EXam 2

Question 1

Where is the primary somatosensory cortex located?

Answer 1

It is located on the front of the parietal lobe. It is separated with the primary motor cortex by the central sulcus.

Question 2

Where is the primary motor cortex located?

Answer 2

End of the frontal lobe and is separated with the primary sensory cortex by the central sulcus.

Question 3

The amount of the sensory cortex devoted to each body part depends on what?

Answer 3

The need for fine control and sensitivity.

Question 4

What three subtypes of sensory information does the sensory cortex include?

Answer 4

1. Touch
2. Pain/Temperature
3. Muscle/joint position sense

Question 5

Sensory info (touch, pain, temp, proprioception) is channeled through _______________ ultimately feeding into _______.

Answer 5

three parallel pathways in spinal cord and brainstem

feeding into the area of S1 associated with that body part.

Question 6

Whats the first modality of somatosensory sense?

Answer 6

Discriminative touch

Question 7

Discriminative touch

Answer 7

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.

Question 8

What are the four receptor subtypes in the skin involved in the perception of discriminitive touch?

Answer 8

1. Free nerve endings
2. Meisnner corpuscles
3. Ruffini endings
4. Pacinian corpuscles

Question 9

What sensory info is received by free nerve endings? Where are they located?

Answer 9

Pain; epidermis

Question 10

What sensory info is received by Meisnner corpuscles? Where are they located?

Answer 10

Slow vibrations, rough texture

Located in the epidermis

Question 11

What sensory info is received by Ruffini endings? Where are they located?

Answer 11

pressure and compression

located in the dermis

Question 12

What sensory info is received by pacinian corpuscles? Where are they located?

Answer 12

Fast vibration, fine detail

Located in subcutaneous layer

Question 13

What does it mean by saying somatosensory representation is dynamic?

Answer 13

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.

Question 14

What is the second modality for somatosensory sensation?

Answer 14

Pain and Temperature

and includes sensations of itch and tickle

Trigeminal nerve stimulation

Question 15

What stimulates the trigeminal nerve?

Answer 15

pepper, ammonia, tear gas

Noxious stimulation of the eyes, nose, and mouth.

This is why hot sauce is actually pain and not taste.

Question 16

What is the third modality of somatosensory sensation?

Answer 16

Proprioception

Question 17

Proprioception includes receptors for what?

Answer 17

muscle stretch, joint position, and tendon tension

Question 18

Information from proprioceptors send signals to where?

Answer 18

Cerebellum

The cerebellum sends real time feedback regarding the orientation of the body

Question 19

M1 codes ____ and not _______.

Answer 19

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.

Question 20

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?

Answer 20

The spinal cord alone can manage these transitions via the central pattern generators (CPGs) without any input from the brain

Question 21

Pre-motor cortex

Answer 21

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.

Question 22

Where is the supplementary motor area located?

Answer 22

Superior medial frontal cortex

Question 23

What region of the brain does the supplementary motor area feed information into?

Answer 23

The pre-motor cortex

Question 24

What does the supplementary motor area mediate?

Answer 24

well-learned movements, without the need for explicit sensory cues

SMA is highly active when you imagine performing an action when its physically impossible.

Question 25

What serves as the “gate” between the pre-motor and the primary motor cortex?

Answer 25

The basal ganglia

Question 26

The basal ganglia’s role in motor functioning?

Answer 26

The basal ganglia mediates the onset and offset of an action.

Question 27

What is responsible for the movement ‘tuning’ in real time?

Answer 27

The cerebellum

-Cerebellum serves to coordinate and refine the complex balance of sensory-motor integration during a movement