The lungs are the principal organs of respiration. A human body has a pair of lung present inside the rib cage above an arched muscle called the diaphragm. The lungs are covered by two thin membranes called pleura. The lungs are cone-shaped organs with spongy texture. This spongy texture helps in the incorporation of inhaled

Bronchi The wind pipe branches into two smaller tubes. These tubes are called the bronchi (in plural), or bronchus (singular). Each bronchus opens into a lung. The main function of the bronchus is to conduct air into the lungs. In lungs, the bronchus divides further into several tributaries called bronchioles, just like a branch of

Pharynx The pharynx is a muscular tube which extends from the base of the skull to the oesophagus. It makes a bridge between the nasal cavity and the larynx and the oesophagus. It is common to both the respiratory tract and the digestive tract. In the respiratory tract it acts as an air passage during

Nasal Cavity The nostrils open into the nasal cavity which is the space inside the nose between the base of the skull and the roof of the mouth. It connects the nostrils to the upper part of the pharynx (throat). The whole cavity is covered with mucous membrane (lining that secretes slimy fluid) and tiny

Respiratory System The respiratory system is a set of organs that help a human being to breathe. Breathing is the process of inhaling oxygen and exhaling carbon dioxide. The respiratory passage consists of the nose, nasal cavity, pharynx, trachea, bronchi, lungs and diaphragm. Human beings can involuntarily control the process of breathing but overall the