Blood typing

• Blood, a fluid connective tissue, constitutes about 5 liters or 8% of total body weight, continuously circulating through blood vessels.

Blood Components

• Plasma is the liquid extracellular matrix, making up one of the major components of blood.
• Formed elements, including cells and cell fragments, are suspended in plasma
  • Erythrocytes are red blood cells (RBCs).
  • Leukocytes are white blood cells (WBCs).
  • Platelets are small cellular fragments.

Blood sample layers after being centrifuged

• The top layer is plasma, constituting about 55% of the total volume.
• The middle layer, known as the buffy coat, consists of leukocytes and platelets, making up only 1% of blood volume.
• The bottom layer is erythrocytes, comprising the remaining 44% of the total volume; the percentage of blood volume composed of erythrocytes is called the hematocrit.

Functions of Blood

• Blood exchanges gases by transporting both oxygen and carbon dioxide.
• Blood distributes solutes as plasma transports ions, nutrients, hormones, and wastes, regulating ion concentrations in tissues.
• Blood performs immune functions by transporting leukocytes and immune system proteins throughout the body.
• Blood maintains body temperature as it carries away heat generated as a by-product of chemical reactions.
• Blood facilitates clotting through platelets and certain proteins, forming blood clot to seal damaged vessels and prevent further loss.
• Blood maintains acid-base homeostasis by maintaining blood pH between 7.35 and 7.45, remaining relatively constant due to buffering systems.
• Blood stabilizes blood pressure; blood volume is a major factor in determining blood pressure.

Plasma

• Plasma is a pale yellow liquid of which 90% is water, a major factor in determining viscosity which is the thickness of the fluid.
• Lower water levels result in greater viscosity and sluggish blood flow.
• Plasma proteins form a colloid and account for about 9% of the plasma volume.
• Albumin, a large protein synthesized in the liver, is responsible for the blood's colloid osmotic pressure, drawing water into the blood by osmosis.
• Immune proteins (gammaglobulins) are also known as antibodies. They are made by leukocytes and are components of the immune system.
• Transport proteins bind to lipid-based molecules otherwise incompatible with the mostly water-based plasma, allowing transportation of these molecules in the blood.
• Clotting proteins help stop bleeding from injured blood vessels by forming blood clots with assistance from platelets.
• The last 1% of plasma volume consists of several small molecules mostly dissolved in water, forming a solution.
• These molecules can be readily exchanged between blood and interstitial fluid in most capillary beds.

Erythrocytes and Oxygen Transport

• Erythrocytes (red blood cells) shape and components facilitate their transport of oxygen and carbon dioxide through the blood

Structure of Erythrocytes

• A typical erythrocyte (red blood cell/RBC) is a biconcave disc which is a flattened, donut-shaped that is concave on both sides.
• Shape increases surface area of cell, vital for gas exchange.
• Mature RBCs are anucleate, having lost their nucleus during maturation, and they also lack most other cellular organelles.
• The lack of a nucleus and organelles creates room in cytosol for enzymes and nearly 1 billion oxygen-binding hemoglobin (Hb) proteins.
• Hemoglobin consists of four polypeptide subunits: two alpha (α) chains and two beta (β) chains.
• Each polypeptide is bound to an iron-containing compound called a heme group.
• An iron ion in each heme group is oxidized when it binds to oxygen in regions of high oxygen concentration (such as the lungs), forming a red molecule called oxyhemoglobin (HbO₂).

Hemoglobin continued

• Releases oxygen in regions of low oxygen concentration, such as tissues surrounding systemic capillary beds.
• Binds to carbon dioxide (CO₂) to form carbaminohemoglobin in areas with low oxygen levels, accounting for ~23% of CO₂ transported in the blood.
• Binds to carbon monoxide (CO) to form carboxyhemoglobin, with a stronger bond to iron than oxygen, which changes the shape of Hb making it unable to unload oxygen into oxygen-deprived tissues, leading to death.

Erythrocyte Life Span

• Erythrocyte life span is brief, ranging from 100-120 days due to damage from the harsh environment.
• The cells cannot self-repair since they lack means for repair, having lost the majority of their organelles during maturation.
• The body must continuously manufacture new erythrocytes.

