Which of the following characterizes acute bronchitis? Multiple select question.A deep cough that expectorates mucusAn infection of the primary bronchiAn infection of the alveoliAn infection of secondary bronchiAn upper respiratory infection

Acute bronchitis is characterized by:

1. A deep cough that expectorates mucus: This is one of the most common symptoms of acute bronchitis. The body produces mucus to trap the virus or bacteria causing the infection, and coughing helps to clear this from the body.

2. An infection of the primary bronchi: Acute bronchitis is an infection of the bronchi, the main airways to the lungs. This can be caused by a virus or bacteria.

3. An infection of secondary bronchi: The infection can also spread to the secondary bronchi, smaller airways that branch off from the primary bronchi.

Acute bronchitis is not typically characterized by:

1. An infection of the alveoli: This is more characteristic of pneumonia, a more serious lung infection.

2. An upper respiratory infection: While acute bronchitis can be caused by an upper respiratory infection, it is not itself an upper respiratory infection. It affects the lower respiratory tract, specifically the bronchi.