Chapter 17 - Blood

17.1 - Functions of Blood

1) Transportation

• Delivering oxygen and other nutrients

• transport waste to elimination stations

• transports hormones from endocrine organs to effectors

2) Regulation

• manages temperature - contricts or dilates

• regulates pH - blood is an alkaline reserve

• maintains fluid volume - blood pressure

3) Protection

• Platelet blood vessels clot to prevent blood loss

• White blood cells prevent infection

17.2 - Blood elements

- blood is a fluid tissue - a connective tissue

• Formed elements - living blood cells

• Platelets - cells fragments that form clots to stop bleeding -

• Plasma - liquid that blood circulates through made 92% of water and make up 55% of blood

• Buffy coat - thin whitish layer made of WBC and platelets - less than 1% of blood

• Erythrocytes - Red blood cells (RBC) 45% of blood

• Hematocrit - the percentage of red blood cells in the total volume of blood

  • males - 47% give or take 5%

  • females - 42% give or take 5%

Physical characteristics and Volume

- color of blood depends on oxygen content higher in content = lighter red, less = darker red

• Normal Blood pH - 7.35 - 7.45

• Erythrocytes make the blood more thick so to many RBC can make circulation harder

• Erythrocytes are made with hemoglobin which is an iron protein so less RBC is prob iron deficiency

Blood Plasma

• plasma contains hormones, nutrients, gases, wastes, electrolytes, proteins, & water

  • most plasma proteins are produced by the liver

  • plasma proteins 8% of plasma

• Albumin - 60% of plasma protein

  • helps transportation of some molecules

  • helps keep stable pH

  • helps keep water pressure in bloodstream

• Globulins - protein in plasma - 36%

  • transports hormones and vitamins - alpha & beta

  • gamma - fights infections - antibody

• Fibrinogen - protein in plasma - 4%

  • forms blood clots

  Formed Elements

• Blood cells are amitotic - don’t divide

17.3 - Erythrocytes RBC

• Erythrocytes - 7.5 micrometers in diameter - discs with depressed center

  • no nucleus

• Hemoglobin - protein that makes RBC - binds to oxygen easily

  • transports oxygen

  • 13-18 grams/ 100 mL

  • heme - red iron pigment

  • globin two alpha and two beta peptide chains - iron in the center of peptide chain circle

• Spectrin - protein that allows blood vessels to change shape and then go back

• RBC is 97% hemoglobin

• RBC doesn’t consume any oxygen they carry

• Carry carbon dioxide to lungs

  Function of RBC

• 1 RBC contains 250 million hemoglobin and 1 billion oxygen molecules

• Oxyhemoglobin - when oxygen binds to iron in the hemoglobin

• Deoxyhemoglobin - oxygen detatches from oxygen

• Carbaminohemoglobin - when carbon dioxide binds to the globin amino acids in hemoglobin

  Production of RBC

• hematopoiesis - the production of blood

• Red bone marrow - made of connective tissue - makes RBC

  • makes 100 billions / 1 ounce of blood per day

• hematopoietic stem cell / hemocytoblast - immature stem cells that could be any blood cell type

  Stages of RBC production:

• myeloid stem cell - stem cell that develops into RBC, platelets, and many WBC

• Proerythroblast - commited RBC developer cell

• basophilic erythroblasts - immature RBC that contains high concentration of ribosomes making stain blue under microscope

• polychromatic erythroblast - immature RBC that produces hemoglobin

• orthochromatic erythroblast - immature RBC - changes blue color to the pink and red

• reticulocyte - young RBC - contains a network of clumped ribosomes

• reticulocyte counts - a blood test that measures the number of immature red blood cells (called reticulocytes) in your blood

  1. Proerythroblast:

  The earliest stage of erythropoiesis.

  Formed from a hematopoietic stem cell in the bone marrow.

  2. Basophilic Normoblast:

  Characterized by a large, centrally located nucleus and basophilic (blue-staining) cytoplasm.

  Hemoglobin synthesis begins at this stage.

  3. Polychromatophilic Normoblast:

  The nucleus becomes smaller and the cytoplasm acquires a pink-gray color due to the presence of both hemoglobin and residual RNA.

