Don’t try this at home
There’s a scene in Tarantino’s Pulp Fiction in which John Travolta’s character, a hitman called Vincent Vega, who has escorted his boss’s wife home after an evening out, returns from the bathroom to find her unconscious on the floor. Mia (Uma Thurman) has taken a bag of heroin from his jacket pocket and, mistaking the white powder for cocaine, snorted a line and collapsed. Vincent throws her into a car and hurtles round to his dealer’s house. The dealer fills a syringe with adrenaline and tells him to stab it into Mia’s heart; Vincent slams it through her breastbone and pushes the plunger. Her eyes flicker, she convulses, and then, shocked into life like the Bride of Frankenstein, she suddenly sits up, wide awake and gasping for breath.
I was a medical student when Pulp Fiction came out, and my understanding of human bodies was based largely on dead ones, but I knew that an intracardiac injection of adrenaline was a bad idea. It’s the wrong drug (the correct antidote is naloxone), and the wrong technique: an IV injection is the thing. But a stab in the heart makes better cinema, and everyone thinks they know about adrenaline’s effect on the body. We hear of adrenaline junkies and adrenaline highs; we talk about ‘running on adrenaline’.
I first learned about adrenaline, and the glands that produce it, from a headless and limbless torso, skinned and sprayed with preserving fluids. Each Friday afternoon in anatomy class it was unzipped from a white body bag labelled ‘1101-Female’. The smell of the preserving fluids was overwhelming at first, as was the nip they brought to the eyes. Once you recovered, you could see that the abdominal wall had been cut from the flanks to the pubis bone so that a frontal flap of stomach muscles could be lifted, the way you’d open a car bonnet. The abdominal viscera are covered by the peritoneum, a sheeny lining like shrink-wrap, which makes it possible for the organs to glide against one another without causing irritation (it’s inflammation of this lining that causes the pain of appendicitis). Some of the organs had been liberated from the peritoneum, so it was possible to heft the intestines out of the way, weigh them down with the spleen, wedge up the liver and reveal the retroperitoneal organs, such as the kidneys, pancreas, parts of the colon and the adrenal glands.
The adrenal glands have that name because they lie by the kidneys: ad-renal. Ancient anatomists like Herophilus and Galen didn’t notice them because in death the glands look similar to fat, and the kidneys are embedded in particularly rich fat (this is suet, present in humans as it is in animals). It was the Renaissance anatomist Bartolomeo Eustachi who first spotted the glands, though he had no idea what their purpose was. He observed their excellent blood supply and their close association with the kidneys. They have bulky bundles of nerves, connected to the sympathetic nervous system, parallel trunks of nerves that run down either side of the spine like train tracks – part of the ‘autonomic’ system, the internal calibration of our bodies over which we have little control. Among other functions the sympathetic system is involved in preparing our bodies for action, in what have become known as ‘fight or flight’ responses, and it is aided in this by the hormone adrenaline. Sympathetic nerves work locally, but adrenaline is released into the bloodstream and so acts throughout the body. It is released when we’re frightened or angry, and when we exert ourselves physically. It incites the liver to pour out glucose as fuel for muscles, the airways to open in order to make breathing more effective, the heart to accelerate and the pupils to dilate. Its effect on the brain is to make us more attentive and alert. An overdose can be fatal.