Untitled Quiz

Blood Functions

• Blood maintains homeostasis through several processes
• Transport of gases, nutrients, and waste products: Oxygen is transported from lungs to cells, and carbon dioxide from cells to lungs. Nutrients and water are also transported and waste products are eliminated via the kidneys.
• Transport of processed molecules: Many substances are produced in one part of the body and travel via the blood to another part for modification, like vitamin D precursors.
• Transport of regulatory molecules: Hormones and enzymes regulate bodily processes throughout the body by transporting them.
• Regulation of pH and osmosis: Buffers maintain blood pH (7.35-7.45). Osmolarity is also regulated for maintaining fluid and ion balance.
• Maintenance of body temperature: Blood circulates throughout the body, transporting heat to maintain a stable internal temperature.
• Protection against foreign substances: Immune cells (WBCs) and chemicals protect against microorganisms and toxins
• Clotting formation: Blood clotting is the first step in tissue repair after damage to blood vessels, preventing blood loss.

Blood Composition

• Blood is classified as a type of connective tissue. It consists of a liquid matrix (plasma) and cells/cell fragments (formed elements).
• Plasma makes up about 55% of the total blood volume and roughly 8% of the total body weight. It consists mainly of water (91%), proteins, and other solutes.
• Formed elements make up approximately 45% of the blood volume. These are red blood cells (erythrocytes), white blood cells (leukocytes), and platelets.

Formed Elements

• Red blood cells (erythrocytes): Biconcave disk shape, oxygen and carbon dioxide transport. They make up 45% of total blood volume.
• White blood cells (leukocytes): Spherical and have a nucleus, defend against pathogens; five types with specific functions (granulocytes and agranulocytes).
• Platelets (thrombocytes): Cell fragments involved in preventing blood loss through clotting.

Blood Cell Production (Hemopoiesis)

• Blood cell production, called hematopoiesis, occurs in red bone marrow and lymphatic tissues.
• All formed elements originate from stem cells (hemocytoblasts).
• Specialized growth factors regulate the development and number of formed elements.

Red Blood Cells

• Normal red blood cells are disk-shaped, with thicker edges and thinner center.
• The biconcave shape increases surface area for gas exchange.
• Red blood cells lack a nucleus and most organelles during development.
• Red blood cells live for about 120 days.
• Hemoglobin is the protein responsible for their red color, crucial for oxygen transport.

White Blood Cells

• Classified as granulocytes or agranulocytes, based on their appearance in stained preparations.
• Granulocytes contain large cytoplasmic granules visible under a light microscope. These include Neutrophils, Basophils, and Eosinophils.
• Agranulocytes have small granules that are not easily visible under a light microscope. These include Lymphocytes and Monocytes.
• Each type of white blood cell has a specific function in the body's immune response.

Platelets

• Platelets are minute fragments of cells, lack nuclei and consist of some cytoplasm.
• They are involved in the clotting process.
• Important in maintaining blood vessel integrity due to the formation of platelet plugs.
• Platelet plug formation is a vital component of hemostasis (blood clotting and prevention of blood loss).

Blood Clotting

• A complex process involving many chemical reactions, initiated by vessel damage, regulated by various clotting factors.
• Three main stages are: Activation of clotting factors; conversion of prothrombin to thrombin; and thrombin converting fibrinogen to fibrin.
• The process is regulated by anticoagulants to prevent unwanted clotting.

Blood Grouping

• Blood types are determined by antigens on the surface of red blood cells.
• The ABO blood grouping system has four principal types: A, B, AB, and O, based on the presence of specific antigens.
• Mismatches in blood types during transfusions can lead to serious reactions, requiring careful matching.

Complete Blood Count (CBC)

• A complete blood count (CBC) assesses several blood components, particularly red blood cell count, hemoglobin, hematocrit, and white blood cell count.
• These measurements provide information regarding overall blood health.

Blood Chemistry

• Blood chemistry involves blood plasma composition and the analysis of dissolved/suspended materials, assisting in diagnosing various conditions.
• Measuring levels of certain substances can help diagnose disease states and function levels of the organs.