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Body Lab 3-5 / Week 06 / Tuesday
2/6
Week 06 · Digestion

Tuesday

Down the stretchy tube
// Food's long trip, powered by the Sun
⏱ about 15 min

Tuesday: Down the Stretchy Tube

Rocket drops a marble into a cardboard tube. It zooms straight down. "Food just falls into the stomach, right?"

Raven holds up a long sock with a ball inside. "What do you notice if I squeeze behind the ball?"

The ball inches forward, squeeze by squeeze.

Nova blinks. "Your food tube has muscles," she says. "Gravity is not doing all the work."

The esophagus

After you swallow, food goes into your esophagus (ih-SOF-eh-guss).

The esophagus is a stretchy tube from your throat to your stomach.

In an adult, it is about 10 inches long. That is about 25 centimeters.

Remember the flap from last week? The epiglottis covers the windpipe when you swallow.

So food goes down the esophagus, not into the lungs.

Squeeze, squeeze, squeeze

Food does not just fall down the esophagus.

Muscles in its walls squeeze in waves. They push the food along.

The muscle behind the food squeezes. The muscle in front of the food relaxes.

This squeezing wave has a science name: peristalsis (pair-ih-STAL-sis).

The trip down the esophagus takes only about 2 or 3 seconds.

Safety first
Use a clean, old sock and a soft ball or a small orange.
Squeeze gently with your hands.
Nothing goes in your mouth.
  1. Put the ball into the open end of a long sock.
  2. Hold the sock flat on a table.
  3. Squeeze the sock just behind the ball.
  4. Move your squeeze a little forward. Squeeze again.
  5. Keep going until the ball comes out the toe end.
ESOPHAGUS CHECK
  • Read the question.
  • Tap your answer.
Where does the esophagus carry food?
How does food move down the esophagus?
In the sock model, what does the sock stand for?
StatementTrue or false?
Food just drops down the esophagus with no help.?
The muscle in front of the food relaxes.?
The epiglottis helps keep food out of the windpipe.?
The trip down the esophagus takes about 2 or 3 seconds.?
WHY THIS EXERCISEMuscles squeeze food along in waves, and the trip is quick.
The food tube is called the ____.
The squeezing wave is called ____.
About how many inches long is an adult's esophagus?
WHY THIS EXERCISEAn adult esophagus is about 10 inches, or 25 centimeters, long.
A BOLUS GOES DOWN
  • ?The bolus enters the esophagus.
  • ?You swallow the bolus.
  • ?Muscle waves squeeze it down.
  • ?The bolus reaches the stomach.
  • ?The epiglottis covers the windpipe.
WHY THIS EXERCISEThe epiglottis guards the windpipe, then peristalsis carries food to the stomach.

Excellent squeezing! Rocket's idea was a great guess to test. Tomorrow food lands in a stretchy mixing bag.

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