Erythropoiesis

• Hematopoiesis takes place in red bone marrow, where formed elements in blood are produced by hematopoietic stem cells (HSCs).
• Erythropoiesis is a specific hematopoietic process producing erythrocytes from HSCs, taking ~5-7 days to complete.
• It begins when HSCs differentiate into progenitor cells called erythrocyte colony-forming units (CFUs), which are committed to forming only one cell type.
• Erythrocyte CFUs differentiate into proerythroblasts when the hormone erythropoietin (EPO), secreted by the kidneys, is present.
• Proerythroblasts develop into erythroblasts, rapidly synthesizing hemoglobin and other proteins.
• The nucleus in erythroblasts shrinks as it matures and is eventually ejected, resulting in a reticulocyte.
• Reticulocytes enter the bloodstream after ejecting remaining organelles by exiting through pores in sinusoidal capillaries of bone marrow.
• Regulation of Erythropoiesis occurs when erythropoietin triggers a negative feedback loop which maintains hematocrit within a normal range.
  • Process
    • When blood oxygen levels are low, the kidney cells detect.
    • The kidneys then produce more erythropoietin and release the hormone into the bloodstream, which increases the rate of erythropoiesis in bone marrow.
    • Production of erythrocytes increases, increasing blood levels of oxygen.

Erythrocyte Death

• Erythrocyte destruction occurs via trapping in spleen sinusoids then spleen macrophages digest erythrocytes and hemoglobin breaks down into amino acids, iron ions, and heme.
• The spleen is an organ located in the upper left abdominal cavity.
• Heme is converted to biliverdin (greenish pigment) which is then made into bilirubin (yellowish waste product).
• Iron ions and amino acids are recycled to make new hemoglobin in the red bone marrow, with iron ions transported back via transferrin.
• Bilirubin is sent to the liver for excretion.

Anemia

• Anemia is a condition defined as a decreased oxygen-carrying capacity of the blood.
• Causes and forms
  • Decreased hemoglobin
    • Iron deficiency anemia, the most common form, is caused by dietary iron deficiency, reduced intestinal absorption of iron, or slow blood loss.
    • Lack of functional heme groups prevents erythroblasts from synthesizing oxyhemoglobin.
    • Anemia of chronic disease also common, develops as a result of cancer and interferes with iron transportation from the liver to red bone marrow.
    • Deficiencies in vitamin B6, malnutrition, poisoning with drugs or heavy metals (such as lead), and pregnancy can all decrease hemoglobin levels.
  • Decreased hematocrit
    • Factors that reduce the number of erythrocytes in blood lower the hematocrit, such as from acute injury to stomach ulcers which leads to significant loss of circulating erythrocytes
    • Pernicious anemia results from Vitamin B12 deficiency and interferes with DNA synthesis of rapidly dividing cells, like hematopoietic cells in bone marrow.
    • Erythrocyte destruction because of bacterial infections, immune system or liver diseases, and lead poisoning can lead to hemolytic anemia.
    • Aplastic anemia may result from medications or exposure to ionizing radiation which can inhibit or stop erythrocyte production in red bone marrow (cause is often unkown).
  • Abnormal hemoglobin.
    • The most common example of abnormal hemoglobin is sickle-cell disease. - Individuals with a single copy of the defective gene have sickle-cell trait and are generally asymptomatic. - Individuals with two defective copies of the gene have sickle-cell disease and produce abnormal hemoglobin S (HbS).
    • When oxygen levels are low, RBCs containing HbS change into a sickle shape, leading to erythrocyte destruction in small blood vessels, reducing circulating erythrocytes

Anemia Symptoms

• General symptoms include pallor (pale skin), fatigue, weakness, and shortness of breath.
• Elevated numbers of circulating reticulocytes will occur because the body will produce EPO.
• Severe anemia can elevate heart rate, attempting to increase cardiac output to match the oxygen demand.

