Exam 9 (CH. 14)

Question 1

what areas of cortex generate motor outputs? What is different about these areas? Where do they get inputs and where do they send outputs?

Answer 1

• primary motor cortex (area 4), supplementary cortex (area 6), premotor cortex (area 6) .
• area 6: important for planning movements, generating intent, and converting to action. “premotor”. Anticipate movements, mirror neurons
  area 4: (M1) important for the execution of movements.
• inputs through the thalamus
• brain stem and spinal cord

Question 1

What is a premotor cortex? Supplementary motor cortex?

Answer 1

• the lateral part of cortical area 6, involved in the control of voluntary movement.
• the medial part of cortical area 6; involved in the control of voluntary movement.

Question 2

Be familiar with the structures and levels of control in the motor hierarchy.

Answer 2

Strategy: the goal of the movement and movement strategy that best achieves the goal.
- Structures are: Neocortex and basal ganglia
Tactics: the sequences of muscle contractions, arranged in space and time, required to smoothly and accurately achieve the strategic goal.
- Structures are: motor cortex and cerebellum
Execution: activation of the motor neuron and interneuron pools that generate the goal-directed movement and make any necessary adjustments of posture.
- Structures are: spinal cord and brain stem

Question 3

What are some diseases that affect movement? What is their root cause? How can this be helped? What are some emerging therapies?

Answer 3

• (Huntington’s) CRISPR,
  Hyperkinesia, dyskinesias (abnormal movements) , dementias (impaired cognitive abilities), and a disorder of personality are the symptoms of Huntingtons
  organic basis: profound loss of neurons in the caudate nucleus, putamen, and globus pallidus with additional cell loss in the cerebral cortex and elsewhere.

(Parkinson’s) Dopa treatments
symptoms: slowness of movement (brady), difficulty in initiating willed movements (akinesia), increased muscle tone (rigidity), and tremors of the hands and jaw.
Organic basis: degeneration of certain substantia nigra neurons and their inputs to the striatum.

Question 4

What are the descending motor pathways? What does each contribute to behavior?

Answer 4

• Ventromedial (involuntary movements): use sensory information about balance, body position, and the visual environment to reflexively maintain balance and body posture
• Lateral Pathways (voluntary movements):

Question 5

How does primary motor cortex generate output?

Answer 5

large pyramidal neurons in layer V of the motor cortex project axons, via the corticospinal tract, to the ventral horns of the spinal cord. the axons directly excite pools of extensor motor neurons and indirectly (via interneurons) inhibit pools of flexor motor neurons that serve as antagonists of the extensors.

Question 6

What is the role of the cerebellum with movement? What are symptoms of cerebellar problems?

Answer 6

• to detect the difference, or “motor error,” between an intended movement and the actual movement, and, through its projections to the upper motor neurons, to reduce the error.
• movements become uncoordinated and inaccurate, a condition known as ataxia.
  they can also have dyssynergia( and dysmetric

Question 7

What is the motor loop through the thalamus? What structures are involved, and how do they influence one another? What disease(s) affect this loop? How can treatments help?

Question 8

Compare and contrast the somatosensory and motor maps.

Answer 8

the motor map is more coarse; not high resolution because of how we use our body many possible combinations. different stimulation parameters illustrate different movements