The respiratory, or pulmonary, system has the function to deliver oxygen to the blood, and remove carbon dioxide on the way out. Within human beings, the respiratory system is well developed and very complex. The respiratory tract consists of respiratory organs that all work together in an intricate system. The organs are:



The Nasal Cavity. The Nasal Cavity is situated above the mouth, and accesses the external atmosphere through the nostrils, and internally it accessed the pharynx with the internal nostrils. The nasal cavity helps filter out dust particles from the outside environment with the cilia and with mucus.

The Pharynx. After entering through the nasal cavity, air next goes to the pharynx. There, the pharynx opens into the larynx or voice box through the glottis. The pharynx is actually shared by the respiratory system with the digestive tract. Luckily, the glottis is usually covered by the cartilage epiglottis when we swallow food, so we donat choke.

Larynx:- It is cartilagious box like structure located at the tracheal opening. When we swallow some food material,the larynx moves up or down to allow safe passage of air or food. Larynx contains two vocal chords which vibrate and produce sound while we speak.

Trachea:- Larynx is followed by trachea.It is tube about eleven centimeter in length and twenty five centimeter in diameter. Its wall is provided with incomplete C-shape cartiligious ring which keep the trachea in dilated position and prevent it from collapsing.

The Bronchi and Bronchioles: At the lower end of the trachea, are the two primary bronchi. These bronchi lead to the lungs, both to the right and left side. The right bronchus is split into three bronchi that extend separately into the three lobes of the right lung. In a complimentary fashion, the left bronchi splits into two bronchi that connect to the two lobes of the left lung.

The Lungs. Located in the thoracic cavity, there are two lungs, which is the last stop for air within the respiratory tract. Our lungs are a dark colored, spongy bag like structure that is incredibly elastic, allowing for them to expand and contact with each breath. The lungs rest on a sheet of muscle called the diaphragm. The diaphragm is one of the structures that surrounds the thoracic cavity, like the vertebral column and the sternum. The diaphragm forms the floor of the thoracic.

The lungs are probably one of the most complex organs in the respiratory tract, with the right lung divided into three lobes and the left lung divided into two. The lungs are enclosed by the pleural cavity, which is itself surrounded by two membranes that secrete an oily matter called pleural fluid, which permeates the Pleural cavity.