Sputum

Sputum refers to a mixture of saliva and mucus that is typically coughed up from the respiratory tract. It serves as a valuable diagnostic tool in various respiratory diseases.

Overview

Sputum is produced in the lower respiratory tract and may change in color, consistency, volume, and odor based on the presence of pathogens, inflammation, or other disease processes. It is a crucial specimen in microbiology and pathology due to its informative content about the state of the lungs and bronchi.

Sputum

Production and Composition

• Under normal circumstances, mucus is produced by the goblet cells and submucosal glands in the respiratory tract to trap dust and other foreign particles. This mucus is then moved up to the throat by ciliary action where it is typically swallowed unconsciously. During respiratory infections or other lung conditions, the volume and character of this mucus can change, leading to expectoration as sputum.
• Sputum may contain a variety of components, including mucus, cellular debris, immune cells, microorganisms, and sometimes blood (Hemoptysis). Its appearance can give clues about the underlying condition causing its production.

Clinical Significance

• Healthcare professionals often ask patients to produce a sputum sample when they suspect certain respiratory diseases. This can then be examined under a microscope (sputum gram staining), cultured to identify pathogens (sputum culture), or analyzed for abnormal cells (Cytology).
• Some specific diagnostic tests include:
• Tuberculosis diagnosis: Sputum samples are used for AFB staining and mycobacterial culture.
• Pneumonia diagnosis: Sputum can be used to identify causative organisms.
• Lung cancer screening: Sputum cytology can sometimes detect cancer cells.
• Diagnosis of Cystic fibrosis: Sputum is tested for high levels of certain enzymes.

See Also

• Mucus
• Respiratory tract
• Phlegm

References

Sputum Resources
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