Youssef Refaat - Curios Nerd

Kidneys are a sign of evolution. How? Kidneys are these 2 bean-shaped organs that lie in your posterior abdominal wall and are responsible for filtering waste products from your blood to your urine. They are in the abdominal region When we study the kidney during fetal development, you will be surprised by how humans and fish are related. In the fetus, you develop 3 pairs of kidneys instead of the 1 pair that we are familiar with. The 1st kidney to develop is called  pronephros  ( develops near the neck - yes you had kidney in your neck when you were fetus ), the second one is called  mesonephros (develops in the abdomen),  and the third pair is called  metanephros (develops in the pelvis.)  The pronephros and mesonephros degenerate and the metanephros is the only one that continues and it gives rise to your kidney. Here how they looked like. As you see, pronephros and mesonephros degenerate.  Metanephros  remains. Here is a zoomed-...

UPDATE 1 - VERSION IS AVAILABLE HERE! DON'T MISS THE NEW DETAILS ABOUT COVID 19   https://curiosnerd.blogspot.com/2020/04/updated-how-people-die-from-corona.html   UPDATE 2 - I HAVE UPLOADED THE DIAGNOSTICS PART COVID-19 Diagnostics As we know, the number of people dying from COVID 19 is increasing day after another. Firstly, we need to know that the infection itself may not kill you. You can get the infection and then it goes away from you like normal influenza, but why some people die from it? T his is called acute respiratory distress syndrome . You alveoli normally contain no fluid as in the below picture. They get filled with air then this air diffuses to the blood capillary below. This is called the blood air barrier The exact mechanism or cause is not completely understood. However, during inflammation, whether it is happening inside the lungs (due to the viral or bacterial infection) or in other organs, the triggering insult to the tissue usually results...

I wish I could tell parents that they are killing their kids with the type of diet they offer them. It became normal the kids eat tons of chocolates, pizzas, fried food, and burgers. It became a regular diet for rich kids. Let’s see why parents are killing their kids. The huge amount of chocolate and pizzas kids eat is very rich in carbohydrates (which are simply glucose.) Normally, when we exceed the amount of carbohydrates our body needs, they will be converted to fat and stored in our bodies. When we eat excess amounts of this food, we will have high levels of fat in our bodies, and, thus, high levels of LDL. LDL is a lipoprotein that is responsible for delivering fat to our tissue since fat can’t normally dissolve in our plasma. High levels of LDL are considered to be the main cause of atherosclerosis. These high LDL levels, when in excess, are deposited inside our blood vessels(the intima layer) initiating inflammation and causing blood vessels to become stiffened and become mo...

As a student doctor, I have seen many patients who had cancers growing in their bodies and don’t feel it and don’t have any symptoms until it is too late (until the tumor has metastasized to other organs) I have seen a patient who has lymphoma (a type of blood cancer) He didn’t feel anything; he literally had no symptoms, but one day he started to have some symptoms related to his respiratory system like cough, dyspnea, hemoptysis. When he did a chest x-ray, he was found to have massive pleural effusion (water on the lung) due to the tumor metastasized to his lung. He had an x-ray similar to that. Look at the left lung! Not only that but he also, when he was asked to do a CT scan on his abdomen, he was found to have the tumor metastasized to his liver. (Can you see these blackish areas? These are multiple tumor masses growing at his liver) I knew that this patient had a very bad prognosis and he most likely will pass away in a few months. It is very sad to know that. The...

https://www.youtube.com/watch?v=9sHR8VFpSR4 This is called  sudden cardiac death  or  cardiac arrest.  It happens with even athletes. I have seen many football players who die suddenly in the match. Sudden cardiac arrest (SCA) and sudden cardiac death (SCD) occur when the heart abruptly begins to beat in an abnormal or irregular rhythm (arrhythmia). Without organized electrical activity in the heart muscle, there is no consistent contraction of the  v entricles, which results in the heart's inability to generate an adequate  c ardiac output (forward pumping of blood from the heart to rest of the body). The most common type of arrhythmia is ventricular fibrillation. Here is how it looks like: The most common reason is  hypertrophic cardiomyopathy . This is a condition in which a portion of the heart becomes  t hickened without an obvious cause. This results in the heart being less able to pump blood effectively. This could be due to a gene...

