The Human Body - [The Digestive System - Esophagus]

The Esophagus

If you've ever choked on food, your food may have "gone down the wrong way." That's because there are two openings at the back of your mouth. One opening leads to your windpipe, which carries air into your lungs. As you swallow, a flap of tissue called the epiglottis seals off your windpipe, preventing the food from entering.

epiglottis - a flap of tissue that seals off your windpipe, preventing the food from entering.

Multiple Choice

What is a flap of tissue that seals off your windpipe, preventing the food from entering.

• Epiglottis

• Esophagus

• Enzymes

• Saliva

The Esophagus (continued)

The food goes into the esophagus, a muscular tube that connects the mouth to the stomach. The esophagus is lined with mucus, a thick, slippery substance produced by the body. Mucus makes food easier to swallow and move along.

esophagus - a muscular tube that connects the mouth to the stomach
mucus - a thick, slippery substance produced by the body

Multiple Choice

What is a muscular tube that connects the mouth to the stomach?

• Epiglottis

• Esophagus

• Mucus

• Digestion

Multiple Choice

What is a thick, slippery substance produced by the body?

• Saliva

• Mucus

• Enzymes

• Powder

The Esophagus (continued)

Food remains in the esophagus for only about 10 seconds. After food enters the esophagus, contractions of smooth muscles push the food toward the stomach. These involuntary waves of muscle contraction are called peristalsis. Peristalsis also occurs in the stomach and farther down the digestive system. These muscular waves keep food moving in one direction.

peristalsis - involuntary waves of smooth muscle contractions

Multiple Choice

What is peristalsis?

• Voluntary waves of smooth muscle contractions

• Involuntary waves of smooth muscle contractions

Lab Zone

Modeling Perstalsis

1. Obtain a flexible plastic straw.

2. Hold the straw vertically and insert a small bead into the top of the straw. The bead should fit snugly into the straw.

3. Pinch the straw above the bead so the bead begins to move down the length of the straw.

4. Repeat Step 3 until the bead exits the straw.

How does this action compare with peristalsis? What do the bead and straw represent?

Lesson Complete
Great Job!