  4. Orthochromatic Normoblast:

  The nucleus is lost and the cytoplasm becomes a deep pink color.

  5. Reticulocyte:

  The cell is released from the bone marrow into the bloodstream.

  It still contains a reticular network of RNA, which can be visualized with special stains.

  6. Mature Erythrocyte:

  The reticular network disappears and the cell becomes a fully functional red blood cell with a characteristic biconcave shape.

  ^ whole process take 15 days

  Regulation and Requirements for Erythropoiesis

• iron, amino acid, and vitamin B helps create blood

  Hormonal controls

• Erythropoietin (EPO) - a hormone produced primarily by the kidneys that stimulates the production of red blood cells (erythrocytes) in the bone marrow

• HIF / hypoxia-inducible factor - a protein complex that helps the body respond to low oxygen levels, or hypoxia

  EPO - Blood oxygen drop causes:

  1) excessive RBC destruction or bleeding

  2) iron deficiency

  3) high altitudes or pneumonia - reduced oxygen

• Testosterone - enhances production of EPO which gives them a higher RBC

• 65% of body’s iron supply is in hemoglobin in RBC

• Ferritin - protein that stores iron

• Hemosiderin - brown iron containing pigment broken down by RBC’s

• Transferrin - transports iron to bone marrow for RBC production

Fate and Destruction of RBC

Life span - 100-120 days

• old, dying RBC go to spleen

• Macrophaces destroy/ get rid of erothrocytes

• Bilirubin - a yellow-orange pigment that is produced when red blood cells break down

• urobilinogen - a yellow substance that is produced when red blood cells are destroyed

• stercobilin - a bile pigment that gives feces its brown color - breakdown of hemoglobin

Erythrocytes disorders

• a condition in which the body does not have enough healthy red blood cells or hemoglobin

  3 groups of anemia:

  • blood loss - Hemorrhagic anemia

    - rapid - ex: stabbed - fixed by replacing blood

    - chronic blood loss

  • not enough RBC

    - failure of red bone marrow

    - iron deficiency anemia

    - microcytes - red blood cells (RBCs) that are smaller than normal

    - Pernicious anemia - autoimmune disease - a type of anemia caused by a deficiency in vitamin B12

    - intrinsic factor - a protein in the stomach that helps absorb vitamin B12

    - macrocytes - abnormally large red blood cells

    - Renal anemia - happens when the kidneys are damaged, they can't signal the body to make enough red blood cells, leading to anemia

    - Aplastic anemia - rare blood disorder where the bone marrow fails to produce enough blood cells

  • too many/ not destroyed RBC

    - hemolytic anemia -a condition in which red blood cells are destroyed prematurely, leading to a decrease in the number of healthy red blood cells in the bloodstream

    - Thalassemias - enetic blood disorder that directly results in decreased production of hemoglobin

    - Sickle-cell anemia - a lifelong blood disorder that causes red blood cells to become misshapen and sickle-shaped. This prevents the cells from flowing through blood vessels easily

    - Hydroxyurea - medication that is used to treat leukemia and sickle cell anemia

  - Polycythemia - too many RBC that causes blood to be to thick

  - Polycythemia vera - bone marrow cancer

  - Secondary polycythemias - a secondary response to another medical issue causing the overproduction of red blood cells

  - occurs normally in residents living in high altitudes

• Blood doping - when an athlete draws blood so that the body reproduces blood supply then they reinject the blood giving them more oxygen and speed for an even

  • can be dangerous leading to stroke or heart failure

14.4 Notes: Leukocytes and WBC

• WBC or white blood cells - essential part of our immune system protects the body from infection, virus, and bacteria

• diapedesis - the passage of blood cells through the intact walls of the capillaries, typically accompanying inflammation

  • WBC uses diapedesis

• amoeboid motion - a crawling-like way that cells move by changing shape

• positive chemotaxis - the movement of a cell or organism towards a higher concentration of a chemical stimulus

• leukocytosis - a condition in which there is an abnormally high number of white blood cells (leukocytes) in the blood

  Phrase for memorizing lukocytes:

