Central Nervous System
The Central Nervous System (CNS) consists of the brain and spinal cord. It is the control center of the body, and it receives and processes information from the PNS. The brain is responsible for higher functions such as thought, memory, and emotion, while the spinal cord is responsible for transmitting signals between the brain and the rest of the body.
Peripheral Nervous System
The Peripheral Nervous System (PNS) consists of all the nerves that extend from the CNS to the rest of the body. It is further divided into two main parts: the somatic nervous system and the autonomic nervous system.
Somatic Nervous System
The Somatic Nervous System is responsible for voluntary movement and sensory perception. It is composed of sensory neurons that transmit information from the sensory organs to the CNS and motor neurons that transmit signals from the CNS to the skeletal muscles, allowing for voluntary movement.
The Autonomic Nervous System
The Autonomic Nervous System is responsible for regulating involuntary functions of the body such as heart rate, digestion, and breathing. It is further divided into the sympathetic and parasympathetic nervous systems.
Sympathetic Nervous System
The Sympathetic Nervous System prepares the body for a "fight or flight" response, increasing heart rate, blood pressure, and respiration, and decreasing digestive activity. This response is activated in response to stress or danger.
Parasympathetic Nervous System
The Parasympathetic Nervous System restores the body to a state of relaxation after a stressful event. It decreases heart rate and blood pressure while increasing digestive activity.
Overall, the nervous system is essential for the proper functioning of the human body. It allows us to sense and respond to the environment, communicate with others, and maintain homeostasis. Dysfunction of the nervous system can lead to a range of disorders, including Parkinson's disease, Alzheimer's disease, and multiple sclerosis.