Picture a command centre full of computers and workers, forming the central place for an operation to be managed and orders to be carried out. Now imagine that each person has this same centre of operations in their body, called the nervous system. It practically controls everything we do, including our thoughts, feelings, and movements. It even controls our breathing.
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Jetzt kostenlos anmeldenPicture a command centre full of computers and workers, forming the central place for an operation to be managed and orders to be carried out. Now imagine that each person has this same centre of operations in their body, called the nervous system. It practically controls everything we do, including our thoughts, feelings, and movements. It even controls our breathing.
Considering how important the nervous system is, it's important we understand the definition of it overall. We can define the nervous system as:
The nervous system is a network of nerve cells called neurons which transfer messages to and from different parts of the body. It controls movements, responses and automatic bodily functions. It can be split into the central nervous system and the peripheral nervous system.
Neurons receive and transmit information to the cells, comprised of motor neurons, relay neurons, and sensory neurons.
Our nervous systems are crucial to supporting bodily functions and coordinating movements in response to the environment (stimuli).
The nervous system allows you to respond to the environment, clipart.me
To understand the different parts of the nervous system, we must differentiate between the central nervous system and the peripheral nervous system. They are made up of different components, so it's important you remember their differences.
The central nervous system comprises the brain and the spinal cord and controls communications between the brain and the body, acting as a command centre of sorts. The peripheral nervous system connects the CNS to the body to allow the CNS to enact commands.
Parts of our body, such as muscles, skin, and organs, have sensory neurons (when grouped, these are known as nerves). These neurons have receptors that detect stimuli, which leads to messages being sent directly to the CNS.
Motor neurons function by carrying messages from the central nervous system to effectors (organs, muscles or glands) so that they can perform a function.
The spinal cord facilitates the transfer of messages to and from the brain to the peripheral nervous system. It is also involved in reflex actions e.g. startle response.
The spinal cord is the column of nerves between the brain and the peripheral nervous system
The peripheral nervous system consists of all the nerve cells which are not in the central nervous system. The spinal cord activates the peripheral nervous system, which is collectively responsible for gathering and sending information to different body parts through nerves.
This is how our body controls automatic functions such as heartbeat, blood flow, and stimulus responses which seem 'automatic' to us.
The peripheral nervous system can be split into two sections:
Somatic nervous system | Autonomic nervous system | ||||
A network of nerve fibres that transmit and receive information from the senses (for example, visual and auditory information).It also directly controls voluntary muscular movements. These nerve fibres pass information to and from the CNS using myelinated sensory and motor neurons. (Myelin acts as an insulation layer - the neurons are layered to aid faster transmission). | A network of nerves that receives and transmits information from the organs.It controls involuntary body functions (for example, heartbeat and digestion)The autonomic system operates automatically, without conscious direction (hence 'autonomous')The autonomic is further divided into two systems:
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Think of the autonomic nervous system as one that helps us react to situations, particularly those considered an 'emergency'.
It connects our brain to our endocrine system, which is a network of glands and organs that secrete hormones into the blood.
It may help to clearly underline and distinguish how both parts of the nervous system function.
The CNS is responsible for receiving information from the sensory neurons and powering and regulating psychological processes. Any adequate responses are passed to the body via the peripheral nervous system.
It may help to think of the spinal cord as an extension of the brain down the body, directing and aiding the brain to control the voluntary movements of the body.
The somatic nervous system in the PNS comprises nerves that function by sending messages to and from the senses (external stimuli) and muscles (internal) to and from the spinal cord (CNS).
The autonomic nervous system in the PNS functions by regulating involuntary bodily actions such as rises in temperature, arousal, heart rate, and more. It has two divisions: the sympathetic and parasympathetic nervous systems:
If someone is experiencing a fight or flight response, the autonomic nervous system shifts from the parasympathetic system to the sympathetic system. Energy is readily available to use, and our heart rates increase, as well as our breathing and body temperature.
When the threat is no longer evident, the ANS returns to the parasympathetic system in control.
Did you know that when the autonomic nervous system detects a fight or flight situation, our brain produces a hormone called endorphins, known as a natural painkiller produced by the body that is released from the hypothalamus and pituitary glands?
