What is the name of the flap of cartilage that closes to prevent food and liquid from entering the air passages during swallowing? Epiglottis Vocal cords Larynx Nasolacrimal duct

## Step 1<br />The question is asking for the name of the flap of cartilage that prevents food and liquid from entering the air passages during swallowing. This is a biological function that is crucial for the respiratory system.<br />## Step 2<br />The options provided are Epiglottis, Vocal cords, Larynx, and Nasolacrimal duct. Each of these options is a part of the human body, but they have different functions.<br />## Step 3<br />The Epiglottis is a flap of cartilage that covers the windpipe while swallowing, preventing food and liquid from entering the air passages. This function aligns with the description given in the question.<br />## Step 4<br />The Vocal cords are responsible for sound production, not for preventing food and liquid from entering the air passages.<br />## Step 5<br />The Larynx is the voice box, not a flap of cartilage.<br />## Step 6<br />The Nasolacrimal duct is a part of the tear system, not related to the respiratory system.