Respiratory system

• The respiratory system is divided into two sections, upper and lower.
• Upper respiratory tract includes the nose, nasal cavity, pharynx (throat), larynx (voice box) and trachea (windpipe).
• Lower respiratory tract consists of bronchi, bronchioles, alveoli and lungs.
• The function of the respiratory system is to supply the body with oxygen and removes carbon dioxide by breathing.
• Breathing involves inspiration (inhalation) and expiration (exhalation).
• Expiration occurs when diaphragm relaxes upward and internal intercostals relax downward, decreasing thoracic volume and increasing pressure inside chest cavity.
• Inspiration occurs when diaphragm contracts downwards and external intercostals contract upwards, increasing thoracic volume and decreasing pressure inside chest cavity.
• Gas exchange occurs in the alveoli
• The upper respiratory system is to warm, humidify and filter the air entering the airway
• The lower respiratory system is where gas exchange takes place between the lungs and bloodstream
• The pharynx is located at the back of the mouth behind the tongue
• The larynx is located at the entrance to the trachea and is the passageway for air to enter the lungs
• The epiglottis covers the opening into the larynx during swallowing to prevent food from going into the windpipe
• The trachea is located in front of the oesophagus
• The lungs are located in the thoracic cavity
• The lungs are divided into sections, or lobes and contain a large system of air carrying tubes called the respiratory tree.
• The bronchioles end in tiny sacs called alveoli which have a very thin wall that allows oxygen to diffuse easily across them
• Bronchiole branches off from the bronchial tube and ends in an alveolus
• There are two lobes in the left lung and 3 lobes in the right lung
• The diaphragm is a muscle that separates the thoracic cavity from the abdominal cavity
• The intercostal muscles are between ribs and allow us to breathe by expanding our chest cavity
• The bronchi are the two tubes that the trachea branches into inside of the lungs
• Bronchioles are smaller branches of the bronchi
• Pleural fluid lubricates the pleurae so they can slide over one another during breathing
• Alveoli are tiny air sacs where gas exchange occurs with blood vessels called capillaries
• Crackle lung sounds are a sound often heard during inspiration. High pitched discontinuous crackling sounds.
•  Rhonchi lung sounds are sonorous wheezes, loud, low, coarse sounds that sound like a snore. Coughing may clear sound. Heard during inspiration and expiration.
• Rhonchus is a low-pitched gurgling or rattling sound, usually heard on inspiration (breathing in) or both inspirations and expirations. It may be caused by mucous secretions in the airway.
• Stridor is a loud, harsh, high-pitched sound produced when there is an obstruction in the upper part of the respiratory tract such as the larynx or epiglottis.
• Wheeze lung sounds are high-pitched whistles or squeaks. Hear them when there is narrowing of an airway. Can be caused by asthma, COPD, allergies, infection, etc.
• Variation to health status includes rapid breathing, coughing, chest pain, wheezing