2 Respiratory System Consists of the respiratory and conducting parts Respiratory partSite of gas exchangeConsists of bronchioles, alveolar ducts, and alveoliConducting partProvides rigid conduits for air to reach the sites of gas exchangeIncludes all other respiratory structures (e.g., nose, nasal cavity, pharynx, trachea)Respiratory muscles: diaphragm and other muscles that promote ventilation
3 Major Functions of the Respiratory System To supply tissues with oxygen and dispose of carbon dioxideRespiration: four distinct processes must happenPulmonary ventilation: moving air into and out of the lungsExternal respiration: gas exchange between the lungs and the bloodInternal respiration: gas exchange between blood and tissuesTransport: transport of oxygen and carbon dioxide between the lungs and tissues
4 General Anatomy Upper respiratory tract: The nose, Mouth, pharynx, and Larynx.Lower respiratory tract:The trachea, Bronchi, Alveoli, and Lungs.The thoracic cavity consists of:Right and left pleural cavities (the parietal pleura lines the thoracic cavity, and the visceral pleura adheres directly to the lung tissue.Mediastinum.
5 Respiratory ZoneBegins as terminal bronchioles, feed into respiratory bronchioles.Respiratory bronchioles lead to alveolar ducts, then to terminal clusters of alveolar sacs composed of alveoliApproximately 300 million alveoli:Account for most of the lungs’ volumeProvide great surface area for gas exchange
8 Gross Anatomy of the Lungs Lungs occupy all of the thoracic cavity except the mediastinumRoot or Hilum: site of vascular and bronchial attachmentsCostal surface: anterior, lateral, and posterior surfaces in contact with the ribsApex: narrow superior tipBase: inferior surface that rests on the diaphragm
11 Blood Supply to LungsLungs are perfused by pulmonary and bronchial arteries.1- Pulmonary arteries:Supply systemic venous blood to be oxygenatedUltimately feed into the pulmonary capillary network surrounding the alveoliPulmonary veins: carry oxygenated blood back to the heart2- Bronchial arteries:Provide systemic blood to the lung tissueArise from aorta and enter the lungs at the hilusSupply all lung tissue except the alveoli
13 Pleurae Thin, double-layered serosa Parietal pleura Covers the thoracic wall and superior face of the diaphragmContinues around heart and between lungsVisceral pleuraCovers the external lung surfaceDivides the thoracic cavity into three chambersThe central mediastinumTwo lateral compartments, each containing a lung
14 Mediastinum Divided into: anterior, middle, and posterior portions. Anterior mediastinum contains: the thyroid and thymus glands.Middle mediastinum contains: heart and great vessels, esophagus, and trachea.Posterior mediastinum contains: descending aorta and spine.
15 Chest X-Ray ReviewImaging techniques used to investigate chest pathology include:Plain X-Ray filmComputed Tomography (CT Scan)Magnetic Resonance Imaging (MRI)Ultrasound (US)Angiography
16 Radiographic signsSilhouette sign: opacity near the heart so you can not detect the heart boarder easily.Notes from the radiographs: opacity frontal and heart frontal so lesion is frontal.
19 Air BronchogramOpacity in the lung contains a tree filled with air (bronchi contains air but alveoli opaque).Lesion arises from the lung not chest wall or pleura or mediastinum.Air bronchogram=alveolar pathology=consolidation (lung filled with liquid).
20 Pulmonary nodule: well defined lesion less than 3cm. Mass: well defined lesion more than 3cm.
21 To interpret chest x-ray differentiate between Focal lesionDiffuse lesion
22 Focal lesions Nodules Masses Cavities: sphere filled with air. Patches: opacity contains air bronchogram.
30 CT is needed to show if the lesions are cystic or solid
31 Patch An ill defined lesion with air bronchogram. Air bronchogram: air filled bronchi passing through opaque lung.Pulmonary lesion.Alveolar pathology.Consolodation.Patch may be due to:Pneumonia or infarction.
32 Pneumoniais an inflammatory condition of the lung affecting primarily alveoli.It is usually caused by infection with viruses or bacteria.Typical symptoms include a cough, chest pain, fever, and difficulty breathing
34 Diffuse lung disease We have 4 radiographic pattern: Reticular pattern e.g. Pneumonia, Bronchitis: Confluent small ill-defined densities produce a reticular pattern.
35 2. Ground glass pattern: increase in density in areas of ground glass and air trapping in lower lobes in patients with hypersensitivity pneumonitis (inflammation of lung tissue). Pneumonia is pneumonitis combined with consolidation (is a region of (normally compressible) lung tissue that has filled with liquid) due to infection.