Introduction to the Nervous System

How does our body control and coordinate each aspect of everyday life? Answer: Through the body’s nervous system.... read more

The nervous system is a complex and highly organized physiological network that serves as the body's primary communication and control system. It enables organisms to respond to internal and external stimuli with remarkable precision and speed. Anatomically it is divided into two main parts: the central nervous system (CNS) consisting of the brain and spinal cord, which act as the main processing centres for the entire system together with the peripheral nervous system (PNS), made up of all the nerves in the body facilitating communication. The PNS can be further subdivided into the somatic nervous system, which controls voluntary movements and sensory information, and the autonomic nervous system, which regulates involuntary functions such as heart rate, digestion, and respiratory rate.

The nervous system is comprised of billions of neurons and supporting cells, providing support for its ability to respond to internal and external stimuli. Neurons, the highly specialised cells of the nervous system, serve as fundamental building blocks designed to transmit information via electrical and chemical signals. One of their defining features is their excitability allowing for discreet communication throughout the body. However, equally important to maintaining health and functionality of the nervous system are glial cells. These cells provide critical support, protection, and nutrition to neurons.

Functionally, the nervous system can be divided into a sensory component, responsible for receiving and processing sensory information from the environment and the body. It involves various sensory receptors, neural pathways, and brain regions that interpret sensory data. The motor component is responsible for initiating and controlling both voluntary and involuntary movements. It involves motor neurons, neural pathways, and brain regions that plan, initiate, and execute movement. Neither system works in isolation, rather they are highly interconnected and work together to facilitate coordinated responses to stimuli. For example, sensory feedback informs the motor system about the external environment and the state of the body, allowing for appropriate adjustments and responses. In addition to these fundamental systems, our nervous system also contains the limbic system. This system is comprised of a complex set of structures within the CNS that plays a crucial role in regulating emotions, memory, and certain aspects of behaviour. It works closely with the rest of the nervous system to integrate emotional and cognitive processes, influencing various physiological and psychological responses.

In this lecture series, we will explore the fundamental properties of the nervous system, including its anatomical and cellular basis together with a brief overview of several key aspects required to understand the basic structure and function of this complex system. We will also touch on changes that can occur to our nervous system due to aging or injury.