The Nervous System
Central Nervous System - brain and spinal cord
Peripheral Nervous System - the structures of the nervous system outside of the brain and spinal cord
Somatic Nervous System
The somatic nervous system is a subdivision of the peripheral nervous system. It controls voluntary and conscious motor movement, as well as sending sensory information from the limbs and body to the spinal cord and brain.
The somatic nervous system has a motor (efferent) pathway and a sensory (afferent) pathway.
Autonomic Nervous System
The autonomic nervous system (ANS) is a subdivision of the peripheral nervous system (PNS).
- Coordinates involuntary responses to the environment to help maintain homeostasis.
- Has motor and sensory components.
- Sensory component from viscera (internal organs).
- Motor component to involuntary muscles (smooth, cardiac) and glands.
- The motor component of the ANS can be divided into two major branches: the sympathetic nervous system and the parasympathetic nervous system. These two innervate the same organs but have opposing effects.
Parasympathetic Nervous System
The parasympathetic nervous system controls "rest and digest" functions.
Sympathetic Nervous System
The sympathetic nervous system controls "fight or flight" functions.
