Respiratory system

Welcome to this lecture on Respiratory System, providing an overview of the structure and key functions of the human respiratory system, including the pathways and organs involved in gas exchange. We will discuss how oxygen is supplied to the blood and carbon dioxide is removed in the alveoli, focusing on the mechanisms of breathing and the role of regulatory centres in the brain. Additionally, we will review common respiratory disorders such as asthma, COPD, pneumonia, cystic fibrosis, and pulmonary fibrosis, highlighting how these conditions affect respiratory function.. The human respiratory system includes organs and passages for breathing and gas exchange. Air enters through the nose or mouth, where it is filtered, warmed, and humidified in the nasal cavity and pharynx. It then passes through the larynx and cartilage-supported trachea, which splits into right and left bronchi for each lung. Inside the lungs, bronchi branch into smaller bronchioles, ending in microscopic alveoli. The lungs are in the thoracic cavity, protected by the rib cage and separated from the abdomen by the diaphragm, ensuring efficient gas exchange. The respiratory system's primary function is gas exchange—supplying oxygen to the blood and removing carbon dioxide. This occurs in the alveoli, tiny sacs with single-cell-thick walls surrounded by capillaries carrying deoxygenated blood. Oxygen from inhaled air diffuses into the blood, binding to haemoglobin in red blood cells,