What function does the appendix serve?

Great question, we have no idea!

So, the appendix is about a couple of centimetres. It sits on the end of your cecum - which is the first part of your large bowel, where your large bowel connects to your small bowel, in the right lower side of your abdomen. It's cheeky, and it causes problems in people. 

We think it was a bit of a remnant stomach or something from the olden days, that then got really small, and is useless. So, there are people who are rarely born without an appendix. We've never proved what it can do, but there is quite interesting evidence that if you have inflammatory bowel disease - so something like Crohn's or ulcerative colitis - if you have your appendix still in, sometimes you respond better to different medications, and you do better. That's really weird and no one knows why. 

But, the appendix currently serves no function that we can use other than to be annoying. 

How do you prepare for surgery?

It's important for both us and the patients to prepare for surgery. So, part of us preparing for surgery is when you see someone in a clinic, if it's an elective operation, you have to think about the approach of what you're going to do. So, part of preparing for surgery is definitely deciding if it needs doing - because any surgery presents risks to people. You have to talk through the risks and benefits with the patient, as part of what's called the informed consent process. They have to know all of the risks, all of the benefits, and want to have it done. 

We can make our recommendations, but ultimately the patient has to decide if they're happy to go ahead with the surgery if they are able to do so. If it's an emergency operation, or an operation that's for cancer, or something very severe, and the person isn't able to give their consent and able to say what they want, because they have problems such as learning difficulties, or if they have dementia, or cognitive impairment - then we have like an MDT process. Which is getting everyone involved and deciding what's in the best interest for the patient. 

Personally, before you go into an operation, you have to get them to sign the consent form, and in doing so, you have to say what you're going to do. You have to know what you're going to do - are you going to do an open operation? Are you going to do a keyhole operation? What are you going to do and what are the things that you might have to do?

If you're doing something simple, you will generally put what you're going to do. If you're going to do it as a keyhole operation, you always have to prepare for it to become an open operation, because you can't always do a keyhole. Then you have to figure out what you might have to do if things go wrong. So, depending which part of the body you're going into, you have to think about the steps of the operation. So before I go in, and start an operation, I'll walk through the steps right from where I position myself around the patient, which side am I going to be on, because you think about which dominant hand you use. If you're doing a keyhole operation, you think where you're going to stand, and where there has to be a screen. You have to be able to see the screen best to be able to coordinate with your hands. 

Then you go through each of the steps of the operation, what you need to ask for at each step, because some things need to get ready. So, if you need to put clips on something, some point you need to think when am I going to need to do that, when do I need to ask the nurse who's giving you the equipment to do that, and how am I going to approach this depending on what information I've got about the patient, whether you've got scans, what the patient's pathology is, what you're doing, and then you walk through the steps. 

Before I scrub up, before I get ready for the patient, I'll go through every step of the operation and then as you're going in often you verbalise what you're doing as you're going along, even if you're the most senior person in the room, just to sort of make sure you're doing everything at every step. Patients prepare for surgery as well, so especially big surgeries. They go to things like surgery school, so that they're at the fittest they can be beforehand. It's a process, we'll get it right first time, which means if a person is as optimised, and as informed as they can be at the time of surgery and everyone's the most prepared - it's less likely to go wrong. 

Are there toxic ingredients in home cleaning products?

Absolutely, there are.

A lot of these cleaning products are very good because they have a very high pH, so they're quite alkaline. This allows for efficient cleaning, it's able to kill harmful bacteria. It's able to work with water to efficiently scrub out grime, dirt, and so on. 

However, these chemicals with such high pH - they can also cause quite a lot of harm, especially if they're ingested.  Even on skin, you can have skin absorption of alkaline substances such as bleach, and that could cause irritation, redness, rash - and you must wash immediately. 

Usually, they do not even recommend using any soap because that could even interact with the potential, maybe if you have bleach in your hand, it's just water - you want to remove it from the site as soon as possible. 