Never Let Monkeys Eat Bananas

Neutrophils , Lymphocytes, Monocytes, Eosinophils, Basophils

There are 2 types of leukocytes

• Granulocytes - large and short lived - spherical shaped

  • Eosinophils

    - 2-4% of leukocyte supply

    - two lobes

    - destroy parasitic worms

  • basophils

    - rarest 0.5-1% of WBC supply

    - has U or S shaped purple nucleus

• Histamine - released by basophils in response to inlammation and allergies that causes allergic reactions - make blook vessels dilate

• Antihistamine - a type of medication that blocks the effects of histamine, a chemical released by the body in response to allergic reactions

  • neutrophils

    - most common WBC

    - have 3- lobes

    - kills bacteria

• defensins - a group of peptides that are part of the innate immune system and help fight infection

• Polymorphonuclear leukocytes - are termed professional phagocytes because they are specially equipped to seek and destroy invading microorganisms

• Respitory burst - a rapid increase in oxygen consumption and the production of reactive oxygen species (ROS) by phagocytic cells, such as neutrophils and macrophages

  Agranulocytes:

• Agranulocytes - don’t have visible granules

  • Lymphocytes - large dark purple nucleus - 25% of WBC’s

    - identified by diameter

    - mostly found in lymph nodes and spleen

• T lymphocytes - fights directly against tumor and virus infected cells - called T cells

• B lymphocytes - B cells - mature into plasma cells in response to antigens

• Plasma cells - Plasma cells are antibody-producing factories that play a key role in the immune system's defense against pathogens

• antibodies - Y-shaped blood protein that chemically binds to unwanted substances like bacteria to get rid of it

  • monocyte - 3-8% of WBC’s - Dark purple U shaped nucleus

• Macrophages - made from monocytes - white blood cell that surrounds and kills microorganisms, removes dead cells, and stimulates the action of lymphocytes

  Production and Life Span of Leukocytes - leukopoiesis

• Leukopoiesis - production of WBC

• Interleukins - proteins that act as chemical messengers between white blood cells and other cells

• colony-stimulating factors (CSFs) - proteins that regulate the production and function of blood cells, primarily white blood cells (granulocytes and macrophages)

• lymphoid stem cells - a type of progenitor cell that gives rise to all the cells of the lymphoid immune system - turn into T&B cells

• myeloid stem cells - a type of primitive blood cell that give rise to RBC, platelets, neutrophils, eosinophils, basophils, and monocyte

• promyelocytes - immature white blood cells that are found in bone marrow - precursor to usually neutrophils

• myelocyte - an immature white blood cell (granulocyte) that is produced in the bone marrow

• band cell - stage when cell develops a nuclei arc starting to develop lobes

  2 lineages of agranulocytes

  1) Monocytes come from myeloid cells - the monocyte goes from myeloid cell, monoblast, then premonocyte, to monocyte

  • live for months

  2) T&B lymphocytes - go from lymphoid stem cell, T or B lymphocyte precursor, then T or B cells

  • live for a few hours to decades

  WBC disorders:

• Leukemia - to many abnormal WBCs

  • myeloid leukemia - myeloblasts descendants

  • lymphocytic leukemia - lymphocytes

  • acute leukemia - quickly advancing - affect more children

  • chronic leukemia - slowly developing - affect more of the elderly

  • WBCs flood red marrow harming the production of RBCs

• Infectious Mononucleosis - kissing disease/ Mono

  • to many lymphocytes - grow to be really large

17.5 - Notes:

• Platelets - small, colorless cell fragments in our blood that form clots and stop or prevent bleeding

• megakaryocytes - large, specialized cells found primarily in the bone marrow

  • contain seratonin, calcium, and variety of enzymes

• thrombopoietin - a hormone that regulates platelet production in the body

• megakaryoblast - a large, immature cell found in the bone marrow that acts as the precursor to a megakaryocyte

  • platelets come from megakaryocytes

17.6 Notes - Homeostasis

• homeostasis - process of maintaining a stable internal environment in the body - stopic the bleeding

  1) Vasoconstriction: The damaged blood vessel constricts to reduce blood flow.

