L6 - Cortical Sensorimotor Systems

Question 1

How many layers are there in the cerebral cortex?

Answer 1

6

Question 2

What are the layers of the cerebral cortex called?

Answer 2

Lamina

Question 3

What are Brodmann’s areas based on?

Answer 3

Based on cell types and ratios of different laminae, rather than function.

Question 4

How many areas does Brodmann’s map of the brain have?

Answer 4

52.

Question 5

What do Betz cells do?

Answer 5

Project directly from the motor cortex down to motor neurons (5%) and the spinal tract (brain stem and spinal cord)

Question 6

Alpha motor neurons can be referred to as what?

Answer 6

Lower motor neurons

Question 7

What are Betz cells often referred to as?

Answer 7

Cortical tract neurons/upper motor neurons.

Question 8

What are the 3 types of spinal interneurons that are innervated by Betz cells?

Answer 8

• Red nucleus
• Pontine Reticular Formation
• Medullary Reticular Formation

Question 9

What is the result of having different pathways from the motor cortex to spinal interneurons?

Answer 9

Different propagation delays due to varying numbers of synapses.

Question 10

If the left M1 area is stimulated using TMS, what action in the individual might result and why?

Answer 10

Wave like response in right hand muscles, due to the varying propagations of the different pathways between the motor cortex and the interneurons in the spine.

Question 11

Individual neurons can innervate multiple _____?

Answer 11

Muscles

Question 12

Multiple neurons can innervate _____?

Answer 12

Single muscles

Question 13

The motor cortex is most useful for what?

Answer 13

Finely controlled precision muscle movements, especially when force regulation is required.

Question 14

Is the role of M1 in learning more about acquisition or retention?

Answer 14

Retention

Question 15

What does SMA stand for?

Answer 15

Supplementary motor area

Question 16

What does PMC stand for?

Answer 16

Pre Motor cortex

Question 17

What are SMA and PMC for?

Answer 17

Planning movements and selection of specific movements, not the execution

Question 18

What are the two areas within SMA and what are they each for?

Answer 18

• SMA proper, involved in learning, bimanual co-ordination, movement sequences and internally generated movements (e.g. fidgeting)
• pre-SMA, involved in the execution of movements.

Question 19

What does dPMC stand for?

Answer 19

Dorsal pre motor cortex.

Question 20

What is the dPMC for?

Answer 20

• Preparing movement

- Learning conditional actions to external cues (traffic lights)

Question 21

What does vPMC stand for?

Answer 21

ventral pre motor cortex

Question 22

What is the function of the vPMC?

Answer 22

• Sensory guidance of movement
• Visuomotor control during grasping
• Mirror neurons

Question 23

Where were mirror neurons first discovered?

Answer 23

PMv/vPMC

Question 24

When are mirror neurons activated?

Answer 24

(in monkeys) When a goal directed action is undertaken, and the same goal directed action is seen or heard by someone else.

Question 25

What is the PPC?

Answer 25

Posterior Parietal Cortex

Question 26

What is the PPC for?

Answer 26

• Maintains the spatial arrangement of the body in the external environment
• Continually integrates sensory and motor input.

Question 27

Is reading required to further understand this topic?

Answer 27

Most definitely.