory integration

Answer 17

slide 18

Question 18

what is Sensory integration:

Answer 18

The process of combining different sensory signals.

->Typically leads to more accurate information than can be obtained from individual senses alone.

Question 19

what is Vection:

Answer 19

An illusory sense of self motion produced when you are not, in fact, moving.
Example: Being stopped in your car at a light next to a semi. The semi begins to roll forward and you press on the brake because you feel as if you are rolling backwards.

Question 20

what is Rotational vection

Answer 20

Subjects have the illusion of tilt but do not feel as if they turn upside-down.

• The vestibular system’s sense of gravity stops the illusion.

Question 21

what is Motion sickness:

Answer 21

Results when there is a disagreement the vestibular system, and vision.
-> Could be an evolutionary response to being poisoned

Question 22

what are Vestibulo-spinal reflexes

Answer 22

A whole family of reflexes that work together to keep us from falling over
Without vestibulo-spinal responses, we would be unable to stand up in the dark.
Patients with vestibular loss actually over-compensate for body sway.
Galvanic vestibular stimulation

Question 23

what is Somatosensation:

Answer 23

Collectively, sensory signals from the skin, muscles, tendons, joints, and internal receptors.

Question 24

what is Kinesthesia:

Answer 24

Perception of the position and movement of our limbs in space.

Question 25

what is Proprioception:

Answer 25

Perception mediated by kinesthetic and internal receptors (e.g. stomach).

Question 26

what is the Strange case of neurological patient Ian Waterman

Answer 26

Cutaneous nerves connecting Waterman’s kinesthetic and tactile mechanoreceptors to brain destroyed by viral infection
Lacks kinesthetic senses, dependent on vision to tell limb positions

Question 27

what are Touch receptors (mechanoreceptors):

Answer 27

Embedded in outer layer (epidermis) and underlying layer (dermis) of skin.

Question 28

Touch receptors (mechanoreceptors): Embedded in outer layer (epidermis) and underlying layer (dermis) of skin.
Multiple types of touch receptors
Each touch receptor can be categorized by three criteria:

Answer 28

1. Type of stimulation to which the receptor responds
2. Size of the receptive field
3. Rate of adaptation (fast versus slow)

Question 29

what are Tactile receptors

for

Answer 29

Feeling the shape of your key in your pocket requires the SA I (and maybe also the FA I) channel.

Shaping your fingers to grasp the key involves the SA II channel.

As you insert the key into the lock, your grip force increases so that the key does not slip, thanks to your FA I channel.

Finally, your FA II channel tells you when the key has hit the end of the keyhole.

Question 30

All touch fibers eventually bundle up together into a nerve that enters where

Answer 30

the spinal cord between each vertebral disc.

Question 31

Each area of the skin innerveted by a specific nerve is called awhat.

Answer 31

dermatome

Question 32

How finely can we resolve spatial details?

Answer 32

Two-point threshold:

Question 33

what is a Two-point threshold

Answer 33

The minimum distance at which two stimuli are just perceptible as separate.

Question 34

Like sensitivity to pressure, spatial acuity varies across the body, what show the highest acuity

Answer 34

Extremities (fingertips, face, and toes) show the highest acuity.

Question 35

what does the Dorsal column-medial lemniscal (DCML) pathway do

Answer 35

Carries signals from skin, muscles, tendons, and joints

Question 36

Most fibers project directly where

Answer 36

to the gracile and cuneate nuclei.

Question 37

Ascending inputs remain ipsilateral until when

Answer 37

they cross at the level of the pyramids in the medulla

Question 38

After a second synapse in the thalamus, fibers reach what

Answer 38

the somatosensory cortex

Question 39

Touch sensations are represented how

Answer 39

somatotopically in the brain

Question 40

go over the whole lecture too hard to do over flash cards

Answer 40

ugh