Molecules that are essential

Every chemical in your body is important. But there are some that seem to be the first among equals. This SciShow video list those that might be viewed as most important. Some parts are a bit complicated, but check it out nonetheless. You will find as we go through Chapter 3, some of this will be less mysterious.

What the brain looks like on the inside

The structural organization of the brain is very impressive, and not the mish mash of wires running about at random. In recent years with the development of a ‘see-through brain’ in which fibre paths or certain neurons can be stained, we can now visualize aspects of the brain in ways that we could not earlier. This video from Nature Video, describes a method to visualize the brain using an approach developed by Karl Disseroff. It is absolutely stunning?

An introduction to Mendelian genetics | Biomolecules | MCAT | Khan Academy

A very nice description of basic Mendelian inheritance. Unlike other videos on this topic it explains what alleles are (two or more versions of a gene), and why you might inherit several different phenotypes related to blood type (A, B, AB and O).

Theories of evolution Lamarck vs Darwin | Evolution | Biology | FuseSchool

A brief history of these concepts is provided. In both cases environment is important to evolution, with some key exceptions. After watching this, and learning about epigenetics, should we conclude that Lamarck was entirely incorrect?

How to read the genome and build a human being | Riccardo Sabatini

The genome is complex, but many scientists have been attempting to interpret the genetic code and how it translates into specific phenotypes. This entertaining and impressive video demonstrates how machine learning has been used to determine how humans are built.

Epigenetics: Suppressing the actions of genes

We have talked about epigenetics to a considerable degree in this chapter (and others). This SciShow clip ought to help you understand this concept. There are several ways in which epigenetic changes occur, which are described very well in this video. Importantly from the health psychology perspective is the consideration that our diet, experiences or stressors, can have epigenetic effects, and under some circumstances, the epigenetic changes can be passed on across generations.

Epigenetics - our bodies' way to change the destiny written in our DNA

Moshe Szyf | TEDxBratislava

So, does your mom’s behaviour when you were very young affect your behaviour and illness vulnerability? Of course, it does. There are a variety of psychosocial factors that have these effects. But there is more to it than that. Mom’s behaviours can influence how the offspring’s genes are expressed being modified through epigenetic changes. This fascinating presentation explains why epigenetic changes can be adaptive, but why they can also be risk factors that lead to adverse effects

Human genome and the evolution of medicine | Stylianos Antonarakis | TEDxThessaloniki

Here we see how genes and environment interact to produce particular diseases (breast cancer, Alzheimer’s disease). It is particularly given that we all likely carry genetic risk factors.

Can trauma be inherited? SciShow

Here we learn about the way in which trauma can be passed on over generations through epigenetic changes. Alternatives are provided to epigenetic changes that can account for intergenerational transmission.

What is historical trauma?

This is an absolutely superb description of collective, historical trauma. It describes the influence of these experiences on multiple generations. The focus is largely on Indigenous Peoples and African American people but is equally applicable to other groups.

CRISPR. The good and the risky

Most readers will have heard of the push that exists to deal with illnesses by engineering the genome. In fact, a method referred to as CRISPR (this acronym is for clustered regularly interspaced short palindromic repeats – it is obviously a good idea to simply use the acronym) allows the removal and replacement of components that make up a gene, which we would like to alter. Understandably, because of its potential uses, this methodology has become the darling of the gene world and two of its originators, Emmanuelle Charpentier and Jennifer Doudna, won the Nobel Prize in Chemistry in 2020. There is no doubt that CRISPR and an associated methodology, Gene Drive, can have enormous effects on human well-beings and could potentially alter features of species that endanger us. Thus, scientists have gathered to define which procedures should be deemed ethical, which problems should be tackled, and conversely, which issues need to be avoided. The first of these two videos explains how CRISPR-Cas9 is used to edit genes (this clip comes from Nature Videos), whereas the second, which is a Risky Bites video describe how CRISPR and Gene Drive can be used to eradicate disease carrying mosquitos.

Oxygen free radicals

Oxygen is basic for living cells. However, when oxygen levels are too high and appear in the wrong places, these molecules can be destructive. You might have heard the terms oxygen free radicals or reactive oxygen species, which refers to the form of oxygen that is not good for us. This video clip from SciShow describes how oxygen goes bad and can harm or even kill us.

