59 Fun Facts About Adrenaline

Because 'Adrenalin' was a registered trademark in the US, American medicine adopted which generic name for the hormone?

Epinephrine became the US generic name because a drug firm was already selling the hormone as Adrenalin. Britain kept adrenaline, so one hormone still goes by two names.

A few neurons in which part of the brain, the one that controls heartbeat and breathing, also make adrenaline?

The medulla oblongata, at the base of the brainstem, holds a small cluster of adrenaline-making neurons that help control the circulation. The adrenal glands still supply almost all the adrenaline in the blood.

Where in the body are the suprarenal glands?

Above the kidneys, one perched on each, yet they are not part of the urinary system. They belong to the hormone system and simply share the kidneys' address.

Adrenaline is often credited for 'hysterical strength', as in the classic tale of a mother lifting what off her trapped child?

A car is the usual object, and a few real cases exist: in 2006 an Arizona man raised a Camaro off a trapped cyclist. Science can't test it, since no lab can make volunteers believe they are about to die.

The outer cortex of the adrenal gland produces which class of chemical messenger?

Steroids are the cortex's product, every one of them built from cholesterol. The gland's core works almost as a separate organ and makes adrenaline instead.

What name is given to the adrenaline-producing cells at the core of the adrenal gland?

Chromaffin cells are named for their affinity for chromium: chromium salts stain them brown, which makes them stand out under a microscope.

Adrenaline and dopamine are both built from which amino acid, first isolated from cheese?

Tyrosine takes its name from 'tyros', the Greek for cheese, where the chemist Justus von Liebig found it in the 1840s. The body turns it into dopamine, then noradrenaline, then adrenaline.

A surge of adrenaline after a sudden shock or loss is thought to cause which temporary heart condition?

Broken heart syndrome, or takotsubo cardiomyopathy, mimics a heart attack even though the coronary arteries are clear. Doctors think stress hormones briefly stun the heart muscle, and most people recover fully.

Chemically, how does adrenaline differ from noradrenaline?

It has an extra methyl group, which an enzyme in the adrenal core adds to noradrenaline. That enzyme is boosted by stress hormones seeping in from the gland's outer layer.

Adrenaline, noradrenaline and dopamine belong to which family of compounds?

Catecholamines survive only a few minutes in the blood before enzymes break them down, so the adrenal glands must keep topping up the supply for as long as an alarm lasts.

Adrenaline exerts its effects by binding to which two classes of receptor?

Alpha and beta were the names Raymond Ahlquist gave the two receptor types in 1948. His idea later gave drug designers their target for the beta blockers.

Which physiologist first described the fight-or-flight response during the 1910s?

Walter Cannon set the idea out in a 1915 book. As a medical student in the 1890s he had turned the newly discovered X-rays on animals to watch how they swallow.

Which term did the physiologist behind 'fight or flight' coin for the body's tendency to keep its internal conditions stable?

Homeostasis is why you shiver when cold and sweat when hot: the body senses the drift and pulls itself back. Blood sugar and water are held steady in the same way.

What happens to the pupils during the fight-or-flight response?

They dilate, which lets in more light for a sharper view. Eye surgeons borrow the effect, using adrenaline to keep the pupil wide during operations.

Which part of the heart, its natural pacemaker, does adrenaline act on to raise cardiac output?

The SA node is a small cluster of cells that sets the pace of every heartbeat. A medical student, Martin Flack, first spotted it in 1906 in the heart of a mole.

What effect does adrenaline have on insulin secretion by the pancreas?

It inhibits it, acting through receptors on the pancreas's insulin-making cells. With less insulin about, more sugar stays in the blood as ready fuel.

Adrenaline acts as a hormone in the blood, but it also does duty as which other kind of chemical messenger?

A neurotransmitter is a chemical that carries a signal from one nerve cell to the next. Adrenaline has only a bit part there, since its close cousin noradrenaline does most of that work.

As part of the fight-or-flight response, what happens to the blood's ability to clot?

It speeds up, which would curb the bleeding if a fight ended in a wound. The catch comes in people whose arteries are already narrowed, where a bad shock can help to set off a dangerous clot.

Which almond-shaped part of the brain sounds the alarm that sets off the body's adrenaline response?

The amygdala takes its name from the Greek for almond. When it senses danger it alerts the hypothalamus, the command centre that signals the adrenal glands.

Which branch of the nervous system, named from the Greek for 'fellow feeling', triggers the adrenaline rush?

Sympathetic nerves work like a car's accelerator, priming the body for action. Their partner, the parasympathetic branch, is the brake that calms everything down once the danger has passed.

Which body system does the fight-or-flight response slow down to free up energy for the muscles?

The digestive system is put on hold, since a meal can wait when a threat cannot. Once the danger passes, the opposing 'rest and digest' response switches it back on.

