Final answer:
The trachea is the structure that connects the throat to the lungs. It branches into bronchi, which further divide into smaller bronchioles and end in the alveoli where gas exchange occurs.
Step-by-step explanation:
The structure that connects the throat to the lungs is the trachea. When we breathe in, air travels from the pharynx to the trachea. The trachea then branches into two bronchi, which further divide into smaller bronchioles, and finally end in the alveoli. Gas exchange between the lungs and blood takes place in the alveoli.