trachea - a very important part of the respiratory tract that connects the larynx to the bronchi.That it passes air into the lungs with the necessary amount of oxygen.The trachea is a tubular hollow organ.The length of the tube ranges from 8.5 to 15 centimeters, depending on the physiology of the organism.But before we consider the main functions of the trachea, should be familiar with its anatomy.
Location trachea .The trachea begins at the cricoid cartilage at about the level of the sixth cervical vertebra.The third part of the tube is at the level of the cervical spine, and the rest - in the thoracic region, where the trachea ends at the level of the fifth thoracic vertebra.In this section of the trachea divides into two bronchi, forming a fork - a point of bifurcation, which is intertwined with the aortic arch.
If we consider the cervical part of the body, the front of it is a part of the thyroid gland.Throughout the rear tracheal tube adjacent to the esophagus.On each side is a neuro-vascular bundle, which includes fibers of the vagus nerve, the internal jugular vein and carotid arteries.
trachea: structure .If we look at a cross-section of the trachea, we can see that it consists of several layers - the actual mucosa, submucosa, and cartilage of the adventitia.The functions of the trachea, as well as any other body part depend on the structure, so you need to consider each part in more detail.
The mucosa - presented ciliated stratified epithelium, which lies on the basal membrane.Cilia cells move towards the larynx.The composition also includes epithelial stem cells and goblet, which emit small amount of mucus.There endocrine cells that produce serotonin and noradrenaline.The basal membrane has a lot of elastic fibers.There are smooth, individual myocytes, arranged in a circle.
submucosal - a fibrous, loose connective tissue.It is in this layer is the bulk of nerve fibers and small vessels, which are responsible for the regulation and perfusion.
hyaline cartilage layer is formed by incomplete cartilage, which occupies two thirds of the circumference of the tracheal tube.Between a cartilage ring connected cords.The number of cartilage in humans ranges from 16 to 20. Behind formed membranous wall, which is in contact with the esophagus.Thus, the passage of the bolus does not interfere with the respiratory process.
adventitia of the trachea - a thin connective tissue that covers the outside of the tube.
As you can see, the anatomy of the trachea is not that complicated.
functions trachea .The main function of the tracheal tube - it is carrying air to the lungs.But this is not all of the functions of the trachea.
As already mentioned, the mucous membrane of the trachea is covered with ciliated (ciliated) epithelium movements which are directed towards the larynx and oral cavity.Furthermore, goblet cells secrete mucus.After contact with the air in the trachea of small foreign bodies such as dust particles are enveloped by mucus and the cilia movement pushed back in the throat and pass into the throat.Thus, trachea and performs a protective function.In the event that a large foreign body begins cough reflex, in which the trachea is significantly narrowed lumen.
It is known that the cleansing and warm air is in the nasal cavity, but partly fulfills this function and trachea.Moreover, a resonator trachea during speech because air pushes the vocal cords.
To summarize, we can see that, despite the relatively simple structure, the trachea has a number of very important functions, without which the existence of the human organism is impossible.