Respiratory System PDF

Respiratory system Main parts The upper respiratory tract is formed by the nose, mouth, pharynx and larynx. Air passes through the two nostrils (nares) into the nasal cavities where the air is warmed and moistened. From the nasal cavities the air passes into the pharynx, or throat. The pharynx pro...

Respiratory system Main parts The upper respiratory tract is formed by the nose, mouth, pharynx and larynx. Air passes through the two nostrils (nares) into the nasal cavities where the air is warmed and moistened. From the nasal cavities the air passes into the pharynx, or throat. The pharynx provides a common passageway for air entering the larynx and food entering the oesophagus. There is the epiglottis (closure), that prevents the entrance of food and fluid into the respiratory tract. The larynx is a tube-like structure made up of muscles and a series of cartilage rings, the largest ring is called Adam´s apple. It contains the vocal cords which are responsible for the sound production. The lower respiratory tract consists of the trachea, bronchi and two lungs. The trachea enters the thoracic cavity and connects with the bronchi. It provides a passage for air to reach the lungs. The bronchi and lungs are situated in the thoracic cavity. The right bronchus is shorter. Each bronchus enters a lung where it branches into bronchioles. The lungs are two large organs. The right lung is divided into three lobes and the left one into two lobes. Disorders and diseases of respiratory system Acute bronchitis – is an inflammation of the trachea and bronchial tubes. The risk factors are: dusty, damp and foggy atmosphere and smoking. It is characterized by a persistent dry cough that may last several weeks. The components of treatment are antibiotics, humidifying the air at night, medication to suppress coughing and increased fluid intake. Chronic bronchitis – results from recurrent attacks of acute bronchitis or exposure to chemical irritation from cigarettes, smoke and dust. It is uncurable, but early treatment prevents progression and lung damage. Asthma – is a chronic disorder manifested by attacks of dyspnoea. The main cause of asthma is allergy, such as hay-fever, or hypersensitivity to certain drugs or food. The second cause is emotional stress. Pneumonia – is an accute inflammation of the lungs. The symptoms are: fever, chills, chest pain, increased pulse and respiration and painful coughing. Antibiotic therapy is immediate. Tuberculosis – is an infectious disease caused by a bacillus and can invade any of the body´s tissues: bones, joints, kidneys, lungs and other organs. It requires long-term treatment with combined antibiotics. The incidence of lung carcinoma is greater in males than females. The causative factors are:cigarette smoking, atmospheric pollution and exposure to dust and chemical gases.