EXam 2 Flashcards
Where is the primary somatosensory cortex located?
It is located on the front of the parietal lobe. It is separated with the primary motor cortex by the central sulcus.
Where is the primary motor cortex located?
End of the frontal lobe and is separated with the primary sensory cortex by the central sulcus.
The amount of the sensory cortex devoted to each body part depends on what?
The need for fine control and sensitivity.
What three subtypes of sensory information does the sensory cortex include?
- Touch
- Pain/Temperature
- Muscle/joint position sense
Sensory info (touch, pain, temp, proprioception) is channeled through _______________ ultimately feeding into _______.
three parallel pathways in spinal cord and brainstem
feeding into the area of S1 associated with that body part.
Whats the first modality of somatosensory sense?
Discriminative touch
Discriminative touch
Includes touch, pressure, and vibration perception.
Allows us to “read” raised letters with our fingertips, to describe the shape and texture of an object without seeing it.
What are the four receptor subtypes in the skin involved in the perception of discriminitive touch?
- Free nerve endings
- Meisnner corpuscles
- Ruffini endings
- Pacinian corpuscles
What sensory info is received by free nerve endings? Where are they located?
Pain; epidermis
What sensory info is received by Meisnner corpuscles? Where are they located?
Slow vibrations, rough texture
Located in the epidermis
What sensory info is received by Ruffini endings? Where are they located?
pressure and compression
located in the dermis
What sensory info is received by pacinian corpuscles? Where are they located?
Fast vibration, fine detail
Located in subcutaneous layer
What does it mean by saying somatosensory representation is dynamic?
It expands and contracts with activity.
For example if one body part is extra stimulated for several months, the region of the somatosensory cortex devoted to that body part will experience an expansion.
What is the second modality for somatosensory sensation?
Pain and Temperature
and includes sensations of itch and tickle
Trigeminal nerve stimulation
What stimulates the trigeminal nerve?
pepper, ammonia, tear gas
Noxious stimulation of the eyes, nose, and mouth.
This is why hot sauce is actually pain and not taste.
What is the third modality of somatosensory sensation?
Proprioception
Proprioception includes receptors for what?
muscle stretch, joint position, and tendon tension
Information from proprioceptors send signals to where?
Cerebellum
The cerebellum sends real time feedback regarding the orientation of the body
M1 codes ____ and not _______.
The primary motor cortex codes actions and not muscles.
AKA it stimulates pre-packaged muscle groups to comeplete a smooth action
This allows the stimulation of one region of the primary motor cortex to activate multi-joint movements.
Automized motor actions such as walking, walking up stairs, etc are managed outside of our conscious awareness. What manages these changes in our locomotion patterns?
The spinal cord alone can manage these transitions via the central pattern generators (CPGs) without any input from the brain
Pre-motor cortex
Pre-motor does all the planning and preparation for controlled motor behavior
Pre-motor activity precedes primary motor cortex activity
Pre-motor activity ceases when overt movement begins.
Where is the supplementary motor area located?
Superior medial frontal cortex
What region of the brain does the supplementary motor area feed information into?
The pre-motor cortex
What does the supplementary motor area mediate?
well-learned movements, without the need for explicit sensory cues
SMA is highly active when you imagine performing an action when its physically impossible.
What serves as the “gate” between the pre-motor and the primary motor cortex?
The basal ganglia
The basal ganglia’s role in motor functioning?
The basal ganglia mediates the onset and offset of an action.
What is responsible for the movement ‘tuning’ in real time?
The cerebellum
-Cerebellum serves to coordinate and refine the complex balance of sensory-motor integration during a movement
