Divisions of the Nervous System

Central Nervous System (CNS)

• Composed of the brain and spinal cord

• Responsible for processing sensory information, integrating data, and generating responses

Peripheral Nervous System (PNS)

• All neural tissue outside the CNS

• Includes cranial nerves (emerging from the brain) and the spinal nerves (emerging from the spinal cord)

PNS Division: Sensory (afferent) Division

Transmits impulses from sensory receptors to the CNS

PNS DIvision: Motor (efferent) Division

Transmits impulses from the CNS to muscles and glands

Motor Division Subdivisions: Somatic Nervous System

Controls voluntary movements of skeletal muscles

Motor Division Subdivisions: Autonomic Nervous System (ANS)

Controls involuntary functions, including smooth, cardiac muscle, and glands

ANS Division: Sympathetic Division

Prepares the body for stress or emergency situations (“fight or flight”), increasing heart rate, dilating bronchi, and redirecting blood to skeletal muscles.

ANS Division: Parasympathetic Division

Promotes “rest and digest” functions, such as reducing heart rate, stimulating digestion, and promoting urinary function.