  2) Platelet plug formation: Platelets stick to the damaged area to form a temporary plug.

• prostacyclin - a lipid mediator produced by the lining of blood vessels (endothelium). It plays a crucial role in maintaining cardiovascular health and preventing blood clots

• Adenosine diphosphate (ADP) - a molecule that stores and transfers energy in cells. It's also involved in blood clotting - causes more platelets to stick

• Serotonin - help with blood clotting by causing blood vessels to constrict and promoting platelet aggregation at the site of a wound

• thromboxane A₂ - a substance that causes blood clotting and vasoconstriction - It's produced by platelets and endothelial cells.

  3) Coagulation: Coagulation factors in the blood amplify the clotting effects to stabilize the plug.

• procoagulants/clotting factors - substances that promote blood clotting, or coagulation - They include platelets, blood factors, and proteins

  3 stages of coagulation

  1. Pathways to prothrombin activator

  • - intrinsic - pathway is triggered when blood comes into contact with an abnormal surface - triggered by platelets, collagen, or glass

    - extrinsic - pathway is triggered when blood is exposed to tissue factors

    usually extrinsic pathways are triggered by traumas - triggered by TF or F3

    - extrinsic pathway is faster

    • Factor 3/ Tissue factor - protein that when exposed to blood triggers the clotting affect

    • prothrombin activator - a complex of proteins that converts prothrombin into thrombin, which helps blood clot

    - both pathways work together

    2. Common pathway to Thrombin

  • Prothrombin activator converts prothrombin to thrombin

    3. Common pathway to the Fibrin Mesh

  • Fibrin Mesh - thin network of sticky proteins that trap red blood cells and platelets in a stable structure that seals wounds.

  • thrombin causes fibrinogen to turn into fibrin

  • fibrinogen - a protein found in the blood that plays a crucial role in blood clotting - produced in the liver

  • fibrin - insoluble protein that forms blood clots

  • Factor XIII fibrin stabilizing factor - blood protein that cross links fibrin stands together to make it stable to form fibrin mesh

  • Anticoagulant - factors that stop blood clots

  • 3-6 minutes is how long a clot takes to form

  4) Clot formation: The platelet plug and fibrin form a solid clot.

  • Clot retraction - a physiological process that occurs after blood clotting to stabilize and strengthen the clot

  • clear, yellowish liquid that remains after blood has clotted. It is a component of plasma, the liquid portion of blood, and contains various proteins, electrolytes, and other substances

  • Platelet derived growth factor PDGF - a group of proteins that help heal wounds and repair damaged blood vessels

    How does PDGF work?

    PDGF binds to and activates receptors on cells, which stimulates cell growth

    PDGF changes cell shape and motility

    PDGF stimulates chemotaxis, which is when cells move toward a gradient of PDGF

  • Fibrinolysis - the process of breaking down blood clots

  • Plasmin - primarily responsible for breaking down blood clots by degrading fibrin

  • Plasminogen - a protein produced primarily by the liver that circulates in the blood as an inactive precursor to the enzyme plasmin

  • tissue plasminogen activator (tPA) - An enzyme made in the body that helps dissolve blood clots

  5) Clot lysis and tissue remodeling: The clot dissolves and is replaced by normal tissue as the injury heals.

Factors limiting clot growth or Formation:

Protein C pathway:

Activated protein C (APC), generated by thrombin binding to thrombomodulin on endothelial cells, actively inhibits factors Va and VIIIa, limiting clot propagation.

Antithrombin:

Directly inhibits thrombin, preventing further fibrinogen conversion to fibrin.

Heparin sulfate:

Found on endothelial cells, acts as a cofactor for antithrombin, further enhancing its ability to inhibit thrombin.

Endothelial cells:

Healthy endothelial cells release prostacyclin, a molecule that inhibits platelet aggregation and promotes vasodilation, preventing unnecessary clot formation.

Fibrinolytic system:

Plasminogen is converted to plasmin, an enzyme that actively breaks down fibrin clots.

Rapid removal of coagulation factors: The body's immune system breaks down blood clots after they form.

Inhibition of activated clotting factors: Natural anticoagulants like protein C, protein S, and antithrombin limit clot formation.