The chemist who patented Adrenalin helped give Washington, D.C. which famous gift in 1912?

Cherry blossom trees came to Washington after Jokichi Takamine offered 2,000 of them in 1909. That first shipment arrived infested with insects and had to be burned, so Tokyo sent 3,020 replacements.

Before its first synthesis in 1904, where did medical adrenaline come from?

Animal glands were all there was: the hormone was extracted from the adrenals of farm animals such as sheep and oxen. The German chemist Friedrich Stolz made the first synthetic adrenaline in 1904.

Besides severe allergic reactions, which emergency is injected adrenaline used for?

Cardiac arrest teams inject adrenaline every few minutes to help restart the heart. A British trial of 8,000 patients found it saved more lives, but could not show that more of them recovered well.

Where should an adrenaline injection be given for a suspected severe allergic reaction?

The outer thigh takes the drug up quickly, which is why it is preferred to the upper arm. In an emergency the needle can go straight through clothing.

The electronics inside the Auvi-Q, a rival to the EpiPen, let it do what during an emergency?

Give spoken instructions: a recorded voice talks the user through each step. In a maker-run trial with dummy pens, 85% of untrained adults got every step right, against 20% with an EpiPen trainer.

Which company raised the price of a two-pack of EpiPens from about $100 to $600 between 2007 and 2016?

Mylan bought the rights in 2007 and raised the price year after year. After a public outcry in 2016 it brought out a generic version of its own product at about half the price.

When Charles Richet gave dogs a second, tiny dose of sea-anemone toxin weeks after the first, what was the result?

Fatal shock followed, though the same dogs had survived the first dose. Richet named the reaction anaphylaxis, his Greek coinage for the opposite of protection, and it won him the 1913 Nobel Prize.

Adrenaline is the first-line treatment for anaphylaxis, which in children is most often triggered by what?

Food leads in children, with milk, peanuts and tree nuts the usual culprits. In adults the pattern shifts, and medicines such as antibiotics become the more common cause.

Adrenaline is often added to local anaesthetics, where it helps the numbness last and stops what?

Surface bleeding is cut because adrenaline narrows the small blood vessels nearby. The same squeeze keeps the anaesthetic from being carried away, which is why a dentist's injection lasts so long.

Inhaled adrenaline is used to ease which childhood illness, known for its seal-like barking cough?

Croup narrows a child's windpipe, and breathed-in adrenaline eases it within half an hour. The relief fades after about two hours, so children are watched for a few hours before they go home.

Adrenaline eye drops have been used to treat which condition, by helping fluid to drain from the eye?

Glaucoma is usually a matter of pressure building up inside the eye. Adrenaline drops ease it by helping the fluid drain away, and they appear to slow the making of new fluid as well.

What are the most common side effects of adrenaline as a medication?

Shakiness and anxiety top the list because the injected drug does just what the body's own rush does. Sweating and a pounding heart often come along with them.

A pheochromocytoma can flood the body with adrenaline, bringing attacks of sweating and a pounding heart, but what is it?

A tumour, as the ending '-oma' usually signals: it grows in the adrenaline-making core of an adrenal gland and releases the hormone in bursts. Surgery to remove it is the only cure.

Why are beta blockers, which blunt the effects of adrenaline, banned in target sports such as archery and shooting?

They steady the hands by slowing the heart and damping tremor. At the 2008 Olympics the North Korean pistol shooter Kim Jong-su lost a silver and a bronze medal after testing positive for one.

Adrenochrome forms when adrenaline oxidises, but what does the '-chrome' in its name refer to?

Colour, from the Greek 'khroma': adrenochrome is the pigment that turns stale adrenaline pink, the cue to replace an old injector. The metal chromium was named from the same word, for its colourful compounds.

In the 2006 film Crank, Jason Statham's character must keep his adrenaline flowing to survive what?

A synthetic poison, injected while the hitman Chev Chelios sleeps, will stop his heart unless he keeps the adrenaline coming. Critics summed the film up as the 1950 noir D.O.A. crossed with Speed.

Research on extreme sports and so-called adrenaline junkies has centred on which personality trait, measured by Marvin Zuckerman's scale?

Sensation seeking is the taste for novel, intense experiences, whatever the risk. It climbs between the ages of 10 and 15, then levels off or falls, and men on average score higher on it than women.

Which emotion has been studied most in relation to adrenaline?

Higher adrenaline correlates with an aroused state of negative emotion.

What does the adrenaline released during an emotional event tend to do to the long-term memory of it?

Strengthens it, so that the events that matter most are the ones that stick. In a 1994 study a beta blocker took that edge away: it dulled volunteers' recall of an upsetting story but not of a neutral one.

