Body Builders
Smooth Operators
String Theory
Chemical Connections
Get a Move On
100

The clingy Saran wrap of your insides that won’t leave any organ alone.

What is fascia?

100

The solo performers of the smooth muscle world, each doing their own thing like stubborn cats.

What is multiunit smooth muscle?

100

A single “BOOP” from your muscle when it gets poked.

What is a twitch?

100

The chemical Cupid delivering love notes from your brain to your muscles.

What is acetylcholine?

100

The extrovert muscle, always showing off by contracting.

What is the agonist?

200

These mini gym bros live inside your muscles and do the heavy lifting, one rep at a time.

What are myofibrils?

200

The synchronized swimming team of your digestive system, working in perfect rhythm.

What is visceral smooth muscle?

200

The awkward pause between “Hey, let’s contract!” and the muscle actually doing something.

What is the latent period?

200

The grumpy housekeeper who shreds those love notes right after they’re read.

What is acetylcholinesterase?

200

The introvert muscle, quietly relaxing while others do the work.

What is the antagonist?

300

The thin spaghetti strands that your muscles twirl when they flex.

What is actin?

300

The part of your muscle that’s basically the homebody of attachments—it doesn’t move.

What is the origin?

300

When your muscles play Jenga and pile up their efforts to make you stronger.

What is summation?

300

The pre-workout stash in your muscles, giving them a quick energy boost.

What is creatine phosphate?

300

The supportive bestie muscle who cheers on the lead actor.

What is the synergist?

400

The thick spaghetti strands that shove the thin ones for fun (and strength).

What is myosin?

400

The drama queen of muscle attachments, always needing to be the center of attention by moving.

What is the insertion?

400

The “No breaks, full speed ahead!” level of muscle contraction.

What is complete tetanic contraction?

400

Your muscles’ personal oxygen-filled water bottle.

What is myoglobin?

400

The cool crew of a single neuron and its exclusive muscle fiber gang.

What is a motor unit?

500

The muscle’s tangled web of straws—both the kind you sip from and the kind that bend like crazy.

What is the sarcoplasmic reticulum?

500

The bossy lead muscle that won’t let anyone else take credit for the job.

What is the prime mover?

500

The process of convincing your laziest muscle friends to finally help out.

What is recruitment?

500

The IOU oxygen check your body writes after sprinting for the bus.

What is oxygen debt?

500

The postman delivering messages from your brain that say, “Let’s move!”

What is a motor neuron?