Deficient clotting factors: A lack of clotting factors, such as those caused by liver disease, can impair blood's ability to clot.

Dysfunctional clotting factors: Elevated levels of fibrinogen or factor VIII, or dysfunctional fibrinogen, can contribute to blood clotting disorders.

Inflammation: Inflammatory mediators can increase platelet count and responsiveness to thrombin, while decreasing fibrinolytic activity.

Blood-thinning medications: Certain medications can affect clotting time.

Homeostasis Disorders:

• Thromboembolic disorder - cuases unwanted blood clots

  • thrombus - a blood clot that forms within a blood vessel

  • embolus - a blood clot or foreign object that breaks away and travels through the bloodstream to block a blood vesse

  • embolism - essentially, a "traveling clot" that obstructs blood circulation when it gets stuck in a vessel.

  • anticoagulant drugs - drugs that help prevent unwanted blood clots

    • Aspirin - drug that stops platelet plug formation

    • heparin - injectable most common anticoagulant for blood transfusion patients

    • Warfarin - orally - reduces stroke in which a patient is at risk for blood pooling in the heart - blocks vitamin K

  • Bleeding disorder

    • Thrombocytopenia - there is not enough platelets in the blood

      • petechiae - red or purple dots on the skin signaling bleeding underneath the skin

    • Impaired Liver Function - reducing the production of essential clotting factors, leading to a prolonged clotting time and increased bleeding risk

    • Hemophilia - a rare, inherited bleeding disorder that prevents blood from clotting properly

      • causes bleeding into joints and muscles

      • hemophilia is caused by Factor 8 - crucial protein in the blood clotting process

      • have lower immune system

      • patients depend on transfusion

    • Disseminated Intravascular Coagulation - happens from pregnancy complications or an incompatible blood transfusion

      • a life-threatening condition characterized by widespread clotting throughout the body

17.7 - Transfusion

Cardiovascular system minimizes blood loss

1) reducing volume of affected blood vessels

2) higher production of red blood cells

Transfusing RBC’s

• whole blood transfusions - only when blood loss is rapid

• Packed red blood cells or PRBCs - infusion of mostly just RBC’s

  Human Blood Groups

• antigens - substances that trigger an immune response in the body

  • Ex: mismatched RBC’s or bacteria

  • Antigens determine blood type and group

• agglutinogens - are proteins produced by foreign cells or genetic material

• ABO blood groups - determined by type A or B agglutinogen

  • type O blood has neither A or B agglutinogen

• Agglutinins - antibodies that cause particles, such as bacteria or red blood cells, to clump together or agglutinate

Rh Blood Groups

• Rh factor - protein on RBC's that tell you whether you have negative or positive Rh

• anti- Rh antibodies - proteins produced by the immune system of an Rh-negative person when exposed to Rh-positive blood

  • the antibodies attack the Rh positive blood cells rupturing them

• Hemolytic disease of the newborn/erythroblastosis fetalis - when the mother and her baby do not have the same Rh factor

  Transfusion Reactions

• Transfusion reaction - where the recipient's body reacts negatively to the donated blood

  Transfusion reaction problems

  1) transfused blood cannot transport oxygen

  2) red blood cells clump stopping blood flow

• universal donor - type O blood that can donate to any other blood type

• universal recipients - Group AB blood can recieve blood donations from anyone

• autologous transfusion - patient donates their own blood ahead of time then when needed then transfuse the blood back into themselves

  Blood Typing

• Cross matching - a test that determines if a donor's blood is compatible with a recipient's blood

Restoring Blood Volume

Saline or multiple electrolyte solution helps restore blood plasma and overall blood volume

17.8 Notes - Blood tests

• lipidemia - a medical condition characterized by abnormally high levels of lipids (fats) in the blood

• differential white blood cell count - determines size of individual leukocytes

• prothrombin time - test to assess the bloods ability to clot

• platelet count - tests blood for thrombocytopenia

• CMP - (comprehensive metabolic panel) - a blood test that measures various substances in the blood to assess overall health

  • chemistry test

• CBC ( complete blood count) - a common blood test that measures the number and types of various cells in the blood