So, this is why you have a lot of those hazard labels on cleaning products telling you whether it's corrosive, or whether it is an alkaline and so on, and telling you especially - do not drink.

What signs do you look for for a healthy brain?

That's actually a really cool question because we often focus on the unhealthy things in the body, or when it comes to science, or medicine. But understanding what is healthy is actually quite essential as well. 

I think how we define this, is that there are certain abilities we look for, that someone is able to do in their daily life. So with a healthy brain, it's not like you should never forget things - but you shouldn't have excessive forgetfulness. For example, you should be able to carry on your day knowing what you're doing. So, you shouldn't have excessive forgetfulness, and you should be able to do your motor behavior properly - which means that you will walk, you fold things, you do your daily life. You will open doors, you sit down, and then if you have to run - you run. So these are motor abilities that are controlled by the brain. So we expect someone with a healthy brain to be able to do them anytime they wish. 

The cognitive part of the brain is quite essential as well, we can call this mental health, or your mood.

There are certain diseases that we call - mood disorders. So, this defines that like, of course, this doesn't mean that you won't have any emotional changes in the day, but you should be able to have those changes. So that's what's why it's important, so you can feel happy. But then if something bad has happened, you can feel sadness - then come back to your normal state.

So, these changes should be at a level that doesn't affect your day negatively. So that's kind of a healthy state that you're able to feel things, change your mood, but then come back - to whatever the regular state you are. Sometimes if the regular state is leaning towards one mood, then you start thinking - maybe there might be an issue there.

Apart from that, I think cognitive and motor behavior is the main thing that we look at as a first insight. I don't want to give such a detail saying that you shouldn't feel any negative things because then people start thinking - oh, I feel low today - am I not healthy? It's not like that, your day should be content within, and then you should be functioning properly. So, we can conclude that you are actually at a normal stage.

Sleeping is another important part of a healthy brain, because it's the time that the brain shuts down, rests, and actually continues working in the background. This is why we say we should sleep, especially if we are trying to learn things, because the learning is being actually completed, processed while you're sleeping.

So that's another important thing - if your brain is not able to shut down, especially long term, maybe you can start thinking maybe there's a problem there.

Why do some people with severe dementia often remember songs and rhymes?

This is a good question. It tells us the thing about the nature of the disease, actually - so Dementia or Alzheimer's. So, Alzheimer's is one type of dementia. Dementia is a bigger spectrum, about our memory and the function of the brain.

If you think the nerve cells are working together, they are not physically always in touch, but they are working with each other. So this will send a signal, and this will receive the signal - this will initiate a process. Our memory is functioning like that as well. So, we remember things because these neurons are able to communicate.

What happens in dementia cases, that communication is loosened. In time, those neurons die, because they are not able to function. The more we lose the neurons, the more we lose memory and our body function. So, in those cases, people remember old memories more than recent memories, because old memories have more.

Remember that if you have repeated something more, your brain will have that memory more often, so if you have done something today for the first time, and if you develop dementia, you won't have that storage strong enough so you can remember again. One of the symptoms of dementia cases is that you actually lose the ability to store, so this is why you actually don't remember, because you actually didn't store it. 

But you haven't had the disease since you were born, so the disease appeared later, so you already have certain memories stored, and then you have repeated them in songs and rhymes. They actually also have different memories than the short-term memory, you know, the daily things. The long-term memory is stored a bit differently, so this is why we still, you know, when we have those diseases, we still remember the old things, but not the recent things.

But the more disease progresses, that part will be affected as well. Those things will be maybe forgotten, but they are so strong. So this is why, you know, people will remember their parents, but maybe not their own children, because it's relatively recent compared to your parents' memories.

How do new drugs or treatments get approved for prescribed use?

This takes years and a lot of research, a lot of pain for scientists, and maybe sweat of PhD students, master students, a lot of grants from the funders and money. It's a long process. It starts in the labs, research labs usually.

