L4 - Body Senses Flashcards
How do we know where we are and where objects are?
What are the three body senses systems?
Proprioceptive System
Somatosensory System
Vestibular System
What is depth perception?
The judgement of the location of objects in depth.
What does the Somatosensory System involve?
It involves Touch and Proprioception.
What does the Vestibular System control?
Balance and Posture Control
Touch is all controlled by the same sensory function.
True or False
False
There are many different types of sensory functions and receptors that manage how we feel things.
What are the 3 types of Proprioception? What are they measuring?
Muscle Spindles (muscle length)
Golgi Tendon Organs (muscle tension)
Joint Receptors (joint position)
this probably isn’t necessary
What are the 4 steps of the cell response for touch?
1. Dorsal root ganglia
2. Brainstem
3. Thalamus
4. Cortex
(In the picture, there is an inhibitor at A which creates a delayed response from B)
What is Somatosensory Two Point Perception?
Measures the distance between when you can distinguish two points of contact on different parts of the body.
Tongue, lips very sensitive. Legs, back not so much.
Is it possible to recognise an object (object perception) through just touch?
Why?
Yes
We seem to have a representation of that space in our minds.
The face and hands have more somatosensory cortex representation than the entire rest of the body.
True or False
Where is the somatosensory cortex in the brain?
True.
The somatosensory cortex is the blue line (located in the postcentral gyrus, found in the parietal lobe).
The bottom right image is how much somatosensory information is represented in each part of the body (how sensitive each part is).
What are the systems that encode information in the Vestibular Labyrinth?
Semicircular Canals
and
Otoliths
What do the Vestibular Organs do for us?
They enable sensing of movement.
In the semicircular canals and otoliths, there is a small area of sensory epithelium contains hair cells
What do the hair cells do and how?
epithelium definition: (“the thin tissue forming the outer layer of a body’s surface and lining the alimentary canal and other hollow structures.”)
The displacement of these hair cells signals a change in position.
The kinocilium and the stereocilia are?
What do they do?
Kinocilium - single tall hair cell
Stereocilia - numerous shorter hair cells
Their displacement in the direction of the kinocilium increases cell activity
At what angle are the hair cells to one another?
They are all at right angles (90°) to one another so you can determine your location in any direction.
Which direction are you moving when you:
1. Yaw
2. Pitch
3. Roll
- Turn head left or right
- Move head forward or backwards
- Move head left or right
What do the Otoliths contain?
The Utricle and Saccule
Also hair cells
How does the Otolith work?
The displacement of the hair cells by gravity is used as a signal for position change.
What are the Semicircular Canals?
What is in them?
What do they do?
They are 3 canals in the Vestibular System at 90 degrees to one another.
They have hair cells (crista) in a gelatinous mass (cupula)
When the head moves, causes the displacement of the crista so we can tell where we are.
What is the 4 step pathway from the Vestibular Organs to the Vestibular Cortex?
Vestibular Organs
Vestibular Nuclei in Brainstem
Thalamus
Vestibular Cortex
What does this system help you do?
It helps you keep balance and the maintenance of that balance over time.
