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  • Coronaviruses are a large family of viruses that are known to cause illness ranging from

  • the common cold to more severe diseases such as Middle East Respiratory Syndrome and Severe

  • Acute Respiratory Syndrome.

  • A novel coronavirus or the SARS CoV-2 is a new strain of coronavirus that has not been

  • previously identified in humans.

  • Coronavirus spreads from person to person through small air droplets.

  • Let us say a person with Covid-19 sneezes or exhales in front of you and you inhale

  • the viral particles coming out of his mouth.

  • The virus will then travel to the respiratory system.

  • Epithelial cells of your bronchi which are the main airways in your lungs, bronchiole

  • , the smaller passageways and most important the tiny air sacs at the end called the alveoli,

  • are the main targets.

  • Epithelial Cells are like the safety shields of the body, forming a covering of all the

  • body surfaces.

  • Unfortunately, they are the prime cellular targets of the novel coronavirus because of

  • the ACE-2 receptors which acts as the entry point.

  • The virus enters the cell using the spike protein on its surface that binds on a receptor

  • of the target cells.

  • Viruses have their own genetic code but they lack the machinery to copy their DNA.

  • So once inside like a Trojan horse, the virus then hijacks and transforms the cell into

  • a viral protein making factory.

  • The infected cells now serves the virus, synthesizing thousands and thousands of viral proteins

  • and assembling them, which are later released to enslave more cells and the process continues.

  • As the infected cells die, they release proteins called Cytokines and Damage-associated molecular

  • patterns.

  • Cytokines are like messenger proteins which acts as a signal to activate the immune system.

  • Macrophages, one of the most specialised cells of the immune system gets activated.

  • The macrophages then begin to secrete inflammatory cytokines which results into acute inflammation

  • inside the lung.

  • To be specific, they release, IL-1, IL-6, IL-8, TNF alpha and IFN gamma.

  • These cytokines migrate to the capillaries that line the alveoli.

  • Capillaries are the smallest blood vessels having an endothelial lining comprised of

  • endothelial cells.

  • The inflammatory cytokines increase the spaces between endothelial cells causing the capillaries

  • to leak.

  • As the fluid from the capillaries, starts accumulating inside the alveoli it becomes

  • difficult to breath.

  • This condition is called as Pneumonia.

  • The inability to get enough oxygen into the lungs raises the risk for developing hypoxemia,

  • where the blood oxygen level drops.

  • Also carbon dioxide will start accumulating inside which is called as respiratory acidosis.

  • As there is increase in the secretion of cytokines, it will induce the expression of a very important

  • molecule on the endothelial lining of blood vessels, called Vascular cell adhesion protein.

  • This acts as a magnet, it attracts neutrophils to the site of the injury, inside the alveoli.

  • Neutrophils are white blood cells whose main function is to kill and clean out the invading

  • pathogens.

  • They kill the virus by secreting proteases and reactive oxygen species, but it comes

  • with a price, which is the damage of the tissue itself.

  • The cycle will repeat leading to more inflammation and fluid accumulation.

  • Type 1 alveolar cells, which are involved in the process of gas exchange between the

  • alveoli and the blood, are damaged.

  • Type 2 alveolar cells, which are responsible for making the alveoli open, also gets damaged.

  • As a result alveoli will collapse which will further contribute to hypoxemia.

  • Additionally, the cytokines secreted by the macrophage will result in the microscopic

  • clotting of platelets and red blood cells called as microthrombus or the blood clot.

  • This will lead to more hypoxemia and complete lung failure.

  • As all these cytokines are secreted into the system circulation, they will have a very

  • bad effect causing abnormal blood clotting.

  • Blood clots starts forming throughout the body, blocking small blood vessels.

  • This is known as Disseminated intravascular coagulation, which is a serious disorder.

  • So it all began with a nasty cold and a viral pneumonia, from acute respiratory distress

  • syndrome it progressed to pulmonary embolism and then ultimately led to multi organ failure

  • due to abnormal blood clotting.

  • It isn't the virus that kills you, but the way your body reacts or fails to react against

  • the virus that causes death.

  • There is no 100 percent effective treatment as of yet, but we don't need to panic as

  • stress is going to help the virus more.

  • Remember 94 percent of the patients recover from it despite the type of symptoms they

  • show.

  • Thoroughly wash your hands with alcohol-based hand rubs or soaps, avoid any physical contact

  • and stay away from crowds and if you have any symptoms remain calm and contact your

  • health services.

  • It is really not the end of the world, we just need to break the chain.

  • Don't you all think our so body is amazing, constantly fighting off infection and disease?

  • Comment below your thoughts and subscribe for more such wonderful videos.

  • Thank you for watching, Stay happy Stay Curious.

Coronaviruses are a large family of viruses that are known to cause illness ranging from


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How Does Coronavirus Affect Our Body | COVID 19 Explained

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    Jost Lin に公開 2021 年 05 月 23 日