Bronchus

Bronchiolar epithelium 1 - SEM

Bronchial wall thickness (T) and diameter (D)

Bronchi

Relations of the aorta, trachea, esophagus and other heart structures

Bronchus refers to one of the two main branches of the trachea that carry air into the lungs. The trachea divides into the right and left bronchi, with the right bronchus being wider, shorter, and more vertical than the left. This anatomical structure is a crucial part of the respiratory system, facilitating the passage of air to and from the lungs for gas exchange.

Structure

The bronchi are made up of cartilaginous rings and smooth muscle. They branch into smaller tubes called bronchioles which further divide into even smaller passages ending in the alveoli, where gas exchange occurs. The inner lining of the bronchi is ciliated and secretes mucus to trap foreign particles, preventing them from entering the lungs.

Right Bronchus

The right bronchus is shorter, wider, and more vertical than the left. It divides into three secondary bronchi, each leading to a different lobe of the right lung. Due to its anatomy, it is more common for aspirated (inhaled) foreign objects to end up in the right bronchus.

Left Bronchus

The left bronchus is narrower, longer, and more horizontal compared to the right. It divides into two secondary bronchi for the two lobes of the left lung. Its structure is slightly more complex due to the position of the heart.

Function

The primary function of the bronchi is to conduct air from the atmosphere to the lungs and vice versa. They play a key role in the body's ability to obtain oxygen from the air and remove carbon dioxide from the blood. The mucus and cilia lining the bronchi also help to clean the air by trapping and moving debris out of the respiratory system.

Clinical Significance

Several conditions can affect the bronchi, including:

- Bronchitis: Inflammation of the bronchi, often due to infection or exposure to irritants. - Bronchiectasis: Chronic condition involving the abnormal widening of the bronchi, leading to mucus build-up and infection. - Asthma: A chronic condition where the bronchi become inflamed and narrowed, making it difficult to breathe. - Bronchogenic carcinoma: A type of lung cancer that originates in the bronchi.

See Also

- Respiratory system - Lung - Trachea - Bronchioles - Alveoli