Functions Of The Central Nervous System

FUNCTIONS OF THE CENTRAL NERVOUS SYSTEM

 It is one of the portions in which the nervous system is divided is constituted by the brain and spinal cord, it is covered by three membranes called generically meninges protected by bone wraps, which are the skull and the spine respectively respectively.

This is responsible for perceiving stimuli from the outside world, processing information and transmitting impulses to nerves and muscles, is responsible for connectFor the brain, spinal cord and frontal lobe.

The nervous system has three basic functions: the sensitive that is responsible for perceiving internal and external changes, the integrator which analyzes sensory information and makes appropriate decisions and the motor that causes muscles or gland responses.

The spinal cord, this other portion of (CNS) that is constituted by a series of ramifications, have their origin in the brain trunk and descend along the spine, has as its main function connect the brain with the peripheral nervous system (SNP), both afferent and efferent. This structure deals with the mobility of all the necessary muscles so that we can perform any activity;The brain intervenes only to initiate and stop this activity, or when an unforeseen event arises in the realization of said activity.

The brain is the best known organ of the central nervous system, is responsible for processing the information that comes from the five senses, as well as controlling movement, emotions, memory, cognition and learning (it is the center of intellectual functions). The brain can be divided into two parts: Telencéfalo and DIENCEFALO.

Parts of the central nervous system

1. Cerebellum.- Integrates the information it receives from the 5 senses and the brain, maintains our fluid and coordinated movement.
2. Hypothalamus.- Controls involuntary actions and survival of sexual behavior and emotions.
3. Tálamo.- Controls the great sensitivity routes as well as the control of movement and tone.
4. Cerebral cortex.- Governs the functions superior to those that we are aware, such as sensory perception, the 5 senses, voluntary movement, language, emotions and thoughts.
5. Spinal bulb.- Regulates and controls visceral functions such as swallowing, nausea, sneezing, arterial perception and chemiorreceptors.
6. Pituitary gland.- Regulates organism processes by secretion.
7. Brainstem.- This controls vital functions such as heartbeat and breathing.
8. Spinal cord.- Conducts sensations to the brain and carries impulses of voluntary and involuntary movement.

Left hemisphere

The left hemisphere is the dominant in most people, in which there are 2 structures related to the linguistic capacity of man, such as the "Broca area" and the "Wernicke area" which are specialized in language in languageexclusive to human being.

The specific function of the ‘Broca area’ is the oral expression, an area that produces speech and the ‘Wernicke area’ has as a specific function the understanding of language, since it is the receptive area of speech.

Functions of the left hemisphere: 

In addition to its verbal function, it has the capacity to analyze and ability to make logical reasoning.

Neuron

It is the structural and functional unit of our nervous system, they are specialized cells that transmit and receive electrical signals in the body.

Parts of a neuron:

 Soma or pericarion or cell body, dendrites, axon, ranvier nodules, Schwann cells or neurolemocytes, myelin sheath.

Types of neurons:

• Sensory neurons.-They collect information about what is happening inside and outside the body, and take it to the CNS so that it can be processed
• Motor neurons.- They obtain information from other neurons and transmit orders to your muscles, organs and glands.
• Interneurons.- They connect a neuron with another, these neurons receive information from other neurons and transmit information to other neurons.

Neuron functions:

 Receive signals (or information), integrate the signals received, communicate the signals to white cells.

Nerve impulse

Electrochemical messages are transmitted by the nerves to a coordination center that dictates the answers and sends them to the effector organs, to the muscles (whether smooth or striated), which as an answer will execute a movement.

The nerve impulse only spreads in one sense, when a neuron is stimulated, electrical changes that begin in the dendrites, pass through the neuronal body, and end in the axon. The nerve impulse is not transmitted with the same speed in all neurons, they also depend on whether or not the axon is surrounded by cells, Schwann cells, which produce a white substance, myelin sheath, which prevents the passage of thenervous impulse and makes it to ‘jump’ between spaces without myelin sheath (Ranvier nodules), so the speed will be greater.

Arteries

The irrigation of the brain comes from the arterial circle of the brain and of different cerebral arteries, exist and are divided into 3 categories:

Cortical arteries

• Anterior cerebral artery
• Medium cerebral artery
• Posterior cerebral artery

Central arteries

They are terminal arteries that are intended for the basal nuclei and lower wall of the third ventricle (diencephalon).

Coroid arteries

They are intended for choroid cloth, choroid plexus of the third lateral ventricle ventricles.

Hypothalamus

The hypothalamus controls the processes or functions such as:

• The hypothalamus controls the following processes or functions:
• Body temperature in homeooterms.
• Thirst and urine production, controls the balance of water and salts from the organism.
• Food ingestion.
• Uterine contractions and milk ejection in mammals.
• Coordinates the autonomic nervous system, this affects the activity of smooth and cardiac muscle, as well as that of the exocrine glands.

