Where does the passage of signals through the nervous system begin?
With the receptors (General, Special Sensory, or Proprioceptors).
What do General Receptors convert stimuli into?
Action potentials (e.g., touch, pain, pressure).
Which nerves carry signals from receptors toward the CNS?
Afferent Nerves.
Which spinal cord structure do sensory signals enter through?
The dorsal root.
What is the function of integrative neurons in the CNS?
They receive and interpret sensory signals.
What structure filters and prioritizes sensory information before it reaches the cerebral cortex?
The thalamus.
How does the CNS make learned activities faster?
By increasing myelination on frequently used pathways.
Which nerves carry motor commands away from the CNS?
Efferent Nerves.
Which spinal cord structure do motor signals leave through?
The ventral root.
What two areas provide input to the motor pathways?
The cerebellum and the medulla pyramids.
What are the “Effectors” that carry out the CNS response?
Skeletal muscles (somatic), smooth/cardiac muscle (visceral/autonomic), or glands.
What is the superior and inferior extent of the spinal cord?
It runs from the medulla oblongata to the level of the second lumbar vertebra (L2).
What is the tapered end of the spinal cord called?
The Conus Medullaris.
What structure anchors the spinal cord to the sacrum?
The Filum Terminale.
What is the bundle of nerves extending downward from the lower vertebrae called?
Cauda Equina (“horse tail”).
Which enlargement contains nerve roots that supply the arms?
The Cervical Enlargement.
Which enlargement contains nerve roots that supply the legs?
The Lumbar Enlargement (it is physically located in the thoracic vertebral region).
What are Ascending Tracts?
Sensory pathways that travel up the spinal cord toward the brain.
What is the function of the Fasciculus gracilis and cuneatus tracts?
They carry touch, pressure, and proprioception to the cerebral cortex.
Which tract carries pain, temperature, touch, and pressure to the thalamus?
The Spinothalamic tract.
What are Descending Tracts?
Motor pathways that travel down the spinal cord from the brain.
What is the function of the Corticospinal tract?
It carries motor signals from the motor cortex to skeletal muscles.
Which descending tract controls muscle tone and is involved in waking from sleep?
The Reticulospinal tract.
What is a Plexus?
A network of nerves formed by the joining and re-sorting of fibers from the ventral rami of spinal nerve roots.
