Bring Up Blood—How our oxygen gets carried throughout our body

There are not many things we need to do to survive, but there is one action, in particular, that is critical for life. Luckily for us, most of us do it unconsciously, and that is breathing. When I say breathing, I am not only talking about lungs, bronchi, alveoli and passive gas diffusion. Even though those structures and actions are essential and play a large part in respiration, they are responsible for ventilation only. However, with ventilation alone, we cannot sustain our body in its entirety. To keep each and every one of our limbs intact, we need to bring all of this oxygen we inhale further from the lungs and closer to our limbs. And that’s where the blood comes into play, and that part is called perfusion. Yet, blood does not only serve to feed the rest of our bodies with oxygen; it has way more responsibilities. It’s basically our life essence. 

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So, our blood is actually way more than a reddish gooey liquid that leaks out of our skin when we injure ourselves. It’s indeed packed with many elements that are, of course, accountable for respiration but also protection, nourishment and waste removal. First of all, when we talk about blood, it’s practically impossible not to talk about our red blood cells; since those cells give human blood its most observable characteristic, or more precisely, its famous crimson colouration. Interestingly, not all animals have red blood. In some lizards, blood can be lime green; in some octopuses, blue; and in some fishes, virtually colourless. The reason why our blood shows that colouration is thanks to some protein called hemoglobin. It is precisely this protein that gives colour to our red blood cells, and since red blood cells outnumber all other elements, our blood consequently takes that crimson hue. Here, one might think that hemoglobin only serves as a blood pigment, but it does not. 

Hemoglobin is actually the protein in charge of carrying oxygen to our entire body. Its name comes from the presence of four heme groups, forming a tetramer. Each heme group contains one iron atom that can bind one oxygen molecule. So all hemoglobins can carry throughout the body four oxygen molecules each. Still, the heme groups are not only in charge of ferrying oxygen throughout our body, but it is also responsible for clearing part of the carbon dioxide by transporting it to the lungs. The binding of carbon dioxide to hemoglobin produces carbaminohemoglobin responsible for almost a quarter of carbon dioxide elimination. Yet, hemoglobin is not the only protein capable of carrying oxygen. There is also hemocyanin which can be found in some invertebrates instead of hemoglobin. 

The particularity of this molecule is that it contains copper instead of iron, giving this protein a blue colour. And this is the reason why some octopuses have blue blood. As for green blood, it is not caused by the absence of hemoglobin; nor the presence of another (green-pigmented) oxygen-binding protein. It is merely the result of red blood cells decay. When the hemoglobin-rich red blood cells break down, they leave behind a protein called biliverdin, which -you may get from its name- possess a green pigmentation. Even humans produce biliverdin, but it is highly toxic and assuredly deadly to us. So, we remove it like crazy, leaving our blood with mainly red pigments. However, some lizards can tolerate incredible amounts of this protein that can even supplant red blood cells concentration. The more abundant presence of biliverdin leaves the blood with a lime green colour. 

As for some fishes, most specifically cold water fishes, their blood does not bear any colour and is usually completely transparent. In this case, the culprits for the colourlessness are the red blood cells, or more precisely, its lack. Under cold temperatures, hemoglobin-rich blood can get so thick that it can jeopardize respiration entirely and can actually be more of an impediment than an advantage. The use of cold ocean water directly as an oxygen source is definitely a smart choice since it contains more oxygen than regular sourced water. So rich, in fact, that using red blood cells to carry it is overkill. Water merely gets incorporated directly into the blood that carries its oxygen throughout the body.

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As I said previously, there are way more components in the blood than only the red blood cells, precisely three more: platelets, white blood cells and plasma. Platelets are in charge of forming blood clots whenever an injury occurs. In such circumstances, it is of the utmost importance that the blood coagulates to stop any internal or external hemorrhages from forming. Uncontrolled hemorrhages can lead to organ failures, seizures, coma, and eventually death. And as for white blood cells, they are also vital players. Without them, our immune systems would be compromised. They are our first line of defence against potential pathogens and chemicals. They can recognize a vast array of pathogens and chemicals and signal their presence to the body. It is the first step that leads down to an enormous chain reaction. And if you think that white blood cells are marvellous, wait for plasma. 

