UB Lab Exercise 5: Blood PDF

University of Bridgeport 1. Lab Exercise 5: Blood Objectives: This week’s laboratory exercise was designed to prepare students to learn the Blood....

University of Bridgeport 1. Lab Exercise 5: Blood Objectives: This week’s laboratory exercise was designed to prepare students to learn the Blood. By the end of the lab, students should know: 1. Identify the major components of blood. 2. Differentiate between the various formed elements of blood. 3. Understand Blood typing. List of Materials: This lab requires each student to have in addition to their normal supplies: 1. Personal Laptop/Table (No chrome) 2. Pen/Pencil 3. Notebook 4. Models and Model Posters. University of Bridgeport 2. Formed Elements of Bloodt: Blood consists of liquid and solid components. Plasma is the liquid portion of blood and composes about 55% of the total blood volume. Plasma is about 90% water. The remaining portion of plasma is made up of proteins, ions, glucose, amino acids, dissolved gasses, and wastes. The solid components of blood are known as formed elements, which account for about 45% of the total blood volume. Formed elements include erythrocytes (red blood cells), leukocytes (white blood cells), and thrombocytes (platelets). Red blood cells (RBCs) are by far the most numerous of the formed elements. There are approximately 4-6 million/mm3 RBS; they outnumber white blood cells (WBCs) by about 600 to 1. The RBC to platelet ratio is approximately 16 to 1. Table 1. Formed Elements. University of Bridgeport 3. Table 2. Formed elements (continued). Figure 1. Blood sample (a) non-centrifuged; (b) centrifued. University of Bridgeport 4. Figure 2. Blood smear. White Blood Cell Testing: Since WBC function is important in immunity. WBC tests may be performed to determine if a person has an infection or illness. The normal range for WBCs is between 2800 and 15,000 cells per milliliter of blood. Leukocytosis is an abnormally high number of WBCs, which often indicates that an infection is present. Leukopenia is a lower than normal WBC count. Any disease or disorder that disrupts the function of bone marrow can result in leukopenia. Viral infections, autoimmune disorder, and any disease that can cause harm to the immune system can also lead to leukopenia. Although knowing the total WBC count can be useful, conducting a differential count is often more informative. A differential white blood cell count measures the percentage of each type of WBC in the sample and indicates the presence of any abnormal or immature cells. University of Bridgeport 5. Blood Typing: Cell markers called antigens are found on the surface of cells. ABO blood groups are determined by the presence or absence of two primary antigens: A and B. Their presence or absence determines which of the four primary blood types an individual has. The four primary blood groups are A, B, AB, and O. A third important antigen found on the surface of red blood cells in some individuals is the Rhesus (Rh) factor. If RBCs have the Rh antigen, the blood is classified as Rh positive (Rh+). If the antigen is absent, the blood is classified as Rh negative (Rh-). Most of the American population (85%) is Rh+. Blood plasma contains proteins called antibodies that detect foreign (non-self) antigens. The antibodies present are for antigens not found on an individual’s RBCs. For example, a person with A antigens on the RBCs will have anti-B antibodies in the plasma, but not anti-A antibodies. If antibodies detect non-self antigens, they bind to those antigens, linking them together and forming a clump of cells. This process is called agglutination, which results in the destruction of the clumped cells (hemolysis). This is why blood-typing prior to transfusion is critical. Table 3. Reactions of Various Blood Types University of Bridgeport 6. Table 4. Major Blood Types.  7. Blood Disorders Hematology is the study of blood, blood-forming-tissues, and blood disorders. Blood disorders include any number of inherited or acquired disorders that affect one or more parts of the blood and prevent them from properly performing their job. Examples are shown in Table 5. Blood disorders can be chronic or acute and may or may not be curable. Many disorders can be identified by viewing a blood smear. Table 5. Selected Blood Disorders  8. Table 5. Selected Blood Disorders (continued) Abnormal Blood Clotting Hemostatsis refers to the stopping of blood flow. Hemostasis consists of three steps: blood vessel spasm, platelet plug formation, and coagulation. Blood coagulation should only occur in response to injury. A healthy person's body has mechanisms in place to ensure that abnormal blood clots do not form spontaneously. An abnormal clot is called a thrombus. A clot that breaks away from the vessel wall and travels through blood vessels is referred to as an embolus. Any type of abnormal clot can be extremely dangerous because it can block flow to critical organs such as the brain, heart and lungs.  9. Atherosclerosis The smooth lining of blood vessels usually discourages the accumulation of platelets and clotting factors. Atherosclerosis results when fatty deposits called plaque build up in and on the vessel walls. Plaque consists of cholesterol, fatty substances, calcium, cellular waste, and fibrin (a clotting material). If plaque is exposed in the lumen, a clot may form. Anticoagulant drugs may be used to prevent clot formation or to dissolve existing clot. Some cells such as basophils and mast cells secrete heparin, an anticoagulant compound that works to prevent the formation of abnormal clots. Figure 3. Cross section of an artery showing atherosclerosis with thrombosis (20x) University of Bridgeport 9. In-Lab Assignment 5: After reviewing with the instructor, complete the lab exercise. On canvas, go to “Assignments” tab and click on “In-Lab Assignment 5” This exercise is not a quiz but will be using a quiz template in order to grade automatically. Read each instruction carefully per question in order to complete the assignment. Complete this assignment before leaving class. This assignment is only open during the time of the class. You have three attempts. Answers will show at the end of the week. After completing the assignment, show the instructor or TA to mark you off. Use models to complete assignments.