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Blood Vessels · Chapter 6 of 7
Most cholesterolA lipid molecule that is a key component of cell membranes and a precursor for bile acids and steroi is made in the body, statins act on the liverA large organ that produces bile, detoxifies blood, and stores nutrients., and the one drug that should protect her vessels is the one her muscles won’t tolerate.
The question you will answer
The obvious treatment for her rising LDL is a statin — so why did it make things worse?
Opener · Homemade Cholesterol · about 1½ minutes
The opener is the same narrated animation you will watch in Scene 1.
Watch the opener first. It sets the question; the chapter answers it.
1
Read the chart
Patient chart · Stina
March 2026 · age 50
Labs
Cholesterol “sky-high” despite a careful diet.
Trial
Statin started. Within ten days: leg and back aches, headaches, eye symptomsSubjective experiences reported by the patient (e.g., nausea, fatigue)., dehydrationA condition in which fluid loss exceeds intake, leading to a decrease in total body water.. Stopped after three weeks.
Confounder
Baseline inflammatory muscle pain (see The Muscular System) — the new ache is hard to attribute.
Imaging
Coronary calcium; phlebolith.
This chapter writes line 6 of Chart Clue #16.
Your prediction
The statin was the right drug for her LDL. It failed because…
Open the one you’d bet on. Nothing is recorded, and the answer isn’t here — the scenes will test your bet.
It could not lower cholesterol that comes from food
Hold it — and check where statins actually act.
A known side effect collided with a problem she already had
Hold that, and think back to the muscle module.
Her inflammation destroyed the drug
Keep it in mind; watch what statins do in the liver and what they can do in muscle.
From Stina’s diary
March 2026 · age 50 · “The statin”
“You get a pill for one number at a time, and the pill lands on a body that is already on fire.”
2
The story
Three short movements: the case, the anatomyThe study of the structure of the human body. and physiologyThe study of how the body functions., then the tie back to Stina. Each links to the scene where you’ll see it move.
I · The Fix That Backfired
The plan was straightforward: lower the LDL, slow the plaque. Stina started a statin — and within days her muscles ached. The aching was hard to interpret, because she has lived with inflammatory muscle pain for years; now a new drug had been layered on top of it. The trial was stopped and the cholesterol question stayed open.
See it move: Scene 1 · The Liver Makes Most of It · Scene 3 · Statins, Calcium, and the Muscle Callback
II · Homemade Cholesterol
Most cholesterol is made in the body, much of it by the liver, rather than eaten — the liver ships it out on LDL and reclaims it on HDL, which is why careful eating moves LDL only so far. Calcium hardens maturing plaques and can mineralize an old venous clot into a phlebolith. Statins lower LDL by blocking cholesterol synthesis in the liver, but a well-known side effect is muscle ache — and colchicine taken with a statin raises that risk, which matters for her now.
See it move: Scene 1 · The Liver Makes Most of It · Scene 2 · LDL versus HDL · Scene 3 · Statins, Calcium, and the Muscle Callback
III · Four Findings, No Clean Story
Her cholesterol is mostly made in her own body, so a statin was exactly the right move; but the trial was stopped for muscle aches that blur against her FMF myalgia. Left behind is a muddled picture — climbing lipidsOrganic molecules including fats, oils, and steroids., premature calcium, a calcified clot and a derailed treatment — four findings waiting for one driver.
See it move: Scene 3 · Statins, Calcium, and the Muscle Callback
3
Watch · explore · think · check
3 scenes. Each one has a short animation or a slide, something to explore, a true/false spot-check of your thinking, and a quick check. Every scene gives you an evidence card for your board.
How to read the scenes
- Animation (dark teal) — a short animated explainer, one idea each
- Slide (dark teal) — a still to study: a micrograph, a diagram or a map
- Explore (purple) — something to push on while you watch
- Game (purple) — a quick challenge
- Think (gold) — reason it out, then spot-check yourself with a few true/false questions; not graded
- Check (gold) — a quick H5P that scores itself
Scene 1 of 3
The Liver Makes Most of It
LDL out, HDL back.
