Nervous System Quiz

Painkillers relieve the symptoms of pain but do not treat the cause. They work by affecting the chemicals which interact with our pain receptors, reducing the strength of the message to the CNS, and therefore reducing pain intensity.

The nervous system is a collection of specialised cells which have the role of detecting stimuli, interpreting them and then organising responses. Stimuli could be internal or external and as part of the process of homeostasis, the nervous system has a role in maintaining the body’s internal conditions to allow survival and maximising the efficiency of other systems. For example, the skin has receptors that detect the temperature of the surroundings. If it is too hot, the nervous system can organise responses by using effectors which are either muscles or glands.

The other aspect of homeostasis involves the hormonal system which acts in a less targeted way and has more general effects on the body than the nervous system.  

Through the system of neurones, the brain and spinal cord (also known as the Central Nervous System or CNS) are able to understand what is happening and then make appropriate decisions about suitable actions. As a more general example, if an animal (including humans) saw a threat such as a preditor, the eyes would pass on the information via sensory neurones to the brain. The brain would then interpret the information and send electrical signals via the motor neurones to the muscles of the legs which would then begin to run away. The nervous system, therefore, is an essential part of survival, both for early Homo species and animals all around the World.

Relay neurones are part of a more urgent system that bypasses the central nervous system in order to respond rapidly to threats to the body. For instance, if your hand touched a stinging nettle or another sharp plant, the receptors in the hand would rapidly send an electrical signal towards the central nervous system via sensory neurones. The relay neurones located in the spinal cord would intercept the signal and send an automatic response instruction to the effectors (muscles) to make them move away, thus avoiding further injury. 

The nervous system is truly fascinating but why not take another quiz on Enzyme Action or Enzymes and Nutrition?