The building blocks of the nervous system

Personal/Fitness Training Blog

The nervous system is vital to our daily functioning as it controls sensory, integrative and motor functioning. In fact, it’s so vital that – without it – we are technically dead even though our heart may still be beating.

What makes up the nervous system?

Dr Jasvinder Chawla, Chief of Neurology at Hines Veterans Affairs Hospital, says that the nervous system is divided into two parts:

  • The Central Nervous System (CNS), which is made up of the brain and spinal cord, and
  • The Peripheral Nervous System (PNS), which is made up of nerves that connect the rest of the body with the CNS.

According to experts at Northeastern University, the two parts of the brain which are most involved with exercise are the cerebellum, which controls – among others – the speed at which we perform movements as well as the brain stem that controls aspects such as blood pressure and heart rate.

What are the parts of a nerve?

Nerves are made up of billions of neurons. There are three components to a nerve:

  • The cell body contains a nucleus (in other words, a centre) as well as other items such as lysosomes and mitochondria.
  • The axon which is responsible for transferring nervous impulses to the organs of the body.
  • The dendrites which gather information from the body’s organs and feed it back to the nervous system.

Neurons are classified depending on the function that they perform:

  • Sensory neurons (also called sensory receptors) transmit signals from the effector site to the CNS.
  • Interneurons transmit impulses between neurons.
  • Motor neurons transmit impulses from the CNS to the effector site.

What is an effector site?

An effector site is the place where we see things happen because of a nerve impulse. So, for example, during the bicep curl, the brain would send an impulse to the hands to lift the barbell or dumbbells to perform the exercise. The hands, in this case, would be the effector site.

The importance of sensory receptors in fitness

Sensory receptors can be found in every part of the body. They are responsible for relaying environment stimuli to the CNS in order to produce an appropriate response.

These receptors are divided into four categories:

  • Mechanoreceptors, which are responsible for sensing touch and pressure,
  • Nociceptors, which are responsible for sensing pain,
  • Chemoreceptors, which are responsible for the sense of taste and smell, and
  • Photoreceptors, which are responsible for sensing light and darkness.

Fitness professionals are most concerned with mechanoreceptors as these are found in the muscles, tendons, joints and ligaments. When the muscle tissue stretches, compresses, experiences traction or tension, they will send signals to the CNS for the appropriate movement to take place.

As a personal trainer, you will need to have an intimate knowledge about the anatomy and physiology of the human body so that you can advise your clients accordingly. Trifocus Fitness Academy’s Personal Training Certification is just such a course as it will equip you will all the knowledge that you need in order to soar in your career as a personal trainer. Click here for more information.