File Name: blood composition and function .zip
Identify the primary functions of blood, its fluid and cellular components, and its characteristics. Recall that blood is a connective tissue. Like all connective tissues, it is made up of cellular elements and an extracellular matrix. The cellular elements—referred to as the formed elements —include red blood cells RBCs , white blood cells WBCs , and cell fragments called platelets. The extracellular matrix, called plasma , makes blood unique among connective tissues because it is fluid.
1. Composition of Blood and its Functions
Blood functions and composition pdf. Upcoming SlideShare. Like this document? Why not share! Embed Size px. Start on. Show related SlideShares at end. WordPress Shortcode. Bioinformatics Follow. Published in: Education. Full Name Comment goes here. Are you sure you want to Yes No. Suresh Babu.
Bimal Mondal. Kavisha Kavisha. No Downloads. Views Total views. Actions Shares. No notes for slide. Blood functions and composition pdf 1. Females have around litres, while males have around litres. This difference is mainly due to the differences in body size between men and women.
Its mean temperature is 38 degrees Celcius. Whole blood is about 4. This viscosity is vital to the function of blood because if blood flows too easily or with too much resistance, it can strain the heart and lead to severe cardiovascular problems. Blood in the arteries is a brighter red than blood in the veins because of the higher levels of oxygen found in the arteries.
An artificial substitute for human blood has not been found. Functions of blood Blood has three main functions: transport, protection and regulation. Transport Blood transports the following substances: Gases, namely oxygen O and carbon dioxide CO , between the lungs and rest of the body Nutrients from the digestive tract and storage sites to the rest of the body Waste products to be detoxified or removed by the liver and kidneys Hormones from the glands in which they are produced to their target cells Heat to the skin so as to help regulate body temperature Protection Blood has several roles in inflammation: Leukocytes, or white blood cells, destroy invading microorganisms and cancer cells Antibodies and other proteins destroy pathogenic substances Platelet factors initiate blood clotting and help minimise blood loss Regulation Blood helps regulate: pH by interacting with acids and bases Water balance by transferring water to and from tissues Composition of blood Blood is classified as a connective tissue and consists of two main components: 1.
Plasma, which is a clear extracellular fluid 2. Formed elements, which are made up of the blood cells and platelets The formed elements are so named because they are enclosed in a plasma membrane and have a definite structure and shape.
All formed elements are cells except for the platelets, which are tiny fragments of bone marrow cells. Leukocytes, also known as white blood cells WBCs Platelets Information on re-publishing of our images Leukocytes are further classified into two subcategories called granulocytes which consist of neutrophils, eosinophils and basophils; and agranulocytes which consist of lymphocytes and monocytes.
The formed elements can be separated from plasma by centrifuge, where a blood sample is spun for a few minutes in a tube to separate its components according to their densities. This volume is known as the haematocrit. WBCs and platelets form a narrow cream-coloured coat known as the buffy coat immediately above the RBCs. Blood plasma Blood plasma is a mixture of proteins, enzymes, nutrients, wastes, hormones and gases.
The specific composition and function of its components are as follows: Proteins These are the most abundant substance in plasma by weight and play a part in a variety of roles including clotting, defence and transport. Collectively, they serve several functions: They are an important reserve supply of amino acids for cell nutrition. Cells called macrophages in the liver, gut, spleen, lungs and lymphatic tissue can break down plasma proteins so as to release their amino acids.
These amino acids are used by other cells to synthesise new products. Plasma proteins also serve as carriers for other molecules. Many types of small molecules bind to specific plasma proteins and are transported from the organs that absorb these proteins to other tissues for utilisation.
The proteins also help to keep the blood slightly basic at a stable pH. Plasma proteins govern the distribution of water between the blood and tissue fluid by producing what is known as a colloid osmotic pressure.
There are three major categories of plasma proteins, and each individual type of proteins has its own specific properties and functions in addition to their overall collective role: 1. Albumins, which are the smallest and most abundant plasma proteins.
Reductions in plasma albumin content can result in a loss of fluid from the blood and a gain of fluid in the interstitial space space within the tissue , which may occur in nutritional, liver and kidney disease. Albumin also helps many substances dissolve in the plasma by binding to them, hence playing an important role in plasma transport of substances such as drugs, hormones and fatty acids.
Globulins, which can be subdivided into three classes from smallest to largest in molecular weight into alpha, beta and gamma globulins. The globulins include high density lipoproteins HDL , an alpha-1 globulin, and low density lipoproteins LDL , a beta-1 globulin.
HDL functions in lipid transport carrying fats to cells for use in energy metabolism, membrane reconstruction and hormone function. HDLs also appear to prevent cholesterol from invading and settling in the walls of arteries. LDL carries cholesterol and fats to tissues for use in manufacturing steroid hormones and building cell membranes, but it also favours the deposition of cholesterol in arterial walls and thus appears to play a role in disease of the blood vessels and heart.
