A brain injury to a patient results in facial paralysis. Which descending tract is most likely affected?

1. corticospinal tract
2. corticobulbar tract
3. rubrospinal tract
4. tectospinal tract
5. reticulospinal tract

corticobulbar tract

Figure 15-2 (look at description at top)

Identify the structure labeled "5."

1. upper motor neuron
2. first-order neuron
3. dorsal root
4. second-order neuron
5. ventral root

ventral root

Figure 15-2 (look at description at top)

Identify the origin of the axon labeled "2."

1. lower motor neuron
2. ganglionic neuron
3. second-order neuron
4. upper motor neuron
5. decussation neuron

upper motor neuron

Figure 15-2 (look at description at top)

Identify the type of information that travels along the structure labeled "4."

1. proprioception to the cerebral cortex
2. pain and crude touch sensations
3. fine touch to the cerebral cortex
4. visceral motor commands to smooth muscle
5. motor commands to skeletal muscles

motor commands to skeletal muscles

Figure 15-2 (look at description at top)

The axon labeled "2" synapses with which structure?

1. 1
2. 5
3. 3
4. 6
5. 4

5

Motor neurons whose cell bodies are within the spinal cord are called ________ neurons.

1. postganglionic
2. preganglionic
3. lower motor
4. upper motor
5. somesthetic

lower motor

the basal nuclei

1. provide the background patterns of movement involved in voluntary motor activities.
2. exert direct control over lower motor neurons
3. initiate conscious motor activity
4. act as gatekeeper, filtering out unnecessary sensorimotor activity
5. activate spinal reflexes

provide the background patterns of movement involved in voluntary motor activities.

The pyramids on the ventral surface of the medulla oblongata are formed by fibers of the ________ tracts.

1. corticospinal
2. vestibulospinal
3. reticulospinal
4. corticobulbar
5. tectospinal

corticospinal