In science, the nerve cell is called a neuron. This is a special cell designed to transmit excitations within the body. It is essential for the exchange of information.
What is a nerve cell?
The transmission of impulses is the most important task of the nerve cell . Specifically, an organism should succeed in transmitting signals between the brain and the body organs. Billions of neurons are responsible for this in the human body. The union of the nerve cells forms the nervous system. Depending on their structure and properties, the totality of neurons can be divided into cell groups. In particular, a distinction is made between motor and sensory neurons.
- Motor neurons are responsible for the communication of brain and body muscles. Specifically, the body should succeed in processing environmental stimuli without error and react with impulses in time.
- Sensory neurons connect the brain with the sensory organs. In combination, gap-free communication is achieved throughout the body. Interneurons form a special form. These are nerve cells that transport information over long distances. Local signals can thus be directed to different parts of the body.
Anatomy and structure
In terms of structure, a nerve cell can be divided into different components, each with its own area of responsibility. To begin with, the reception of a stimulus is the main focus. Here, the dendrites play an important role. They receive body stimuli with a strongly branched branch system. Subsequently, the information obtained is passed on to the cell body, the so-called soma. On the soma is the axon hillock, which collects the received stimuli. Further transmission takes place only when a sufficient intensity has been reached. In the form of an electrical potential, the signal reaches the presynaptic terminals. The axon acts as the connection. It is surrounded by lipid-rich cells and is thus electrically insulated. The presynaptic terminal knobs convert the electrical signal into a chemical impulse. The chemical signal is responsible for the release of neurotransmitters. They enable further information transfer in the so-called synaptic cleft (synapse). This is a hurdle to the next neuron. The process is repeated from neuron to neuron. Depending on the type of neuron, the anatomy may differ in its expression.
Function and tasks
The system of neurons is essential for the maintenance of bodily functions. The constant exchange of communication between the brain, sensory organs and muscles enables timely response to the environment. This begins with the control of respiration, body temperature and blood circulation. Added to this are metabolism, energy supply and sensory functions. The reflex is also one of the most important tasks. The special feature of a reflex is that a bodily reaction is carried out independently without the involvement of the brain. Instead, the spinal cord is responsible for information processing. To enable a quick reaction, an impulse is sent directly in the spinal cord and executed by the affected body muscles. In retrospect, it still appears to the person as if he or she had performed a conscious movement. This is due to the fact that the brain takes control of the respective muscle region a short time later. However, the nerve cells are also considered to play a major role in learning. Specifically, synapses play an important role. Learning processes take place in a specific brain region, the hippocampus. The synapses located there undergo functional changes during learning. The changes result in an increase in the intensity of impulses in the recipient cell. Repeated learning thus has the purpose of making stored information more accessible. This is accompanied by the side effect that new synapses are formed. This can be compared to a trail. The more often it is used, the more accessible it becomes. If it is no longer used, it eventually becomes overgrown. This happens in a similar way in the brain. If information is not requested, synapses are degraded, while the intensity of impulse transmission decreases. Specifically, this is forgetting.
Diseases and ailments
Diseases and disorders of the nervous system are called neurodegenerative diseases. These are diseases that occur sporadically and progress slowly. In most cases, they can be attributed to hereditary causes. In neurodegenerative diseases, damage to nerve cells occurs, impairing the functionality of the nervous system. Dementia and movement disorders are eventually the result. Among the best-known diseases of the nervous system is Alzheimer’s disease]. In most cases, Alzheimer’s occurs above the age of 65 and is responsible for more than 60 percent of all dementia cases. Dementia, in turn, is a disease of the brain in which cognitive, emotional and social abilities decline. This can be attributed to a degeneration of the nerve cells located there. Deficits arise especially in the functionality of short-term memory. A severe form of the neurodegenerative disease is the [progressive supranuclear gaze palsy]] (PSP). Damage to existing neurons occurs in the basal ganglia. The basal ganglia are brain areas that are responsible for controlling automatic movements. As a result, patients are no longer able to maintain their balance, control their eyes and coordinate swallowing. In addition, there are impairments in speech control. After three to ten years, PSP eventually leads to death. Medications succeed in delaying the progression of the disease and alleviating symptoms.
