Blood - Wikipedia. Blood is a body fluid in humans and other animals that delivers necessary substances such as nutrients and oxygen to the cells and transports metabolic waste products away from those same cells. Plasma, which constitutes 5. Albumin is the main protein in plasma, and it functions to regulate the colloidal osmotic pressure of blood. The blood cells are mainly red blood cells (also called RBCs or erythrocytes), white blood cells (also called WBCs or leukocytes) and platelets (also called thrombocytes). The most abundant cells in vertebrate blood are red blood cells. These contain hemoglobin, an iron- containing protein, which facilitates oxygen transport by reversibly binding to this respiratory gas and greatly increasing its solubility in blood. In contrast, carbon dioxide is mostly transported extracellularly as bicarbonate ion transported in plasma. Vertebrate blood is bright red when its hemoglobin is oxygenated and dark red when it is deoxygenated. Some animals, such as crustaceans and mollusks, use hemocyanin to carry oxygen, instead of hemoglobin. Insects and some mollusks use a fluid called hemolymph instead of blood, the difference being that hemolymph is not contained in a closed circulatory system. In most insects, this . In my last newsletter, I wrote about how most people with sleep trouble think they have too much energy and simply can’t settle down. I also discussed that one of. Infection with a virus is a common cause of hepatitis. The five viruses primarily associated with hepatitis are named in the order of their discovery. Pain is an unpleasant feeling that is conveyed to the brain by sensory neurons. The discomfort signals actual or potential injury to the body. White blood cells help to resist infections and parasites. Platelets are important in the clotting of blood. Arthropods, using hemolymph, have hemocytes as part of their immune system. Blood is circulated around the body through blood vessels by the pumping action of the heart. In animals with lungs, arterial blood carries oxygen from inhaled air to the tissues of the body, and venous blood carries carbon dioxide, a waste product of metabolism produced by cells, from the tissues to the lungs to be exhaled. Medical terms related to blood often begin with hemo- or hemato- (also spelledhaemo- and haemato- ) from the Greek word . Contradictory statements here. Reduce your fat intake for a healthy liver, but eat all these fats for a healthy liver.?In terms of anatomy and histology, blood is considered a specialized form of connective tissue, given its origin in the bones and the presence of potential molecular fibers in the form of fibrinogen. Functions. These blood cells (which are also called corpuscles or . By volume, the red blood cells constitute about 4. Whole blood (plasma and cells) exhibits non- Newtonianfluid dynamics. If all human hemoglobin were free in the plasma rather than being contained in RBCs, the circulatory fluid would be too viscous for the cardiovascular system to function effectively. Human blood fractioned by centrifugation: Plasma (upper, yellow layer), buffy coat (middle, thin white layer) and erythrocyte layer (bottom, red layer) can be seen. Blood circulation: Red = oxygenated, blue = deoxygenated. Illustration depicting formed elements of blood. Two tubes of EDTA- anticoagulated blood. Left tube: after standing, the RBCs have settled at the bottom of the tube. Right tube: Freshly drawn blood. One microliter of blood contains: 4. Mature red blood cells lack a nucleus and organelles in mammals. The red blood cells (together with endothelial vessel cells and other cells) are also marked by glycoproteins that define the different blood types. The proportion of blood occupied by red blood cells is referred to as the hematocrit, and is normally about 4. The combined surface area of all red blood cells of the human body would be roughly 2,0. The cancer of leukocytes is called leukemia.
