Final Lecture 18: March 28 Flashcards
what is considered our “sixth sense”?
vestibular system and our sense of equilibrium
Modalities and qualities of spatial orientation
Sense of linear motion
Sense of angular motion
Sense of tilt
what is Sense of linear motion :
the perceptual modality that senses translation.
what is -> Sense of angular motion:
the perceptual modality that senses head rotation from side to side (as if to say “no”).
what is -> Sense of tilt:
the perceptual modality that senses head inclination with respect to gravity.
Sense of linear motion
Sense of angular motion
Sense of tilt
these are considered what
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
The main peripheral component of the vestibular system is what
the labyrinth:
what is the labyrinth:
an elaborate set of interconnected chambers.
The labyrinth has many things in common with what
the cochlea (hair cells, endolymph, etc.).
The labyrinth consists of what
two otolith organs, the utricule and saccule, and three semicircular canals
Hair cells are located in the
what
utricule and saccule,
tree ampullae located where
at the basis of the semi-circular canals.
The two otilith organs are responsible for perception of: what
1) linear accelaration, and 2) gravity.
The semicircular canals are responsible for perceiving what
of rotatation.
what is th Principle of equivalence
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)
go over the lecture for the vestibular system– cant do in flash cards
do it
starting at sensory integration
slide 18
what is Sensory integration:
The process of combining different sensory signals.
->Typically leads to more accurate information than can be obtained from individual senses alone.
what is Vection:
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.
what is Rotational vection
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.
what is Motion sickness:
Results when there is a disagreement the vestibular system, and vision.
-> Could be an evolutionary response to being poisoned
what are Vestibulo-spinal reflexes
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
what is Somatosensation:
Collectively, sensory signals from the skin, muscles, tendons, joints, and internal receptors.
what is Kinesthesia:
Perception of the position and movement of our limbs in space.
what is Proprioception:
Perception mediated by kinesthetic and internal receptors (e.g. stomach).
what is the Strange case of neurological patient Ian Waterman
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
what are Touch receptors (mechanoreceptors):
Embedded in outer layer (epidermis) and underlying layer (dermis) of skin.
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:
- Type of stimulation to which the receptor responds
- Size of the receptive field
- Rate of adaptation (fast versus slow)
what are Tactile receptors
for
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.
All touch fibers eventually bundle up together into a nerve that enters where
the spinal cord between each vertebral disc.
Each area of the skin innerveted by a specific nerve is called awhat.
dermatome
How finely can we resolve spatial details?
Two-point threshold:
what is a Two-point threshold
The minimum distance at which two stimuli are just perceptible as separate.
Like sensitivity to pressure, spatial acuity varies across the body, what show the highest acuity
Extremities (fingertips, face, and toes) show the highest acuity.
what does the Dorsal column-medial lemniscal (DCML) pathway do
Carries signals from skin, muscles, tendons, and joints
Most fibers project directly where
to the gracile and cuneate nuclei.
Ascending inputs remain ipsilateral until when
they cross at the level of the pyramids in the medulla
After a second synapse in the thalamus, fibers reach what
the somatosensory cortex
Touch sensations are represented how
somatotopically in the brain
go over the whole lecture too hard to do over flash cards
ugh
