The lungs are the organs responsible for the exchange of oxygen and carbon dioxide between the air and the blood via the bronchial tree. Tuberculosis (TB) is a granulomatous disease which primarily infects the lungs but can spread to other vital organs. It is caused by bacteria called Myobacterium tuberculosis and if went untreated, can be fatal. TB is spread through the air when a person who is infected coughs or sneezes and a person nearby breathes the air. People who have been diagnosed with HIV are at a higher risk of contracting TB since their immune systems are weaker. Other risk factors include having diabetes, use of alcohol and drugs. In this paper I will discuss the normal functions and anatomy of the lungs and how TB effects these functions.
The lungs are located in the thoracic cavity above the diaphragm. They are large and cone-shaped in which the tip of the organs are called the apex. The anterior surface of the lungs is called the costal surface, the medial surface is called the mediastinal surface and the base is called the diaphragmatic surface. Both lungs are divided into lobes, lobules, and segments. The right lung has three lobes called the superior, middle, and inferior lobes. They are separated by the horizontal and oblique fissures. On the medial surface there is point called the hilus where the bronchi and blood vessels enter and leave. The left lung, being smaller, has two lobes called the superior and inferior lobes. They are separated by the oblique fissure.
Each lung is actually a composition of 150 million alveoli. There are two types of alveolar cells; squamous (Type I) and great (type II). Squamous alveolar cells cover 95% of the surface area of an alveolus while great alveolar cells only cover 5%. However great alveolar cells are more numerous than squamous alveolar cells. Squamous cells are responsible for the rapid diffusion of gases between the air and blood. Great cells repair alveolar tissues and secrete a substance to coat alveoli and bronchioles.
There are two types of Tuberculosis: Latent TB infection and TB disease. Latent TB is the infection that occurs in a patient who has not been previously exposed to the disease and has not been sensitized. TB Disease occurs when the immune system is not able to fend off the disease and the bacteria become active and multiply. Of patients who contract the disease, approximately 5% of them actually develop TB to the full extent.
When you breathe in, air containing carbon dioxide (CO2) and oxygen (O2) it moves down your trachea; a tunnel containing cartilage and smooth tissue. Air then travels through two hollow tubes called bronchi; narrow branches lined with smooth muscle, mucosal and ringed cartilage to support the structure. The bronchi divide out into smaller tunnels called bronchioles; are small branches 0.5-1mm, lined with muscular walls to help dilate and constrict the airway. At the end of the bronchioles are little air sacs called alveoli; which assist in gas exchange of O2 and CO2. (Eldridge, 2016) Towards the end of alveoli are small blood vessel capillaries. O2 is moved through the blood stream through theses small blood vessels (capillaries) at the end of the alveoli and the CO2 is then exhaled. (RolandMedically,
Paul Farmer was born in Massachusetts in 1959, went to Harvard Medical School, became a doctor, and ended up living and working in Haiti. He co-founded an organization in 1987 called Partners in Health (PIH). The philosophy behind the organization is that everyone, no matter who or where has a right to health care. Paul Farmer and PIH have already made amazing progress in Haiti, Peru, and several other countries, helping people get the care they need. PIH’s website lists a detailed history of they and Farmer’s work in Haiti. When Paul Farmer first came to Cange, Haiti as a medical student in 1983, the place was in shambles. In 1956, a dam was built on the Artibonite River, flooding the village and forcing the residents to move up into the hills. Many of these displaced villagers were still essentially homeless after nearly thirty years, and had little access to quality health care. With the founding of the Zanmi Lasante clinic later in 1983, Farmer and his friend Ophelia Dahl set the people of Cange on the road to recovery by providing access to doctors, medicine, and emergency care, all completely free. (“Partners”) One of Farmer’s focuses was on tuberculosis (TB) and has had much success on this front. Through new studies and methods such as active case finding and community health workers, as well as his work with multidrug-resistant TB, Paul Farmer has revolutionized treatment of tuberculosis in Haiti and around the world.
To better understand how COPD affects an individual you should first know how the lungs function. When you breathe in air it first goes through your trachea then into your bronchioles. Once in the bronchioles the air goes to the air sacs called alveoli. In the alveoli, the gas exchange occurs with the capillaries. Gas exchange is when the oxygen enters the bloodstream and carbon dioxide enters the alveoli. During the breathing process, alveoli will inflate when inhaling and deflate while exhaling.
Healthy lung tissue is predominately soft, elastic connective tissue, designed to slide easily over the thorax with each breath. The lungs are covered with visceral pleura which glide fluidly over the parietal pleura of the thoracic cavity thanks to the serous secretion of pleural fluid (Marieb, 2006, p. 430). During inhalation, the lungs expand with air, similar to filling a balloon. The pliable latex of the balloon allows it to expand, just as the pliability of lungs and their components allows for expansion. During exhalation, the volume of air decrease causing a deflation, similar to letting air out of the balloon. However, unlike a balloon, the paired lungs are not filled with empty spaces; the bronchi enter the lungs and subdivide progressively smaller into bronchioles, a network of conducting passageways leading to the alveoli (Marieb, 2006, p. 433). Alveoli are small air sacs in the respiratory zone. The respiratory zone also consists of bronchioles and alveolar ducts, and is responsible for the exchange of oxygen and carbon dioxide (Marieb, 2006, p. 433).