Animation · narrated, with captions
Homemade Cholesterol
Module 16 · 16.6 · Opener and Scene 1 · 5 scenes · about 1½ minutes · narrated. Press Play to start; the words appear in the caption box under the picture.
Scene 1
Paused
Keyboard: when the picture has focus, Space plays or pauses, the left/right arrow keys move between scenes, and M mutes or unmutes.
Text description and full narration
Five-scene narrated animation (about 1½ minutes) with captions. The liver sits on the left; a blood vessel runs right to a tissue cell, with LDL travelling out along its upper half and HDL travelling back along its lower half.
Scene 1 · Two inputs (0:00–0:19)
On screen: “Most cholesterol in your blood was not eaten.” A liver, with two arrows into it: a thin grey arrow from a plate of food (“From your plate: small”) and a thick dark-red arrow (“Made in the body: much bigger — much of it in the liver”); the liver glows.
Narration: Most of the cholesterol in your blood — it wasn’t eaten. Picture the liver with two inputs: a small arrow from your plate of food, and a much bigger arrow for cholesterol that the body makes itself. The body makes most of its own cholesterol, and much of that happens in the liver.
Scene 2 · LDL goes out (0:19–0:30)
On screen: A blood vessel draws out from the liver to a tissue cell (“Tissue cells”), and orange LDL particles stream along its upper half toward the cell: “LDL → out to the tissues.”
Narration: The liver packages cholesterol into LDL particles, and then it ships them out to the tissues that might need it.
Scene 3 · Into the wall (0:30–0:39)
On screen: One LDL particle drops out of the vessel into an artery cross-section below, which shows a small pale streak: “Some LDL slips into artery walls: it feeds a plaque.”
Narration: Along the way, some LDL slips into artery walls, and that’s the particle that starts and feeds a plaque.
Scene 4 · HDL comes back (0:39–0:48)
On screen: Blue-studded HDL particles stream the other way along the lower half: “← HDL: back to the liver.”
Narration: HDL particles work in the other direction. They collect cholesterol from tissues and carry it back to the liver.
Scene 5 · Where statins act (0:48–1:30)
On screen: The plate and its thin arrow fade (“✗ not the main input”). A purple statin capsule flies onto the thick arrow, a red ✗ appears, and the thick arrow fades to a thin one: “Statins block cholesterol synthesis in the liver.” Three LDL particles travel back into the liver (“← the liver pulls more LDL out of the blood”) and most of the LDL stream disappears: “Blood LDL falls ↓.” Card: “For Stina: LDL kept climbing on a careful diet. The liver was the right place to look; the statin, in theory, the right drug. What went wrong with it: next scene →”
Narration: So, when a careful diet doesn’t bring LDL down, the diet is not the main input. That’s also why statins — they act where they do. Statins block cholesterol synthesis in the liver. The liver pulls more LDL out of the blood to make up for it, and blood LDL falls. For Stina, whose LDL just kept climbing on a careful diet, the liver was the right place to look, and the statin was theoretically the right drug, but what went wrong with it — that’s the next thing.
Explore
Tip the balance
Stina ate carefully, and her LDL stayed sky-high. Here is the whole path: what a plate brings in, what the liver makes on its own, and where each food lever pushes. Make a guess, then work the levers and watch the scale.
The kitchen
Four food levers. Each one works at a different spot on the path.
The pharmacy
One drug for comparison. It works on the liver’s own production line, not on food.
Stina’s statin trial is Scene 3. Here it is only a yardstick.
Typical diet. This is the starting point: LDL 100. Pull a lever and this box explains what moved.
The balance
Where the liver’s cholesterol comes from. Parts per 100 on a typical day.
Left pan: made in the body, 75 parts. Right pan: from your plate, 25 parts.
Blood LDL, with a typical diet set to 100
- Typical diet100
- A careful diet like Stina’s87
- Best diet on paper75
- Typical diet + statin60
- Best diet + statin45
Why this matters for Stina
A careful diet like hers had already banked about half of what food can do. The heavy pan on the scale is the cholesterol her own liver makes, and no kitchen reaches it. That is why her clinicians turned to a statin, the one tool that works on the heavy side, and why it mattered so much when her body would not tolerate it.
