Century of Synapses
Keep Your Brain in Mind
Milestone Myelin
Cranial Nerve Countdown
Punny Reflexes
100

This “executive” part of the brain is essential for planning the next 100 days (and beyond).

What is the frontal lobe?

100

This “fight-or-flight” system has you sprinting when rounds run late.

What is the sympathetic nervous system?

100

This cell wraps nerves with myelin, giving your axons a “100-meter dash” advantage.

What is the oligodendrocyte?

100

CN II helps you see clearly—even after 100 PowerPoint slides on stroke.

What is the optic nerve?

100

After 100 days of residency, this knee reflex might be “overworked.”

What is the patellar reflex?

200

One hundred billion of these tiny connectors keep our neurons talking.

What are synapses?

200

The “100-day blues” might be mistaken for a stroke in this brain artery’s territory.

What is the middle cerebral artery?

200

When myelin is lost, as in this demyelinating disease, 100 meters feels like a marathon.

What is multiple sclerosis?

200

CN VII allows this 100-watt smile, even post-night float.

What is the facial nerve?

200

Residents sometimes have this “primitive” reflex—especially before coffee.

What is the grasp reflex?

300

This “wrinkly” brain structure has about 100,000 miles of blood vessels.

What is the cerebral cortex?

300

This “little brain” helps you stay balanced after 100 days of call shifts.

What is the cerebellum?

300

Myelin helps increase this—kind of like cramming 100 facts into one resident’s head.

What is conduction velocity?

300

This cranial nerve is tested when you stick out your tongue after 100 cups of coffee.

What is the hypoglossal nerve (CN XII)?

300

A sleepy resident might be “toeing the line” with this Babinski sign.

What is the plantar reflex?

400

Residents after 100 days might feel this is “fried,” but it’s actually where memories form.

What is the hippocampus?

400

The “100-hour call shift” makes this part of the brain, key for sleep cycles, very unhappy.

What is the hypothalamus?

400

In the PNS, these cells act as myelin’s wrapping paper—call them “100 layers of insulation.”

What are Schwann cells?

400

“Hearing” 100 questions on rounds uses this cranial nerve.

What is the vestibulocochlear nerve (CN VIII)?

400

After 100 hours awake, your reflexes feel as slow as this neurotransmitter’s inhibitory action.

What is GABA?