So, if we have a mechanistic insight about the disease mechanism, let's say, we know that this might be the reason for that disease appearing. This is not functioning, and this is why it is happening. Then if you're able to target that dysfunction, maybe you are able to correct somehow, or you are blocking something, and it's making it work. If you know that level of information, you start trying components in the lab. Usually you can start trying them on the cells in a culture petri dish. Then if it responds positively, according to your hypothesis, then you move to the animals. You test the same outcome on the animals. If it is still correlated to what you are thinking, then you apply for clinical trials, which means that you apply to the agencies. 

So for example, you know, an agency linked to the NHS in the UK, or there's FDA in the US. You reach out to them saying that you have a component, you tried cells, you tried animals, and now you wanna gain access to the clinical trial, to human trials in the hospitals. Then there are a lot of checks in between, of course, those agencies, this is why they exist. They sit down and check whether your data is consistent, whether what you're saying is correct. You put placebo trials as well, which means that you don't actually give the components, but in the placebo trial, you shouldn't see the effect that you're assuming to see in the component category. So, all these checks are done, and then the clinical trials start. 

Usually it's a small population of patients that are chosen by the hospital, and with the developer together that they have they have given to the medicine and effect observed. So, if this passes well, then you can get the full approval. But, the first human trial doesn't mean that you're trying to hurt those people, or you have a risk of hurting those people. Of course, before that step, there's a lot of research, and approvals are taken and you have actually shown the effect. The only thing that sometimes we see is that things work on cells, and it works on mice as well - but sometimes it doesn't work on humans because at the end, all the similarities we have, we are different species, different organisms, but the mice in the lab, the closest we can get. So this is why we are relying on that outcome.

But there will be cases that you are not going to see the same in the human condition. Then you either stop continuing the drug, or if you see a positive outcome, then it gets approval by the agencies, and then it goes on to the market and used.

How do surgeons and anaesthetists work together?

It's very important for the surgeons and the anaesthetists to work together. There is always a little bit of friendly banter between the two. They are saying that they're not putting them to sleep quick enough, and them saying we're not operating quick enough. But when you have a really good surgeon anaesthetic team, when you work together and communicate, it makes everything run so much better. 

So, the anesthetists, we ask them if they will put patients to sleep. So if it's an emergency setting and someone's a bit older, more complicated, we work with them to say, this is what we want to do. Are you able to put them to sleep for us to do that? Sometimes they'll say no, and then we'll say, OK, so we can't do that operation. Then we have to make a decision about what the best thing to do is. Often they'll say we can do it, but it's really risky, in which case then it helps us to counsel the patient. But then they can establish the best way to put them to sleep. They're really important for pain management, so they can do procedures before they go to sleep, or while they're asleep, or after they wake up. In terms of they can put what's called an epidural in, or a spinal anaesthetic in which gives better pain relief for big operations afterwards. So we need to think about that. We need to tell them what they're going to do so they can try and anticipate what to do from that perspective. 

They can also suggest to us that we can do operations that aren't putting people to sleep, so we can put them under a different type of anaesthetic whether awake but paralysed, or under a local anaesthetic for higher risk patients if they are more likely to have problems with the general anaesthetic. Then during the operation, they tell us if they're concerned, if something we're doing is causing their heart rate to go up, or their blood pressure to go down, then we have to speak to each other to try and make sure that the risks to the patient are as low as possible throughout. 

We also, we work together electively before the operation and especially in emergency settings when the anaesthetists are covering different specialties, we have to communicate with them to make sure that their patients are coming, and getting prepared as quickly as possible to reduce the time between operations that people are sitting around waiting for things to happen. 

So when you have a good anaesthetist and a good surgeon that work together very well, it's great. If there's a little bit of animosity, then it doesn't work quite so well. But it's nice in the elective setting often for a list on say a specific day of the week, it'll be the same surgeons, and the same anaesthetists, and they've seen the patients beforehand. So, that's much better. That's more common with sort of cancer lists and big case lists. With day cases and smaller lists, then you often get a bit of a mismatch in difference, because those patients are high turnover. But we love our anaesthetists, and hopefully they love us as well.