Our blood also thickens with blood vessels restricting to prepare for any potential injury.
The human nervous system is composed of multiple divisions, freepik.com/macrovector
Neurotransmitters are the chemicals that are released from nerve cells in the nervous system. They function by passing chemical messages between neurons across a very small gap between the neurons, known as the synapse. This is called synaptic transmission.
An electrical impulse is triggered and travels down to the end of the neuron, where vesicles containing neurotransmitter molecules release them into the synapse. The molecules are grasped by receptors on the next neuron so that the impulse can be passed onwards.
The synapse can be thought of as an empty, in-between space crucial for transmission to occur.
In the 1880s, William James and Carl Lange came up with a theory of emotion. In short, they proposed that bodily changes to external events instigate emotional responses.
For Jame and Lange, when an individual is sweating, has an increased heart rate and deeper breathing, it is these alterations which cause them to experience the emotion of fear or nervousness.
Thus, they believed that stimulus led to physiological reactions to occur.
It is an important early study investigating the fight or flight response.
Whilst it was one of the earliest theories of a emotion in modern psychology, not everyone has been convinced of its accuracy.
Parts of the nervous system can become damaged, which is considered neurological damage. If someone is a victim of this damage, it can have a direct effect on the way they think, feel, and behave. Some disorders are listed below.
Spinal Cord Injury: If someone is to suffer from any damage to their spinal cord, it can disrupt electrical impulses, thus signals, from being transmitted throughout the body which prohibits movement. Depending on the severity, this can result in partial or complete paralysis.
Prefrontal Cortex Damage: the prefrontal cortex control impulses and helps us to make rational decisions. If damage is done to this area, it can cause a shift in behaviour for people who can become more impulsive and even potentially violent.
A study by Raine et al. (1997) found that murderers had less activity occurring in the prefrontal cortex region, which may be considered one reason for their impulsive behaviour.
Agnosia: Agnosia is a rare disorder where someone cannot process sensory information. With visual agnosia, whilst they may be able to see an object, such as a chair, they cannot recognise that it is a chair. This is because the information sent from the eyes (organ) to the brain (CNS) cannot be comprehended.
Prosopagnosia: this is an extremely rare form of agnosia where an individual cannot recognise faces despite being able to see them. Around 1 in 50 people suffer with some form of prosopagnosia. It can be caused by damage to part of the frontal lobe known as the fusiform face area.
The nervous system is a network of nerve cells called neurons which transfer messages to and from different parts of the body. It controls movements, responses and automatic bodily functions. It can be split into the central nervous system and the peripheral nervous system.
The central nervous system is the part of the nervous system which controls communications between the brain and the body by coordinating messages and passing them between the two. The central nervous system comprises the brain and the spinal cord.
The autonomic nervous system is a subsection of the peripheral nervous system and can be classified as a network of nerves which controls internal organs and glands. It controls involuntary (unconscious) bodily physiologic processes such as heartbeat and digestion and can be further divided into the sympathetic and parasympathetic sections.
The main function of the nervous system is to transfer signals from the brain to different parts of the body, such as organs and glands and vice versa. We can think of its main function as a command centre, where all movements, sensations, and automatic functions are controlled and maintained.
The peripheral nervous system is the part of the nervous system excluding the brain and the spinal cord. It consists of nerves throughout the body which pass on information between the brain and the rest of the body. It can be split into the somatic nervous system and the autonomic nervous system.
What is the autonomic nervous system?
The autonomic nervous system is responsible for regulating involuntary bodily functions.
What are some examples of bodily functions regulated by autonomic nervous system?
Some examples are: heart rate, breathing, sexual arousal, salivation and digestion.
What are the two important neurotransmitters within the autonomic nervous system?
acetylcholine (parasympathetic nervous system) and norepinephrine/noradrenaline (sympathetic nervous system)
The autonomic nervous system is split into what two parts?
The sympathetic nervous system and the parasympathetic nervous system.
What is the sympathetic nervous system primarily responsible for?
The fight-or-flight response
Is the fight-or-flight response related to the sympathetic or parasympathetic nervous system?
Sympathetic nervous system
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