Nervous System

What is the nervous system?

The nervous system is the system that directs, supervises and controls all functions and activities of the body. It comprises a set of regulatory organs and a network that interconnects these organs with the rest of the organism.

For example, while you are reading this, your nervous system deciphers the images you see, controls the movement of your eyes and hands, as well as focusing your attention and storing the memory of what you are seeing. At the same time, it allows you to breathe without your realizing it.

parts and functions of the human nervous system

Main organs of the human nervous system and their functions.

The organs of the nervous system are made up of specialized cells called neurons and auxiliary cells called glia. The neurons They are responsible for transmitting information between the nervous system and the other organs of the body. They do this by forming fibers that we know as nerves. The glia provide support and maintenance to neurons.

The nervous system has evolved from invertebrate animals to vertebrates. In most vertebrate animals, the nervous system consists of a coordinating center (the central nervous system, CNS) and a neural connecting network (the peripheral nervous system PNS).

Parts of the human nervous system

Nervous system-concept map

Central Nervous System

The central nervous system (CNS) is the control center for the most complex functions, such as emotions, learning, communication, and sensations. The organs of the CNS are wrapped in protective membranes, known as the meninges. It is made up of the brain and spinal cord.

The brain consists of:

  • The brain: organ that controls voluntary actions, is located in the head protected inside the skull. It is related to learning, memory and emotions.
  • The cerebellum: coordinates the movements, reflexes and balance of the body.
  • The medulla oblongata: Directs the activities of internal organs such as breathing, heartbeat, and body temperature.
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The spinal cord connects to the brain and extends along the vertebral column. It is mainly in charge of involuntary movements, such as when we step on a thorn with our foot and lift it up almost immediately.

See also Brain.

Peripheral nervous system

The peripheral nervous system (PNS) encompasses all the nerves that leave the central nervous system to the body. The cranial nerves originate in the brain and receive information from the head and neck. Spinal nerves originate in the spinal cord and run to the extremities, trunk, and abdomen.

The peripheral nervous system is divided into:

  • somatic nervous system: transmits sensory information from the body to the brain and motor information from the brain to the muscles. It includes sensory nerves, motor nerves, and mixed nerves.
  • Vegetative or autonomic nervous system: controls the functioning of internal organs; includes the sympathetic nervous system and the parasympathetic nervous system.

nervous system

See also Neuron.

functions of the nervous system

  1. coordinate movements: The brain sends signals through the spinal cord and nerves to the muscles, causing them to contract and relax to move.
  2. Interpret stimuli coming from outside: Animals react to the conditions of the external environment that they capture through the senses and that are sent to the brain to be analyzed.
  3. Relate to other beings: communication between individuals is mediated by the nervous system.
  4. Learn and remember skills and experiences: Memories, memory and learning are capacities determined by the nervous system.
  5. Keep the inner workings unconscious: breathing, digestion and blood circulation are carried out without our conscious intervention thanks to the nervous system.
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Hall, J. (2016) Guyton and Hall Treatise on Medical Physiology 13ed. Elsevier. Barcelona.

Rye, C., Wise, R., Jurukovski, V., DeSaix, J., Choi, J., Avissar, Y. (2016) Boundless Biology. OpenStax CNX. Houston Texas.