As soon as I turned 18, I started donating blood during each blood drive organized by my school. I felt that it was a particularly satisfying and easy way to give back to my community. However, once I had my first tattoo done, it got particularly more complicated to donate blood. So after six donations, I entered a period when I didn’t give out blood and that lasted for about six years. Three years ago, I got a call from a plasma center; they were recruiting. Plasma seemed like a compelling option, and it was also more convenient as this center was permanently based. Yet, even though I knew what plasma was, I realized that I didn’t entirely understand what it was. Thanks to my firsthand encounter with plasma, I can now enjoy its importance more closely than ever. Plasma is what holds all the blood proteins and their other components in suspension. In plasma, we can find some more proteins like globulin, albumin and fibrinogen. Globulin helps fighting infection, liver function and forming blood clots. Albumin is there to keep water from leaking out of our blood and transport things like hormones, enzymes and vitamins in our body. Fibrinogen is a clotting factor. Plasma can also carry hormones, glucose, electrolytes, carbon dioxide and oxygen.  

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Plasma is indispensable for immunocompromised patients as it helps them get some precious antibodies. For these patients especially, blood transfer can be harmful as it may contain certain viruses, like cytomegalovirus, that can be harmless in healthy patients but, for them, can cause severe disease. Plasma can also be needed by patients with severe burns or blood disorders. Fortunately, plasma donations are even more convenient to make than blood donations, which take two weeks in between each of them instead of eight. This rapidity is made possible by its extraction method. Whereas each blood donation requires us to form back every component of blood: platelets, white blood cells, red blood cells and plasma, plasma donation only requires us to form back plasma. Even though during plasma donation, we also extract blood from our veins, only plasma is collected. The rest is immediately returned to the body. Plasma can be separated from other blood constituents easily using a centrifuge. Once separated, everything that is not plasma is brought back into a solution and returned to the donor. 

However, whenever the situation arises where a dearest one might need blood, we may feel compelled to give them ours, but it’s probably a bad idea. If blood types do not match, we may cause them to develop some deadly clotting. Blood types are actually a result of two things: antigens and rhesus factor, and together can create up to 8 different blood groups. There are two possible antigens, A and B, and we indicate O in the absence of both antigens. The rhesus factor is a protein that can be present on the surface of our red blood cells. When the protein is present, we say that our blood is positive and negative when the protein is absent. In my case, I am B-positive which is the same as my fiancée. It is pretty weird as the Canadian prevalence of this blood type is only 7.6%. It would have been much more likely if our blood type were A-positive (36%) or 0-positive (39%). Yet, the rarest blood type remains AB-negative with only 0.5% of the population. It means that statistically speaking, only one person out of a group of 200 people may be AB-negative. Also, O-negative individuals are considered universal donors as they may give their blood to anyone and AB-positive universal receiver as they can obtain the blood of virtually anyone. Now, what blood type are you?

I thank you infinitely for reading this post and if you would like to know more about the mysteries that surround us, please join my subscription list to keep up with my newest content. If you have any questions, please add them to the comment section and I’ll make sure to answer them as soon as humanly possible.

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Bring Up Breathing—How We Get This Precious Oxygen in Our Blood

These last few days, I kept reading about the importance of staying active. Magazines and newspapers keep warning us over and over again about the danger of living a sedentary life. To avoid that constant threat, we are often not required to do much intense physical activity; we only need to move. When done regularly, yoga is one of those exercises that allow your body to remain at work. Still, its benefits extend far beyond its evident efficacy in keeping us toned. Yoga requires that its followers bring their consciousness back to their breathing. By inhaling and exhaling mindfully, they can check in and adjust their breathing rhythm if need be. When done purposefully and adequately, yoga can allow us to maximize oxygen absorption. However, this process is not so transparent for all of us, so let’s dive in even further.

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Breathing happens and, most of the time, we do not even realize it. It is one of the few mechanisms performed both consciously and unconsciously. Thus we often are driven to ignore that it is even there in the first place. Breathing is always present, always waiting to surface back into our consciousness. Possessing two different methods of regulation is a clear indication that both hold necessary functions for our survival. However, before we can attempt to explain them, we must first describe the fundamentals of breathing.

Breathing, also called ventilation, is a process that enables the exchange of carbon dioxide, produced by our metabolism, with oxygen readily available in the air. Although our atmosphere is composed mainly of nitrogen (78%), there is still a vast amount of oxygen (21%). To allow the transfer of this oxygen to our blood, we must first inhale. When I breathe, I often let air in through my mouth since my nose is frequently blocked. Even though both these orifices are good options to draw in air, some say that breathing through the nose is preferable. It seems that the nose with its filtration power can serve as the first line of defence against encountered pathogens.

Then, the oxygen makes its way to the lungs, where its transfer to the blood will occur via passive diffusion. Passive diffusion only means that the gas will move towards the lowest concentration sites without any help. In other words, the oxygen will move from our lungs to the blood. Not dissimilar to swimming in a river following the same direction as the current. The carbon dioxide will simultaneously be ejected from the blood into our lungs once again by passive diffusion.

