Ääreishermoston

The peripheral nervous system, or ääreishermosto in Finnish, refers to all parts of the nervous system outside of the brain and spinal cord. It comprises nerves that branch out from the central nervous system to reach all parts of the body, including limbs, organs, and skin. The peripheral nervous system is further divided into two main functional divisions: the somatic nervous system and the autonomic nervous system.

The somatic nervous system controls voluntary movements by transmitting sensory information from the skin, muscles, and joints to the central nervous system, and motor commands from the central nervous system to the skeletal muscles. This system is responsible for our conscious interactions with the external environment.

The autonomic nervous system, on the other hand, regulates involuntary bodily functions such as heart rate, digestion, breathing, and glandular secretions. It operates without conscious thought and is divided into the sympathetic and parasympathetic nervous systems, which often have opposing effects to maintain bodily homeostasis. The sympathetic nervous system prepares the body for action (fight or flight), while the parasympathetic nervous system promotes relaxation and energy conservation (rest and digest). Together, these systems ensure the continuous and efficient operation of vital bodily processes.