When you inhale, the air enters and your respiratory system brings oxygen throughout the body.
The respiratory system includes the nose, throat, trachea, kind of tube, bronchi, which are smaller tubes and the lungs.
Oxygen enters the lungs to reach the blood.
The blood brings it to each cell of the body.
In these billions of cells, oxygen burns foods by transforming them into energy.
This produces waste, carbon dioxide.
When you expire, you chase it out of your body with the expelled air!
The lungs consist of five lobes,
The right lung has three parts, three lobes while the left has only two to leave room for the heart.
When a lobe is damaged, the others continue to function!
A lung weighs about 500 grams.
In the adult it has the size of a balloon!
The lungs contain millions of tubes where the air circulates.
The trachea coming from the throat is divided into two large bronchi, which continue to divide into smaller and smaller bronchioles,
The smaller ones end in tiny bags or alveoli.
The oxygen passes through the wall of the alveoli and is found in the blood.
The throat serves for the passage of food and air.
When you choke by swallowing something wrong, food tries to go through the trachea, instead of the esophagus.
Let's take the time to eat!
The trachea has a small trap, the epiglottis, which normally closes when you swallow.
The bronchi are ducts integrated into the respiratory system of the body.
The two principal bronchi, or stem bronchi, are born at the termination of the trachea, and plunge into each lung.
Bronchioles are the first branches of the respiratory tract that do not containcartilage.
They are the prolongation of the bronchiand are less than a millimeter in diameter, thus allowing access of the air to the alveoli.
The pulmonary alveoli are thin follow sacs which prolong the respiratory tract, where gaseous exchanges with the blood are made!
They are located at the extremities of the bronchioles.
The oxygen in the air is inspired in the lungs to enter the bloodstream.
Your heart acting as a pump will distribute the oxygen throughout the body.
Let's see how this distribution is made...
Carbon dioxide-laden blood regains the heart through canals: the veins.
The inferior and superior vena cava bring "unclean" blood to the right auricule, where it will be transferred to the lungs through the pulmonary trunk and pulmonary arteries.
The oxygen-enriched blood leaves the lungs through the pulmonary veins to gain the left auricle and leave the heart through the bulkier artery of the body, the aorta to be distributed throughout the body.
The gaseous exchange, carbon dioxide/oxygen
Is made at the level of the capillaries,
which are the finest and smallest bloodvessels, their diameter corresponds roughly to that of a hair, hence its name.
Their role is to bring the nutrients and oxygen to the various organs( lungs, intestines, muscles...) and then to bring back to the heart, in return, waste like carbon dioxide!
Their very thin walls allow direct exchangesbetween the blood and the tissues.
These vessels are fragile: in case of shock, their rupture can cause a subcutaneous hematoma!
The muscles of respiration are the muscles that move the ribs and thus modify the volume of the rib cage.
The muscles that lift the ribs are called inspiratory muscles.
The muscles that lower the ribs are called expiratory muscles.
The main muscles are the diaphragm and the scalene, accompanied secondarily by the interosseous muscles: inspiratory muscles, inserted on the wall of the thorax.
Scalene muscles are muscles that connect the cervical spine to the thorax.
They are responsible for the draw: when someone asphyxiates, he pulls on the ribs and the collarbone, thanks to the muscles of the neck, still have a chance to breath!
The diaphragm is the main muscle of respiration.
It ensures inspiratory and expiratory movements.
It forms a partition between the thorax and the abdomen.
It is inserted on the vertebral column and on the lower periphery of the thorax: it has the shape of a vault.
In order to protect themselves, the lungs produces a kind of glue called mucus, which traps dust.
Protection of the lungs occurs at three levels:
In the upper airways,
the air enteringthrough the nose is warmed,moistened and dusted
This adaptation continues throughout the trachea and bronchi.
In the trachea and in the bronchi, thanks to the treadmill constituted by the eyelashes, the secretions(dust and mucus) are reassembled and normally swallowed.
In case of excessive production, the cough becomes indispensable and they are partly expectorated.
Sneezing, blowing or coughing are natural ways of eliminating secretions.
In the pulmonary alveoli, cells called macrophages digest dust and microbes...thanks to the enzymes they contain!