Lungs What Are the Lungs?

Lungs

What are the lungs?

The lungs form a part of the respiratory system. It is situated inside the rib cage in the chamber of the chest. The lungs are spongy, light, large, round and inflatable organ that performs the function of supplying oxygen and removal of carbon dioxide from the blood. Lungs are a pair of huge soft organs that almost cover the chamber of the chest. The left lung is comparatively smaller than the right lung that provides room for the heart chest cavity. While breathing, air is taken into the body through the nose and the mouth, which later proceeds down through a pipe known as the trachea. Trachea is divided into two pipes known as the primary bronchi. Each primary bronchus is connected to each lung. These bronchi branches out into tiny air paths which is later taken into smaller air sacs known as alveoli. All these organs, beginning from the nose till the alveoli gives the picture of a downside up tree. The alveoli are situated around very small blood vessels. It is that part of the lungs where gases move to and fro the blood. ("Organs-Lungs," n. d.)

Oxygen is transported into the blood from the alveoli while carbon dioxide formed in the blood during catabolism of nutrient cell is transported back into the alveoli. The normal intake of air in a minute is calculated as five hundred ml. This quantity of air taken in is fifteen times a minute. If more oxygen is required by the body, the nervous system enhances the speed to breathe more air. This condition arises in a person while exercising. Breathing action is performed by the expansion and contraction of the breathing muscles and the diaphragm. While breathing in, the muscles surrounding the lungs are contracted to put the ribs apart and create space in the chest cavity. This activity is performed to decrease the pressure in the lungs and enable the entry of air into the lungs. While breathing out, these muscles expand to allow the ribs to join together. This is how air is flown in and out of the lungs. ("Organs-Lungs," n. d.)

2. Describe the lungs role in the normal functioning of the human body and its contribution to maintenance of homeostasis.

Lungs give the energy required for the human body to function. This power is taken from the air in the atmosphere. The lungs act as the moderator through which this power is passed on to the body by breathing in and breathing out. When breathing stops in a body, all other organs also stop functioning. A simple example to prove the importance of lungs in our day-to-day activity is the impact on our breathing while walking fast or climbing up the stairs quickly. Thus, lungs are essential for the normal functioning of a body. (Fitch, 1850) While administering anesthesia it is important to stabilize homeostasis of the patient. This can be maintained by continuously observing the functioning of the cardiovascular system. Observation of the patient includes continuous check on the change in color of the mucus membrane, auscultation or electrocardiogram and blood pressure. Respiratory system should also be monitored. A change in the color of the mucous membrane shows that oxygenation is taking place. While conducting surgeries that take a long duration, the lungs are manually inflated to avoid atelectasis. Immediate recovery of the patient is expected if there is enough cardiopulmonary function during the surgery. (Bennett, 1996)

3. What are the anatomical, physiological, and cellular mechanisms behind the structure or performance parameter?

Breathing is a vital function of the body since it is through this process the oxygen required to form the energy that maintains life is taken in. While breathing air through the nose and the mouth, it is taken to the lungs via the trachea or windpipe. The air then moves through two huge air paths known as bronchi. Bronchi are divided into tiny pipes known as bronchioles which carriers oxygen to alveoli which constitute a million of air bags. Alveoli look similar to miniature balloons with very delicate walls comprised of blood vessels. The walls are very delicate that oxygen passes through it to get into the bloodstream. Thus oxygen is transported to the entire body from the alveoli. Hence by breathing in, the oxygen required for the function of the body is taken in and by breathing out the unwanted carbon dioxide formed as a part of breathing is given out. ("Lung Anatomy," 2008)

The breathing in and breathing out of gases takes place when the lungs are exposed to fresh air. Respiration takes place due to the routine contraction and expansion of the lungs. While breathing in, the diaphragm contracts and the intercostal muscle of the rib cage pulls air to the lungs. Later these two muscles work together to enable the expansion of the lungs. While breathing in, there is a reduction in the intrathoracic force and increase in intra-abdominal force. Contraction of the intercostals muscles leads to the opening up of the chest wall while the contraction of the diaphragm moves down the organs of the abdomen. In the case of opposite movement of the chest or the stomach, it suggests that any one of the system is feeble. (Effros, 2006)

