Nose and Nasal Cavity, Sinuses, Pharynx, Larynx, Trachea, Lungs, Bronchi, Alevoli-4

Lungs

A pair of cone-shaped organs called the lungs are located in the thoracic cavity. The esophagus, major vessels, heart, and other mediastinum-resident organs stand between the right and left lungs. Oblique and horizontal fissures divide the right lung into three lobes (upper, middle, and lower). Upper and lower lobes of the left lung are separated by an oblique fissure. The left lung is smaller than the right lung because of the space the heart takes up.

Structure of the Lungs

The diaphragm is bordered inferiorly on all sides and the rib cage superiorly on all sides of the thoracic cavity. The apex, which is the highest, narrowest section, is located 2.5 cm above the level of the middle third of the clavicle, into the root of the neck and above the first rib. The base, which sits on the diaphragm, is the broadest, most inferior section. Concave and semi-lunar in shape, the base. There are 3 lobes in the right lung and 2 in the left lung. The costal, mediastinal, and diaphragmatic surfaces are the three surfaces of the lungs.The lung's costal surface is broad, convex, and smooth. It is connected to the intercostal muscles, costal cartilage, and costal pleura, which separates the ribs. The costal surface is connected to the thoracic vertebrae posteriorly and is known as the vertebral component of the costal surface. The heart and pericardium are located in the middle mediastinum, which has a concave mediastinal surface. The base of the lung, which rests on the dome of the diaphragm, is formed by the concave diaphragmatic surface. The anterior, inferior, and posterior margins of the lungs are present. Where the cardiac notch on the left lung is located, the anterior border is where the costal and mediastinal surfaces meet anteriorly. The lung's diaphragmatic surface is bounded by the inferior border, which also divides it from the costal and mediastinal surfaces. The posterior boundary is where the mediastinal and costal surfaces meet at the side of the thoracic vertebrae. at the side of the thoracic vertebrae in the back. The veins, nerves, and other structures that enter the lungs pass through the Hilum, or root, of the lung, which is located at the level of T5-T7 on the mediastinal surface of the lung.

The Pleura

Two layers of serous membranes called pleura surround and guard each lung. The parietal layer and the visceral layer are the two different kinds. The thoracic cavity's wall is lined with the outer parietal layer. Each lung is covered by the inner visceral layer. The pleural cavity, a small space between these two membranes, houses a tiny amount of watery fluid called pleural fluid. As a result of less friction, breathing is made easier for the lungs thanks to this fluid.

Because of the partial vacuum and airtightness of the pleural cavity surrounding the lungs, its pressure is lower than that of the surrounding air. The lungs have a tendency to stay inflated because the pressure inside of them is higher than the pressure in the pleural cavity around them.

Blood Supply

• Both the pulmonary and bronchial arteries supply blood to the lungs. The bronchial and pulmonary veins drain the venous blood.

Nerve Supply

• The lungs are supplied by the phrenic and thoracic nerves.

Functions of the Lungs

• Their main duties involve transferring oxygen from the atmosphere into the capillaries and releasing carbon dioxide into the atmosphere from the capillaries.