The Nervous System: Anatomy and Function
by Yuvi K - December 16, 2023
What is the Nervous System?
The nervous system is a complex, sophisticated network that works together to control and coordinate the activities of all parts of your body. It consists of specialized cells called neurons and associated supportive and connective tissues, all acting together to receive and process information from the environment around you, and use that information to detect changes and initiate appropriate responses.
Anatomy of the Nervous System
The nervous system is divided into two major parts: the central nervous system and the peripheral nervous system.
Central Nervous System (CNS)
The Central Nervous System (CNS) is composed of the brain and the spinal cord. The brain is the major structure of the CNS. It is responsible for receiving sensory stimuli, processing information, and initiating responses. It is protected by the bones of the skull. The spinal cord is a long, thin bundle of nerves extending from the brain and extending from the neck to the lower back. It also relays messages back and forth between the brain and the rest of the body, and is protected by the vertebral column (spinal column).
Peripheral Nervous System (PNS)
The Peripheral Nervous System (PNS) consists of all the nerves that extend outside of the brain and spinal cord. It can be further divided into two main categories:
- Somatic Nervous System (機能性神経系, Kino Kaishikenkei): Controls the voluntary movements of the body’s muscles.
- Autonomic Nervous System (オートネム働き, Atonemu Hataraki): Controls the involuntary functions of the internal organs and glands.
Basic Functions of the Nervous System
The nervous system plays an essential role in processing and responding to sensory stimuli from the environment. It is responsible for the following functions:
- Receiving and Processing Information (受け取りと処理, Uketori to Shori): The nervous system receives information through specialized cells, called neurons, that form connections and transmit signals throughout the body. These signals are then processed and interpreted by the brain, enabling it to make complex decisions.
- Initiating Motor Responses (動作応答の始動, Dosa Oto No Shido): Once the information is processed, the brain will initiate the appropriate motor response, such as movement, changes in heart rate, and many more.
- Regulating Autonomic Activities (オートネム活動の調整, Atonemu Kasso No Chosei): The autonomic nervous system is responsible for controlling the involuntary activities of the body, such as digestion, breathing, and many more.
How Does the Nervous System Work?
The nervous system works by transmitting electrical signals via neurons throughout the body. These neurons are specialized cells that can both respond to stimuli and transmit information.
Neurons
Neurons are made up of various functional parts, including a cell body, dendrites, and an axon. The cell body is the main part of the neuron, responsible for producing proteins and energy. The dendrites are short branches that receive electrical stimuli from other neurons, and the axon is a long single fiber that transmits electrical impulses away from the cell body.
Nerve Impulses
The transmission of electrical signals in neurons is known as an action potential. Action potentials move along the axon, triggering the release of neurotransmitters when it reaches the end of the axon. Neurotransmitters then enter the synaptic cleft (the space between neurons) and bind to receptors on the dendrites of nearby neurons, allowing the message to move forward.
Conclusion
The nervous system is an intricate and complex network of neurons and tissues responsible for processing and responding to stimuli and coordinating the activities of the body. It is composed of the CNS and the PNS, which are composed of specialized neurons and tissues that transmit and receive electrical signals. These signals enable the body to initiate appropriate responses and regulate autonomic activities, bonding together the body’s complex activities into one cohesive unit.
