The Neurological System

The Neurological System

The branches of science that will help you understand the body parts and functions are anatomy and physiology. Anatomy deals with the study of the human body (the component parts, structure and position) and physiology the study of how the body functions.

Body Systems

The body comprises of a number of systems including the: Cardiovascular system, Digestive system, Endocrine system, Muscular system, Neurological system, Respiratory system and the Skeletal system.

The Neurological System

All of our body systems work in conjunction with each other and none are capable of working in isolation. The nervous system controls and coordinates the functioning of all other systems in response to our surroundings. Each stimulus or change in our environment is detected by our senses and messages are interpreted by the brain that in turn, sends directions to the various organs to respond and adapt according to the external conditions which affect our body.

The function of the Neurological System is to transmit and receive a constant series of messages via electrical impulses to and from the control centre situated in the brain. These messages are either those receiving "information" from various body tissues via the sensory nerves, or those initiating the function of other tissues such as organs, muscles, etc.

The nervous system is divided into the central nervous system (CNS) that includes the brain and spinal cord, and the peripheral nervous system (PNS) comprising cranial nerves and spinal nerves. The PNS includes nerves emerging from the brain (cranial nerves) and nerves emerging from the spinal cord (spinal nerves). These nerves are divided into sensory nerves that conduct messages from various parts of the body to the CNS, whilst motor nerves conduct impulses from the CNS to muscles and glands. The PNS is further divided into the Somatic System (SNS) and Autonomic System (ANS), depending on the area of the body these messages are transmitted to and from.

The SNS consists of sensory neurons from the head, body wall, extremities, and motor neurons to skeletal muscle. The motor responses are under conscious control and therefore the SNS is voluntary. Certain peripheral nerves perform specialised functions and form the autonomic nervous system; they control various activities that occur automatically or involuntarily such as the contraction of smooth muscle in the walls of the digestive system. The autonomic system is further divided into the sympathetic and parasympathetic systems. These two systems provide nerve stimuli to the same organs throughout the body, but bring about different effects.

The Sympathetic Nervous System helps prepare the body for "fight or flight" and create conditions in the tissues for physical activity. It is stimulated by strong emotions such as anger and excitement and will therefore speed up heart rate, increase the activity of sweat glands, adrenal glands, and decrease those of the digestive system. It also produces rapid redistribution of blood between the skin and skeletal muscles.

Conversely, the Parasympathetic Nervous System slows down the body and helps prepare for a more relaxed state, ready for digestion and sleep. It will therefore increase peristalsis of the alimentary canal, slow down the heart rate, and constrict the bronchioles in the lungs. The balance between these two systems is controlled to create a state of homeostasis that is where the internal stability of the bodily systems are maintained in response to the external environment.

Effect of exercise on the neurological system

Good coordination and balance is vital to the sports person. The quicker the reactions, the more chance the individual has of having "the edge" over the opposition, or of improving his or her personal best. As with most of the Systems, the neurological system can be trained and improved with repetitive exercises. New and extended movements may be progressively attempted, practiced and perfected involving action with the musculoskeletal systems and, as importantly, the voluntary nervous system to initiate those actions.

It is also important to realise that to some extent nerves serving muscles under our conscious control work in pairs and therefore when rehabilitating an injured part it is often beneficial to exercise and stimulate the symmetrically uninjured part as well.

We have already noted how other systems may benefit from exercise and these improvements take place with the help of the neurological system. Like other systems, the neurological system may be adversely affected by smoking, lack of sleep, poor diet and stress.

The nervous system is adversely affected by age. As we grow older neurons are lost and not replaced. There is also a decreased capacity for transmitting impulses to and from the brain and both voluntary and reflex actions become slower.