Test #3 Chapter 14

Question 1

Describe the ways axons from the brain descend through the spinal cord

Answer 1

The lateral pathways: Involved in voluntary movement and under direct cortical control.
Ventromedial pathways - Involved in control of posture, locomotion, and are under brain stem control

Question 2

Descibe the Corticospinal tract

Answer 2

Originates in frontal lobe and somatosensory areas of parietal lobe, pass through the medulla and decussate junction between medulla and spianl cord. One the largest tracts

Question 3

How many areas are in the motor cortex?

Answer 3

6.
Prefrontal areas and parietal lobes are interconnected and represent highest level of motor control. areas 6 and 4 account for majority of descending corticospinal tracts

Question 4

Where are the major input area?

What is the basal ganglia?

Answer 4

Comes from the Ventral Lateral Nucleus, which receives major input from basal ganglia.
Basal ganglia consists of the caudate nucleus, putamen, and globus pallidus. The caudate and putamen are the major target of cortial input to basal ganglia.
The globus pallidus is the source of output to the thalamus

Question 5

Describe the Basal Ganglia

Answer 5

The cortex sends signals to the putamen, the putamen makes inhibitory synapses in the globus pallidus, which make inhibitory synapses with neurons in the VLo. The VLo sends excitatory signals to the motor area 6. This controls willed movements.

Question 6

Describe the cerebellum

Answer 6

Recieve input from motor cortex, brainstem, and spinal cord, modulates this input, and in turn projects back to the cortex via thalamus