Functionele afdelingen van het zenuwstelsel

The nervous system senses, integrates, and responds to various stimuli. Based on bodily control, the central nervous system cannot be divided functionally, but the peripheral nervous system, or PNS, has two functional divisions.

The sensory or afferent division consists of nerves that carry external information from sensory receptors to the CNS.

In contrast, the motor or efferent division comprises nerves that relay impulses from the CNS to effectors like muscles and glands.

The motor division is subdivided into the somatic and autonomic systems. The somatic branch controls skeletal muscle movement— both voluntary and specialized involuntary movements called reflexes.

The autonomic branch controls smooth and cardiac muscle and glands, subconsciously regulating physiological processes.

The autonomic branch consists of the sympathetic and parasympathetic divisions, which regulate opposing functions. For instance, the sympathetic division can increase the heart rate while the parasympathetic division slows it down.

The enteric nervous system, a third division of the autonomic branch, consists of a network of neurons that regulates movement and secretions of the gastrointestinal tract.