Tuberculosis or TB is an airborn infection caused by inhaled droplets that contain mycobacterium tuberculosis. When infected, the body will initiate a cell-mediated hypersensitivity response which leads to formation of lesion or cavity and positive reaction to tuberculin skin test (Kaufman, 2011). People who have been infected with mycobacteria will have a positive skin test, but only ones who have active TB will show signs and symtoms. Basic signs and symptoms include low grade fever, cough with hemoptysis, and tachypnea. They may also show pleuristic chest pain, dyspnea, progressive weight loss, fatigue and malaise (Porth, 2011).
Only the smallest particles of the coal dust make it past the nose, mouth, and throat into the alveoli found deep in the lungs. The alveoli, or air sacs, are responsible for exchanging gases with the blood, and are located at the end of each bronchiole. Microphages, a type of blood cell, gather foreign particles and carry them to where they can either be swallowed or coughed out. If too much dust is inhaled over a long period of time, some dust-laden microphages and particles collect permanently in the lungs causing black lung disease.
Person, A. & Mintz, M., (2006), Anatomy and Physiology of the Respiratory Tract, Disorders of the Respiratory Tract, pp. 11-17, New Jersey: Human Press Inc.
Active TB patients are IGRA positive and are symptomatic. The granuloma model: macrophages get infected in non-activated macrophages, necrosis occurs, lymphocytes also activate macrophages. MTB continue to grow and spread. The tubercles bexome liuqified and extracellular bacterial growth ensue, releases liquifed caseous material into the bronchiole causes causing and this can be transmitted tooter people.
Chronic bronchitis is a disorder that causes inflammation to the airway, mainly the bronchial tubules. It produces a chronic cough that lasts three consecutive months for more than two successive years (Vijayan,2013). Chronic Bronchitis is a member of the COPD family and is prominently seen in cigarette smokers. Other factors such as air pollutants, Asbestos, and working in coal mines contributes to inflammation. Once the irritant comes in contact with the mucosa of the bronchi it alters the composition causing hyperplasia of the glands and producing excessive sputum (Viayan,2013). Goblet cells also enlarge to contribute to the excessive secretion of sputum. This effects the cilia that carry out the mechanism of trapping foreign bodies to allow it to be expelled in the sputum, which are now damaged by the irritant making it impossible for the person to clear their airway. Since the mechanism of airway clearance is ineffective, the secretion builds up a thickened wall of the bronchioles causing constriction and increasing the work of breathing. The excessive build up of mucous could set up pneumonia. The alveoli are also damaged enabling the macrophages to eliminate bacteria putting the patient at risk for acquiring an infection.
TB is a disease that can cause a serious illness and can damage a person's
two pleural lobes on the sides. The three main parts of it's body are called the
Parker, Steve. "Chronic Pulmonary Diseases." The Human Body Book. New ed. New York: DK Pub., 2007.
To explain normal functioning of the respiratory system, it is best to know that the respiratory system in human beings is comprised of the upper respiratory tract that consists of the nasal passages, pharynx and the larynx. The lower respiratory tract is composed of the trachea, the primary bronchi and the lungs. The primary function of the respiratory system is to supply oxygen to the blood in the body. Oxygen is delivered to all parts of the body. The respiratory system does this while breathing is taking place. During the process of breathing, one inhales oxygen and exhales carbon dioxide. This exchange of gases within the thoracic cavity takes place at the alveoli within the body (Grant, 2004). The average adult's lungs contain about 600 million of these air-filled sacs that are surrounded by capillaries (Grant, 2004). The inhaled oxygen passes into and through the alveoli and is diffused through the capillaries into the arterial blood. Meanwhile, the waste-rich blood from the veins releases the carbon dioxide into the alveoli. The carb...
Primary tuberculosis is the initial infection of the host, usually being mild and asymptomatic. A healthy person recently infected with the mycobacterium may exhibit flu-like symptoms and has no reason to suspect tuberculosis. Left untreated, the bacilli infect and multiply within pulmonary alveolar macrophages, migrating to the hilar lymph nodes. An immune response is exhibited by the T-helper cells, and inflammation develops at multiple sites. A person may test positive in the tuberculin skin test at this point, and a chest x-ray may shows opacities in the lungs.
Active tuberculosis only develops in about 10% of infected persons, remaining dormant in the rest; although the latent infection may later progress to active disease years later, especially in immune-compromised individuals. 9 Infection by MTBC may involve any organ of the body, but clinical presentation is most common in the lungs (pulmonary TB). General symptoms include fever, loss of appetite, weight loss, fatigue and severe cough with bloody sputum (hemoptysis) which may lead to death if untreated. 10 Mortality rates without treatment are high: in a study of natural history of TB in HIV-negative patients, 70% died within 10 years. 11 Tuberculosis remains a major health problem in the world...