Jess L arts & crafts

Page 1 of a Magic School Bus-style comic.

The scientist introduces themself: "Heya, I'm Jess! I'll be your guide today on our tour of…"

The Marvelous Gastrointestinal Tract

The scientist climbs into an apple and invites the reader to join, saying "Hop on into this ole apple. We're going in worm style."

Location: Mouth

Scientist saying "Careful of the gnashers."

Teeth start digestion by physically breaking apart food (aka mechanical digestion). The tongue and jaw muscles are some of the stongest muscles in the body!

A cookie is no match for mechanical digestion.

Amylase: an enzyme in saliva that turns starch into simpler sugars. Lipases are simliar but work on fats instead.

You can think of these enzymes as scissors that cut long molecules into smaller ones.

Page 2

Location: Esophagus

The scientist, upside down in the throat, explains "The peristalsis does wonders for my back."

Peristalsis: wave-like contractions that push food through the digestive tract.

The scientist then falls through the open lower esophageal sphincter into the stomach, losing a shoe on the way.

Location: Stomach

The scientist lounges in stomach acid as if it were a pool, saying "Make yourself comfy, we'll be here for a few hours.

Hydrochloric acid (HCl): activates enzymes that break down proteins. The low pH (1-3) also protects us from many disease-causing organisms, but our stomach cells need mucus for protection.

Off to the side, a half-submerged bacterium regards the scientist with curiosity.

Helicobacter pylori: one of the few bacteria that can live in the stomach. Can cause stomach ulcers, but are usually harmless.

Page 3: a busy factory floor with a snaking conveyor belt (representing the small intestine) holding many packages that must be unboxed and processed.

Location: Small intestine

Safety poster reads: Divide & Conquer! Lipases and Bile are in charge of Fat boxes, Trypsin and Proteases are in charge of Protein boxes, Amylases are in charge of Starch boxes.

More lipases, trypsin, proteases, and amylases are arriving from the pancreas while bile arrives from the gallbladder. The start of the conveyor belt (duodenum) contains a large pile of mixed boxes and represents chyme.

Chyme: partially digested food from the stomach.

At the jejunum, the digestive enzymes and compounds open the boxes they are in charge of and feed contents to enterocytes.

Enterocytes: specialized intestinal cells that absorb nutrients from food.

Some contents remain on the conveyor belt and travel to the ileum section, where enterocytes finish consuming the nutrients. By the end of the conveyor belt, only dietary fiber packages remain.

Dietary fiber cannot be digested by humans. They move to the large intestine.

The scientist observes the busting factor and declares it "A model of teamwork."

Page 4

The scientist, now in a car, travels through a neighborhood by car.

Location: Large intestine.

The road consists of Ascending Avenue, Transverse Street, Descending Road, and curves to the Landfill. Along the way, the scientist observes snapshots of the residents' lives.

Anthropomorphized bacteria train the immune system, ake vitamins + other nutrients, and break down food parts we can't digest (for example, the dietary fiber packages from earlier.

At the end, the scientist, clad in a poop emoji hat, falls into the toilet. The tour has finished.