Is raw milk, or unpasteurised milk, generally safe to drink?

So, in terms of inherent substances in the milk, yeah, there isn't anything per se that we need to take care of in cow's milk, in normal healthy cows. Normal healthy cows being the big caveat here, because if you have got some subclinical mastitis - mastitis is a very, very common infection that may be shed into the milk. That won't necessarily be great for a human drinking it. 

The big one that you would be concerned about with unpasteurised milk is tuberculosis, bovine tuberculosis. So, the way that milk is pasteurised in the UK, pasteurisation is not a standardised process. When you pasteurise, you pasteurise with a given pathogen in mind. So, pasteurisation is heat treatment, right? But, how hot and for how long are the questions.

The protocols that we use as standard for processing milk in the UK are intended to reduce the load of bovine TB, because back in the 50s, post-war, we were trying to ramp up agriculture, because we'd all been starving for a few years. No one liked rationing from what I'm told. I wouldn't like it either. Bovine TB was a big deal. So, they put in place a control program from then, and pasteurisation was one of the elements of that, to stop it spreading through the human population. 

Now, TB is kind of making a bit of a comeback in humans, but typically in overcrowded urban areas, and human TB rather than bovine TB. So, that would be my main concern about drinking raw milk. 

Full disclosure, I will happily drink raw milk. Quite a number of the farms around here and I try not to play favourites, because there's a lot of them who I'm connected with in some way. There's normally vending machines, so you could go along with your bottle. You pay, it's normally a pound, or £1.20 for a litre of milk. To a farmer, that's amazing. I can't highlight how amazing that is. So, classically, they'll be paid like 35, maybe 40p for a litre of milk. You've given them two and a half times that. So, that's really, really good in terms of their business. So yeah, I will happily do that. If I knew a farmer had issues with TB, I may be a little bit more reluctant. So, where I live as well is one of the higher risk TB areas of the UK. So maybe, here I'd be a little more reticent. If you're in a low TB area, you've probably got very little to worry about. Bit of a trade off. 

I guess probably in terms of feeding it to anyone immunocompromised, it's probably a no-no. Very young children, probably a no-no. But, for kind of healthy adults outside of the TB issue, which is an issue of everyone, probably pretty safe. But, on the other hand, we pasteurise for a reason, right? So, you forget the safety measures of your peril. Most of the time it'll be okay, but on the one that it isn't, it's probably going to be regretted. So, yeah, raw milk, tentative thumbs up.

What are some of the reasons why cancer returns in patients?

This is important in the way that it also tells us about the complexity of the disease. So when someone develops cancer cells, those cells probably will develop a tumour - which means that there is an accumulation of cancer cells in a region. So it develops a kind of ball, imagine it like that - which means that cells divide themselves enough that you can, even in skin cells - skin cancers, for example, you can feel the tumour with your hand on your skin, and it's going to be in that region. 

Then this could be treated by the available treatments, could be surgery, could be combined with chemotherapy. So then we target those cancer cells and try to kill them as much as possible, but even with few cells left with the same mutation - they could reinitiate that process.

So this is why with the ‘all clear’ - of course, they monitor as much as they can. The tests available in medical settings now are trying to cover as much as they can. But, it's not easy to say if there isn't even one single cell left, because cancer cells could be metastatic - which means that they can migrate from one region through blood to another region in the body.

So, if one cancer cell makes it to the blood and then migrates, they can go and colonise another region or they can invade another region, and then they can continue dividing themselves there. Also, cancer cells are another fascinating side of the cancer, but also sad for the patient - of course, as they are quite responsive and dynamic, so when we treat them with something to kill them, they can dynamically reshape themselves - so then they can escape from that drug.

