Category Archives: Human Health & Physiology (Core & AHL)
Meet Your Brain: Royal Institution Christmas Lectures
Professor Bruce Hood explores the human brain in this series of lectures from the Royal Institution in London. The trailer is below and in time all the lectures should appear on the RI Channel Website here (Vimeo channel here).
If you can access BBC iPlayer, you can keep up with the lectures here.
The theme of the 2010 Lecture series by Mark Miodownik was “Size Matters”, again relevant to the IB Biology course and available to watch in full from the RI Channel website.
The End of AIDS?
World AIDS Day is almost upon us again: 1st December. This video was tweeted by @StephenFry today – give it a look over to see how ARV drugs may be used in prevention as well as treatment.
[vimeo 32317889]To find out more, visit the End to AIDS website, where you can also read a history of World AIDS Day.
Sex, Lies and Cigarettes
I came across this video via Steve Harton’s Hartonline Bio website and clicked on it because of the Indonesia connection. I’m glad I did, though it made me quite angry.
Aldi
Having spent most of the last eight years in Indonesia, I have long been concerned about the ubiquity of the tobacco industry and the all-pervasive nature of the advertising. Everything – literally everything – is sponsored by tobacco. From TV and movies to sports (!), some schools (!!) and music concerts. There is no escaping the message that smoking is cool, good for you and leads to an exciting life.
So how did it get this way when the developed world is shunning the dangers of smoking?
This 40-minute documentary by Vanguard puts it all in context. From the viral video sensation of Aldi the smoking baby, to the simple, ruthless economics of exploiting a developing country and targeting their children as an emerging market, the film-makers lay it out clearly and passionately. It focuses too on the work of an anti-smoking action group who face the huge challenge of taking on big tobacco in a country where so much depends on it – it’s a major cash crop and source of income.
This video is a YouTube upload, but there are clips and resources on the official Vanguard page.
I loved the bit where the Miss Indonesia contestants help the film-maker crash the World Tobacco Asia conference!
Some questions and thoughts to consider when watching the movie:
- Near the end of the movie, there is a quote from Warren Buffett: “I’ll tell you why I like the cigarette business. It costs a penny to make. Sell it for a dollar. It’s addictive. And there’s fantastic brand loyalty.” Although he has changed his stance on tobacco, it neatly illustrates the bottom-line ethos of business.
- As a publicly-owned company, your main responsibility is to the shareholder – you must maximise profits. Discuss the ethics of targeting children in emerging economies as a market.
- Accepted science states that tobacco is addictive and harmful to human health. Why then has this not been recognised by the Indonesian government?
For more good documentaries, have a look at Vanguard's website.
How We’ll Stop Polio for Good
This TED Talk by Bruce Aylward is amazing – watch it! Particularly important for HL Biology students.
Find out more about the work of the Global Polio Eradication Initiative. You can donate through Rotary International or click on the map below to track their progress.
2006 Map of Global Polio, from the Global Polio Eradication Initiative.
Digestion (Core) and Flip Thinking
Digestion – something you only want to go in one direction. But learning about digestion doesn’t have to go one way. As we are trying to reduce the burden of homework and to make any time spent working outside class as effective as possible, we’re going to try Flip Thinking.
Essentially, your homework takes place before class and you complete only the objective 1 command terms (the bits you don’t need me for). With that out of the way and a foundation in the language and diagrams of the topic, we can focus on the more complex items together.
Come to class with the objective 1 command terms completed in the Essential Biology for Digestion (Core). I have highlighted them in yellow. This should take no more than one of your study periods. If it takes longer, stop and let me know how far you got, as well as how effectively you were working.
Come to classes prepared with your laptop and don’t forget the resources we have available.
Here goes:
Further resources:
Essential Biology 6.1 Digestion (Core)
Key question: How many links can you make from Digestion to the others topics we have already studied in IB Biology?
……….o0O0o……….
I cannot take credit for this idea. Check out these resources:
- Flip Thinking from John Burrell (Click4Biology)
- Eric Mazur’s Science education research group
- Flip Thinking from Daniel Pink
- The Homework Myth by Alfie Kohn
If, however, you find that this helps or hinders your progress, be sure to let me know.
Inside Nature’s Giants
Channel 4’s fantastic series has just ended in the UK (I’m back for a holiday), and I can’t wait for the DVD. This is the kind of natural history quality that the BBC normally has a monopoly on, but C4 have presented something outstanding here.
Fin Whale Dissection
Over the four episodes, Mark Evans presents dissections of four giants of the animal world: elephant, whale, crocodile and giraffe. On hand is the expert anatomist Joy Reidenberg, who does a great job of taking apart and explaining their findings. Richard Dawkins takes the opportunity to point out some of the wonders of evolution in the animals, using anatomical and computer-graphic explanations. It’s great.
Embedded below are part one and part two of the second episode: fin whale. Rather than dissect at the Royal Veterinary College as normal, their challenge was to dissect this whale which washed up on the coast of Ireland before it exploded with decomposition.