It is considered as an integrating center of reflexes, receives signals from internal sensory receptors and, in response, sends orders through roads in which very few synapses intervene to quickly generate regulatory responses.

The parties or nuclei of the hypothalamus are:

• Arcuato nucleus
• Anterior hypothalamic nucleus
• Posterior hypothalamic nucleus
• Lateral nuclei
• Mamilar nucleus
• Paraventricular nucleus
• Preoptic nucleus
• Supraoptic nucleus
• Supraquiasmatic nucleus
• Ventromedial nucleus
• Dorsomedial nucleus

Brain stem

It is the largest communication route in the brain, spinal cord and peripheral nerves, also controls several functions including breathing, heart rate regulation and primary aspects of sound location and is formed by gray and white substance.

The gray substance forms nuclei inside the white substance, which can be subdivided into three types:

1. Segmental centers that represent the real origin of the cranial pares.
2. Cerebral trunk nuclei
3. Reticular formation or substance

Brodman area

It receives this name to the set of imaginary divisions in which the cerebral cortex can be divided and that allows the identification of concrete regions of this, this division was proposed by the psychiatrist Korbinian Brodmann in 1909.

Parietal lobe

The parietal lobe contains an area known as the primary sensory area is where skin impulses, such as heat, cold, pain and touch, are interpreted.

The parietal lobe has two main functions: Somato sensation and sensomotor integration, it can also be considered as the bark of association, since it integrates visual, auditory and sensory somato information in order to guide the behavior.

Occipital lobe

The occipital lobe is one of the smallest brain lobes, and occupies a small portion of the rear of the brain, its best utility of the occipital lobe is the processing of visual information.

Temporary lobe

The temporal lobe is responsible for the processing of auditory information of the ears (hearing), since it houses our ability to receive and interpret auditory information.

Frontal lobe

The lobe of greater functional importance in the human species is considered, occupying a third of the total brain, the functions that this lobe performs are different and depend on the concrete area of it, it is involved both in the control of movements, as well as in thehigh -level mental functions or in the control of behavior and emotions. The frontal lobe is divided into two large territories: motor cortex and prefrontal cortex.

Hard body

Transmit the information from one hemisphere to another, the parts of the corpus callosum are: peak or rostrum, genu or knee, body and splenium or rodete.

Internal capsule

The internal capsule is a brain region in which two very important nerve fiber tracts converge such as the corticospinal tract and corticobulbul.

Its anatomical structure is made up of, the previous arm, the posterior arm, composition of its nerve fibers.

Tàlamo

Its function is to be a bridge of communication between relevant brain parts, it has three structures:

1. Specific connection nuclei.
2. Nonspecific connection nuclei.
3. Association nuclei.

Baseline ganglia

Basal ganglia are located on an area called Striated Corps: two bodies of gray substance separated by a fiber beam, called internal capsule. It consists of:

• Striated body.
• Cauded nucleus.
• Putamen.
• GLOBUS PALLIDUS.
• Black substance.
• Accumbens nucleus.
• Subthalamic nucleus.
• Red substance.

White substance

It is composed of myelinized nerve fibers or neurons axons, we find them in the central structures of the brain, such as the thalamus and the hypothalamus, and between the brain trunk and the cerebellum.

Gray substance

It is the essential component of the central nervous system, and is formed by neuronal bodies and neuropilos, occupies approximately 40% of the entire brain in humans, and consumes 94% of oxygen.

Embryonic Development of the Central Nervous System

For embryonic development we must take into account gastruulation at this stage, the first indication of nervous system formation (the establishment of the neural plate) is presented and the neuralization is given the formation of the neural tube.

The limbic system

The system contributes to the continuation of the species, as well as the preservation of the individual, within these functions is also the behavior of feeding, aggression, emotional states, the autonomous, behavioral and endocrine aspect of sexual responses.

The meninges

These are connective membranes that surround and protect the brain and spinal cord of outside Asía inside:

• Duramadre: Meninge more external constituted by connective tissue, is divided into cranial dura and the spinal durable.
• Aracnoids: It is constituted by Mesothelio and connective tissue.
• Piamadre: constituted by connective tissue, intimately involves the spinal cord and brain.

Cerebrospinal fluid

Liquid that protects the brain and spinal cord, the cerebrospinal fluid is formed in the coronoid plexus that are located in the encephalic ventricles.

You have a mechanical protection function, thus shocking blows that a person can receive, also release nutritional substances that are filtered from blood to the brain and spinal cord.