Last night's viewing - Keeping Britain Alive: the NHS in a Day, BBC2; Pop! The Science of Bubbles, BBC4

Keeping Britain Alive: the NHS in a Day – the results of a transverse biopsy on the National Health Service – has a very simple question at its heart: "If we could see what this institution does in one day, what would it make us think?" My guess is that the makers of the series pretty much know the answer to this question already.

It's theoretically possible to watch this kaleidoscopic account of health care and think, "Goodness, this is a terribly inefficient way of organising things. The free market would do it so much better." But it's pretty unlikely, and – at times – explicitly contradicted. Here's John, 85 years old, and having his cataracts done. His wife thinks the NHS is marvellous: "We saw it start," she explains, "and prior to that the doctor's man came round once a week and most people paid sixpence, which was a lot of money in those days." Want those days back again, do you, you brute? No, I thought not. What's required of you, as viewer, is sentimental homage to an institution at the heart of our national sense of self.

I'm not sure I'd care to spend much time with you if you find it easy to resist the sentiment, though. Because what Keeping Britain Alive draws on is the deeply human complexity covered by those three brisk initials, the NHS. The stories in last night's episode ranged from the work of a community GP on a Scottish island, making sure that an old lady's dying was dignified, to a high-risk neurological surgery, conducted on a patient it wouldn't cure but for whom it might buy more time. Daryl's operation was the lead, actually; in part, I suspect, because it had to be conducted while Daryl was conscious, so that the surgeon would know if he'd gone too far with his scalpel. "Woah... It's gone a bit wishy-washy there," Daryl said suddenly at one point. Don't worry, his surgeon replied, I just poured in a bit of water.

There was the occasional flash of light relief, most notably from a guileless pair gathering requests for a hospital radio broadcast ("Bob Marley?" the DJ prompted helpfully, after a black patient took a little too long to come up with a song title). But generally this was about people at the gravest moments of their life, their imagined futures smashed and replaced with something held together by forlorn hopes and a faith in medical technology. And at a time when we've heard a lot about the NHS's failures of tenderness, it was helpful to be reminded that overwhelmingly it doesn't fail, and that its care extends in ways that would have an insurance company checking actuarial tables. Around 80 per cent of NHS surgery, for instance, is now carried out on patients over the age of 75. Looking into Daryl's brain-pan, as his surgeon scraped away at malignancy, I found myself thinking of his tumour as a kind of metaphor for the NHS itself – inextricably embedded in our culture and sending out spidery tendrils everywhere. Only this time benign and keeping us alive.

In Pop! The Science of Bubbles, you could virtually feel the yearning that Dr Helen Czerski might turn out to be a female Brian Cox. Look, here's an underwater shot of her snorkelling through sea-foam. And here she is doing one of those giddy confessions of intellectual infatuation with facts that have become a Cox trademark. She comes pretty close and this was an intriguing programme, exploring the abstract implications of bubbles and their applied properties (from the turbo-boosting of penguins to detergent-free cleaning). It was also – by chance or calculation – a quiet corrective to decades in which the contributors to such documentaries were overwhelmingly male. Some of the earliest breakthroughs in bubble physics were made by a German woman called Agnes Pockels, using equipment she found in her kitchen, and the field still seems to attract a lot of women. It won't be very long, I hope, before this isn't worth remarking on.