Of course, they are not going to do it the moment we are giving the drug for the first time, but then the ones that remained - if they find the way to escape from that effect of that drug, they might come back, and they might even be a bit stronger, because they probably now have developed resistance to that drug.

So, this is why we monitor those patients throughout their lives just in case, as it might reappear again. But this doesn't mean that this will happen. There are many patients that are given all clear and don’t have it at all again. Also, there are some cases that you might see it's coming back, and if you realise it in good time, you can still continue treating it and then get a positive outcome.

What does the belly button do?

So when you are a baby, before you come out, your belly button is where your main blood vessels go from the placenta of your mother and they carry oxygen and nutrients through the belly button into the foetus. So their lungs aren't functional yet, so they're not breathing, they're just surrounded by fluid. 

In order to get oxygen and sugar and everything from the placenta and from the mother, the blood vessels run through where your belly button is. When you are born, you can breathe and you can take things orally. So you don't need the belly button to do this anymore. So the belly button, where the umbilical cord is, that's clamped off and cut when you are born. Those blood vessels are still there, but then they sort of shrink away because you don't need them. The umbilical sort of stalk falls off this little remnant after the cord's cut and you're left with this little usually inner or outy. 

But because of where those blood vessels used to be and where they go away, that is the quickest point of access into the abdomen because that was where things went into your tummy. So when we use it for keyhole surgery, we know that the little stalk connects to the sort of muscles and the layers of the abdominal wall.

So it's the point where everything else is usually out of the way and it's the easiest point to get into the tummy. People can get little hernias through the belly button because there was a weakness there, they're sort of closed up. So babies can have those when they're born. It's normal to have those when you're born and normally they go away and by the time you're about two or three, but sometimes they don't go away. And then we have to fix them, which is fun. But that's what we use it for - it's a physiological use up until you're born and then we use it as a bit of a bit of a cheat to get into the tummy. 

Does ethnicity have an impact on neuron degeneration?

So, let's define neuron degeneration first. The word degeneration is referring to something that has been generated, and they are degenerating. So they kind of exist, and they are like now dying back, or disappearing.

When we were embryos in embryonic development, we started having neurons, brain development and when we were born, we grew our neurons. If they don't have any problem, they will function properly for the rest of our lives. But if they have some problems, neurons are one of the types of the cells that, despite having some problems, can make us long live, at a level that we don't realise those problems yet.

This is why neurodegenerative disease is usually diagnosed at our late ages. So some problems were actually there since birth, but like neuron managed itself to function until a certain age. Then there was an accumulation of that problem, and then couldn't cope with it anymore. 

Is there any difference in terms of ethnicity in those things? I wouldn't say this is at the molecular or genetic level, because ethnicity is a term I would, as a person, I would use more at the social and cultural level. Of course, we have genetic sharing, and within the same ethnic group, we will have more sharing compared to others. But don't forget that that falls into the 1% difference.

The other things, what you expect from an embryo and how it develops, it's going to be the same. If there is a certain type of exposure of things for a certain ethnicity, in a certain region, then you might see that this is impacting the disease development more than others. You know, for example, the regions that lack sunlight affecting vitamin D level, which people conclude saying that the prevalence of multiple sclerosis - which is a type of brain disease, is seen more in those areas. 

Does this define an ethnic link? I'm not sure about that. These things to me are more like environmental factors that ethnic groups are living in. It's not about their genes that's doing something extra, or differently than others to them.

Why do we sometimes cry when we are happy?

So, built into this question is a sense of disbelief that we could possibly cry when happy, because probably tears have been associated culturally with being upset, or being sad. But, we have to ask the question, what is the function of crying? 

Research on various animals, as well as on humans, would suggest that crying is an emotional regulation strategy. So, when your nervous system gets overwhelmed with emotion, and reaches the peak experience of emotion - it somehow has to open the valve, and let off some steam, so that it can bring itself back down to what we would call - homeostasis. Which just refers to normal functioning balance in the nervous system, because the nervous system doesn't want to be too hot, or too cold for too long. 