Leukocytes and Immune Function

• Leukocytes or white blood cells (WBCs) are larger than erythrocytes.
• They use the bloodstream as transportation, but generally don't perform their functions within blood since WBCs adhere to blood vessel walls, then squeeze between endothelial cells to enter surrounding tissue.
• Granulocytes are named this way because they readily distinguished because cells have a sinble nucleus composed of multiple connected lobes and contain cytoplasmic granules
  • The cytoplasmic granules contain lysosomal granules and granules that are only the granuloctye
• Agranulocytes lack visible cytoplasmic granules but do contain lysosomes. (like granulocytes)

Leukocyte Types

• List of WBCs, from most to least abundant: Neutrophils, Lymphocytes, Monocytes, Eosinophils, Basophils
• Easy way to remember this list: Never Let Monkeys Eat Bananas

Granulocytes

• Neutrophils are the most common leukocyte, typically found at 3000-7000 neutrophils/mm³ of blood (40-70% of WBC).
  • They are active phagocytes that ingest and destroy bacterial cells.
  • Also referred to as polymorphonucleocytes (polys or PMNs) due to the uniquely shaped nucleus composed of three to five lobes.
  • Injured cells release chemicals that attract neutrophils (chemotaxis) causing the cells to exit into injured tissues.
  • The contents of the cell will directly kill other bacterial cells, attract more neutrophils and other granulocytes and to enhance inflamation
• Eosinophils have bilobed nucleus, usually 100-400 eosinophil's per mm³ of blood in the body (1-4% of WBCs).
  • They are phagocytes that will injest foreign molecules.
  • Respond to infections with parasitic worms and allergic reactions
  • Granules contain enzymes and toxins specific to parasites, also chemicals that mediate inflammation
• Basophils are the least common leukocyte and has an S-shaped nucleus.
  • The body usually has 20-50 basophils per mm³ of blood (0-1% of WBCs)
  • Chemicals within granules mediate inflammation causing histamine-containing granules and contain heparin (anticoagulant).

Agranulocytes

• Lymphocytes are the second most common leukocyte in blood, containing 1,500-3,000 lymphocytes per m3 of blood (25-40% of WBCs).
  • Two basic types with similar appearances but different functions.
  • Both types are activiated by cellular markers found on all cells called antigens
  • Serve function in immune response.
  • B lymphocytes (B cells):

    • When activated, produce antibodies to bind/remove antigen tissue.
      

    • Each population of B lymphocytes produces antigen-binding antibody for a specific structure.
    • These cells become immunocompetent in bone marrow
  • T lymphocytes (T cells):
    • Also activated by specific antigens.
    • Do not produce antibodies, have membrane-bound receptors for individual antigens.
    • Activate other immune system components and directly destroy abnormal body cells (virally infected, cancer) and become immunecompetent at thymus.
• Monocytes are recognized as the largest leukocyte, and contain a large U-shaped nuclei with 100-700 monocytes per mm of blood (4-8% of WBCs)
  • Only circulate in blood briefly before exiting capillaries to enter tissues where some mature into macrophages.
  • The cells will activate other components via displaying phagocytosed antigens to other leukocytes.

Complete Blood Count

• A Complete Blood Count (CBC) is an important test for anemia and other conditions.
• A blood sample is drawn and examined under a microscope and by an automated analyzer to evaluate number and characteristics of blood cells, including:
  • RBC count in cells per milliliter (used to calculate hematocrit).
  • Hemoglobin concentration
  • RBC characteristics (size, volume, concentration of hemoglobin in cytosol).
  • Platelet count and volume.
  • Numbers and types of leukocytes

Leukemia

• Leukemias are cancers of blood cells or bone marrow, and can be classified as acute or chronic by speed of development.
  • Acute Leukemia will cause a rapid increase and accumulation immature or abnormal blood cells
  • Chronic Leukemia-Slow accumulation of mature but still abnormal
• Also classified by cell line from which abnormal cells derive
• Lymphocytic leukemia comes from lymphoid cells.
• Myelogenous leukemia comes from myeloid cells.
• Acute lymphocytic leukemia is the most common leukemia in children.
• Abnormal cancer cells crowd the marrow, reducing the ability that make health cells and they flow in the blood stream.
• Treatment and prognosis vary; generally acute forms spread faster and aggressively.