Which third 'F' do researchers often add to 'fight or flight' as another common reaction to danger?

Freeze comes first for many animals: holding dead still helps them escape a predator's notice. It is fight or flight put on hold, and the heart can even slow down while the animal waits.

Bartolomeo Eustachi, who first described the adrenal glands, gave his name to a tube in which organ?

The ear's Eustachian tube carries his name, though he was probably not the first to describe it. Most of his copper-plate engravings were lost for some 140 years after his death and only reached print in 1714.

Which physician's 1855 monograph on the 'suprarenal capsules' gave his name to a disease of failing adrenal glands?

Thomas Addison wrote when nobody knew what the glands were for. A year later another researcher removed them from animals, which died within hours, showing that life depends on them.

Which US president hid a failure of his adrenal glands that causes fatigue and darkens the skin?

John F. Kennedy was given less than a year to live when he was diagnosed in London in 1947. He won the White House regardless, and his illness was not publicly confirmed until after his death.

Goosebumps are a leftover of the adrenaline reflex that does what for a frightened cat?

Makes it look bigger: a tiny muscle at the base of each hair tugs it upright, fluffing the cat up to warn off an attacker. On thinly haired humans the same reflex only raises bumps.

How do people fare without the adrenaline-making core of their adrenal glands, provided the outer layer is spared?

They live normally, because nerve endings all over the body release noradrenaline, which does much the same job. Losing the gland's outer layer is another matter, and is fatal unless its hormones are replaced.

What do hormone specialists say about 'adrenal fatigue', the idea that long-term stress wears the adrenal glands out?

It is a myth, concluded a 2016 review of 58 studies, and no society of hormone specialists recognises it. Under stress the adrenal glands make more of their hormones, not less.

Which body publishes the List of Essential Medicines, on which adrenaline has a place?

The World Health Organization drew it up as a model, and more than 150 countries have since based their own national medicine lists on it.

What decides whether a child is prescribed the junior or the full-strength adrenaline autoinjector?

Weight decides it, because the recommended dose is 0.01 mg for each kilogram. Pens deliver fixed doses, so US labels give the 0.3 mg adult pen to anyone of 30 kg or more and half of that to lighter children.

Neffy, the first needle-free adrenaline treatment for anaphylaxis, comes in what form?

A nasal spray, one squirt into one nostril, meant for people who put off treatment because they dread injections. The FDA approved it on studies in 175 healthy adults, where it raised adrenaline in the blood about as much as a jab.

Salbutamol, known in the US as albuterol, took over from adrenaline as the standard reliever for attacks of which condition?

Asthma attacks were once eased with inhaled adrenaline, which also drives the heart hard. Salbutamol, launched in Britain in 1969 as Ventolin, was designed to act on the airways far more than on the heart.

To raise blood sugar in a hurry, adrenaline makes the liver break down its stores of what?

Glycogen is glucose packed into branching chains, and the liver breaks it down to keep the blood supplied. Muscles hold glycogen too, but they burn theirs on the spot rather than share it.

Primatene Mist adrenaline inhalers were withdrawn because their propellant harmed what?

The ozone layer was the worry: its CFC propellant fell under the treaty that phased those gases out. It left US shelves at the end of 2011, and a reformulated version with a different propellant won approval in 2018.

A 2020 Harvard study found that the fight-or-flight response has which lasting effect on the fur of stressed mice?

It turns grey, and for good: noradrenaline from the nerves around each hair follicle used up the stem cells that make pigment. Mice with their adrenal glands removed still went grey, which cleared the glands' own hormones.

The Pentagon first used the EpiPen's design to deliver an antidote to what?

Nerve gas was the threat: the Pentagon wanted a way for troops to inject an antidote fast. The same spring-loaded design went to soldiers as the ComboPen and to allergy patients as the EpiPen.

In which Quentin Tarantino film is an overdosing woman revived by an adrenaline shot straight to the heart?

Pulp Fiction took the scene from life: in a Martin Scorsese documentary, Steven Prince recalls reviving an overdosed woman the same way, guided by a medical dictionary and a Magic Marker.

Which position is advised for someone in anaphylaxis who feels faint as their blood pressure falls?

Reclining with feet elevated helps blood return to the heart while pressure is low. NHS advice is blunt about the alternative: do not stand or walk at any time, even if you feel better.

The adrenal glands also make weak versions of which hormones?

Sex hormones: the innermost zone of the adrenal cortex makes weak androgens that the body turns into testosterone and oestrogen. A childhood rise in them brings adult body odour and the first pubic hair.

Which adrenal hormone tells the kidneys to hold on to salt, which raises blood pressure?

Aldosterone makes the kidneys keep sodium and shed potassium; water follows the salt, so blood volume and pressure rise. It is made in the outermost zone of the adrenal cortex.