Blood Lecture 5 PDF

Al Nisour University College Dr. Hussein ali Pharmacy department Stage 1st Lecture 5 Human biology Blood -Blood is a connective tissue. -made up of cellular elements and an extracellular matrix. -The cel...

Al Nisour University College Dr. Hussein ali Pharmacy department Stage 1st Lecture 5 Human biology Blood -Blood is a connective tissue. -made up of cellular elements and an extracellular matrix. -The cellular elements include red blood cells (RBCs), white blood cells (WBCs), and platelets. -The extracellular matrix is plasma, -blood unique among connective tissues because it is fluid. Functions of Blood 1- Transportation -Most of nutrients travel in the bloodstream directly to the liver, where they are processed and released back into the bloodstream for delivery to body cells. -Oxygen diffuse from the breathing air into the blood, which moves from the lungs to the heart,which then pumps it out to the rest of the body. -endocrine glands release their products hormones, into the bloodstream, which carries them to distant target cells. -Blood also picks up cellular wastes and transports them to various organs for removal. -blood moves carbon dioxide to the lungs for exhalation from the body, and various waste products are transported to the kidneys and liver for excretion from the body in the form of urine or bile. 1 Al Nisour University College Dr. Hussein ali Pharmacy department Stage 1st Lecture 5 Human biology 2- Defense -Many types of WBCs protect the body from external threats, such as disease-causing bacteria that have entered the bloodstream in a wound. -Other WBCs seek out and destroy internal threats. -When damage to the vessels results in bleeding, blood platelets and certain proteins dissolved in the plasma, interact to block the ruptured areas of the blood vessels involved. ,protects the body from further blood loss. 3- Maintenance of Homeostasis -body temperature -Blood also helps to maintain the chemical balance of the body. Proteins and other compounds in blood act as buffers, which thereby help to regulate the pH of body tissues. -Blood also helps to regulate the water content of body cells. Characteristics of Blood - Oxygenated blood in the lungs is bright red ,blood that has released oxygen in the tissues is a more bluish red (hemoglobin is a pigment that changes color, depending upon the degree of oxygen saturation). -Normal temperature of blood is slightly higher than normal body temperature about 38 C. 2 Al Nisour University College Dr. Hussein ali Pharmacy department Stage 1st Lecture 5 Human biology -The pH of blood averages about 7.4 -Blood contain many buffers help to regulate pH. -Adult males typically average about 5 to 6 liters of blood. Females average 4‒5 liters. Blood Plasma - plasma is composed 92 percent water: - smaller numbe of regulatory proteins (enzymes& hormones). - Three major groups of plasma proteins 1. Albumin: -the most abundant of the plasma proteins 54%. - Manufactured by the liver. - transport vehicles for fatty acids and steroid hormones. - the most significant contributor to the osmotic pressure of blood; that is, its presence holds water inside the blood vessels and draws water from the tissues. - helps to maintain both blood volume and blood pressure. 2. Globulin (38%) three main subgroups (alpha, beta, and gamma globulins). 3 Al Nisour University College Dr. Hussein ali Pharmacy department Stage 1st Lecture 5 Human biology - The alpha and beta globulins transport iron, lipids, and the fat- soluble vitamins A, D, E, and K to the cells; also contribute to osmotic pressure. - The gamma globulins are proteins involved in immunity (immunoglobulins) 3. Fibrinogen (7%)is produced by the liver. It is essential for blood clotting - Other Plasma Solutes include various electrolytes,such as sodium, potassium, and calcium ions; dissolved gases, such as oxygen, carbon dioxide, and nitrogen. RBC Red blood cell (or RBC), erythrocytes make up about 25 percent of the total cells in the body. - The primary functions of erythrocytes are to pick up inhaled oxygen from the lungs and transport it to the body's tissues, and to pick up some carbon dioxide waste at the tissues and transport it to the lungs for exhalation. - As an erythrocyte matures in the red bone marrow, it extrudes its nucleus and most of its other organelles. - Lacking mitochondria, they rely on fermentation. 