lung

Examples of lung in the following topics:

• Factors Affecting Pulmonary Ventilation: Compliance of the Lungs

  • Lung compliance refers to the magnitude of change in lung volume as a result of the change in pulmonary pressure.
  • Lung compliance is defined as the volume change per unit of pressure change across the lung, and is an important indicator of lung health and function.
  • Compliance is inversely related to the elastic recoil of the lungs, so thickening of lung tissue will decrease lung compliance.
  • A low lung compliance means that the lungs are "stiff" and have a higher than normal level of elastic recoil.
  • Low lung compliance is commonly seen in people with restrictive lung diseases, such as pulmonary fibrosis, in which scar tissue deposits in the lung making it much more difficult for the lungs to expand and deflate, and gas exchange is impaired.

• Lung Cancer

  • Lung cancer is a disease characterized by uncontrolled cell growth in tissues of the lung.
  • Lung cancer is a disease characterized by uncontrolled cell growth in tissues of the lung.
  • Most cancers that start in lung, known as primary lung cancers, are carcinomas that derive from epithelial cells.
  • The main types of lung cancer are small cell lung carcinoma (SCLC), also called oat cell cancer, and non-small cell lung carcinoma (NSCLC).
  • Accounting for 25% of lung cancers, squamous cell lung carcinoma usually starts near a central bronchus.

• Lungs

  • The lungs are cone-shaped—the apex refers to the top of the lung, while the base refers to the bottom of the lung.
  • The right lung is larger than the left lung, and the left lung contains the cardiac notch, a concave impression that the heart lies against.
  • The lungs are divided into lobes by fissures on the outer surface of the lung, and divide further into segments and finally into hexagonal lobules, the smallest divisions of the lungs.
  • The elastic recoil of the lungs automatically pulls the lungs inward during exhalation.
  • The major function of the lungs is gas exchange, which occurs in the alveoli of the lung.

• Lung Volumes and Capacities

  • Lung volumes measure the amount of air for a specific function, while lung capacities are the sum of two or more volumes.
  • Air in the lungs is measured in terms of lung volumes and lung capacities .
  • The lungs are never completely empty; there is always some air left in the lungs after a maximal exhalation.
  • If this residual volume did not exist and the lungs emptied completely, the lung tissues would stick together.
  • The total lung capacity (TLC) is a measurement of the total amount of air that the lung can hold.

• Lobes, Fissures, and Lobules

  • There are three lobes in the right lung and two in the left lung.
  • The right lung is divided into three lobes.
  • It is a small, tongue-like projection of the left lung that is analogous to the middle lobe of the right lung.
  • There is a hilium for each of the lungs found in the mediastinum (backside) of the lungs.
  • The right lung has three lobes and the left lung has two.

• Blood Flow in the Lungs

  • Pulmonary circulation in the lungs is responsible for removing carbon dioxide from and replacing oxygen in deoxygenated blood.
  • From the right ventricle of the heart, blood is pumped through the pulmonary semilunar valve into the left and right pulmonary arteries (one for each lung) and travels through the lungs.
  • Air is inhaled through the nose or the mouth and fills the lungs.
  • The alveoli are the site of oxygen and carbon dioxide exchange in the lungs.
  • Outline the path of pulmonary circulation: blood flow in the lungs

• The Mechanics of Human Breathing

  • During this process, the chest wall expands out and away from the lungs.
  • The lungs are elastic; therefore, when air fills the lungs, the elastic recoil within the tissues of the lung exerts pressure back toward the interior of the lungs.
  • Upon exhalation, the lungs recoil to force the air out of the lungs.
  • Each lung is surrounded by an invaginated sac.
  • A tissue layer called pleura surrounds the lung and interior of the thoracic cavity.

• Lung Capacity and Volume

  • Lung volumes and capacities refer to phases of the respiratory cycle; lung volumes are directly measured while capacities are inferred.
  • Capacity of the lungs generally refers to the total amount of volume of air inside the lungs at certain phases of the respiratory cycle.
  • In general, measuring lung capacity is important because it serves as potentially the best indicator of lung health through quantifying the functional ability of the lungs to cycle air.
  • It is not very reduced in those with obstructive lung diseases.
  • Other important lung volumes related to lung capacity are residual volume (RV) and total lung capacity (TLC).

• Dead Space: V/Q Mismatch

  • Dead space is a broken down or blocked region of the lung that produces a mismatch of air and blood in the lungs (V/Q mismatch).
  • Dead space is characterized by regions of broken down or blocked lung tissue.
  • An example of an anatomical shunt is the effect of gravity on the lungs.
  • As a result, the intrapleural pressure is more negative at the base of the lung than at the top; more air fills the bottom of the lung than the top.
  • Perfusion of the lung is not uniform while standing or sitting.

• Types of Breathing

  • Lung capacity has evolved to support the animal's activities.
  • During inhalation, the lungs expand with air and oxygen diffuses across the lung's surface, entering the bloodstream.
  • During exhalation, the lungs expel air and lung volume decreases.
  • These lungs are primitive and not as evolved as mammalian lungs.
  • In addition to lungs, birds have air sacs inside their body that are attached to the lungs.