Try it: can any combination of food levers tip the scale toward the plate?
Text description of this activity
The diagram is a loop. At top left, a plate holds four things food can bring: cholesterol (orange ring shapes), saturated fat (a pale fat droplet), plant sterols (green ring shapes that look like cholesterol) and fiber (tan strands). An arrow leads to the coiled small intestine. A close-up box beside it shows one villus: a finger of gut lining with a red and blue capillary network and a green lacteal in its core. Cholesterol shapes wait in the gut beside the villus, and when plant sterols are added, green sterol shapes crowd the villus surface. From the lacteal, a dotted green path carries chylomicrons through lymph into the blood, drawn as a long pale band along the bottom with LDL particles in it. From the intestine, the hepatic portal vein (a dark red tube) runs to the liver at top right, carrying recycled bile acids (yellow-green dots), and an arrow leads down to “Out in stool”. A card on the liver shows its cholesterol factory: acetyl-CoA, the enzyme HMG-CoA reductase, and a bar for how much cholesterol it is making. A green bile duct runs from the liver to the intestine, carrying bile acids made from cholesterol. Three arrows connect the liver and the blood: chylomicron leftovers go up to the liver, LDL goes out into the blood, and LDL comes back in through LDL receptors, drawn as small teal Y shapes on the liver’s lower edge. The small intestine, villus, liver, cholesterol, fat droplet, chylomicron and LDL pictures are BioRender illustrations.
How the levers work, with rounded numbers from diet studies summarized by the National Cholesterol Education Program (ATP III); real people vary:
- Less cholesterol in food: less is absorbed, but the liver makes more of its own to make up for it. LDL falls about 4%. More cholesterol in food raises LDL about 4%.
- Less saturated fat: liver cells put out more LDL receptors and pull more LDL from the blood. LDL falls about 9%, the biggest single food lever. More saturated fat raises it about 9%.
- Extra soluble fiber (oats, beans): fiber traps bile acids so they leave in stool instead of riding the portal vein back to the liver. The liver spends cholesterol making new bile acids and pulls in LDL to do it. LDL falls about 4%.
- Plant sterols, 2 g a day: they look like cholesterol and crowd it out of absorption in the gut. LDL falls about 10%, even though the liver makes more to compensate.
- All four together (the best diet on paper): LDL falls about 25%. A careful diet like Stina’s, with less cholesterol and less saturated fat, gets about 13%.
- A statin at a moderate dose blocks HMG-CoA reductase. The liver makes much less cholesterol, adds LDL receptors, and LDL falls about 40%. With the best diet too, about 55%.
The scale compares the two sources of the liver’s cholesterol: about 75 parts in 100 are made in the body and about 25 come from food. Cutting food cholesterol lightens the plate side, but the liver makes up most of it, so the scale stays tipped toward the body. No combination of food levers tips it toward the plate. Only the statin makes the body side much lighter.
Think · not graded
If most of the cholesterol is made in the body, how much can the best diet in the world move the number?
Spot-check your thinking: true or false?
Check · Single Choice
One question: where most cholesterol comes from.
Evidence card 1
Add it to your evidence board
Most cholesterol is made in the body, much of it in the liver — so a careful diet moves LDL only so far.
Scene 2 of 3
LDL versus HDL
Two particles, two directions.
Game
Which particle?
Drag each statement onto LDL or HDL before you look at the figure below.
Slide · a still to study
LDL and HDL Particles
Check your answers: LDL carries cholesterol out from the liver; HDL brings it back. Both are drawn to scale.
Think · not graded
Why do clinicians watch LDL rather than total cholesterol?
Spot-check your thinking: true or false?
Check · Drag the Words
Two particles, two directions.
Evidence card 2
Add it to your evidence board
LDL is the particle that feeds a plaque; hers keeps climbing though she eats carefully.
Scene 3 of 3
Statins, Calcium, and the Muscle Callback
The right drug, the wrong body.