Additionally, the right and the left diaphragm should move at the same time. The inability of any one of the diaphragm to move along with the other will result in the reduced intake of air. A sniff test is ideal to diagnose the proper movement of the diaphragm. Here, the patient is subjected to sniff while the movement of the diaphragm is monitored through fluoroscopy or ultrasound. In a positive case, the diaphragm moves downward during inhalation by enhancing the intra-abdominal force and reducing the intra-thoracic force. Under this condition, the weak side of the diaphragm moves upward. The weakness of the diaphragm results in a wound to the phrenic nerve. The wound may happen in any part of the diaphragm stretching from the C3-C5 of the vertebrae to the thorax and may stretch till the bottom of the diaphragm. Unilateral weakness of the diaphragm leads to a small disorder in the ventilation of the lungs. (Effros, 2006)

In the case of bilateral phrenic nerve weakness when the intercostal and auxiliary respiratory muscles continue to function, ventilation of the lungs cannot be stabilized. Instead, there will be an acute hindrance to the ventilation mechanism of the lungs.Auxiliary respiratory muscles that take part in the ventilation process comprises of scalenus which plays a significant role in routine respiration and sternocleidomastoid muscles which function only during stressed breathing. The capacity of a person to breathe can be found out by fixing a respiratory device blocking the mouth which records the maximum force exerted during inhalation and exhalation. Though breathing in air includes the tightening of the muscle, breathing out is an inactive method and relies on the stretching nature of the pulmonary tissues. While assisting mechanical ventilation, the abdominal muscles and the intercostal muscles should be tightened to verify the impact on the breathing process. The loss of stretching tissues in the lungs is called emphysema. (Effros, 2006)

Patients with this impairment will have difficulty in exhalation. Patients who experience intrathoracic hindrance will use muscles in the abdomen to push the diaphragm up while exhaling. This phenomenon decreases the width of the bronchi which in turn restricts the speed at which a patient can conduct exhalation. This is not a good condition of lung anatomy and hence a better understanding can be obtained from the formation of lungs as an extension of the gastrointestinal tract. Unicellular organisms exchange gas through the easy method of diffusion. The evolution and function or a respiratory system began with the formation of multicellular organisms in the Precambrian age which is estimated to be around 0.5 to 1.0 billion years. Gills are considered to be the first organ that assisted respiration. Remains of the gills are still found in various other organisms. Gills carry the tissues that carry out evagination that assisted gaseous exchange between blood and water. In human lungs, this phenomenon is seen as invaginations of the upper gastrointestinal tract. Hence, the characteristics of lungs make it the perfect organ to maintain terrestrial life. (Effros, 2006)

4. How are the lungs uniquely suited to its function?

Lungs are uniquely crafted in terms of its physiology and anatomy to enable the transportation of carbon dioxide and oxygen. The metabolic activity and exclusive features of the lungs have been recognized for over seventy years. This feature of the lung makes it a vital component in the formation of biological mixtures and medicines. A 1925 research stated that only by the inclusion of lungs in the cycle of the body, the kidneys could diffuse liquid sufficiently. In the absence of the lungs, the defibrinated blood transported to the kidneys formed a restriction to the vessel carrying them. The substance that causes constriction in the blood vessel was called serotonin or 5-HT in 1948. However, it was 1953 that the formation of serotonin was from the lungs was substantiated. It is also observed that detoxification of the blood takes place in the lungs. Later, it was observed that one of the important activities of the lung is to provide chemical filtration by shielding the regular circulation of blood from the attack of vasoactive mixtures and other exogenous compounds present in the arteries. The physiology of the lungs and its location makes the lung exclusively suitable to perform these activities. (Wet; Moss, 1998)

The total output from the cardiac system is obtained by the lungs whereas other organs acquire only a very small quantity of output. The blood that circulates the lungs is subject to the vast capillary endothelial plane of the body which is of seventy square meters. This aspect of output and circulation enable the lung to perform the efficient function of biochemical filtration. With a cardiac production of 5L/min and thirty percent elimination of materials, the rate of pulmonary cleansing is estimated at 1.5L/min. This is however against the presumption that most of the metabolic activities are performed by the liver. Hence most of the metabolic activity of the liver is completed with a proper hepatic blood flow, which is estimated at 1.6 L / min. Earlier research on 5-HT stated that the lungs were able to eliminate or inactivate poisonous materials that passed through the pulmonary movement. Further studies have stated that the lung has a more important role to play in the human body. (Wet; Moss, 1998)

