From Your Lunch to Your Muscles

Science · Organisms & Life Processes · ages 10-11

Name ______________________ Date ____________

Which substances does blood carry in its liquid part to help nourish body cells?
- Whole food pieces and water
- Dissolved nutrients and water
- Water, but no dissolved nutrients
How do simple sugars from digested food enter the blood?
- They cross the small-intestine wall into nearby blood vessels.
- They cross the stomach wall into nearby blood vessels.
- They cross the large-intestine wall into nearby blood vessels.
The digestive system and circulatory system work together to deliver nourishment to the body.
Circle one: True False
A chewed food lump still contains large food molecules. Why can it not enter blood as a whole lump?
- Large food molecules need further digestion before absorption.
- Chewed food must wait until the stomach is empty.
- Whole food must dissolve in blood before it can be digested.
Maria eats a banana. How can sugars absorbed from it reach her brain?
- The intestine sends them straight to brain cells.
- They stay in the gut while energy travels to the brain.
- Blood carries them to the brain.
Water must be digested into smaller food molecules before the gut can absorb it.
Circle one: True False
Order these steps for a sugar from digested food: (1) it crosses the small-intestine wall into blood; (2) digestion releases it from starch; (3) blood transports it toward muscle cells.
- 3, 2, 1
- 1, 2, 3
- 2, 1, 3
Ben says, "My stomach sends whole food straight to my muscles." Which explanation should replace his idea?
- Digestion finishes in the stomach, which sends food pieces to muscles.
- Digestion releases nutrients; blood carries them toward muscle cells.
- Nutrients spread straight from the gut to distant muscles.

Answer key

For grown-ups. Fold this page away before handing over the rest.

From Your Lunch to Your Muscles W1-mt_YSyjTZfjvv-s1

Dissolved nutrients and water · Blood's liquid part carries water and dissolved nutrients. Whole food pieces do not enter blood.
They cross the small-intestine wall into nearby blood vessels. · Simple sugars from digested food are absorbed through the small-intestine wall into nearby blood vessels.
True · The digestive system breaks food down and absorbs nutrients. Circulation transports absorbed nutrients around the body.
Large food molecules need further digestion before absorption. · Chewing reduces food-piece size. Further digestion breaks large food molecules into absorbable molecules. Whole lumps do not enter blood for digestion.
Blood carries them to the brain. · After absorption, blood transports sugars toward brain cells. The sugars do not stay in the gut or bypass blood on a direct intestine-to-brain route.
False · Water can cross the gut wall without being digested into smaller food molecules.
2, 1, 3 · Digestion releases the sugar first. It is then absorbed into blood, which transports it toward muscle cells.
Digestion releases nutrients; blood carries them toward muscle cells. · Digestion releases nutrients for absorption. Blood then provides transport toward distant muscles. Whole food pieces do not travel from the stomach to muscle cells.