So, if you are happy, perhaps what can happen then is the nervous system tries to bring you back down to a more balanced state, and it does that by letting off some of that emotional energy through tears.

Why is there a minimum age for drinking alcohol?

So, research on adolescent development has shown us two important things. First one is that the brain is continuing to develop very quickly, all the way through your 20s into your 30s. The part of the brain that's taking a little bit longer to catch up, is the part of the brain that would be involved in our inhibitions, and stopping us from doing things that are perhaps not very good for us. That takes the longest to develop.

Ironically, the part of the brain that's developing very quickly is the part of the brain that likes taking risks, likes being rewarded, and doing fun things. So, with that knowledge of development, that's why there is a cutoff for drinking, because we need to respect the fact that when you start and you're having fun with alcohol - it's really difficult to stop at that age. 

The second thing that this research has shown us is that adolescents when taking risks, or young people when taking risks, are much more affected by the presence of their peers - so you can think about peer pressure, and peer influence - and they're much more affected by their peers. So, if we accept that with the development of the brains of young people, that the part that would stop them drinking too much is underdeveloped, and the part that wants to drink a lot is overdeveloped, and then you add in the fact that all of the teenage brains are the same way, and then you add the fact that they really influence each other at that age - you can end up with catastrophe.

How long does recovery typically take after surgery?

It is very dependent on the operation. So, people can go home from an operation the same day. If you've had a little lump removed under a local anaesthetic, you can literally walk out of the recovery room and just go home. If you've had a laparotomy - which is a big open cut in the abdomen, where we go inside and ferret around to get your bowels out and things, that can take a good couple of weeks. 

We try to keep people in hospital for as little time as possible. So, even after a really big sort of esophagectomy, which is where you have to go in the tummy and in the chest, two big cuts, and take a big portion of your oesophagus - which is your food pipe out - and join everything back together. It's very high risk. You can, in theory, go home as soon as day eight or nine after the operation, but that doesn't mean you're fully recovered. So, getting to go home doesn't mean the recovery is over. It just means we are trying to reduce the complications we can give people in hospital. 

When you're at home, you can get much better walking around in your own environment. You encourage people to walk, so people in hospitals think they should be in bed all the time - definitely not. You're at less risk of hospital acquired infections, and other complications of being in hospital, blood clots and things like that. So, we always try and get people home as soon as we can, or we can send them to somewhere like a rehab place in the meantime, if they're sort of older and more frail, so that they're in a less high -risk hospital environment but getting more physio support. 

After say a bowel cancer operation, in theory if it's robotic and it's simple, sometimes you can go home after two days - but it can be sort of eight or nine days, depending if you have a complication after surgery or if you're in a lot of pain. 

So, the recovery is definitely based on the operation, the type of operation, and what happens. Keyhole operations and robotic operations - you are much more likely to go home earlier if you don't have a complication than an open operation, and that's mainly pain related, as well as sort of complication related. 

When is the brain most active?

You know what we feel as a human, we are a bit entitled - and we think that we're always thinking about something - but actually we are not always thinking about something.

But, our brain has functions to do constantly, because it's managing our basic functions that we are staying alive, our organs are working, our tissues are communicating. So, these are basic functions of the brain, which is not necessarily extra effort, extra activation, but it is there, and it's constantly working. 

But of course, if we are thinking, what are the most active times - these are the times that we are trying to learn something. We are trying to solve a problem which requires our brain to gather all the knowledge you know already, that it's in the memory. Then it's trying to make something new out of it because you're facing a problem. So, in those moments the brain makes a little bit of higher activation than its usual state.

Interestingly, in one part of our sleep, that brain gets the most active prime time. This is why sleeping is so essential if you are in the process of learning something. We should definitely focus on our sleep, as well as sitting and studying, because our brain processes the information that we put in during the day at night, when we are sleeping.

