Structure:
The brain, encased by the skull
for protection, is the control center for vertebrates.
The brain and the spinal cord are the central nervous system, and the peripheral
nervous system links with it. Motor nerves,
sensory nerves and autonomic nerves
are the primary categories. The structural parts of the peripheral system
are receptors, conductors, and effectors.
Function:
The nervous system actively identifies, interprets and integrates the sensory
stimuli arriving from contacting the environment, and produces electrochemical
impulses for responses distributed through peripheral
nerves. For example, the eyes see images sent through neurons
of the optic nerves to the optic
lobes of the cerebrum for interpretation.
The motor cortex sends back a signal to the skeletal muscles
of the lower extremities, instructing
them to contract, producing a leap. In this example, the retinal cells,
the rods and cones are the sensors, the neurons of Cranial
Nerve I and the motor nerve from the cerebrum are the conductors, and
the muscle cells are the effector cells.
