Introduction
The conditions of our body are controlled in two ways with chemical and nervous responses. Cells known as the receptors help to detect the stimuli (i.e. any changes in the environment). The coordination centre, like the brain, spinal cord or pancreas, that receives and processes information from the receptors around the whole body. Our nervous system helps us to detect and react to various changes in the environment. Sense organs, such as eyes, detect changes and our central nervous system helps in coordinating a response. The conditions inside our body should be carefully controlled if the body is to function effectively. The conditions are mainly controlled by two ways with chemical and nervous responses.
Nervous System
The nervous system functions to control and coordinate various activities of the human body. There are mainly three types of nerves, cranial nerves, spinal nerves and visceral nerves. All the three run throughout the body and help in sending and receiving messages in the form of electrical impulses. Similarly there are also five sense organs present in our body such as eyes, ears, nose, tongue and skin they are known as receptors.
Since, they receive information from the surrounding environment. Thus, a receptor represents a group of cells in the sense organ that is sensitive to a particular type of stimuli such as light, sound, smell, taste, heat, etc. All these receptors send messages in the form of electrical impulses to the spinal cord and brain via the sensory nerves. Another type of nerves known as the motor nerves transmit responses from the brain and spinal cord to the effectors.
An effector represents a part of the body that responds to a specific stimulus according to the instructions sent by the nervous system. The muscles and glands represent effectors of the body. It helps in controlling all our behaviour, thinking and actions. It is via the nervous system only that all other systems of our body work properly. It transfers information from one internal system to another. For example, when we put food in our mouth, it causes the release of saliva from the salivary glands.
The cells that compose the nervous system are known as neurons. Neuron represents the largest cell in the body. It transmits messages that are in the form of electrical impulses or nerve impulses. There are three major components of neurons. The cell body, cytoplasm and a nucleus. Many long and thin fibres come out of the cell body of a neuron. The short fibres are known as the dendrites and the long fibres are known as the axon. The axon is covered by an insulating and protective sheath known as the myelin. It is composed of fat and proteins.
Parts of Nervous System
The nervous system possesses two main parts. Each part comprises around billions of cells known as neurons, or nerve cells. These special kinds of cells send and receive electrical signals throughout the body in order to respond to any stimulus received. The main parts of the nervous system are as follows:
Central nervous system (CNS): our brain and spinal cord together makes up our CNS. Our brain uses our nerves in order to send messages to the rest of our body. Each nerve possesses a protective outer layer known as the myelin. Myelin insulates the nerves and helps the messages to get through.
Peripheral nervous system: the peripheral nervous system comprises many nerves that branch out from the CNS all over the body. This system transmits information from the brain and spinal cord to other different organs such as the arms, legs, fingers and toes. The Peripheral nervous system consists of the following:
- Somatic nervous system: that guides all our voluntary movements.
- Autonomic nervous system: it controls the activities one does without thinking about them.
Relationship between Musculoskeletal and Nervous System
The nervous system functions to control all our voluntary muscle movements. Voluntary muscles are the ones that we control intentionally. Some include large muscle groups in order to perform activities such as jumping. While others use smaller movements, such as pushing a button. Movements occur when:
- Our nervous system (specially the brain and nerves) send messages to activate our skeletal (specially voluntary) muscles.
- Our muscle fibers contract, in response to the stimuli.
- When the muscles get activated it pulls on the tendon. Tendons attach muscles to bones. The tendon pulls the bone, thus making it move.
- In order to relax the muscle, the nervous system sends another message. This impulse triggers the muscles to relax or to deactivate.
- The relaxed muscle releases tension that moves the bone to a resting position.
Activation of Autonomic Nervous System
Autonomic activation refers to an increase in the activity of the autonomic nervous system, that is the physical system responsible for unconsciously maintaining bodily homeostasis and coordinating bodily responses. It is evaluated by comparing the autonomic values which are obtained during a test period to those obtained during rest or the baseline period. Baseline measures usually are taken shortly before test periods. Moreover, they can also be taken well in advance of the test periods or after them. Autonomic activation can concern neuronal activity or activity of visceral structures affected by it, like the ones involved in circulation, respiration, and digestion. The difference between neuronal activation and visceral structure activation is not insignificantly given that an increase in the activity of a visceral structure can be caused via a decrease in the neuronal activity.
Conclusion
The nervous system is composed of nerve fibres and nerve cells that help in transmitting messages to various different parts of the body. It is a significant system found in animals and humans contemporising its function by passing out signals to and from different parts of the body. Nervous system together coordinates with the endocrine system. Here we come to an end of this topic. We hope that this article has helped you clear all your concepts.