1. Respiratory System

2. Respiratory System Consists of the respiratory and conducting parts
Respiratory part
Site of gas exchange
Consists of bronchioles, alveolar ducts, and alveoli
Conducting part
Provides rigid conduits for air to reach the sites of gas exchange
Includes 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 dioxide
Respiration: four distinct processes must happen
Pulmonary ventilation: moving air into and out of the lungs
External respiration: gas exchange between the lungs and the blood
Internal respiration: gas exchange between blood and tissues
Transport: 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 Zone
Begins as terminal bronchioles, feed into respiratory bronchioles.
Respiratory bronchioles lead to alveolar ducts, then to terminal clusters of alveolar sacs composed of alveoli
Approximately 300 million alveoli:
Account for most of the lungs’ volume
Provide great surface area for gas exchange

6. Respiratory Zone

8. Gross Anatomy of the Lungs
Lungs occupy all of the thoracic cavity except the mediastinum
Root or Hilum: site of vascular and bronchial attachments
Costal surface: anterior, lateral, and posterior surfaces in contact with the ribs
Apex: narrow superior tip
Base: inferior surface that rests on the diaphragm

10. Hilum of the lungs

11. Blood Supply to Lungs
Lungs are perfused by pulmonary and bronchial arteries.
1- Pulmonary arteries:
Supply systemic venous blood to be oxygenated
Ultimately feed into the pulmonary capillary network surrounding the alveoli
Pulmonary veins: carry oxygenated blood back to the heart
2- Bronchial arteries:
Provide systemic blood to the lung tissue
Arise from aorta and enter the lungs at the hilus
Supply all lung tissue except the alveoli

13. Pleurae Thin, double-layered serosa Parietal pleura
Covers the thoracic wall and superior face of the diaphragm
Continues around heart and between lungs
Visceral pleura
Covers the external lung surface
Divides the thoracic cavity into three chambers
The central mediastinum
Two 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 Review
Imaging techniques used to investigate chest pathology include:
Plain X-Ray film
Computed Tomography (CT Scan)
Magnetic Resonance Imaging (MRI)
Ultrasound (US)
Angiography

16. Radiographic signs
Silhouette 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.

17. Negative Silhouette
Lesion
Posterior.

18. Q. Lesion anterior or posterior?

19. Air Bronchogram
Opacity 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 lesion
Diffuse lesion

22. Focal lesions Nodules Masses Cavities: sphere filled with air.
Patches: opacity contains air bronchogram.

24. Nodules maybe due to most common
Tuberculoma
Hamartoma
Bronchogenic carcinoma
Metastases
(multiple nodules or solitary)
AVM
Hydatid cyst

25. Benign nodule (Hamartoma and Tuberculoma): If we have pulmonary nodule and the edge is smooth and contains calcification.

26. Bronchogenic carcinoma
Speculated margin nodule= malignancy.
Upper lobe distribution 70%.

27. Bronchogenic carcinoma
Lateral view showing the speculated margin.

28. Hydatid cyst Single or multiple lesions filled with water.
Thin non enhancing margin.
Abscess: thick enhancing margin, usually contains air.

29. X- ray lung abscess

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. Pneumonia
is 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  

33. Pneumonia is accompanied by Consolidation

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.

36. 3. Cystic lesions: air filled cysts.

37. 4. Nodular pattern