Structural and Functional Divisions of Nervous System

PNS Divisions

Sensory (afferent) division Somatic sensory fibers: convey impulses from skin, skeletal muscles, and joints to CNS Visceral sensory fibers: convey impulses from visceral organs to CNS - Motor (efferent) division Transmits impulses from CNS to effector organs - Muscles and glands Two divisions - Somatic nervous system - Autonomic nervous system

Autonomic Nervous System

- Consists of visceral motor nerve fibers - Regulates smooth muscle, cardiac muscle, and glands - Involuntary nervous system - Two functional subdivisions Sympathetic-Your sympathetic nervous system is a network of nerves that helps your body activate its "fight-or-flight" response. This system's activity increases when you're stressed, in danger or physically active. Parasympathetic-Your parasympathetic nervous system is a network of nerves that relaxes your body after periods of stress or danger. It also helps run life-sustaining processes, like digestion, during times when you feel safe and relaxed Work in opposition to each other

Somatic Nervous System

- Somatic motor nerve fibers conduct impulses from CNS to skeletal muscle - Voluntary nervous system Conscious control of skeletal muscles

Central Nervous System (CNS)

Brain and spinal cord of dorsal body cavity Integration and control center - Interprets sensory input and dictates motor output

Peripheral Nervous System (PNS)

The portion of nervous system outside CNS Consists mainly of nerves that extend from brain and spinal cord - Spinal nerves to and from spinal cord - Cranial nerves to and from brain