14: Human Transport Part 1 (IGCSE/GCSE)

[Music] Hello and welcome to Cesset So, this is a Biology revision podcast. Aim to help you with your GCSE Biology revision. Each episode focuses on a different biological topic and in this episode we will be looking at the topic, Human Transport Part 1. By the end of this episode you should be able to describe the components of blood, explain the role of phagocytes and lymphocytes in immunity, and explain how vaccinations work to help prevent the development of infectious diseases. So, without further ado, let's get into it. [Music] Most animals have a circulatory system which is responsible for transporting blood around the body. Blood is an interesting fluid that is made up of four key components. Plasma, red blood cells, white blood cells, and platelets. Each of these components have their own function. Plasma. This is a store-colored fluid. The plasma transports the other components of the blood and many other materials such as digested food like amino acids and glucose, carbon dioxide produced from aspiring cells, urea, a waste product or so produced, hormones released from glands, and heat energy released from aspiring tissues. The second component, red blood cells, are responsible for transport in oxygen around the body. The cell is by a concave in shape to provide a large surface area so more oxygen can be carried. They also contain hemoglobin, which is a protein that binds to oxygen, and they are small and flexible so that they can fit into small capillaries. White blood cells. White blood cells are responsible for providing defense against foreign bodies and pathogens that have entered the body, and finally platelets. These are small fragments of cells that have a role in blood clotting and scab formation which prevents the loss of blood. Okay, well, it's time for our first pit stop. [Music] In this pit stop, you have to identify which component of blood each statement describes. Number one, cells are suspended in a watery fluid that transports them around the body. Number two, if you cut yourself, a scab is formed to prevent blood loss and the entry of pathogens. And finally, number three, hemoglobin is a protein that binds with oxygen. Okay, well, pause the podcast, think about the answers to those questions, and we'll be back with the correct answers in three, two, and one. So you had to identify which component of blood was being described in each of those statements. This statement describes a component plasma. This describes platelets and then finally, number three, hemoglobin is a protein that binds with oxygen. The statement helps to describe the red blood cells. Okay, well, if you got those answers correct, great job and now we're going to move on into the next segment. [Music] The human body is a remarkable structure. Not only is it designed to help us live, it also contains structures to make sure we can live safely. The skin is the first line of defense against anything bad. Sometimes though, foreign bodies and pathogens are able to bypass the skin and enter the body. This is when white blood cells take over as the next line of defense. Although there are many examples of white blood cells, we will just focus on two main examples. The first being phagocytes. These are large in structure and have a low to shape nucleus. They carry out the process known as phagocytosis. This is when a phagocytes detects a pathogen and engulfs it. Digestive enzymes are released to break down and kill the pathogen. The second type of white blood cells are known as lymphocytes. These are also large in structure and contain a large round nucleus that takes up most of the cytoplasm. When pathogens enter the body, they contain antigens on their cell surface. Antigens have a specific shape. Lymphocytes release antibodies, which are proteins. Each lymphocyte is responsible for releasing one type of antibody, which is complementary in shape to the pathogens' antigen. Antibodies will mark the pathogen for other white blood cells to destroy it. Okay, well it's time for our second pit stop. In this pit stop, you have to identify whether each statement is a description of a lymphocyte or a phagocytes. Number one, this cell releases antibodies that mark the pathogen as foreign. Number two, this cell engulfs the pathogen and releases digestive enzymes to destroy it. And finally, number three, this cell has a lobed nucleus. Okay, well, pause the podcast, think about those answers and we'll be back with the correct answers in three, two, and one. So you had to identify whether each statement is a description of a lymphocyte or a phagocytes. So number one, releases antibodies that mark the pathogen as foreign. This is a lymphocyte. Number two, engulfs the pathogen and releases digestive enzymes to destroy it. This is a phagocytes. And then finally, number three, has a lobed nucleus. This again describes a phagocytes. Okay, well if you got those answers correct, great job. And now we're going to move on into the final segment. There are many occasions when scientists know the shape of the antigen and intern the antibody that binds to it. This is very useful when creating vaccinations. Vaccinations are important as they provide protection against infectious diseases. If these go untreated, they can have severe consequences. With a vaccination, a person will receive a harmless or a weakened form of the pathogen. Once in the bloodstream, some specific lymphocytes will recognize their antigens on the surface of the pathogen. This will stimulate an immune response, which includes the lymphocyte releasing more of that specific antibody and the circulation of specific memory cells. This provides immunity for the future in case the same pathogen, but this time the live version enters the body. Okay, well it's time for our final pit stop. These are the end of episode summary questions, so get a note pad, book or fold so that you can write down your answers. Question number one, why don't you suffer from the symptoms of a pathogen after being vaccinated? Question number two, what happens in an immune response? And then finally question number three, what is the function of the antibodies? Okay, well, pause the podcast, give yourself a chance to write down those answers, and we'll be back with the correct answers in free two and one. So you had to answer the following questions, number one. Why don't you suffer from the symptoms of a pathogen after being vaccinated? The correct answer for this is because the pathogen in the vaccine is a weakened or harmless form. The correct answer for this, the lymphocyte cells will produce the complimentary antibody in excess, more memory cells will be produced and are circulated in the bloodstream. The correct answer for this, they attach to the pathogen by binding with the antigens and flags up the pathogen as a farming body, so it can be destroyed by a series of processes, such as phagocytosis. Okay, well if you got those answers correct, awesome job and now we're going to go into the close in segment. So there you have it, human transport part one in a net shell. Remember these episodes are here for you to listen to so take full advantage of them. Be sure to follow me on my social platforms at SSASOS on Instagram for daily biology updates and subscribe to my podcast channel which could be found on most streaming platforms. Join me again for the next episode where I'll be reviewing the topic human transport part two. Why? Because SSA SSA.