4 Al Nisour University College Dr. Hussein ali Pharmacy department Stage 1st Lecture 5 Human biology - lack endoplasmic reticula and do not synthesize proteins, so they are unable to repair themselves. This is why the lifespan of a red blood cell is approximately 115 days. - biconcave disks; that is , Since they lack most organelles, there is more interior space for the presence of the hemoglobin molecules that transport gases. Hemoglobin - large molecule made up of proteins and iron. - It consists of four folded chains of a protein called globin, designated alpha 1 and 2, and beta 1 and 2 - Each of these globin molecules is bound to a red pigment molecule called heme, which contains an ion of iron (Fe2+) - Each iron ion in the heme can bind to one oxygen molecule; therefore, each hemoglobin molecule can transport four oxygen molecules. - In the lungs, hemoglobin picks up oxygen, which binds to the iron ions, forming oxyhemoglobin, travels to the body tissues, where it releases some of the oxygen molecules, becoming darker red deoxyhemoglobin. - Oxygen release depends on the need for oxygen in the surrounding tissues - In the capillaries, carbon dioxide enters the bloodstream. 5 Al Nisour University College Dr. Hussein ali Pharmacy department Stage 1st Lecture 5 Human biology - In patients with insufficient hemoglobin, the tissues may not receive sufficient oxygen, resulting in form of anemia. Lifecycle of Erythrocytes - Erythrocyte production requires several trace elements: iron ,copper, zinc, and several types of B vitamins. - Erythrocytes live up to 120 days in the circulation, after that worn-out , removed by macrophage, located primarily within the bone marrow, liver, and spleen. - The components of the degraded erythrocytes' hemoglobin are further processed 6 Al Nisour University College Dr. Hussein ali Pharmacy department Stage 1st Lecture 5 Human biology - The breakdown pigments formed from the destruction of hemoglobin is biliverdin Blood Typing and Transfusions - Blood groups determined by the presence or absence of specific marker antigen molecules, on the plasma membranes of erythrocytes. - Antigens are substances that the body does not recognize as belonging to the self and that therefore trigger a defensive response from the leukocytes (WBC) of the immune system. - Antigens are generally large proteins - Following an infusion of incompatible blood, erythrocytes with foreign antigens appear in the bloodstream and trigger an immune response. ,with production of Proteins called antibodies (immunoglobulins) Antigens, Antibodies, and Transfusion Reactions - Antibody produced by certain B lymphocytes called plasma cells, attach to the antigens on the plasma membranes of the infused erythrocytes and cause them to stick to one another (i.e. agglutinate). - As the erythrocyte clumps are degraded, in a process called hemolysis, their hemoglobin is released into the bloodstream. 7 Al Nisour University College Dr. Hussein ali Pharmacy department Stage 1st Lecture 5 Human biology - More than 50 antigens identified on erythrocyte membranes, the most significant are two groups: the ABO blood group and the Rh blood group. The ABO Blood Group Both of A and B antigens are glycoproteins. blood type A, in people with A antigen on erythrocytes membrane - erythrocytes have B antigens are blood type B. - AB in People have both A and B antigens on their erythrocytes - People with neither A nor B antigens are designated blood type O. - Individuals with type A blood without any prior exposure to incompatible blood have preformed antibodies to the B antigen circulating in their blood plasma ( anti-B antibodies) , will cause agglutination and hemolysis if they ever encounter erythrocytes with B antigens. - Individual with type B blood has pre-formed anti-A antibodies. - Individuals with type AB blood, which has both antigens, do not have preformed antibodies - People with type O blood lack antigens A and B on their erythrocytes, but both anti-A and anti-B antibodies circulate in their blood plasma. 8 Al Nisour University College Dr. Hussein ali Pharmacy department Stage 1st Lecture 5 Human biology Rh Blood Groups - is classified according to the presence or absence of erythrocyte (Rh). - Only D is clinically important - the Rh group is designated by adding the word positive or negative to the ABO type. A positive (A+) means ABO group A blood with the presence of Rh antigen 9 Al Nisour University College Dr. Hussein ali Pharmacy department Stage 1st Lecture 5 Human biology Disorders of RBC - Anemia result from decrease number of RBCs or hemoglobin - There are more than 400 types of anemia - Anemia in general, is caused by a decrease in red blood cells (or dysfunctional red blood cells), which then reduces oxygen in the body. Iron-deficiency anemia is caused specifically by a lack of iron - result in lower levels of oxygen delivered to body tissues. - Since oxygen is required for tissue functioning, anemia produces fatigue, lethargy, and an increased risk for infection. Decrease oxygen in the brain impairs the ability to think clearly, and may prompt headaches and irritability. Lack of oxygen lead to shortness of breath, the heart and lungs work harder. Polycythemia - An elevated RBC count , elevated hematocrit. - can occur transiently in a person who is dehydrated - a type of bone marrow disease called polycythemia vera causes an excessive production of immature erythrocytes , dangerously elevate the viscosity of blood, raising blood pressure - relatively rare disease that occurs more often in men than women. 10