Q1.Define the components of blood and briefly describe their role.
Whole blood contains red cells, white cells, and platelets (~45% of volume) suspended in plasma (~55% of volume). Red cells, (erythrocytes) carry oxygen from the lungs to your body’s tissue and take carbon dioxide back to your lungs to be exhaled.
White cells, (leukocytes) are one of the body’s defenses against disease. Some white cells travel throughout the body and destroy bacteria, some produce antibodies against bacteria and viruses, and others help fight malignant diseases. The majority of white blood cells are produced in the bone marrow, where they outnumber red blood cells by 2 to 1. However, in the blood stream, there are about 600 red blood cells for every white blood cell. There are several different types of white blood cells. Platelets,(thrombocytes) are small, colorless cell fragments in the blood whose main function is to interact with clotting proteins to stop or prevent bleeding.
Plasma is a fluid, composed of about 92% water, 7% vital proteins such as albumin, gamma globulin, anti- hemophilic factor, and other clotting factors, and 1% mineral salts, sugars, fats, hormones and vitamins.
Q2.Describe the morphology of an erythrocyte and the importance of it. What role does hemoglobin have within the erythrocyte function? Why is iron so important within erythrocyte function?
Normally, RBCs will display a defined morphology in the peripheral blood. Mature RBCs, under normal circumstances, are round, biconcave disc-shaped, anuclear cells measuring approximately 7-8 microns in diameter with an internal volume of 80-100 fL. The term used to express RBCs of normal size is normocytic. Mature red blood cells, under normal circumstances, will also have an appropriate hemoglobin content, giving them a red-orange appearance on Wright-stained smears. These cells will display a central pallor (lighter area inside of the cell) no larger than 3 microns in diameter. This normal morphology is indicated by the term normochromic. It is paramount for RBCs to contain an adequate amount of hemoglobin for the purpose of transporting oxygen to the tissues and carbon dioxide back to the lungs.
Iron in hemoglobin and myoglobin is key because it has special chemical properties that allow it to carry oxygen and then release it to the tissues as needed. Your cells—particularly your working muscle cells—need a regular supply of oxygen to produce energy. Iron-containing hemoglobin is also needed to assist in the elimination of carbon and hydrogen atoms released during the use of carbohydrate and fat fuels for energy, forming carbon dioxide and hydrogen. Thus, having adequate iron stores is particularly important during exercise when the hemoglobin-rich red blood cells shuttle between your lungs and exercising muscle, bringing in fresh oxygen and eliminating carbon dioxide.
Q3.Compare and contrast the various types of leukocytes.
Neutrophils: are the most abundant type of leukocyte. They are highly mobile cells and can move quickly through the body. Neutrophils are often the first responders in cases of injury or infection and are involved in early inflammation. Neutrophils are able to fight off bacterial and fungal infections by ingesting the invading organisms, which are killed and eliminated from the body.
Eosinophils: combat infections, especially those from small parasites. They are also important in fighting off viral infections. Many viruses contain ribonucleic acid, or RNA, as their genetic material. Eosinophils contain molecules that destroy RNA, thereby destroying many viruses. Eosinophils are also involved in allergic responses, as well as the inflammatory process that causes asthma.
Basophils: play a major role in inflammation, especially allergic reactions. They store histamine, a substance that dilates blood vessels and allows blood to flow into the tissues, causing inflammation. Histamine is released from the basophils in response to