The structure of the human respiratory system
The respiratory system
The human respiratory system consists of the nose , the pharynx , the trachea , two bronchi and two lungs , It is called also the respiratory apparatus , the ventilatory system and it is used for the process of the respiration in the organisms .
The nose is very important in our respiratory system as it is the first part of the respiratory system , through it the air enters the body , and it is lined with the mucus layer and hairs to filter the air from the dust and the microbes before entering the lungs .
The function of the nose is very important as it is lined with the blood capillaries to warm the air before entering the lungs , so , we should breathe through the nose not through the mouth .
The trachea is very important in the respiratory system as it is a cartilaginous tube that is existed in the thoracic cavity , You should know that there are the larynx and the epiglottis at the top of the trachea .
The larynx ( the voice box ) is very important in our respiratory system as it contains the two vocal cords which vibrate to produce the sound .
The epiglottis lies at the top of the larynx , and it closes the larynx or the trachea during the swallowing to prevent the food from entering the trachea .
The bottom of the trachea is branched into two narrow tubes called ( bronchi ) which enter the two lungs ( one bronchus in each lung ) .
The trachea is lined with the cilia to eject up the strange objects , It is supported by incomplete cartilaginous rings to be permanently opened for breathing .
The two lungs
The two lungs occupy the thoracic cavity , they are surrounded by ribs ( rib cage ) and they have air sacs ( the alveoli ) in which gases exchange takes place , The walls of the alveoli and the blood capillaries are very thin to permit the exchange of gases .
The lungs are very important in the respiratory system , Each lung contains bronchus which is divided into bronchioles , The bronchioles end in tiny air sacs called the alveoli that are surrounded by networks of blood capillaries .