1. Sputum Sputum is a mucousy substance (consisting of cells and other matter) that is secreted into the airways of the respiratory tract(lungs,bronchi, trachea) and can be coughed up spit out or swallowed. It is produced by surface epithelial cells and submucous glands. It is a 5 µm thick mucos layer that covers the airways and protects bronchial epithelium against inhaled noxious substances.

2. Sputum The produced mucos is transported by the respiratory cilia towards the orpharynx, which might be swallowed or coughed up if its quantity is increased. Normally it is colourless, orderless. It a visoelasic fluid and its viscosity is influenced by the state of hydration of the body,(overnight sputum is more viscose than day sputum). Normal amount of secretion is 100ml per day. Sputum production is increased by injury of the bronchial tree or lung parenchyma, caused by inhaled noxious substances or by inflammation (asthma,bronchitis, pneomonia)

3. Chemical composition 95% water 5 % organic components: Carbohydrates ( such as sialic acid which contribute to its high viscosity) Proteins ( enzymes, immunoglobulins), glycoproteins which also contributes to the visoelastic property of sputum. Lipids DNA from broken WBC Macrophages Bronchial epithelial cells

4. Abnormality of sputum Normal sputum is either white or colorless. Yellow to green sputum can be an indication of pus, infection such as pneumonia. Blood in sputum is called hemoptysis which could be due to e.g ; lung cancer, tuberculosis, lung abcess, haemorrhage,,……. Rust color is due to decomposed Hemoglobin. Very thick (viscose) sputum is a characteristic of cystic fibrosis. Parasites in sputum can occur as in Ascaris.

5. Sputum test A sputum test can include a culture and / or a cytology test on a sample of sputum. A sputum culture is done to: Detect and identify bacteria or fungi that are causing an infection (such as pneumonia or tuberculosis) of the lungs or the airways leading to the lungs. Symptoms of a lung infection may include difficulty breathing, pain when breathing, or a cough that produces bloody or greenish brown sputum. Identify the best antibiotic to treat the infection (sensitivity testing). Monitor treatment of an infection.

6. Sputum test Sputum cytology ; Examines a sample of sputum (mucus) under a microscope to determine whether abnormal cells are present, such as tumor cells. Bacterial cells in a sample of sputum

7. Collecting sputum samples A sputum sample is obtained by coughing deeply and expelling the material that comes from the lungs into a sterile cup. The sample is taken to a laboratory and placed in a medium under conditions that allow the organisms to grow. A positive culture may identify disease- producing organisms that may help diagnose bronchitis, tuberculosis, a lung abscess, or pneumonia.

8. Normal Results In a normal sputum sample there will be no disease- causing organisms present. What Abnormal Results Mean If the sputum sample is abnormal, the results are called "positive." Identifying disease-producing organisms may help diagnose: Bronchitis Lung abscess Pneumonia Tuberculosis

9. Collecting sputum samples Bronchoscopy;. An instrument (bronchoscope) is inserted into the airways, usually through the nose or mouth, or occasionally through a tracheostomy. It can be used to collect samples of tissue or sputum for analysis, to check for growths (such as tumors) in the airways and lungs (performed under certain conditions only).