HOW THE BRAIN WORKS

The brain functions as a structural and functional unit 

formed mainly by two types of cells:

1.  Neurons.

2.  Glial cells.

It is estimated that there are about 100 billion neurons in the entire human nervous system and about 1,000 billion glial cells. Neurons are highly specialized and their functions are to receive, process and transmit information through different circuits and systems. The process of transmitting the information is done through synapses, which can be electrical or chemical.

The glial cells, in turn, are responsible for regulating the

 internal environment of the brain and facilitating the process

 of neuronal communication. These cells are arranged 

throughout the nervous system forming their structure and

 are involved in the processes of development and formation 

of the brain.

Formerly it was thought that glial cells only formed the 

structure of the nervous system, hence the famous myth that

 we only use 10% of our brain. But today we know that it

 performs much more complex functions, for example, they

 are related to the regulation of the immune system and the 

processes of celular plasticity after 

suffering an injury.

In addition, they are essential for 

neurons to function

 properly, as they facilitate 

neuronal communication and

 play 

an important role in the transport 

of nutrients to neurons. 

As you can intuit, the human brain 

is impressively complex.

 It is estimated that an adult 

human brain contains between

 100 and 500 trillion connections and our galaxy has about 

100 billion stars, so it can be concluded that the human brain

 is much more complex than a Galaxy.

How is information transmitted in the brain?

Brain functioning consists of the transmission of information between neurons, this transmission is carried out through a more or less complex procedure called synapse.

The synapses can be electrical or chemical. Electric synapses consist of bidirectional transmission of electric current between two neurons directly, while chemical synapses require intermediaries called neurotransmitters.

Ultimately, when a neuron communicates with another, it activates or inhibits it, the final observable effects on behavior or in some physiological process are the result of excitation and inhibition of several neurons along a neuronal circuit. 

Neurotransmitters and neuromodulators.

The concept of neurotransmitter includes all substances that are released at the chemical synapse and that allow neuronal communication. Neurotransmitters meet the following criteria:

Ø They are synthesized within neurons and are present in axon terminals.

Ø When a sufficient amount of the neurotransmitter is released, it exerts its effects on adjacent neurons.

Ø When they have finished their task, they are eliminated through degradation, inactivation or reuptake mechanisms.

Neuromodulators are substances that complement the actions of neurotransmitters by increasing or decreasing their effect. They do this by joining specific sites within the postsynaptic receptor.

There are numerous types of neurotransmitters, the most important are: Amino acids, which can be excitators, such as glutamate, or inhibitors, such as γ-aminobutyric acid, better known as GABA. Acetylcholine Catecolamides, such as dopamine or norepinephrine Indolamines, such as serotonin.

MADE BY CAMILA PEÑA AND VALERIA CÓRDOVA.