Organs

Where digestion starts — chewing, saliva, and the first enzymes to meet your food.

The muscular tube that moves a swallow down to the stomach, and the valve that keeps it there.

An acid bath and a mixer. It breaks protein down and sets the pace of everything downstream.

Where almost all absorption happens, across a surface area far larger than it looks.

Water, minerals and the microbiome — the last stretch, and the one that decides comfort.

The body's chemical plant: processes everything absorbed, makes bile, and clears what has to go.

Stores bile and releases it on demand, which is what lets you digest fat.

Two jobs in one organ — digestive enzymes into the gut, and insulin into the blood.

The unit everything else is built from, and the structure inside it that turns food into usable energy.

The body's chemical plant: processes everything absorbed, makes bile, and clears what has to go.

Two jobs in one organ — digestive enzymes into the gut, and insulin into the blood.

Sets the pace of metabolism for every cell in the body, from a gland in your throat.

Movement, posture, and the largest consumer of energy you have.

Filters, warms and humidifies air — and is the one place the outside world meets your nervous system directly.

Air-filled spaces that lighten the skull, humidify air, and drain into the nose.

The shared passage for air and food, and the crossroads where the two are kept apart.

The windpipe — a ringed tube that stays open, lined with cells that sweep debris back up.

The branching airways carrying air from the trachea into each lung.

Where air meets blood, across roughly seventy square metres of surface.

The muscle that does the breathing — and the one a slow breath is actually training.

Control, interpretation and memory — including the scent pathway that reaches it without a detour.

The main cable between brain and body, and a reflex centre in its own right.

The wiring that reaches everywhere else — sensation out, instruction back.

The half you do not drive: heart rate, digestion, and the switch between alert and at rest.

Filter stations on the lymph network, where immune cells meet what they are meant to deal with.

Filters blood, recycles old red cells, and holds a reserve of immune cells.

Where T cells learn the difference between you and not-you. Largest in childhood.

The factory — every red and white blood cell you have started here.

The mobile half of the immune system, in several kinds with different jobs.

Your largest organ, your first barrier, and the route every topical drop takes.

The link between the nervous and endocrine systems — temperature, hunger, sleep, and the stress axis.

The gland that instructs the other glands, on orders from the hypothalamus.

Sets the pace of metabolism for every cell in the body, from a gland in your throat.

Adrenaline and cortisol — the short-term response and the long-term one.

Two jobs in one organ — digestive enzymes into the gut, and insulin into the blood.

Eggs, oestrogen and progesterone, and the rhythm of the monthly cycle.

Sperm and testosterone, under the same pituitary instruction as everything else endocrine.

A muscle that never rests, moving your whole blood volume roughly once a minute.

Carry blood away from the heart under pressure, and flex to help move it along.

Carry blood back, mostly uphill, using valves and the squeeze of surrounding muscle.

One cell thick — where the exchange the whole system exists for actually happens.

A tissue, not a fluid: cells, platelets and plasma carrying oxygen, nutrients, heat and signals.

Structure, protection, mineral store and blood factory. Living tissue, constantly rebuilt.

Movement, posture, and the largest consumer of energy you have.

Attach muscle to bone and transmit the pull. Strong, and slow to recover.

Attach bone to bone and set how far a joint is allowed to go.

The smooth, shock-absorbing surface inside a joint. No blood supply of its own.

Where two bones meet — and where comfort in movement is won or lost.

Your largest organ, your first barrier, and the route every topical drop takes.

Small organs in the skin that grow hair, and one of the routes an oil takes inward.

Keratin plates that protect the fingertips — and a visible record of the last few months.

Temperature control, and one of the ways the body clears what it does not want.

Produce sebum, the skin's own oil — the thing most skin care is trying to balance.