Fibrin from the coagulation cascade creates a mesh over the platelet plug. Constitution of normal blood. Parameter. Value. Hematocrit. 45 . The blood plasma volume totals of 2. It is essentially an aqueous solution containing 9. Plasma circulates dissolved nutrients, such as glucose, amino acids, and fatty acids (dissolved in the blood or bound to plasma proteins), and removes waste products, such as carbon dioxide, urea, and lactic acid. Other important components include: The term serum refers to plasma from which the clotting proteins have been removed. Most of the proteins remaining are albumin and immunoglobulins. H values. Blood p. H, partial pressure of oxygen (p. O2), partial pressure of carbon dioxide (p. CO2), and HCO3. An arterial blood gas test measures these. Plasma also circulates hormones transmitting their messages to various tissues. The list of normal reference ranges for various blood electrolytes is extensive. Blood in non- mammalian vertebrates. In non- mammalian vertebrates, however, there are some key differences. In humans, blood is pumped from the strong left ventricle of the heart through arteries to peripheral tissues and returns to the right atrium of the heart through veins. It then enters the right ventricle and is pumped through the pulmonary artery to the lungs and returns to the left atrium through the pulmonary veins. Blood then enters the left ventricle to be circulated again. Arterial blood carries oxygen from inhaled air to all of the cells of the body, and venous blood carries carbon dioxide, a waste product of metabolism by cells, to the lungs to be exhaled. However, one exception includes pulmonary arteries, which contain the most deoxygenated blood in the body, while the pulmonary veins contain oxygenated blood. Additional return flow may be generated by the movement of skeletal muscles, which can compress veins and push blood through the valves in veins toward the right atrium. The blood circulation was famously described by William Harvey in 1. During childhood, almost every human bone produces red blood cells; as adults, red blood cell production is limited to the larger bones: the bodies of the vertebrae, the breastbone (sternum), the ribcage, the pelvic bones, and the bones of the upper arms and legs. In addition, during childhood, the thymus gland, found in the mediastinum, is an important source of T lymphocytes. The liver also clears some proteins, lipids, and amino acids. The kidney actively secretes waste products into the urine. Oxygen transport. It is moved to the right in higher acidity (more dissolved carbon dioxide) and to the left in lower acidity (less dissolved carbon dioxide)About 9. Hgb. About 1. 5% is physically dissolved in the other blood liquids and not connected to Hgb. The hemoglobin molecule is the primary transporter of oxygen in mammals and many other species (for exceptions, see below). Hemoglobin has an oxygen binding capacity between 1. O2 per gram hemoglobin. In a healthy adult at rest, oxygen consumption is approximately 2. Increased oxygen consumption during sustained exercise reduces the oxygen saturation of venous blood, which can reach less than 1. Sustained hypoxia (oxygenation less than 9. Most of it (about 7. HCO. However, the CO2 bound to hemoglobin does not bind to the same site as oxygen. Instead, it combines with the N- terminal groups on the four globin chains. However, because of allosteric effects on the hemoglobin molecule, the binding of CO2 decreases the amount of oxygen that is bound for a given partial pressure of oxygen. The decreased binding to carbon dioxide in the blood due to increased oxygen levels is known as the Haldane effect, and is important in the transport of carbon dioxide from the tissues to the lungs. A rise in the partial pressure of CO2 or a lower p. H will cause offloading of oxygen from hemoglobin, which is known as the Bohr effect. Transport of hydrogen ions. Deoxyhemoglobin binds most of the hydrogen ions as it has a much greater affinity for more hydrogen than does oxyhemoglobin. Lymphatic system. Lymph is collected by a system of small lymphatic vessels and directed to the thoracic duct, which drains into the left subclavian vein where lymph rejoins the systemic blood circulation. Thermoregulation. Increasing blood flow to the surface (e. In contrast, when the external temperature is low, blood flow to the extremities and surface of the skin is reduced and to prevent heat loss and is circulated to the important organs of the body, preferentially. Rate of blood flow. Liver has the most abundant blood supply with approximate blood flow of 1. Kidney and Brain are the second and the third most supplied tissues, with 1. With kidney, adrenal gland and thyroid being the first, second and third most supplied tissues, respectively. Hemoglobin is the most common respiratory protein found in nature. Hemocyanin (blue) contains copper and is found in crustaceans and mollusks. It is thought that tunicates (sea squirts) might use vanabins (proteins containing vanadium) for respiratory pigment (bright- green, blue, or orange). In many invertebrates, these oxygen- carrying proteins are freely soluble in the blood; in vertebrates they are contained in specialized red blood cells, allowing for a higher concentration of respiratory pigments without increasing viscosity or damaging blood filtering organs like the kidneys. Giant tube worms have unusual hemoglobins that allow them to live in extraordinary environments. These hemoglobins also carry sulfides normally fatal in other animals. The coloring matter of blood (hemochrome) is largely due to the protein in the blood responsible for oxygen transport. Different groups of organisms use different proteins. Hemoglobin. Each molecule has four heme groups, and their interaction with various molecules alters the exact color. In vertebrates and other hemoglobin- using creatures, arterial blood and capillary blood are bright red, as oxygen imparts a strong red color to the heme group. Deoxygenated blood is a darker shade of red; this is present in veins, and can be seen during blood donation and when venous blood samples are taken. This is because the spectrum of light absorbed by hemoglobin differs between the oxygenated and deoxygenated states. In cyanide poisoning, the body cannot utilize oxygen, so the venous blood remains oxygenated, increasing the redness. There are some conditions affecting the heme groups present in hemoglobin that can make the skin appear blue—a symptom called cyanosis. If the heme is oxidized, methemoglobin, which is more brownish and cannot transport oxygen, is formed.
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