I am a Christian, and I believe that the universe was created by God. No one really knows the exact absolute answers to your questions. In Stephen hawking’s book, brief answers to big questions, he answered these questions. His answers weren’t absolute, but this was according to what he thought might be right. He said that the universe didn’t need God to be created. If you go back when the whole universe was condensed in a single point, called the singularity, he said that in this way, this singularity behaves very differently from our daily experience. A cup of coffee must be created by someone. However, in the quantum world, things can exist and disappear randomly without the need to be created. It might seem to be counter-intuitive, but this is what the science believes to be true. Also, the big bang itself doesn’t need someone to initiate it. It just initiated itself. It had a complex explanation in his book but again, this is what science believes to be true. Moreover, he sai...

The soreness is perceived as a dull, aching pain in the affected muscle, often combined with tenderness and stiffness. The pain is typically felt only when the muscle is stretched, contracted or put under pressure, not when it is at rest. This tenderness, a characteristic symptom of DOMS, is also referred to as "muscular mechanical hyperalgesia". Although there is variance among exercises and individuals, the soreness usually increases in intensity in the first 24 hours after exercise. It peaks from 24 to 72 hours, then subsides and disappears up to seven days after exercise. The soreness is felt most strongly 24 to 72 hours after the exercise. It is thought to be caused by eccentric (lengthening) exercise, which causes small-scale damage (microtrauma) to the muscle fibers. So as we see there is some damage that happens due to vigorous exercise. How would our bodies respond to this? It induces a state of inflammation to help replace the damaged area. This is not consider...

From our knowledge about evolution, we know that it is based on natural selection, which means that better traits that are compatible with the environment continue, while other traits that are useless will go away. In this manner, every organism on this planet has evolved and will continue to evolve. Also, imagine the bacteria that infect you, these bugs can become resistant to the antibiotic you are taking due to some random mutations that occur in their DNA. The resistant bacteria continue to live and continue to infect you So, we can say that organisms are evolving. How can cancer be evolving as well? Well, malignant tumors have acquired some genetic changes that made these tumors survive in the human body causing more and more damage. The more genetic changes (mutations) acquired by the tumor, the more malignant it becomes and also harder to cure What are some examples of these changes? 1 . Rely on anaerobic glycolysis for energy. Explains why there is more lactic acid produc...

We have to be aware of the difference between oncogenes and proto-oncogenes. Proto-oncogenes are the normal, non-mutate genes that are responsible for driving the cell to divide. They act as the gas pedal of the cell. Functions of proto-oncogene protein products include synthesis of growth factors, growth factor receptors, signal transducers, and nuclear transcribers. Here is a table that shows different proto-oncogenes, their function, and the cancer you get if they are mutated They can get different types of mutations that include : 1. Point mutations (most common mutation; 2. Balanced translocations 3. Insertion of a viral genome (insertional mutagenesis). Disrupts normal chromosome structure and increases genetic dysregulation. 4. Other mutations, such as deletion, gene amplification (multiple copies of a gene), and overexpression (increased gene transcription resulting in the production of too much Mutations of proto-oncogenes cause sustained activity of the genes...

IBD is a complex disease which arises as a result of the interaction of environmental and genetic factors leading to immunological responses and inflammation in the intestine. This initiates an immune response against the gut mucosa that results in IBD (ulcerative colitis or crohn disease) In case of crohn disease, the inflammatory reaction in mediated by T helper 1 cells. While in ulcerative colitis it is initiated by T helper 2 cells. As I mentioned above, there is no specific cause to IBD. It is believed to be interactions between the environment, diet, and genetics. So, genetics play a rule in IBD. Also, if you have one of your relatives who had IBD, your chances of getting IBD increases up to 10 times, so I think genetics are important deciding factor. A genetic component to IBD has been recognized for over a century. Research that has contributed to understanding of the genetics include studies of ethnic groups (e.g., Ashkenazi Jews), familial clustering, epidemiological s...

Did you know that humans evolved from creatures that lived in the water once? But what is the evidence? I won’t go into boring details of how that happened but I will give very interesting evidence from your body! Ready?  Let’s start I want you to try to put your fingers in your neck as in the following image Do you feel the pulsation? Hopefully yes. This is your carotid artery. It is one of the arteries that supply the head and neck with oxygen, and here how it looks in real. Now let’s go back and see how this system in the picture above looked like when you were a fetus inside your mother! This system, during embryological life, is called the aortic arch. (THIS PHOTO ILLUSTRATES THE AORTIC ARCH SYSTEM FOR A FETUS) The aortic arches numbered from 1 to 6 (photos on the left) most of them disappear as you see and only a few of them stay to give rise to the carotid artery and other arteries in the neck (the photo on the right). So, we don’t ne...