Platelets

• Platelets are small cell fragments surrounded by plasma.
• Smallest of formed elements involved in hemostasis to stop blood loss from an injured blood vessel.
• Platelets don't have nuclei or whole cell organelles
• Platelets contain clotting factors, enzymes, some mitochondria, and glycogen deposits to enable them to carry out oxidative catabolism
• They also contain cytoskeletal elemetns including microtubules with actin/mosin filaments within them.

Thrombopoiesis

• Platelet formation by hematopoietic stem cells differientating to megakaryoblasts.
• Megarkaryoblasts develop into megakaryocytes and cycle mitosis without cytokinesis.
• Large cell copies DNA in single nucleus.
• When simulated Megakaryocytes will produce hormone stimulated extensions from bone into the bloodstream to break into thousands of patelets that work after seven to ten days.
• Platelets have limited lifespan of about 7–10 days; then they are removed from circulation by liver and spleen

Hemostasis

• Hemostasis, the bodies process in stopping blood flow that forms a clot through vessels.
• Includes five processes starting with vasualar spasm, plug platelet formation, coaggulation, clout retraction and last is thrombolysis.

Part One Vascular spasm

• Hemastasis begins with a vascular spasm to start to clot vessels.
• Blood flow can be minimized with pressure which locally will help clot and control blood loss.

Part Two Platelet Plug

Injured andothial cells will release willbrand factor.

• Exposed collagen and willbrand factor attract and activate plateletes causing aggregate and seal temporarily with platelet plugs.

Part Three Concgulation.

• Process in molecular glue that all forms together.
• In cascade of events its down in two pathways where college fibers activate
• Damaged tissue activate clotting factors where they all converge and activate fibrin.

Part Four Retration Of Clot

• Actin and myosin Fibers help involved in retretion.
• Serum has all clot proteins forced out.

Part Five-Thromblyis

• Thromplysis is where glue breaks down and heals.

Retraction of Cotting

• Produce endothelium for coagulation.
• Produce prostaglandin and vasodilation; vasodilation; nitric oxide

Regulation Of clotting

• Antibthrombins that combine and new active of what factor and that prevent thrombosis

Clotting Disorder

• Condition of not regulating clottin correctly.
• Bleeding occurs with minor damage through hemophilia where there is less factor to stop the process.
• Hemophiall A is caused by a storage of factor 7, -Hemophilia B is storage of factor nine.
• Forming incorrect Clots leads to the thrombis to obstruct the through the vessel.
• Causes the forming in the legs from DVT whihc can causes.
• Cause pumniary.

Anti-Cot Medication

• Heaperin is immediate but injected.warfains is long term K vitamin by preventing the liver factor
• Aspinrin is a factor contribute.
• TPA help reverse and stroker.

Blood transfusion

• Tranfusions with donor and receptors antigens in a safe way because of biological cells it lead can safer transfusion.
• Abo blodgroup is most clinical used like RH factors.

Blood Typing.

Blood cells features like A. AND B

• Type A where antigen produces . And type B where only antigen produces.
• Type AB blood both occurs where not produce is anti-anitgen

Rhesus monkeys blood group

• D antigen on erynthosis what positive and witouht the antigen is negaitve.
• Type 8 that occur that o positive its more commune that AB negative is not
• Use of antibodies prevent agglutae,
• Agglutination is promoted by hemlysosis. Use of antibodies to prevent this

Blood samples

• Use 3 different kinds aggulanic the factor is presented and obsiere.
• The sample combined and erythosis sample.

Transfusions

• If u produce plasma that means factor is absence
• AB does anti bodies but it preformed can never occur again..RH needs previous blood contaning.
• Donor blood with recepent that is forgin can reject the new match and the transplant.
• Patients if they are not match the system would get infected and damage and can lead to kidney failure

Untarvies donor,

• Doubt dont have the AB or Rh antigens.can giev blood too all kind of emergancy
• AB is most comlaitbe with ando that what all work wiht each that whya is it is called that.

Hemolytic disease.

• That happens during birth where mother gets Rh + and that produce antibodies of it causing to reject the fetus in the later stage.
• RH shot help prevent it.