human-body

Memory is not a recording. It is a reconstruction — assembled fresh each time you recall it, from fragments stored across the cortex. Understanding how encoding, long-term potentiation, and retrieval actually work explains why memories are reliable enough to be useful and unreliable enough to be distorted.

The brain runs on roughly 86 billion neurons, consumes 20% of your body's energy despite weighing only 2% of your body, and rewires itself with every new experience. Here is the mechanism behind all of it.

The heart beats more than 100,000 times per day without a single conscious command, regulated by an electrical system so precise that it can be measured from electrodes on the skin. Here is how that system works, from the first spark in the SA node to the pressure wave that reaches your fingertips.

The immune system is not a single organ or a single type of cell — it is a distributed surveillance network that distinguishes your own tissue from foreign invaders within minutes, then builds custom molecular weapons if the first response is not enough. Here is how.

Sleep is not the brain going quiet — it is the brain running a completely different operating mode. During those hours, it flushes toxic proteins, consolidates memories, and resets emotional circuits. Here is what the science actually shows.

Hiccups are involuntary diaphragm spasms. Learn the neuroscience, evolutionary origins, common triggers, and when hiccups become a medical concern.

Skin's three layers, how it protects you, why it ages, and the biology of pigment, sweat, and sensation in your body's largest organ.

The liver performs over 500 distinct functions and is the only internal organ that can fully regenerate itself from just 25% of its original tissue.

Your heart beats about 100,000 times a day without a single conscious thought. Here's the remarkable engineering behind it.

Gravity shapes everything about an animal — its skeleton, muscles, circulatory system, even brain. Humans evolved on a 1g planet. On a Mars-like 0.38g world, we'd be taller, lankier, weaker, and likely shorter-lived from chronic bone and circulatory problems.