If you can get 4onDemand, all four episodes are available online for a month. They are not available for download, but to really get the full effect, you need a high-quality image – so fingers crossed for the DVD!
For now, visit the official website for some clips and animal autopsy games.
Hybrid Hearts: Stem Cell Transplants 2.0
“Can we use stem cells to make a new heart/eye/lung/liver etc?”
This is the predictable and perennial question that comes up from at least one student when we are looking at stem cells, genetic engineering, cell differentiation and transplanting. Until now, the answer has (perhaps in an oversimplified way) been ‘no’.
We can use stem cell transplants to treat lymphoma. Recently a young woman had a trachea transplant based on stem cell technology. Skin grafts from a patient’s own cultured cells are also possible, as are stem cell-based bladders. However, these are all rather simple technologies.
To treat lymphoma, bone marrow cells are replaced, and are all the same. The trachea transplant was a pre-existing trachea simply coated in the patient’s stem cells to prevent immune rejection. Skin transplants are basically sheets of epidermis that cover a wound, yet do not have the intricate functions of original skin: temperature regulation, secretion, senses. The bladder is a bag.
The challenge with using stem cells to transplant a more complex organ, such as a heart, is that it is not a simple sheet made of one type of cell. It is complex 3D structure, with a range of cells performing specific tasks within the organ. These cells have differentiated to perform their functions: cardiomyocytes (beating cells), vascular endothelial cells (smooth internal surfaces) and smooth muscle cells (blood vessel walls).
How can we get the stem cells to become the right type of cell, in the right position?
The answer to this question could be the key to opening up new doors in the search for viable transplantable organs in medicine, and bears much in common with the trachea case. It also marks a return to form for the NewScientist YouTube channel, who have this short clip of the new hearts in action:
A full article to accompany the footage is here.
In a nutshell:
Decellularised pig heart: the scaffold (NewScientist)
1. Find a suitable transplant organ, such as a pig’s heart.
2. Strip of all cells and DNA, using a detergent. Only the collagen ‘scaffold’ remains, as in the image of the decellularised heart to the right.
3. Coat the scaffold with the recipient’s stem cells.
4. Ensure that the blood supply is adequate and will provide the right signals for differentiation.
What is amazing in this case is how the cells ‘knew’ what specialised cells to become. The leader of the research group, Dr. Doris Taylor, puts it down to the mechanical stimulus of the pressure of the blood in the vessels and chambers and chemical signals from growth factors and peptides that remained on the stripped heart structure.
They even went as far as replacing a healthy rat’s heart with one of these new hybrid hearts. The rat survived for the trial, but she says they need to focus on producing more muscular hearts in order to ensure long-term survival of transplant recipients.
Food for thought:
Read the whole article and some of the links within it. Discuss these questions:
1. What are the potential uses for this kind of transplant technology?
2. What are the current limitations of this method and how might they be overcome?
3. What are the ethical issues related to using hybrid (pig-human) organs in medical transplants? How would you feel if you were the patient?
4. Who are the various stakeholders in this technology and what are their viewpoints?
Useful Sources:
Dr Doris Taylor’s research page from the University of Minnesota
NewScientist Article: Hybrid hearts could solve transplant problem
BioAlive stem cells links and resources
Can stem cells repair a damaged heart? from the NIH
Research reveals how stem cells build a heart, from Harvard news.
Pandemic II: Educational Flash Game
Pandemic II: Spread the World
Thanks to the excellent NotExactlyRocketScience blog for posting the link to this game. Pandemic II is a complex flash game based on strategy, evolution (though more like design) and the spread of disease. The premise is simple – take a pathogen (bacteria, virus or parasite), and watch its spread across the globe. Along the way you can alter the pathogen to change its properties, making it more infectious, more lethal or less noticeable. The aim of the game is to wipe out the population of the world.
It is easy to save using Firefox add-ons.
Check out the game here: http://www.crazymonkeygames.com/Pandemic-2.html
And the tutorials here:
Is it better than the addictive Magic Pen Game or Foldit?
Have a go!
The Kidney
Last topic for the HL Students!
The Kidney is great – it filters our blood, makes urine and ties together so many aspects of the course – cells, membrane transport, osmosis, chemistry of life, hormonal control. We can look at how it is similar to and different from the liver and how its structure reflects its function. I love the kidney.
Here’s the presentation, with some data-y questions at the end.
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More resources here:
Best kidney animation ever from biologymad.com
Quick guide to thekidney from kidneypatientguide.org.uk
Complete tutorial from Sumanas
Bilingual (Chinese and English) guide to the kidney, with rave tunes from hkedcity.net
More Loop of Henle action from the University of Colorado
Hormonal control of ADH from McGraw Hill
Diabetes recap from MedMovie
Kidney quiz from ZeroBio
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Want to see a kidney stone?
Find out more about kidney stones here.
i-Biology 