Final answer:
In the respiratory system, the trachea divides into the right and left bronchi, which enter the right and left lungs, respectively. The bronchi branch into bronchioles, which terminate in alveoli, where gas exchange occurs. The right lung is larger with three lobes, and the left lung has two lobes to accommodate the heart.
Step-by-step explanation:
Anatomy of the Respiratory System
The respiratory system is divided into two main regions: the upper respiratory tract and the lower respiratory tract. Starting with the upper respiratory tract, when we breathe in, air travels from the pharynx to the trachea, or windpipe. The trachea is a tubular passage that leads to the chest and bifurcates into the right and left bronchi which enter the right lung and left lung, respectively. The right lung is larger, comprising three lobes, whereas the left lung has two lobes to accommodate the heart.
The bronchi continue to branch into smaller tubes called bronchioles. These bronchioles are made of cartilage and smooth muscle, lined with cilia, and end in alveoli where gas exchange occurs. The bronchioles do not have the cartilaginous support that the trachea and the bronchi have, allowing for a more efficient transfer of air. Finally, the alveoli are tiny air sacs where gas exchange between the lungs and blood takes place. Surrounded by capillaries, the alveoli are pivotal for oxygen to diffuse into the blood and for carbon dioxide to be exhaled.
The muscular diaphragm is located inferiorly to the lungs and is essential for the process of breathing. The diaphragm contracts and relaxes to facilitate the inflow and outflow of air from the lungs. The entire system is designed to optimize the exchange of gases essential to life.