The throat is a key part of the respiratory system, and works as a safety-net to prevent leakage of food or liquids during swallowing  into the respiratory tract, where the vocal cords contract with the passage of air from the lungs during exhalation. The throat is often exposed to many ailments that may lead to serious illness. Arabstoday spoke to Dr Kamal Itani, an ear, nose and throat specialist in Lebanon, to learn more about the basic functions of the larynx and voice, and essential tips to protect this vulnerable part of the body from disease, especially during the changes of the seasons. Dr Kamal Itani described the throat as an important and vital organ for breathing and swallowing. It operates as a safety-net to prevent the entry of food and drink into the lungs during swallowing as well as preventing the entry of any foreign objects. This is the only function of the larynx in some animals, but it has additional important functions in humans. The ability to speak is mainly based on producing sounds through the proper functioning of the vocal cords. In order to get rid of accumulated secretions and mucus, contraction occurs in the chest and abdomen muscles, thus increasing the air pressure inside the chest cavity, then the vocal cords move apart, pushing  air with mucus out of the body. The most important function of the larynx, according to Dr Itani,  is to fix the rib cage so the forearms and chest muscles can perform their role efficiently, and help to increase the air pressure in the abdominal area whenever the throat is closed . Concerning vocal functions, Itani described the voice as having several functions:\" it is a means of communication and understanding, showing the psychological state of the speaker and his respiratory condition\". Dr Itani explained that  sound is produced from the larynx through moving the vocal cords. When a person inhales, the vocal cords converge,  then the muscles of the chest and abdomen contract and air is pushed out between the two chords which vibrate resulting in sound. By changing the degree of constriction on the vocal cords, differences occur in the tone of voice. For the sound to have power, energy must be available in the form of the amount of air stored in the lungs together. with the two vocal chords and the mucous membrane lining them, as well as a gentle convergence between the chords to produce sound.  As speech continues and energy runs out, the sound slowly fades. In order to be able to continue to speak in one breath, we make up for this weakness by a violent movement of the vocal cords. As for the purity of the sound, it requires a gentle contact between the two chords protected by their mucous membranes. Any imbalance leads to a change in the tone of voice and  hoarseness. Itani explained what happens when we experience difficulty in swallowing, and the most important and dangerous diseases of the throat: \"The throat closes during swallowing and moves to the top. Difficulty in swallowing is caused by a choke in the throat or the valves do not work efficiently enough.\" The diseases which affect the larynx are many, whether simple or extremely dangerous, such as: laryngotracheal trauma which is commonly the result of car accidents, or by a blow to the neck, strangulation, or restriction of the neck caused by wire or rope; as well as acute inflammation of the larynx, paralysis of the throat, chronic sore throat and malignant tumours. Dr Itani explained that  smoking and alcohol are risk factors which can cause throat cancer. Cigarettes contain benzopyrene and other hydrocarbons which are carcinogenic factors for men. Smoking and alcohol together raises the risk of throat cancer fifteen fold as compared to one or other of the causes which has been measured at 2-3 times the risk. Throat cancer running in families has been recorded amongst Japanese and Russias workers, thus genetic factors can play a role in causing cancer of the larynx. . There is also a relationship between  larynx cancer and  occupational exposure to asbestos, mustard gas (ammonia), petroleum products and other chemicals. In response to a question about the causes of shortness of breath, Dr. Kamal Itani explained  that breathlessness can occur suddenly and quickly. The patient may wake up with a choke, cough and shortness of breath as a result of acute inflammation in the throat. This could be as a result of fibrosis or benign or malignant tumour or an imbalance in the nutrition of the vocal chords.. Treatment requires rapid intervention with the help of oxygen. Urgent surgical intervention may be necessary to save the life of the patient by making an incision in the trachea.  Dr Itani shared the following health tips to protect and preserve the larynx.: - Avoid breathing from the mouth, because it has a direct impact on the larynx. A stream of cold, hot,dry or wet air  loaded with environmental pollutants going directly onto the throat and larynx, leads to inflammation, and this results in symptoms such as hoarseness and dry cough. -Stay away from smoking and environmental pollutants from fumes, chemicals, car exhaust and dust. - Do not strain your vocal cords, especially in  professions which depend on using your voice for long periods. - Take rapid and appropriate treatment for any infections which occur in the throat area such as the common cold. - Avoid hormone therapy. It should be done only under the supervision of a medical specialist  as it can affect the larynx of a woman