So imagine the brain is someone that has so many different things, then at night, the other so many different things get a bit low. You don't have to consider how the body is walking, or you don't have to deal with digestion because the person has stopped eating.

So, what you need to do at that time is focus on what is the new information taken in the day. So then you make them in the memory, process them, and then complete the learning, for example. This is why it reaches a level that it's quite active at a certain time of our sleep, but not the same reasons that it is being active during the day maybe.

So, this is why learning and problem solving, and the processing at night, is one of the times that the brain is most active.

What is one health?

One health is an increasingly popular sort of idea within medical and vet circles. Perhaps this is a little bit more on the radar of the vets, but I don't really know the doctor's side of it that well. So, I may be saying out of bounds there.

But, the core premise of one health is that human health and animal health are intrinsically linked, in quite a lot of ways. Very, very broad definition. So, people think of the obvious, you know, are people catching diseases from animals and things like that? Yeah, that's obviously part of it. That's an obvious concern. But, there's even things like, for example, dog ownership is shown to have health benefits. 

So, there's one health case where the interaction between humans and animals is having a health benefit on either. Or I suppose that is the kind of welfare, a welfare very vet's word to use - but there is the well-being perhaps of the more humanised, but implications on a human one, for example, that animals are ill.

So, if there's a big outbreak of disease in dogs, the most recent one I can think of that was really relevant in the UK would be Alabama Rot. That was at the time here, a new and emerging disease. It was fatal and a lot of people were very upset, and just very worried that their dogs would get sick with this condition.

So yeah, one health is all about the different places that human and animal health interact, and it's really, really broad. 

Do I own my body or my body parts?

An interesting question about property rights is whether people own their own bodies, or whether it's possible to own a dead body, or parts of the body like an organ.

So, if you get your tonsils taken out, do you own those extracted tonsils? And what if you die - does anyone own your cadaver? Now under English law at least, the default rule is that nobody owns the human body, or any parts of it. So, nobody owns your dead body, nobody owns your extracted tonsils. 

There are two main exceptions to this. First, if a body part has been taken out of the body, and then it's undergone some kind of process to preserve it for medical or scientific purposes, then the person who does the preserving does own the body part. So, if a doctor takes out my tonsils and then he pickles them, and stores them in a jar for medical examination later - the doctor would own my tonsils. 

Secondly, there's also an exception for reproductive products that are produced by the human body, like semen, or eggs. There's a court case called Yearworth versus North Bristol NHS Trust. In that case, the court held that men have a property right in semen that they gave to a sperm bank for fertility purposes. That property right allowed the men to sue the sperm bank when they negligently lost, or destroyed that semen.

Now, the fact that the human body cannot normally be owned does not mean that you don't have any rights to your body parts, or that anyone can do whatever you like with a dead body.

There are laws like the Human Tissue Act of 2004, and there are two, Human Fertilisation and Embryology Acts, and these statutes place a lot of rules on what could be legally done with human body parts and dead bodies, and when your consent is needed to do certain things with your body parts. However, these rights are not property rights - you could never legally sell your organs.

How accurate are breathalysers compared to blood tests?

When assessing whether someone is over the limit for alcohol consumption, it is based on a threshold of blood alcohol concentration. So, this is set to 0.08% blood alcohol concentration. 

With a breathalyser, it is not measuring the blood alcohol level in your blood. It's measuring the amount of alcohol, or ethanol, in your breath. Therefore, a breathalyser test can only give you an indication of whether you are over the limit. If you have, it's very efficient at measuring ethanol within your breath, but that's not to say it's not as accurate as a blood test. 

A blood test will always give you a more definitive answer to whether you are above that threshold of 0.08% blood alcohol concentration.

Can brain cells regenerate? 