Certain mixtures like the norepinephrine or the 5-HT are either removed completely, incompletely or they are deactivated in the pulmonary movement. There are some associated mixtures like histamine or epinephrine that travel through the lungs without any change. There are certain other hormones that are stimulated by the lungs or sent to the pulmonary movement. This action of the lungs to act differently on different substances proves that the function of the lungs is not restricted to a common filter. However, this leads to a question whether a wound in the lungs would lead to the metabolic inactivity of the lungs. Further, the metabolic activity of the lungs can be used to judge the depth of a wound in the lungs. Hence an image of the lung shows that it not only performs the function of a filter but also functions as a brisk administrator of xenobiotics and hormones. The metabolic activities of the lungs include clinically vital pharmacokinetic outcomes on huge components of exogenous and endogenous materials which are of curiosity to research anesthesiologists. (Wet; Moss, 1998)

5. How do the lungs affect other body systems?

Vigorous action of the body by any kind of exercise can lead to illness. These exercises can be either muscular exertion, rowing, trekking a high slope, running or any movement that leaves the blood to flow quickly to the heart. This quick movement interrupts the free flow of blood through the arteries by causing an abnormal pressure on the lungs, brain, heart and other organs. The effect of such a pressure in the event of heavy exercise will put pressure on the heart and disrupt its normal task and it may even lead to a change in the composition which then affects the great vessels of the body. The heart is more vulnerable to such action if the heart, valves or vessels has undergone a change in its physiology earlier. Another organ which is affected seriously by vigorous exertion of the body is the brain. The damage caused to the brain is severe if the brain is subject to a complex posture or if it is connected through a stooping. This is so because the brain and its vessels are not protected with a muscular layer to withstand heavy force of the blood and the pressure caused by the sudden flow. Hence this phenomenon can cause defective sight, apoplexy, noise in the ears, convulsion, giddiness, palsy and deadness due to the vigorous action of the body. (Williams; Clymer, 1853)

The lungs are also vulnerable to such an impact. The blood which moved into the brain with great force will return to the lungs at the same speed which is above the normal capacity of the arteries connected to the lungs. This leads to congestion in the lungs that causes inflammation of the lungs, dyspnoea, cough, haemoptysis and may even result in changes in the condition of the lungs. The lungs may also sustain wounds due to excessive pressure from deep breath. Excessive muscular exertion may also lead to the distortion of vessels in other organs of the body due to high blood pressure. This leads to haematuria, haemorrhoids, haematemesis and dislocation of the liver. Severe pain experienced while running at a high speed actually occurs due to the changes in the spleen or the liver. More exactly this pain comes out of spasms of the temporary colic in the intestine which arises from the varying pressure of blood in these organs. Certain type of muscular action usually affects a particular set of organs. For example, reading or speaking at a high voice or blowing instruments affects the organs in the respiratory system and the voice. This may result in inflammation, hemorrhage or illness of these internal organs. (Williams; Clymer, 1853)

6. What has research on the lungs taught us?

Of late there are several studies that have researched the anatomy of this organ. These studies have resulted in an idea which is in contrast to the existing theories. Earlier theories said the constitution and task of lungs are inseparable and that the pathology usually denotes a quantitative change from the rule. Mucus cells and glands in the respiratory tract have gained considerable notice only now. Various modern day researches have discovered that around 40 to 70% of water content can be taken from this tract if it undergoes a huge change. The ciliated cells and their role in releasing the mucus were also analyzed. It has resulted in various important observations like the constitution and function of the cilium. While the cilium is stable in several living creatures with its two central and nine lateral filaments, they move at a rate of 1,317 per minute in certain living beings. In this state, the flow of mucus is registered normally at 13.5 mm/minute however this rate changes in the presence of toxic agents. Mucus in the respiratory tract may cause hindrance in a postoperative patient by giving out atelectasis. This hindrance to the bronchial tree usually results in infection and the function of the pulmonary organs will change according to the characteristics of the mucus. (De Reuck; O'Connor, 1962)