Describe the Gross Anatomy of the Lungs; and Define Pneumonia and Outline Briefly the Etiology, Pathophysiology and Radiographic Appearances of Alveolar Pneumonia.
Describe the gross anatomy of the lungs; And define pneumonia and outline briefly the etiology, pathophysiology and radiographic appearances of alveolar pneumonia.
1. Introduction
The lungs are the essential organs of respiration; they are two in number and are placed one on either side within the thorax, separated from each other by the heart. The substance of the lung is light, spongy and porous. The surface is smooth, shining and marked into numerous areas, indicating the lobules of the organs (Lewis, 2000).
2. Gross anatomy of the lungs
The lungs are situated into the thoracic cavity, which are divided into three large spaces: the mediastinum, and the two pleural cavities (Gilroy, MacPherson, Ross & Schuenke, 2008). The mediastinum is an interpleural space (area between the pleural cavities) in the thorax and it consists of the superior mediastinum above the pericardium and the three lower divisions: anterior, middle and posterior (Chung, 2007).
The lungs and the surface of the pleural cavities are lined by a single flat layer of cells called the pleural membrane (Drake, Vogl, Mitchell & Gray, 2005). Fluid between the layers prevents friction with the cavity’s inner wall as the lungs repeatedly expand and contract. The pleura is divided into two major types, based on location: parietal pleura (associated with the walls of a pleural cavity) and visceral pleura (adheres to and covers the lungs) (Drake et al., 2005). The visceral pleura, lines the inner wall of the pleural cavity; covers the lobes and root of the lung (Leonard, 1995) However, the inner surfaces of the cavities (parietal pleura) are divided into four parts depending on its location: costal, diaphragmatic, mediastinal and cervical (see figure 1) (Clemente, 2006).
Surfaces
The lung has three surfaces: a convex surface abutting the rib cage, more sharply curved posteriorly than anteriorly; a concave mediastinal surface, and a concave diaphragmatic surface conforming to the convexity of the
1. Introduction
The lungs are the essential organs of respiration; they are two in number and are placed one on either side within the thorax, separated from each other by the heart. The substance of the lung is light, spongy and porous. The surface is smooth, shining and marked into numerous areas, indicating the lobules of the organs (Lewis, 2000).
2. Gross anatomy of the lungs
The lungs are situated into the thoracic cavity, which are divided into three large spaces: the mediastinum, and the two pleural cavities (Gilroy, MacPherson, Ross & Schuenke, 2008). The mediastinum is an interpleural space (area between the pleural cavities) in the thorax and it consists of the superior mediastinum above the pericardium and the three lower divisions: anterior, middle and posterior (Chung, 2007).
The lungs and the surface of the pleural cavities are lined by a single flat layer of cells called the pleural membrane (Drake, Vogl, Mitchell & Gray, 2005). Fluid between the layers prevents friction with the cavity’s inner wall as the lungs repeatedly expand and contract. The pleura is divided into two major types, based on location: parietal pleura (associated with the walls of a pleural cavity) and visceral pleura (adheres to and covers the lungs) (Drake et al., 2005). The visceral pleura, lines the inner wall of the pleural cavity; covers the lobes and root of the lung (Leonard, 1995) However, the inner surfaces of the cavities (parietal pleura) are divided into four parts depending on its location: costal, diaphragmatic, mediastinal and cervical (see figure 1) (Clemente, 2006).
Surfaces
The lung has three surfaces: a convex surface abutting the rib cage, more sharply curved posteriorly than anteriorly; a concave mediastinal surface, and a concave diaphragmatic surface conforming to the convexity of the
References: of the Chest Radiographs: Central Care Health System .(2007). X-ray of a normal chest. Retrieved June, 20, 2010, from http://64.143.176.9/library/healthguide/en-us/support/topic.asp?hwid=zm6148. Mayo Clinic. (2007). X-ray showing pneumonia. Retrieved June, 20, 2010, from https://www.bcbsri.com/BCBSRIWeb/images/image_popup/pneubig.jpg. Baert, A.L. (2000). Encyclopedia of Diagnostic Imaging. Volume 1. Springer. Shetty, N., Tang, J.W. & Andrews, J. (2009). Infectious Disease: Pathogenesis, Presevention and Case Studies. Willey-Blackwell ----------------------- Right Lung (3 lobes) Left Lung (2 lobes)