The lungs are the bodies of breathing

Lungs

The lungs are the bodies of breathing. They make it possible to remove blood from carbonic gas produced by the cells of the organization and to replace it by oxygen necessary for their operation.

The lungs are located in the thorax, under the coasts

They are 2: the right lung, composed of 3 lobes, and the left lung, composed him of 2 lobes, thus leaving place for the heart under the coasts.
Between the 2 lungs a space, the médiastin is, through which the esophagus passes, the trachea and the bronchi and where are the heart, large vessels as well as lymphatic vessels and ganglia.

The plèvre

The lungs are surrounded by 2 layers which form the plèvre: one of the layers is stuck to the thorax, the other with the lungs. They slip one against the other; between the two is a virtual cavity. It is the plèvre, which allows that the lungs are stuck to the thoracic wall. When the air enters the plèvre, the lung falls apart of the wall, it recroqueville on its bronchus and is not functional any more; it is a pneumothorax.
When the plèvre is inflammatory (infection, cancer,…) “water” appears between the 2 layers; one speaks about pleurisy.

The trachea and bronchi

It is the trachéo-bronchial tree which connects pulmonary fabric outside: it is composed of the trachea felt in front of the neck under the skin; with entered the thorax, it is divided into two bronchi: a right bronchus for the right lung and a left bronchus for the left lung. Each bronchus is still divided into smaller bronchi energy towards the pulmonary lobes then they ramify more and more as the branches of a tree to finish out of bronchioles in the air cells, which form small bags at the end of each one.
The trachéo-bronchial tree is papered of a ciliée mucous membrane which secretes a mucus and which pushes back towards outside dust inhaled, tar,… When this mucous membrane is attacked, it is inflammatory and secrete more mucus (glaires).
Cough makes it possible to evacuate glaires, foreign bodies… It signs a bronchial irritation.

Breathing

Breathing is made up of two movements which utilize the respiratory muscles, in particular the intercostaux diaphragm and muscles. The widening of the rib cage inserts the air in the lungs and its tightening makes some leave.
To the inspiration, the air, rich in oxygen, enters by the nose or the mouth, passes by the trachea then the bronchi and bronchioles to arrive in the cells.
The gaseous exchange is done between the cells and the blood of the pulmonary capillaries through the alveolar walls: the oxygen in air passes in blood; the carbonic gas of blood passes in the cells.
During the expiry, the air enriched out of carbonic gas and impoverished of oxygen is rejected outside by the same way.

When blood is impoverished out of oxygen, it is dark.
When an insufficiency of the respiratory function occurs, the sick person present of the bluish ends (end of the nose, ear lobe, nails), one speaks about cyanosite.

Sounding

The respiratory movements are studied by the sounding thanks to a stethoscope.
One hears the air well circulate in the bronchus, to fill the cells.
An asymmetry of the sounding between the 2 lungs or on the level them lobes can direct towards a localized pathology. For example if a pulmonary lobe is quiet with the sounding, it can be a question of an infectious attack of this lobe.
Pathological added again noises can direct towards a disease: a whistle with the expiry indicates a bronchial spasm which can direct towards an asthma for example.

The respiratory frequency

Breathing is controlled by the requirements out of oxygen for the organization.
The rate of respiration at rest is approximately 12 to 15 movements per minute.
When the blood oxygen rate decreases, the rate of respiration increases.
It is the case for example at the time of a muscular exercise: the muscles, when they are in action, consume oxygen, its concentration in blood will decrease then and in parallel the carbonic gas concentration will increase and the lungs will be informed that the candence should be increased, then the frequency of the respiratory movements increases. Breathlessness can appear.
The lung diseases which decrease the gaseous exchange or which blocks the air circulation in the bronchial tree cause a reduction in oxygen in blood, an increase in carbonic gas and the appearance of breathlessness.

To retain

The lungs are vital bodies. They are responsible for the breathing which makes it possible to feed oxygen blood necessary for the operation of the cells of the organization and to remove it from its carbonic gas produced by the cells.
Breathing is controlled by the requirements out of oxygen. If the lungs do not satisfy these needs, it will appear breathlessness, a cyanosite.
The sounding with a stethoscope will give an idea of the pulmonary function of a person and will make it possible to the doctor to require or not complementary examinations.