DIVISIONS [ HARMONY ( THE NERVOUS SYSTEM ) ]
The nervous system is an intricate and vital part of the human body. It is responsible for coordinating and controlling various functions, allowing us to interact with the world around us.
Within the nervous system, there are several divisions that work together in perfect harmony to ensure its proper functioning. One of these divisions is the central nervous system (CNS), which consists of the brain and the spinal cord.
The brain is the command center of the nervous system, processing information and sending signals to different parts of the body. It plays a crucial role in cognition, emotions, and behavior.
The spinal cord acts as a messenger, transmitting signals between the brain and the rest of the body. Another essential division is the peripheral nervous system (PNS), which connects the CNS to the various organs, muscles, and sensory receptors.
The PNS can be further divided into the somatic nervous system and the autonomic nervous system. The somatic nervous system controls voluntary movements and relays sensory information to the CNS. On the other hand, the autonomic nervous system regulates involuntary functions such as heartbeat, digestion, and breathing. Within the autonomic nervous system, there are two subsystems: the sympathetic nervous system and the parasympathetic nervous system.
These subsystems work in harmony to create a balance in bodily functions. The sympathetic nervous system is responsible for the body’s “fight or flight” response, preparing it to cope with stress or danger. Conversely, the parasympathetic nervous system promotes a state of relaxation and restoration, helping the body to rest and digest.
Overall, the divisions of the nervous system, including the central and peripheral nervous systems, as well as the autonomic and somatic subsystems, work in perfect harmony to ensure the proper functioning of our bodies. This intricate balance allows us to perceive our environment, think, move, and respond effectively to various stimuli. It is truly remarkable how these divisions come together to create a harmonious symphony within our nervous system.
The peripheral nervous system has two key parts. The sensory divisions is sometimes called afferent, for the Latin for “carrying toward.” It sends signals from sensory receptors all over the body toward the central nervous system.
Sensors in the skin, muscles, and joints are called somatic (“body”) afferent fibers, while those from the internal organs are called visceral afferent fibers.
The other part, the motor or efferent division, sends signals from the central nervous system to the muscles and glands. As these signals cause, or “effect,” changes, they create the motor responses that make the body move.
Most nerve cells act as two-way streets, sending signals back and forth between the brain and extremities. Purely afferent or efferent cells are rare.
The motor division also is divided into parts. The somatic nervous system sends signals from the central nervous system to the skeletal muscles. As it is usually under conscious control, this is sometimes called the voluntary nervous system.
The other part is the autonomic nervous system, which comprises visceral motor fibers that automatically activate the heart, digestive tract, and other body functions.