In the first week of medical school, my cohort was divided into small groups, given big sheets of white paper and assigned the task of drawing organs on a human outline, as our lecturer shouted “liver!”, “ovary … other ovary!”, “appendix!”, “spleen!” It was startling to confront our ignorance and the exercise was formative for me in retaining humility when talking with patients and being curious about what I call their “imaginary anatomy”: how we think our bodies look inside. Despite the smooth, slim, cross-sections we see on the walls of GP surgeries, each of us has this imaginary space that is of interest not only in its deviation from textbook “truth”, but because the idea of our innards affects how we feel about ourselves and what we think our bodies can do for us. This might explain why I chose to become a psychiatrist rather than a surgeon.

As Gabriel Weston writes in Alive, surgeons tend to think they “own anatomy”. Weston is herself a rare breed of surgeon, having read English at Edinburgh University before reckoning with her single biology O-level to join a new course for humanities students who wanted to become doctors. This made her “the least qualified medical student in the country”. Her “soft, arts-loving brain” had to pass as a scientist – an outsider status I share – which got easier once Weston became fascinated by the operating theatre and the “peachy slit” of the scalpel’s opening incision. It’s an obsession that is still evident everywhere in her writing. But she never lost her belief that medicine is dangerously resistant to seeing the body as more than mechanism, the person as more than a case.

After becoming an ENT (ear, nose and throat) specialist, Weston stepped out of full-time practice to present BBC Two’s Trust Me, I’m a Doctor and wrote an acclaimed memoir, Direct Red: A Surgeon’s Story (2009), as well as a novel, Dirty Work (2013). Alive has been a decade in the making, shaped by the “human prism” of ageing, giving birth to and raising twins at 43, a sudden bleed in her son’s brain and a heart condition of her own, first detected as a murmur by her medical student boyfriend in their 20s (peer diagnosis while practising with stethoscopes is not uncommon).

Compared with the dynamism and pace of discovery in physiology and pharmacology, anatomy can seem inert, bloodless, settled. It’s a subject that tends to be taught through tatty dissected specimens and bones smoothed by hundreds of hands. Anatomy literally means “to cut up” the body, and Alive’s chapters do so organ by organ, challenging each’s inherited wisdom with a feminist eye. Weston reminds us that awe is surely the correct response when considering the gut as “the largest sensory organ” in constant communion with the microbiota living within it, the kidneys flushed through with 200 litres of fluid in one turn of the Earth’s axis and a girl infant’s nipples able to produce milk in response to maternal oestrogen from her first moments in the world.

Bodies become more alive to us as they go wrong. “Health is life lived in the silence of the organs,” wrote the French vascular surgeon René Leriche in 1936; if lucky enough to be free of pain and other disabling symptoms, our bodies can feel oddly dead to us. Reading Weston is like a series of jolts back to life: subcutaneous fat is “custard yellow”, the brain is a “soft organ inside a tight box” and her dodgy mitral valve is “like the swinging doors in a saloon bar after a cowboy has made his showy entrance”. Her prose is admirably clean and smart, though not at the expense of tenderness, and thankfully avoids the sentimentality that too often seeps into medical nonfiction.

“Why are we so ready to squander pleasure in the way we teach anatomy?” Weston asks, an approach that especially short-changes women. Knowledge about genitals needs a “rewrite”, she says: the clitoris, rather than the “conduit” of the vagina, is the penis’s true counterpart, but as female desire became pathologised by the Victorians, the clitoris was rubbed out. We have Australian urologist Helen O’Connell to thank for finally mapping the extensive innervation of the clitoris in 2005 (!) to help surgeons preserve its sensitivity. Many are deceived by the small size of the visible clitoral hood, and Weston despairs that we’re all too hung up on what our bodies look like, rather than how they feel. Silicone breast implants undermine their erogenous surroundings, and the first breast enlargement in 1962 was performed on an indifferent woman in exchange for the surgeon pinning back her ears.

Half of Britons can’t label or describe female genitalia. You could argue – and Weston does – that expertise about the body’s sensations from within and under our fingertips is a more important form of knowledge. But high rates of sexual dissatisfaction reported by women suggest no greater levels of expertise here either.

Clinical practice is stubbornly loyal to the familiar. “In a learned sphere like medicine, it’s easy to assume that false ideas will swiftly be replaced by true ones,” Weston writes, but this is far from true. Doctors’ conformity – hello, rule followers and guideline enthusiasts – is essential to make healthcare reliable and safe. But it carries risks too. The chance of surviving a cardiac arrest in the community, getting gold-standard treatment and being discharged home alive is half as likely for women than for men.

This is partly because of a remarkable lack of curiosity and awareness about the biological differences of the female heart and the cardiological impact of circulating hormones, but also thanks to the ways women are primed to think about themselves (“Isn’t it mainly middle-aged men who get heart attacks?”), which delay care, as well as the prejudices of healthcare professionals (“This looks more like a panic attack than a heart attack to me”).

Weston rightly loses patience with “protocols that claim to suit all bodies, when most of the data they’re based on is taken from white male patients”. Change relies on people pushing against the heavy door of tradition – which Alive brilliantly persuades us all to do more forcefully – finding new ways to imagine and inhabit the space beneath our skin.

Kate Womersley is a doctor and academic specialising in psychiatry