Hormones: An overview in three videos

There are many hormones that are important for our normal functioning. This whiteboard video created by Armando Hasudungan does a terrific job of describing the endocrine systems in 21 minutes. He indicates in a link (click on his name in the video) that he is not a doctor or professor, but does this because he likes to draw.

In this next video, produced from Bioidentical Hormone Doctors, David Wolfe covers many hormones, and these are placed in the context of everyday life and health (particularly the influence of various foods)

Finally, this video clip (by Jason Lee) covers several additional regulatory hormones that are not covered in earlier presentations in this set.

How does your immune system work? - Emma Bryce

This simple description of the immune system is meant as introduction to the topic, presented in an interesting and easy to understand manner. It describes different aspects of the immune system and how they operate. This is an absolutely excellent portrayal.

The inflammatory response

This presentation goes deeper into the immune system to explain how inflammatory responses are promoted, including ‘sterile inflammation’ and the role of cytokines in producing these actions. As inflammatory processes induced by environmental factors (e.g. stressful experiences) are important to the development of varied diseases, this video is a very important one.

What causes antibiotic resistance? - Kevin Wu

Antibiotics have been a boon to personkind saving us from all manner of nasty bacteria. However, because of their misuse and overuse this may be coming to an end as bacteria have become more resistant to the effects of antibiotics. As a result, infections could be eliminated readily in earlier years, might not only become ineffective, but might also cause harm. The next two video clips speak to this.


Microorganisms are all over our outsides, and they are plentiful on our insides, particularly within the gut. Microbes typically look gross, and reflexively we think of them as having bad functions, but they do lots of good things, too. This NPR produced video describes the microbiome in a very simple way, and the cartoon microbes look cute rather than scary. The video is meant for kids, but you can learn from it, too.

Immunological factors within the skin

The skin has multiple important functions besides keeping our insides in. This Nature Video clip indicates what the skin is made of and describes immune factors present in skin that protect us from foreign particles that are encountered all the time. Like the other videos from the Nature Video series, the graphics here are remarkable, and the lecture is first class.

Immunological factors within the gut

Some of the microbes in our food are essential for our well-being, but there are some that can be harmful. Our gut has numerous immune factors present to deal with these challenges. This Nature Video provides a terrific description of this process through astounding graphics.

Food for thought: How your belly controls your brain | Ruairi Robertson | TEDxFulbrightSantaMonica

A tremendously interesting description of how our gut influences our well-being and how this occurs. Numerous very good examples are provided as to how and when microbiota do what they do.

Your gut microbiome: The most important organ you’ve never heard of Erika Ebbel Angle | TEDxFargo

This video provides a basic description of how our microbiota and our well-being is affected by what we eat, antibiotic drugs and stressors that we encounter.

The microbes that live with us from cradle to grave

This excellent clip from Nature Videos describes changes in microbiota from prenatal development through to old age. It also explains the involvement of microbiota in disease processes.

Immunological factors within the lungs

Here you will get a mini-lecture concerning what your lungs comprise and how they work. Obviously, the oxygen inhaled with each breath you take is essential for survival, but with each breath there is a good chance that you are also inhaling some crumby stuff present in the air. Fortunately, there are immune factors present in the lungs that can deal with most challenges. However, there are limits to the effectiveness of our protective system. The lungs were not meant to deal with some challenges, such as long-term abuse by cigarette smoke, gasoline fumes and other toxicants, as you will see from this Nature Video. One more thing - - COVID-19 can badly affect a person’s lungs, and if their lungs were already damaged before infection, then they might be in considerable trouble.

Is that new, or did I just notice?

In this clip, prepared by NIHOD, we learn that certain diseases that we do not think much about, at least until they come out of hiding and affect vast numbers of people, can be more frequent that we naively had thought. In the past few decades our diagnostic methods have improved to the extent that we can determine not only who has an illness, but also who had previously been infected (even mildly). Importantly, these techniques can be used as surveillance methods to warn us about emerging problems.

Natural killer cells

Unlike other immune cells, natural killer (NK) cells are able to kill viruses and some cancer cells. It was thought they do not have a memory like T and B cells (as indicated in this video), but recent studies indicated that they may have some degree of memory capacity. This video, produced by Kyle Thornwaite, is very informative and simplifies things to just the right extent

Immunology wars: The battle with HIV

You might have wondered what has made HIV/AIDS as tough to deal with as it has been. This brief clip from Nature Videos will tell you what happens when HIV infection occurs.