Final answer:
The right main bronchus transports air to the right lung and is supported by cartilage, lined with mucus-producing cells, and has cilia to move mucus and trapped particles out of the respiratory system. It branches into a bronchial tree leading to alveoli for gas exchange.
Step-by-step explanation:
Function of the Right Main Bronchus
The right main bronchus plays a crucial role in the respiratory system by transporting air between the trachea and the lungs. After air passes through the larynx, it moves into the trachea, or windpipe. The trachea then divides into the right and left bronchi as it enters the lungs. The right bronchus is responsible for delivering air to the right lung, which is composed of three lobes and is larger to accommodate space for the right side of the heart, creating a feature known as the cardiac notch on the left lung. Like the trachea, the bronchi are supported by rings of cartilage to prevent collapse and are lined with pseudostratified ciliated columnar epithelium. This epithelial layer includes mucus-producing goblet cells that trap debris and pathogens. Hair-like structures called cilia help transport the trapped particles and mucus toward the throat to be expelled.
The primary bronchi continue to branch into bronchial trees within the lungs. These further divide into secondary and tertiary bronchi, then into smaller bronchioles, eventually leading to alveoli, the air sacs where gas exchange occurs. The cartilage in the larger bronchi gives way to elastic fibers in the smaller bronchioles, which rely on inhaled air to maintain their structure. The walls of the bronchi contain smooth muscle innervated by nerves that control their constriction or dilation, aiding in the regulation of airflow to the lungs.