What are the parts of a respiratory system top to bottom?

The main parts of the respiratory system, from top to bottom, are:

1. Nasal cavity: The nasal cavity is the first part of the respiratory system that air passes through. It is located at the top of the nose and is lined with mucous membranes. The nasal cavity helps to filter out dust, pollen, and other particles from the air.

2. Pharynx: The pharynx is a muscular tube that connects the nasal cavity to the larynx. It is also called the throat. The pharynx helps to move air and food into the body.

3. Larynx: The larynx is a cartilaginous structure that contains the vocal cords. It is also called the voice box. The larynx helps to produce sound.

4. Trachea: The trachea is a long, thin tube that connects the larynx to the lungs. It is also called the windpipe. The trachea helps to move air into and out of the lungs.

5. Bronchi: The bronchi are the two large branches of the trachea that enter the lungs. The bronchi are lined with mucous membranes and help to move air into and out of the lungs.

6. Bronchioles: The bronchioles are the smaller branches of the bronchi that lead to the alveoli. The bronchioles are lined with mucous membranes and help to move air into and out of the lungs.

7. Alveoli: The alveoli are the tiny air sacs in the lungs where gas exchange takes place. The alveoli are lined with capillaries, which are small blood vessels. Oxygen from the air diffuses into the capillaries, and carbon dioxide diffuses out of the capillaries into the air.