Composition of Blood: Composition, Functions and Types

Introduction

The transfer of materials around the body requires the use of blood. It transports a wide range of chemicals, including gases, metabolites, nutrients, and hormones, and an exchange mechanism for human tissues. The exchange of O2 and CO2 from the lungs to the rest of the body is one of its most well-known functions. It also carries hormones from glands to receptors where they are needed. The liver and kidneys receive waste products. Additionally, nutrients are transported from the digestive tract to the tissues. Blood is a defender and regulator that has a part in inflammation and controlling pH and water levels.

The composition of blood classification includes plasma and formed elements, such as erythrocytes, leucocytes and platelets.

Body

What is blood?

Blood is a fluid that provides oxygen and nutrients to cells, while also transporting carbon dioxide and other waste products away from them. Blood is a transport liquid pumped to all areas of the body by the heart (or a similar structure), then returned to the heart to resume the process. Blood is a tissue as well as a fluid. It’s called tissue since it comprises comparable specialised cells that perform specific duties. The blood is fluid because these cells are suspended in a liquid matrix (Plasma). Because of the impact of an unfavourable environment on highly vulnerable cells, death will occur within minutes if blood flow is interrupted. However, blood is composed of many constituents that make up its composition, known as the composition of blood definition.

 The circulation, which transports blood through the organs that regulate the concentrations of its components, allows for the consistency of the blood’s composition. Blood transports carbon dioxide from the tissues to the lungs, where it is oxygenated. The kidneys remove excess water and dissolved waste materials. After absorption by the gastrointestinal tract, nutrient compounds derived from food reach the bloodstream. The endocrine system’s glands secrete hormones into the bloodstream, which carries them to the tissues where they exert their effects. Iron generated during the breakdown of old red cells is transferred by Plasma to areas where new red cells are formed and utilised. An effective regulating mechanism keeps each of the various components of the blood within applicable concentration limits.

Components of blood

In humans, blood is an opaque crimson liquid that flows freely but is denser and more viscous than water. Haemoglobin, a unique iron-containing protein, is responsible for its distinctive colour. When saturated with oxygen (oxyhemoglobin), haemoglobin brightens in colour and darkens when oxygen is withdrawn (deoxyhemoglobin). As a result, blood from a vein that has been partially deoxygenated is darker than blood from an artery that has been fully oxygenated. The red blood cells (erythrocytes) make up roughly 45 per cent of the blood volume, while the white blood cells (leukocytes) and platelets (thrombocytes) make up less than 1%. Plasma is a transparent, slightly sticky, yellowish liquid that makes up the fluid portion of the body. Plasma becomes temporarily turbid after a fatty meal. Blood is always fluid within the body, and turbulent flow ensures that cells and Plasma are mixed pretty evenly.

 Plasma

Plasma, or a liquid portion of the composition of the blood, is a complicated solution made up of more than 90% water. All tissues can maintain a normal hydration level because plasma water can freely interchange with that of body cells and other extracellular fluids. Every living cell requires water, the body’s most abundant element. Plasma’s primary solute is a diverse set of proteins that accounts for around 7% of its weight. The high protein content of Plasma distinguishes it from the extracellular fluid of tissues. Water tends to flow from other extracellular fluids to the Plasma due to the osmotic impact of plasma protein. Individual amino acids are liberated from polypeptide chains and absorbed when dietary protein is digested in the gastrointestinal tract.

 Amino acids are transported throughout the body via Plasma, where they are taken up by cells and organised in precise ways to make a variety of proteins. These plasma proteins are released into the bloodstream by the cells. The liver has a large amount of plasma protein.

 Blood Cells

 Red blood cells (erythrocytes), white blood cells (leucocytes), platelets (thrombocytes),plasma are the four major types of blood cells. White blood cells are made up of lymphocytes and phagocytic cells. Red blood cells absorb oxygen from the lungs and distribute it to the tissues; platelets help form blood clots; lymphocytes help with immunity, and phagocytic cells (granulocytes and monocytes) ingest and break down germs and foreign particles. The circulating blood acts as a conduit, transporting different types of cells to other parts of the body where they’re needed: red cells to tissues that need oxygen, platelets to damage sites, lymphocytes to infection sites, and phagocytic cells to microbial invasion and inflammatory sites.

Red blood cells (erythrocytes)

 Red blood cells are highly specialised and well-adapted to transport oxygen from the lungs to all body tissues. Red cells have a diameter of about 7.8 m (1 m = 0.000039 inches) and are shaped like biconcave disks with a large surface-to-volume ratio. When studied under a microscope in fresh blood, red cells appear as yellow-green discs with pale centres. They have no apparent interior features. The volume of packed red cells (hematocrit value) ranges between 42 and 54 percent of total volume in men and 37 to 47 per cent in women when blood is centrifuged to settle the cells; values are slightly lower in infants. Because the book of normal red blood cells is very uniform, the hematocrit value is mostly controlled by the number of red cells per unit of blood.

White Blood Cells (Leucocytes)

Unlike red blood cells, white blood cells (leucocytes) are nucleated and motile independently. They are highly differentiated for their particular roles and do not undergo cell division (mitosis) in the bloodstream, albeit some do. They participate in the body’s defence mechanisms and reparative activity as a whole. In normal blood, white cells per cubic millimetre range from 4,500 to 11,000 per cubic millimetre. During the day, there are fluctuations; lower levels are acquired during rest, and greater values are obtained during exercise. When you expend a lot of physical effort, the count can reach 20,000 per cubic millimetre. The majority of white cells are not in circulation, and those are in transit from one location to another. Their life as living cells is dependent on their ability to produce energy constantly. White blood cells are divided into Granular white blood cells (neutrophils, eosinophils, and basophils) that contains numerous granules in the cytoplasm, and Agranular white blood cells include monocytes, and lymphocytes (T cells and B cells) have few or no granules in the cytoplasm.

Platelets (thrombocytes)

Blood platelets are the smallest cells in the body, measuring between 2 and 4 millimetres in diameter. Although they are significantly more abundant (150,000 to 400,000 per cubic millimetre) than white cells, they take up a far lesser composition of blood volume due to their small size. They lack a nucleus and cannot divide (mitosis) like red cells, but they have a more complicated metabolism and internal structure than red cells. They seem spherical in new blood, but they have a proclivity to extrude hairlike threads from their membranes. They cling to one another, but not to read or white cells. Platelets include tiny granules that contain chemicals that help platelets promote clotting.

Conclusion

Physicians rely on laboratory analysis to get measurements of numerous compositions of the blood, information that is useful or required for disease detection and recognition. Haemoglobin includes a brightly coloured pigment that prevents a ray of light from passing through it. Blood is diluted, and the red blood cells (erythrocytes) are broken down to produce a clear red solution used to quantify haemoglobin content. A photoelectric device is used to quantify haemoglobin content by measuring the absorbance of transmitted light. Because the size and haemoglobin concentration of red cells might alter in disease, changes in the haemoglobin concentration of the blood are not always directly paralleled by changes in the red cell count and hematocrit value.