Скачать с ютуб 💯 The Chemical Composition of Blood Explained with Examples. Watch this video to find out! в хорошем качестве

💯 The Chemical Composition of Blood Explained with Examples. Watch this video to find out!

📢 Receive Comprehensive Mathematics Practice Papers Weekly for FREE 😊 Click this link to get: ▶️▶️▶️ https://iitutor.com/email-list/ ◀️◀️◀️ Mammals have a closed circulatory system. This means all blood is circulated and recycled in the body. This is made up of the heart (a pump), the blood and the blood vessels (transport system). You have seen the importance of the temperature of the blood in maintaining a stable body temperature in an endotherm (such as a mammal). The blood has an important role in distributing heat throughout the body. The blood has a vital role in distributing other substances too. As the main transport system of the body, the watery liquid called blood transfers materials from where they are absorbed or produced to other places in the body where they are needed. The Blood Components and their Composition. These cells make up about 45% of the blood in humans. The rest of the blood is liquid called plasma (55%). These cells make up about 45% of the blood in humans. The rest of the blood is liquid called plasma (55%). The Blood Components. If you were to spin a tube of blood in an instrument called a centrifuge, the spinning would force the solid elements (cells and cell fragments) to the bottom of the tube, leaving the plasma floating on the top as a pale yellow liquid. Plasma is a sticky, yellow, slightly salty liquid that makes up 55% of the blood. It is made up of about 90% water plus various other substances carried in solution. Plasma contains salts carried as ions in solution, as well as large plasma proteins. These salts and proteins play a role in maintaining the pH of the blood. Many substances are transported in the plasma, and their amount in the plasma changes as the blood circulates. These include waste materials such as urea and carbon dioxide, products of digestion such as amino acids and sugars, and hormones. Red blood cells (erythrocytes) are disc-shaped and biconcave and are thinner at the centre than at the edges. Red blood cells contain the pigment haemoglobin. Their function is to transport respiratory gases, particularly oxygen (carried as oxyhaemoglobin), around the body. Some carbon dioxide is also carried (as carbaminohaemoglobin). Red blood cells remain in the blood for about 3 months and are then destroyed in the liver or the spleen. Every second, about 1 million old red blood cells are replaced by new ones. One millilitre of blood contains about 5 or 6 million red blood cells. White Blood Cells. There are several different types of white blood cells (leucocytes). There are between 4 000 and 12 000 in 1mL of human blood. Even though red blood cells are more abundant, white blood cells are much larger. White blood cells are the cells that help the body fight infection. There are a number of different types and sub-types of white blood cells which each have different roles to play. Two important types of white cells are phagocytes and lymphocytes. The Phagocytes (the Basophil, Neutrophil and Eosinophil white blood cells) surround and ingest bacteria, foreign bodies and dead cells, and these foreign substances at areas of infection or injury. Lymphocytes act specifically against foreign material. They make antibodies, which help the body’s defence against disease. Monocytes recognise and mark cells that are foreign to the body, to be destroyed by lymphocytes. Transport in multicellular animals is necessary to move nutrients and wastes around the body. This occurs in a watery medium, the blood.