Body Systems
Vol. I–III The Overlooked Systems Evidence graded throughout

BODY
SYSTEMS

An illustrated field guide to the plumbing, drainage, and maintenance work your body performs without asking permission. Three volumes, drawn by hand, with every claim graded for how well the evidence actually holds up.

Contents

Contents

Book One
Line-art plate of the glymphatic system An engraved-style illustration of a brain in profile, showing ventricles at the centre and wavy current lines radiating outward toward the cortex, representing fluid clearance. PERIVASCULAR SPACE CHOROID PLEXUS CORTICAL SURFACE
Fig. 01 — The Glymphatic Current
Book One · The Glymphatic System

Current

Every night, cerebrospinal fluid washes through channels around your brain's blood vessels, carrying out the metabolic debris a long day leaves behind. It's not a metaphor for rest — it's plumbing, and it mostly runs while you're unconscious.

Your brain does not idle at night. It runs a rinse cycle, and skipping it doesn't save you time — it just lets the sediment build.
AEvidence

The glymphatic system clears metabolic waste, including proteins linked to neurodegeneration, predominantly during deep sleep.

BEvidence

Sleep position appears to influence how efficiently the brain clears waste, based largely on animal studies so far.

CEvidence

Chronic sleep restriction may impair glymphatic clearance over time, though long-term human data remains limited.

Continue to Flow & Touch →
Book Two
Line-art plate of the lymphatic system An engraved-style illustration of a torso in outline, showing lymph nodes as small circles connected by curved vessel lines converging near the collarbone. THORACIC DUCT — return to blood CERVICAL NODES AXILLARY NODES INGUINAL NODES
Fig. 02 — The Drainage Network
Book Two · The Lymphatic System

Flow & Touch

Blood has a heart to push it. Lymph has none — it moves because you do. Every step, breath, and stretch nudges fluid through a quiet network of vessels and nodes on its way back to circulation.

You were taught your heart moves blood. Almost nobody teaches you what moves everything else.
AEvidence

The lymphatic system has no central pump; movement, breathing, and muscle contraction drive its flow instead.

BEvidence

Manual lymphatic drainage techniques can reduce swelling in people living with lymphedema.

DEvidence

Dry brushing is widely marketed to "stimulate" lymphatic flow, though direct evidence for the claim in humans is thin.

Continue to How to Sleep →
Book Three
Line-art plate of a night's sleep architecture An engraved-style chart showing a stepped hypnogram across wake, REM, light and deep sleep stages, alongside a small circadian dial split between day and night. WAKE REM LIGHT DEEP A NIGHT'S HYPNOGRAM CIRCADIAN DIAL
Fig. 03 — A Night, Charted
Book Three · Rest as Infrastructure

How to Sleep

Sleep isn't a single switch you flip — it's a sequence of stages your body insists on cycling through, timed by a body clock that's easy to disrupt and slow to forgive. This book treats sleep the way an engineer would: as infrastructure, not a virtue.

Sleep is not the seventh thing on the list. It's the ledger the other six get checked against.
AEvidence

Light exposure — especially in the blue wavelengths — suppresses melatonin release and shifts circadian timing.

BEvidence

A consistent wake time is one of the more reliable levers for improving overall sleep quality.

CEvidence

The "optimal" amount of deep sleep likely varies more by individual than popular wearable targets suggest.

Continue to Field Notes →
In Brief

In Brief

Short, graded findings collected across all three volumes — the kind of marginalia you'd underline.

AEvidence

Waste clearance in the brain runs mostly while you're unconscious — not while you're awake and hydrating.

BEvidence

Elevating the legs can meaningfully assist lymphatic return in people who sit or stand for long stretches.

CEvidence

Cold exposure is a popular lymphatic "hack"; evidence for a direct lymphatic benefit, apart from general circulation, is still early.

AEvidence

Naps longer than roughly twenty to thirty minutes risk entering deeper sleep stages, making grogginess on waking more likely.

DEvidence

Claims that specific foods "detox" the lymphatic or glymphatic system are not supported by controlled human research.

BEvidence

Alcohol in the hours before sleep is associated with measurably worse sleep architecture, not just a rougher morning.

Masthead

Masthead

Written by Elena Marsh
Illustrated in ink by Tobias Reyes
Evidence grading Reviewed by an independent panel of clinicians and researchers

Where to find the books

In hardcover wherever books are sold, and in most local library systems. Volumes One through Three are designed to be read in any order — and re-read on the nightstand.

Evidence grades reflect the weight and consistency of published research at the time of writing. They describe how settled the science is — not medical advice, and not a substitute for a conversation with your own clinician.