Cells of the brain final explanation

January 9 / 2018

Stage: c) taking action

Approaches to learning: Transference skills

NERVE CELLS: The nerve cells (also known as neurons) are in charge of receiving and transmitting electrical impulses and chemical signals to other neurons, muscles or glands, there are around 100 billion neurons present in the brain and 13.5 million in the spinal cord.

The neuron structure consists of a cell body (also known as the soma), where most of the neuronal proteins are synthesized, the soma  holds the nucleus and the dendrites which are the ones that are in charge of receiving and processing messages coming from other neurons. Emerging from the soma comes something known as the axon, a canal where  the message (also known as input) passes through, the axon also determines wether the message is worth passing down to the axon terminals or not. The axon is covered by a substance called the myelin sheath which makes sure the axon is well insulated and passes the nerve impulse rapidly. At the end of the neuron, there are the axon terminals (also known as synapses) , whose job is to make connections with the dendrites of another neuron in order to carry the information transmitted in the form of chemical messengers (called neurotransmitters) down to another neuron. 

There are four different types of neurons; interneurons, receptor, sensory, and motor neurons. They work with the central nervous system (CNS) and the peripheral nervous system (PNS), together they all aid in the performance of movement are reflexes in the body.

First of all, come the receptor neurons that receive stimuli from the senses (sight, smell, touch, taste, and listening), they take up the signal and then transmits it to an interneuron through their synapse in order for the message to be delivered to a sensory neuron.

The sensory neuron's job is to carry the message all the way to the central nervous system (CNS) in order for it to be processed, once the stimuli has been processed it is sent to a motor neuron through an interneuron.
The motor neurons are those that will be telling your muscles which actions to perform based on the stimuli that has been delivered to them, for example petting a dog or picking up a banana.

The interneurons are those that connect one neuron to another, meaning they receive information from one neuron and transmit is to another, for example, they get information from a sensory neuron and transmit the message to a motor neuron. Interneurons are only present in the central nervous system (CNS)


GLIA CELLS: The glia cells are those that support in the functioning of the nervous system, they aid in the nourishment, protection and structural support of neurons, there are about 10 to 50 more glia cells than neurons in the brain.

There different types of glia cells in the nervous system, they are; astrocytes, microglia, oligodendrocytes, Schwann, ependymal and satellite glial cells.

Astrocyte cells help regulate blood flow in the brain, they aid maintaining the composition of the fluid that surrounds neurons, and the regulation of communication between neurons in the synapse, they also help nourish neurons. Microglia cells are in charge of removing dead cells, pathogens and other debris. Oligodendrocyte  and Schwann cells produce myelin (the insulating substance present in the axons of neurons). Ependymal cells are those that line the ventricles and secrete cerebrospinal fluid. And finally, the satellite glial cells, which cover the cell body of neurons, so in other words, they are like the barrier that protects the soma.