Animation · narrated, with captions
The Fix That Backfired
Module 16 · 16.6 · Scene 3 · 5 scenes · about 1½ minutes · narrated. Press Play to start; the words appear in the caption box under the picture.
Scene 1
Paused
Keyboard: when the picture has focus, Space plays or pauses, the left/right arrow keys move between scenes, and M mutes or unmutes.
Text description and full narration
Five-scene narrated animation (about 1¼ minutes) with captions. A small March 2026 calendar stays in the top left.
Scene 1 · March 2026 (0:00–0:21)
On screen: A calendar reads MARCH 2026. A purple statin capsule moves onto a liver (“Blocks cholesterol synthesis in the liver”). A blood-LDL meter beside it is nearly full (“sky-high”) and drops to a low level (“LDL comes down”). “★ Among the best-supported drugs in medicine.”
Narration: Stina started a statin — that sounds like a tongue twister — but Stina did start a statin for cholesterol that was, by then, sky-high. Statins lower LDL by blocking cholesterol synthesis in the liver, and they’re among the best-supported drugs in medicine.
Scene 2 · The new ache (0:21–0:34)
On screen: A leg glows red (“legs hurt”), a headache icon (“head ached”) and an eye with a red glow (“eyes bothered her”) appear; the statin capsule is crossed out: “she stopped it”. A pink skeletal muscle fibre glows red: “Statin-associated myalgia.”
Narration: Within weeks, her legs hurt, her head ached, and her eyes bothered her, so she stopped it. Muscle aches are a very well-known statin side effect, called statin-associated myalgia.
Scene 3 · The old ache (0:34–0:52)
On screen: “In most patients: easy to read the aches.” “Stina is not most patients.” The red-glowing fibre is labelled “New: statin-associated myalgia”, and a second fibre below glows purple: “Old: inflammatory myalgia, for years — the myalgia thread from the muscle module.”
Narration: In most patients, a doctor can read those aches very cleanly. Stina’s not most patients. She’s lived a life with inflammatory muscle pain for years, and that myalgia thread was from a muscle module way long ago.
Scene 4 · Which is which? (0:52–1:03)
On screen: “A new ache layered on top of an old one”: the two fibres slide together until their red and purple glows overlap, and a large question mark appears: “How much is the drug?” “How much is her disease?”
Narration: So when a new ache is layered on top of old ones, nobody can really say how much was the drug and how much was her existing disease, whatever that disease may be.
Scene 5 · The wrong body (1:03–1:26)
On screen: The statin capsule fades and is crossed out (“The statin trial stopped”); the LDL meter climbs back up (“question stays open ?”). Card: “The drug that should have protected her inflamed vessels was the one her body would not tolerate. The right drug, the wrong body.”
Narration: The trial stopped, and the cholesterol question — it kind of stayed open. The one drug that should have protected her inflamed vessels was the one that her body just would not tolerate. The reason is as much about her baseline as it is about the pill.
Explore
Two aches, one leg
Two kinds of muscle pain can land in the same legs. One arrived with a pill. The other has been part of Stina’s life for years. Compare where each one hurts, then sort the clues a doctor can use and see which kind of clue actually tells them apart.
Where it hurts
Statin muscle aches
Striped areas: where it usually aches
Where: the big muscles, usually the same on both sides: thighs, hips, calves, and often the lower back.
FMF muscle pain
Dotted areas: where it hurts
Where: the legs, especially the calves after activity. During a fever attack, severe pain that can spread through the legs.
Look at both maps. Stina’s statin weeks brought leg and back aches. From the maps alone, could anyone say which kind of pain that was?
Sort the clues
For each clue, decide what it points to. Some clues point one way. Some fit both, so they can’t tell.
0 of 7 sorted.
What sorted cleanly?
The pattern: clues about where it hurts, how it feels and the CK fell into “can’t tell”. Clues about when sorted cleanly: when it started, what came with it, and what happened when the pill came back.
For Stina: her aches began within ten days of the first pill, a statin-shaped clue. But she has lived with inflammatory muscle pain for years, so her legs alone can’t settle it. Her calendar is the better witness.