HDL and LDL therefore play important parts in the regulation of cholesterol and hence have a large impact on cardiovascular disease. Fibrinogen, which is a soluble precursor of a sticky protein called fibrin, which forms the framework of blood clot. Fibrin plays a key role in coagulation of blood, which is discussed later in this article under Platelets.
Amino acids These are formed from the break down of tissue proteins or from the digestion of digested proteins. Being toxic end products of the break down of substances in the body, these are usually cleared from the bloodstream and are excreted by the kidneys at a rate that balances their production. Nutrients Those absorbed by the digestive tract are transported in the blood plasma. These include glucose, amino acids, fats, cholesterol, phospholipids, vitamins and minerals.
Gases Some oxygen and carbon dioxide are transported by plasma. Plasma also contains a substantial amount of dissolved nitrogen. Red blood cells Red blood cells RBCs , also known as erythrocytes, have two main functions: 1. To pick up oxygen from the lungs and deliver it to tissues elsewhere 2. To pick up carbon dioxide from other tissues and unload it in the lungs An erythrocyte is a disc-shaped cell with a thick rim and a thin sunken centre.
On its inner surface are two proteins called spectrin and actin that give the membrane resilience and durability. This allows the RBCs to stretch, bend and fold as they squeeze through small blood vessels, and to spring back to their original shape as they pass through larger vessels.
RBCs are incapable of aerobic respiration, preventing them from consuming the oxygen they transport because they lose nearly all their inner cellular components during maturation. The inner cellular components lost include their mitochondria, which normally provide energy to a cell, and their nucleus, which contains the genetic material of the cell and enable it to repair itself.
The lack of a nucleus means that RBCs are unable to repair themselves. However, the resulting biconcave shape is that the cell has a greater ratio of surface area to volume, enabling O and CO to diffuse quickly to and from Hb.
Haemoglobin carries most of the oxygen and some of the carbon dioxide transported by the blood. Circulating erythrocytes live for about days.
As a RBC ages, its membrane grows increasingly fragile. Without key organelles such as a nucleus or ribosomes, RBCs cannot repair themselves. Many RBCs die in the spleen, where they become trapped in narrow channels, broken up and destroyed. Haemolysis refers to the rupture of RBCs, where haemoglobin is released leaving empty plasma membranes which are easily digested by cells known as macrophages in the liver and spleen. The Hb is then further broken down into its different components and either recycled in the body for further use or disposed of.
White blood cells White blood cells WBCs are also known as leukocytes. They can be divided into granulocytes and agranulocytes. The former have cytoplasms that contain organelles that appear as coloured granules through light microscopy, hence their name. Granulocytes consist of neutrophils, eosinophils and basophils. In contrast, agranulocytes do not contain granules.
They consist of lymphocytes and monocytes. Granulocytes 1. Neutrophils: These contain very fine cytoplasmic granules that can be seen under a light microscope.
Components of blood
Blood is made of of several components, including red blood cells, white blood cells, platelets, and the plasma, which contains coagulation factors and serum. Blood helps maintain homeostasis by stabilizing pH, temperature, osmotic pressure, and by eliminating excess heat. Blood supports growth by distributing nutrients and hormones, and by removing waste. These cells deliver oxygen to the cells and remove carbon dioxide. Blood plays a protective role by transporting clotting factors and platelets to prevent blood loss after injury. These cells—including neutrophils, monocytes, lymphocytes, eosinophils, and basophils—are involved in the immune response.
When a sample of blood is spun in a centrifuge , the cells and cell fragments are separated from the liquid intercellular matrix. Because the formed elements are heavier than the liquid matrix, they are packed in the bottom of the tube by the centrifugal force. The light yellow colored liquid on the top is the plasma , which accounts for about 55 percent of the blood volume and red blood cells is called the hematocrit ,or packed cell volume PCV. The white blood cells and platelets form a thin white layer, called the " buffy coat ", between plasma and red blood cells. The watery fluid portion of blood 90 percent water in which the corpuscular elements are suspended.
- Blood is a viscous fluid formed of cellular element suspended in plasma. cells), and Platelets. - Plasma is a viscous, translucent, yellowish fluid composed of water (90%), proteins (7%), organic salts (1%), and organic compound (2%) such as amino acids, lipids, and vitamins.
Find GPs in Australia. The formed elements are so named because they are enclosed in a plasma membrane and have a definite structure and shape. All formed elements are cells except for the platelets, which are tiny fragments of bone marrow cells. Leukocytes are further classified into two subcategories called granulocytes which consist of neutrophils, eosinophils and basophils; and agranulocytes which consist of lymphocytes and monocytes.