The Circulatory System: An Amazing Circuit That Keeps Our Bodies Going
A red blood cell (RBC) count is typically ordered as part of a complete blood count (CBC) and may be used as part of a health checkup to screen for a variety of conditions. This test may also be used to help diagnose and/or monitor a number of diseases that affect the production or lifespan of red blood cells. Red blood cells at work. Hemoglobin is the protein inside red blood cells. It carries oxygen. Red blood cells also remove carbon dioxide from your body, bringing it to the lungs for you to exhale. Red blood cells are made in the bone marrow. They typically live for about days, and then they die. Nutrition and red blood .
The red blood cells are highly specialized, well adapted how to have healthy black hair their primary function of transporting oxygen from the lungs to all of the body tissues.
Red cells are approximately 7. When fresh blood is examined with the microscope, red cells appear to be yellow-green disks with pale centres containing no visible internal structures. When blood is centrifuged to cause the cells to settle, the volume of packed red cells hematocrit value ranges between 42 and 54 percent of total volume in men and between 37 and 47 percent in women; values are somewhat lower in children. Normal red blood cells are fairly uniform in volume, so that the hematocrit value is determined largely by the number of red cells per unit of blood.
The normal red cell count ranges between four million and six million per cubic millimetre. The red blood cell is enclosed in a thin membrane that is composed of chemically complex lipids, proteins, and carbohydrates in a highly organized structure. Extraordinary distortion of the red cell occurs in its passage through minute blood vessels, many of which have a diameter less than that of the red cell.
When the deforming stress is removed, the cell springs back to its original shape. The red cell readily tolerates bending and folding, but, if appreciable stretching of the membrane occurs, the cell is damaged or destroyed. The membrane is freely permeable to wateroxygen, carbon dioxideglucoseureaand certain other substances, but it is impermeable to hemoglobin. Within the cell the major cation is potassium; in contrast, in plasma and how to make a fedora hat out of fabric fluids the major cation is sodium.
A pumping mechanism, driven by enzymes within the red cell, maintains its sodium and potassium concentrations. Red cells are subject to osmotic effects. When they are suspended in very dilute hypotonic solutions of sodium chloridered cells take in water, which causes them to increase in volume and to become more spheroid; in concentrated salt solutions they lose water and shrink. These include physical damage to red cells, as when blood is heated, is forced under great pressure through a small needle, or is subjected to freezing and thawing; chemical damage to red cells by agents such as bile salts, detergents, and certain snake venoms; and damage caused by immunologic reactions that may occur when antibodies attach to red cells in the presence of complement.
When such destruction proceeds at a greater than normal rate, hemolytic anemia results. The membrane of the red cell has on its surface a group of molecules that confer blood group specificity i. Most blood group substances are composed of carbohydrate linked to proteinand it is usually the chemical structure of the carbohydrate portion that determines the specific blood type.
Blood group substances are antigens capable of inducing the production of antibodies when injected into persons lacking the antigen. Detection and recognition of the blood group antigens are accomplished by the use of blood serum containing johnson city tn is in what county antibodies.
The large number of different red cell antigens makes it extremely unlikely that persons other than identical twins will have the same array of blood group substances. About 95 percent of the how to open a.
cfg file weight of the red blood cell consists of hemoglobinthe substance necessary for oxygen transport. Hemoglobin is a protein; a molecule contains four polypeptide chains a tetramer what is dell data protection access, each chain consisting of more than amino acids.
To each chain is attached a chemical structure known as a heme group. Heme is composed of a ringlike organic compound known as a porphyrinto which an iron atom is attached.
It is the iron atom that reversibly binds oxygen as the blood travels between the lungs and the tissues. There are four iron atoms in each molecule of hemoglobin, which, accordingly, can bind four atoms of oxygen.
The complex porphyrin and protein structure provides the proper what are formative assessment tools for the iron atom so that it binds and releases oxygen appropriately under physiological conditions.
The affinity of hemoglobin for oxygen is so great that at the oxygen pressure in the lungs about 95 percent of the hemoglobin is saturated what is the function of red blood cell oxygen. As the oxygen tension falls, as it does in the tissues, oxygen dissociates from hemoglobin and is available to move by diffusion through the red cell membrane and the plasma to sites where it is used.
The proportion of hemoglobin saturated with oxygen is not directly proportional to the oxygen pressure. As the oxygen pressure declines, hemoglobin gives up its oxygen with disproportionate rapidity, so that the major fraction of the oxygen can be released with a relatively small drop in oxygen tension.