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Our respiratory system has a fascinating structure that is reminiscent of an upside-down tree. Starting with the larynx (or the voice box) that forms the foot of the tree, the trachea would then be its trunk. The branches would be the bronchi and the leaves, the alveoli. However, there is one last structure that this analogy does not encompass, the pharynx. This organ serves to deliver food to the oesophagus and air to the larynx. The larynx will prevent food from entering the lungs. A little bit like a second nose, the trachea will purify, warm up and humidify the air before it reaches the lungs.

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The air will then get directed to the bronchi playing similar roles as mentioned for both the nose and the trachea. Moreover, its principal function is to guide the air to the alveoli. In the alveoli is where the gas exchange by passive diffusion will happen. Together, all these elements form a simplified image of the respiratory system. If we want to go deeper into the subject, we must talk about the ciliated cells scattered all around the nasal cavity (inside the nose), the trachea and the bronchi. Those ciliated cells, along with the mucus, are the ones that are responsible for filtering, warming up and humidifying the air. They accomplish this feat by directing the mucus, produced by some specialized tissue of the nasal cavity, towards the stomach. Once in the stomach, it is digested by gastric acid along with any potential pathogens.

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So if you ever wondered what was responsible for causing our runny nose during cold weather, the answer would be our ciliated cells. The chilling temperature slows down the speed at which the ciliated cells are working, thus causing a surplus of mucus in our nasal cavity. This event is then even further amplified by the water in the air we exhale. This gasified water tends to condensate in our nostrils at low temperatures forming water droplets.

The oxygen absorbed through the lungs will go to the red blood cells that were once carrying carbon dioxides. The exchange is a very lucrative business as it allows us to remove nearly 70% of our waste products while collecting a phenomenal amount of oxygen. All things considered, the efficacy of this system depends very strongly on internal cues. Physiological messengers, like hormones, or signals can alter the speed and the volume of our breathing. This modulation is the one to blame for the huffing and puffing we do after climbing up a steep hill. I just went for a nice walk this afternoon, and I have unfortunately come to realize that my cardiovascular system is no longer as efficient as it once was. Anyhow, my walk, or any physical activities for the matter, recruits muscles. To activate those muscles produces a lot of waste, like carbon dioxide for one.

When carbon dioxide accumulates in our body, it creates acid. Chemoreceptors then perceive this change alerting our respiratory system to work harder. We need to expel this gas while recruiting more oxygen, as we require oxygen for energy (ATP) production. But physical activities are not the only elements that can alter your breathing; anxiety can do that too. This effect is the result of stress hormones, catecholamines and corticosteroids. The former will produce more rapid breathing to adapt to the sudden requirement for energy supply. The latter will do the opposite; slow down the breathing while also making it more shallow.

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So when I catch myself stuck in a sudden wave of anxiety, I try to remember to breathe deeply (also called diaphragmatic breathing). Doing this exercise allows our breathing to come back to its regular rhythm by compressing the diaphragm. Squeezing the diaphragm leads to the activation of the parasympathetic system, causing an effect of general relaxation. The diaphragm is a muscle confined under the lungs and is also the one engaged in our sporadic hiccups. The hiccups are a product of the diaphragm contracting out of rhythm. The closing of the larynx and the vocal cords follow each spasm, which can cause the sounds we may hear. The most plausible role of the hiccups is to create a sharp intake of air in the lungs in between two breaths. This extra effort draws in more air than regular breathing.

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There are two main strategies to stop the course of hiccups. Either putting cold items in your mouth (like gargling cold water or sucking on an ice cube) or increasing the level of carbon dioxide inhaled (breathing from a bag or holding our breath). I prefer taking a deep breath and holding it in. It works every time. What more about breathing can I say? Breathing in itself might be easy, but controlling it is another thing. If you don’t pay enough attention to it, it will positively fall into its default mechanism of autonomous functioning, and you might not like the outcome. As a word of advice, a regular breathing check-in cannot hurt, and you should probably do it as often as you can afford.

I thank you infinitely for reading this post and if you would like to know more about the mysteries that surround us, please join my subscription list to keep up with my newest content. If you have any questions, please add them to the comment section and I’ll make sure to answer as soon as humanly possible.

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Bring Up Biophilia—What makes us particularly attracted to nature

No one can dismiss the amazing feeling we get after spending some time in nature. We instantly feel relaxed and reinvigorated. Some might attribute this effect to time spent far away from work, and even though they could be correct, it is not the whole picture. Biophilia is a relatively new concept that brought the…

Bring Up Blood—How our oxygen gets carried throughout our body

Good evening my dearest followers, Please, take a moment to enjoy this excerpt for my newest post (Bring Up Blood). We could most certainly not live without blood. It is absolutely essential for the survival of our most distant limbs and organs. Even though almost all of our respiration is thanks to our respiratory organs,…