This is one of the fascinating topics in neuroscience, and there is a lot of research going on, because we wish that they could be regenerating. So the word regenerate is referring to something that has existed, so generated, and then something happened. They may be degenerated, so they lose their features and then function. What we want is for them to come back, and gain that function again. 

This is actually an event in which most of our cells are able to do, they kind of can divide themselves with mitosis, and the dysfunctional one, or the damaged cell, dies out and disappears. The healthy cell divides itself and then gives a new one. So, this is kind of for regeneration, it could be. There is another type of regeneration we can think of is that, let's say part of the cell is damaged, and the cell is only repairing that damaged part. So, that could be a regeneration as well. This is in our body we observe.

In most of the tissues when it comes to the brain, it's a bit hard and tricky, and it's evolved in a way that the neurons are not able to divide themselves anymore, so they don't go through mitosis after they become a mature neuron. So this is sad, of course, because when we have a damage in the brain, it means like we lost neurons, and then they are not going to come back. So, this is why we end up having certain diseases. But it might be kind of understandable why it is not. Because if we think about mitosis, cell division, you know, cells will stop their function, and then replicate the DNA and divide. This means that a cell is suspending whatever the function they are doing for a certain time. I think this is understandable why neurons might not like that, because it means part of our brain will be suspended. So, then they can divide themselves. So if you think that they're able to do mitosis. So that could be actually also negative for the body, because you know these are the problems that we can't tolerate neurons not functioning. So maybe this is why it's evolved in that way. 

But still, you know, it could be quite nice, and it could be a treatment for certain diseases. If we are able to see that regeneration. But in the brain, there are other cells apart from neurons that are, for example, glia, which are the supporting cells for neurons. They are able to divide themselves. There are other types of cells, so they can divide themselves. So, it is the neurons that we don't see cell division. There is a lot of research that we are trying to trigger in case of damages. When we have neuronal loss, maybe for that type of situation, we can trigger regeneration.

So there is a lot of research going on, but what we observe in neurons, let's say so a neuron has a cell body. Imagine like it's my hand, and then the axonal part, it's like my arm. If these axonal parts are damaged, we observe that the neuron is able to regenerate that damaged axonal part. So, they can kind of create a new axon, or they can repair the damaged products, one that we observed a little bit. What we don't observe is the full neuron kind of dividing, and renewing itself. But still partial axonal repair is also regeneration. 

So, the answer is, yes, there are cases that we can see regeneration, but not fully in neurons. There are other types of brain cells that we can see fully, renewal and repair. That will be my answer.

How can a polygraph detect when we are lying?

The short answer to that is it cannot, because we've got multiple issues here. The first one to start with is what psychologists have called - operationalisation. Huge word, but basically what it means is how do you measure something. So, something like lying, we can define it as not telling the truth - but how do you know what the truth is, is the first question we have to ask ourselves. If you don't know what the truth is, then you don't know if someone's lying. It's a huge problem. 

So, when we think about operationalisation, we are asking to what extent we can design a measurement that is really, really accurate and really, really good at measuring the thing we're interested in. So in this situation, it's lying. But, we don't know what the truth is a lot of the time. So what we need to do is try to indirectly measure the thing that we're interested in. That's one way of operationalising lying, and you can do that with something called a polygraph. 

A polygraph will measure your physiological responses when speaking about something. The idea being that lying is correlated with, and is associated with bodily experiences of perhaps increased heart rate, or respiration, or getting warmer. 

But, it is just an association. Not everyone who's lying will have that experience. So, the polygraph works, or is supposed to work on the assumption that if we lie, our body responds in a particular way, and we can pick that up. But of course you can see lots of pitfalls in that argument, because perhaps you're hot because you're in a hot room. Perhaps you are responding in a certain way because you've got a medical condition that makes you respond like that all of the time - regardless of whether you're telling the truth, or whether you're lying. 

So, really all the polygraph tests can do is tell us about the physiological response. The question is then can we interpret the physiological body response as an indirect measure of lying - and I don't think you can, at least not all the time.