Veins and arteries are covered the entire bronchial tree. Veins and arteries feed into and out of the lungs. The Respiratory and the Circulatory system work together. Pulmonary Arteries from the right side of the lungs pump oxygen- poor blood into the lungs where it flows through branching blood vessels along the bronchi until it reaches the capillaries that cover the alveoli. (Pulmonary arteries leads to the lungs.) Carbon dioxide then diffuses from the capillaries the alveoli into the capillaries into the alveoli as oxygen diffuses from the alveoli into the capillaries. The oxygenated blood returns to the left sside of the heart to four pulmonary veins.
The lungs are the central organs of the respiration. They are so light that they float in water. The word lung comes from an early Germanic word for “light". The lungs are filled with millions of air pouches, or alveoli, that provide a wide amount of surface area for moving gases both in and out of the blood stream. Pale pink and birth, the lungs darken to gray or even black with age as they pick up carbon particles. These two cone-shaped, spongy organs occupy most of the chest cavity within the ribs. The bronchus and large blood vessels enter each lung. A layer of serous membrane, the visceral pleura, folds back to form the parietal pleura. The visceral pleura is attached to the lungs also covers lung surface, and the parietal pleura connects the thoracic cavity; serous fluid lubricates the “pleura cavity” between these two membranes. The right lung has three lobes, the left has two. Each lobe is composed of lobules that contain air passages, alveolar, nerves, blood vessels, lymphatic vessels, and connective tissues.The alveoli are tiny air cavities of the lungs. Alveoli are the sites of gas exchange between the atmosphere and the blood. The airways have easy access to the bloodstream. The lungs are defenders against airborne invades; dust, pollen, airborne invaders, virus, bacteria and other unwanted substances. Specialized cells in the lung tissue form an important role in the immune system. Hairlike cilia on some cell sweep invaders out of the airways and others detect and pick up foreign matter in the air sacs. The diaphragm’s job is to help pump the carbon dioxide out of the lungs and into the lungs.
Ventilation (breathing), the movement of air in and out of the lungs, is composed of inspiration and expiration. Atmospheric pressure is the force that moves air into the lungs. When pressure on the inside of the lungs decreases, higher pressure air flows in from the outside.
Air pressure inside the lungs is decreased by increasing the size of the thoracic cavity; due to surface tension between the two layers of pleura, the lungs follow with the chest wall and expand. Muscles involved in expanding the thoracic cavity include the diaphragm. As the lungs expand in size, surfactant keeps the alveoli from sticking to each other so they do not collapse when internal air pressure is low. The forces of expiration are due to the elastic recoil of lung and muscle tissues and from the surface tension within the alveoli. Forced expiration is aided by thoracic and abdominal wall muscles that compress the abdomen against the diaphragm. The measurement of different air volumes is called spirometry, and it describes. four distinct respiratory volumes. One inspiration followed by expiration is called a respiratory cycle; the amount of air that enters or leaves the lungs during one respiratory cycle is the tidal volume. During forced inspiration, an additional volume, the inspiratory reserve volume, can be inhaled into the lungs. During a maximal forced expiration, an expiratory reserve volume can be exhaled. Vital capacity is the tidal volume plus inspiratory and expiratory reserve capacities combined. Vital capacity plus residual volume is the total lung capacity. Anatomic dead space is air remaining in the bronchial tree.
Normal breathing is a rhythmic, involuntary act. Groups of neurons in the brain stem comprise the respiratory center, which controls breathing by causing inspiration and expiration and by adjusting the rate and depth of breathing. The components of the respiratory center include the rhythmicity center of the medulla and the pneumotaxic area of the pons.”(). The medullary rhythmicity center includes two groups of neurons: the dorsal respiratory group and the ventral respiratory group. The dorsal respiratory group is responsible for the basic rhythm of breathing. The ventral respiratory group is active when more forceful breathing is required. Neurons in the pneumotaxic area control the rate of breathing. Hyperventilation lowers the amount of carbon dioxide in the blood. The alveoli are the sites of gas exchange between the atmosphere and the blood. When the respiratory works with other organs it is maintaining homeostasis .The alveoli are the sites of gas exchange between the atmosphere and the blood.
The respiratory membrane consists of the epithelial cells of the alveolus, the
endothelial cells of the capillary, and the two fused basement membranes of these layers. Gas exchange occurs across this respiratory membrane. Gases diffuse from areas of higher pressure to areas of lower pressure. In a mixture of gases, each gas accounts for a portion of the total pressure; the amount of pressure each gas exerts is equal to its partial pressure. When the partial pressure of oxygen is higher in the alveolar air than it is in the capillary blood, oxygen will diffuse into the blood. When the partial pressure of carbon dioxide is greater in the blood than in the alveolar air, carbon dioxide will diffuse out of the blood and into the alveolus. Gases are transported in association with molecules in the blood or dissolved in the plasma. Over 98% of oxygen is carried in the blood bound to hemoglobin( part of red blood cells made of protein and transports oxygen and some carbon dioxide) red blood cells, producing oxyhemoglobin. Oxyhemoglobin is unstable in areas where the concentration of oxygen is low, and gives up its oxygen molecules in those areas. More oxygen is released as the blood concentration of carbon dioxide increases, as the blood becomes more acidic, and as blood temperature increases. A deficiency of oxygen reaching the tissues is called hypoxia and has a variety of causes. Carbon dioxide may be transported dissolved in blood plasma. Most carbon dioxide is transported in the form of bicarbonate. When carbon dioxide reacts with water in the plasma, carbonic acid is formed slowly, but instead much of the carbon dioxide enters red blood cells, where the "enzyme carbonic anhydrase speeds this reaction. Carbaminohemoglobin also releases its carbon dioxide which diffuses out of the blood into the alveolar air.
Emphysema is a lung disorder that damage healthy lungs by destroying healthy alveolar walls; forming abnormally large air spaces that cannot deflate properly to take in air during exhalations. People with emphysema become constantly tired and breathless with mild exercise. They began to compensate for a decrease oxygen intake with rapid inhalations. Cigarette smoking is the most common cause, but polluted air, and industrial contaminants can also harm the lung tissue and cause emphysema. Emphysema cannot be reversed, but can be treated; quit smoking, careful exercise, oxygen therapy, bronchodilators lung volume reduction, and lung transplants.
Lung cancer is a cancer that starts in the lungs. There are two main types of lung cancer,; non-small cell lung cancer is the most common type of lung cancer, and small cell lung cancer makes up about 20% of all lung cancer cases. If the lung cancer is made up of both types, it is called mixed small cell/and large cell cancer. Lung cancer is the most deadliest form of cancer for both men and women in the United States. Lung cancer is more common in older adults. Cigarette smoking is the leading cause of lung cancer; furthermore more cigarettes you smoke per day and the earlier you start smoking, the greater your risk for Lung cancer. Also lung cancer have occurred in people that haven't smoked, which the factors for that are high levels of pollution, asbestos, high levels of arsenic in drinking water, and harmful chemicals that your body are exposed to. According to the American Cancer Society, an estimated 3,000 non-smoking adults will die each year from lung cancer related to breathing secondhand smoke. The most interesting fact is that lung cancer is a genetic disease.
The Respiratory System is important because it contains a very important organ called the lungs. In order for the Respiratory System to maintain homeostasis it functions with the cardiovascular and nervous system. Without the Respiratory System the body wouldn't have oxygen which is needed to operate and wouldn’t be able to exhale carbon dioxide.
Citation
Marieb, Elaine Nicpon. Essentials of human anatomy and physiology. 5th ed. Menlo Park, Calif.: Benjamin/Cummings Pub. Co., 1997. Print