Text description of this activity
Two diagrams show the front of both legs, from the hips to the ankles, drawn with the muscles visible. On the first, “Statin muscle aches”, striped orange areas cover both hips, both thighs and both calves, the same on each side, with a note that the lower back is often involved too. On the second, “FMF muscle pain”, dense purple dots cover both calves (pain after walking or standing), sparse dots cover both whole legs (severe, spreading pain during a fever attack), and a circular inset shows the calf muscles from the side.
The clues and what they point to:
Think · not graded
If the ache came from the statin, what should happen a few weeks after stopping it?
Spot-check your thinking: true or false?
Check · Multiple Choice
Why the statin made things worse — pick every true statement.
Evidence card 3
Add it to your evidence board
The right drug collided with a problem she already had: statin muscle aches on top of inflammatory muscle pain.
4
Your evidence board
Every scene gave you an evidence card, and the chart adds more. Drag each card to the column it supports: Known side effect, Neither on its own, or Wrong target. Some cards can honestly go in more than one place — that’s allowed, and the feedback tells you which cards decide the case.
5
Your verdict
Time to decide. Look back at your bet, then build your verdict from statements that hold up — no writing needed.
Look back at your prediction
The statin was the right drug for her LDL. It failed because…
Open the one you chose at the top. Does the evidence support it, refute it, or revise it?
If you bet: It could not lower cholesterol that comes from food
Statins act in the liver, on the cholesterol the body makes — exactly where most of hers comes from. The drug was aimed at the right target.
If you bet: A known side effect collided with a problem she already had
Your bet held. Statin muscle aches are well known, and they landed on muscles that already hurt from her undiagnosed disease, so nobody could read the ache cleanly.
If you bet: Her inflammation destroyed the drug
Nothing suggests the drug stopped working. It was stopped because of the aches — a side effect, not a failure to act.
Build your verdict · no writing
Choose the statement that holds in each set. The ones you keep become your argument.
6
The finding
Sign · statin-intolerant hyperlipidemia with premature calcium
Statin-Intolerant Hyperlipidemia With Premature Calcium
A muddled work-up: hyperlipidemia despite diet, coronary calcium and a phlebolith on imaging, and a statin trial stopped early for muscle aches that blur against her FMF myalgia. Chart entry: four findings with no shared classic cause, waiting for one driver.
Next · Chapter 7
Premature Vascular Aging
Rising LDL, coronary calcium, a phlebolith, statin aches. Each was filed alone. Lay them on one page and name the single driver.
Reliable information on rare diseases
NORD · NIH GARD · Orphanet · MedlinePlus Genetics: FMF · FMF & AID Global Association · Autoinflammatory Alliance · Global Genes · Amyloidosis Foundation
Stina has one rare disease. In the United States, about 1 in 10 people live with one of the more than 7,000 known rare diseases. These organizations are where patients, families and clinicians go for trustworthy information.
Hop to:
← Familial Mediterranean Fever — case home
All pages for Module 16 — Blood Vessels
16.0 Module Overview
16.1 Vessels Aging Too Fast
16.2 Three Layers, Three Vessels
16.3 Pressure and Flow
16.4 The Body’s Highways
16.5 When Walls Go Bad: Atherosclerosis
16.6 Cholesterol, Calcium & Statins
16.7 Premature Vascular Aging
16.8 Conclusion and Assessment
16.9 Evidence Behind the Case
All Modules
- Anatomical Language, Membranes & Homeostasis
- Just Enough Chemistry
- The Cell & Its Transport
- Making Cells & Proteins
- The Integumentary System
- The Skeletal System
- The Muscular System
- Nervous Tissue & the Senses
- The Spinal Cord
- The Brain & the Blood–Brain Barrier
- The Autonomic Nervous System
- Special Senses (in developmentThe process of growth and differentiation.)
- The Endocrine System
- Blood
- The Heart
- Blood Vessels
- The Digestive System
- The Respiratory System
- The Urinary System
- Fluids, Electrolytes & Acid–Base Balance
- The Reproductive System
- The Immune System
List of terms
- cholesterol
- liver
- symptoms
- dehydration
- anatomy
- physiology
- lipids
- development