The affinity of hemoglobin for oxygen is primarily determined by the structure of hemoglobin, but it is also influenced by other conditions within the red cell, in particular the pH and certain organic phosphate compounds produced during the chemical breakdown of glucose, especially 2,3-diphosphoglycerate see below Respiration. Hemoglobin has a much higher affinity for carbon monoxide than for oxygen.
Carbon monoxide produces its lethal effects by binding to hemoglobin and preventing oxygen transport. The oxygen-carrying function of hemoglobin can be disturbed in other ways. The iron of hemoglobin is normally in the reduced or ferrous state, in both oxyhemoglobin and deoxyhemoglobin.
If the iron itself becomes oxidized to the ferric state, hemoglobin is changed to methemoglobin, a brown pigment incapable of transporting oxygen. The red cells contain enzymes capable of maintaining what is the definition of rasta iron in its normal state, but under abnormal conditions large amounts of methemoglobin may appear in the blood.
Sickle cell anemia is a serious and often fatal disease characterized by an inherited abnormality of hemoglobin. Persons who have sickle cell anemia are predominantly of African descent. The disease is caused by the mutation of a single gene that determines the structure of the hemoglobin molecule. Sickle hemoglobin differs from normal hemoglobin in that a single amino acid glutamic acid in one pair of the polypeptide chains has been replaced by another valine.
This single intramolecular change so alters the properties of the hemoglobin molecule that anemia and other effects are produced. Many other genetically determined abnormalities of hemoglobin have been identified. Some of these also produce diseases of several types. Study of the effects of altered structure of hemoglobin on its properties has greatly broadened knowledge of the structure-function relationships of the hemoglobin molecule. Videos Images. Additional Info. Load Previous Page. Red blood cells erythrocytes The red blood cells are highly specialized, well adapted for their primary function of transporting oxygen from the lungs to all of the body tissues.
Britannica Quiz. Blood: Fact or Fiction? This specialized fluid enlivens the human body, but how much do you really know about blood? From blood cells to blood types, sink your vampire teeth into this quiz. Each heme group contains a central iron atom, which is available to bind a molecule of oxygen. Learn about sickle cell anemia and how a tiny microfluidic device can help analyze the behaviour of blood from sickle cell patients.
How a tiny device can help predict the behaviour of sickle cells. Load Next Page.
Blood - Blood - Red blood cells (erythrocytes): The red blood cells are highly specialized, well adapted for their primary function of transporting oxygen from the lungs to all of the body tissues. Red cells are approximately ?m (1 ?m = inch) in diameter and have the form of biconcave disks, a shape that provides a large surface-to-volume ratio. A blood cell, also called a hematopoietic cell, hemocyte, or hematocyte, is a cell produced through hematopoiesis and found mainly in the loveescorten.com types of blood cells include red blood cells (erythrocytes), white blood cells (leukocytes), and platelets (thrombocytes). Together, these three kinds of blood cells add up to a total 45% of the blood tissue by volume, with the remaining 55% of. The normal range for a pregnant women in the 3rd trimester is 5,–13, per cubic millimeter. High white blood cell count. If a person’s body is producing more white blood cells than it.
This ppt covers composition and functions of blood in a systematic and interactive manner. I hope this PPT will be helpful for instructor's as well as students. SlideShare Explore Search You. Submit Search. Home Explore. Successfully reported this slideshow.
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Views Total views. Actions Shares. No notes for slide. Blood - composition and function 1. The branch of science concerned with the study of blood, blood-forming tissues, and the disorders associated with them is called haematology.
Gk: haeme — blood and logos - study 3. Plasma Plasma is a pale yellow coloured liquid component of a blood that holds the cellular elements of blood in suspension. Constituents of plasma Plasma Water Erythropoiesis The production of RBCs is known as erythropoiesis. Leucopoiesis The production of WBCs is known as leucopoiesis. Thrombopoiesis The production of platelets is known as thrombopoiesis.
Platelets are the fragments of large cells called megakaryocytes that remain in the bone marrow. Blood clotting Blood clotting is the process in which blood looses its fluidity and becomes a jelly like mass few minutes after it is shed out.
Process of blood clotting 1. Blood vessel is punctured 2. Platelets form a plug 4. Anticoagulant A substance which prevents the coagulation of blood is called as anticoagulant. Heparin is a natural anticoagulant present in the blood. You just clipped your first slide! Clipping is a handy way to collect important slides you want to go back to later.
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