Question

What structures are in the upper respiratory tract? and the lower?

Answer 1

The URT is from the nose to the larynx; the LRT is from the trachea to the alveoli.

Explanation:

The structures of the Upper Respiratory Tract are (in descending order):
1. Nose (or nostrils)
2. Nasal cavity
3. Mouth
4. Pharynx (throat)
5. Larynx (voice box)

The structures of the Lower Respiratory Tract are (descending from the larynx):
1. Trachea (windpipe)
2. Bronchi (one bronchus into each lung)
3. Secondary and tertiary bronchi
4, Bronchioles
5. Alveoli (air sacs surrounded by capillaries for oxygen and carbon dioxide exchange)