Upgrade to remove ads
Only $35.99/year

The Blood: Day 2: WBC's

Terms in this set (63)

the only formed elements that are complete cells
Leucocytes (WBC)
Granulocytes and Agranulocytes
Leucocytes are divided into two groups called
neutrophils, eosinophils,basophils
granulocytes are further divided into three groups called
monocytes and lymphocytes
agranulocytes are further divided into two groups called
Granulocytes
smaller. microphages, capable of diapedesis (extravasation), LS is a few hours (4-8) in the blood and a few days (4-5) in the tissues
agranulocytes
larger. macrophages, capable of diapedesis (extravasation). LS: monocytes 10-20 hrs in the blood and for years in the tissues. LS:lymphocytes cycle: blood<-->tissue<-->lymph<-->blood.
diapedesis
The movement or passage of blood cells, especially white blood cells, through intact capillary walls into surrounding body tissue. Usually during inflammation.
positive chemotaxis
inflammatory chemicals diffusing away from the inflamed site act as chemotactic agents (agents that attack and ingest invading bacteria).
Neutrophils
60-70% of WBC's (the most common). aka polymorphonuclear leukocytes. Appearance: nucleus usually with 3-5 lobes in S or C-shaped array. Differential count: increases in bacterial infections. Modes of action or functions: phagocytosis and digestion, release enzymes that trigger a RESPIRATORY BURST (a release of enzymes that will kill infectious cells and agents)- superoxide anions (O2), hydrogen peroxide, and hypochlorite form a "KILLING ZONE"
Eosinophils
2-4%. Appearance: nucleus usually has 2 large lobes connected by a thin strand. Differential count: fluctuates greatly from day to night, seasonally, and with phase of menstrual cycle, increases in parasitic infections, allergies,collagen diseases, and diseases of spleen and CNS. Functions: phagocytosis of antigen-antibody complexes, allergens, and inflammatory chemicals, release enzymes that weaken or destroy parasites such as worms
More actions of Eosinophils
KILL PARASITES by producing superoxide anions, hydrogen peroxide, and various toxic proteins. may promote action of basophils and mast cells
Basophils
.5-1%. Appearance: nucleus large and U to S-shaped, but typically pale and obscured from view. Differential count: increases in viral infections and inflammation. Functions:differentiate into macrophages, phagocytize pathogens, dead neutrophils, and debris of dead cells, "present" antigens to activate other cells of immune system
more actions of basophils
SECRETE HISTAMINES (vasodilators) and heparin (anticoagulant) (as do mast cells - ex. basophils that leave the blood stream).
histamines
vasodilators
heparin
anticoagulant
Monocytes
appearance: nucleus is ovoid, kidney-shaped or horseshoe-shaped, light violet. differential count: increases in viral infections and inflammation. functions: differentiate into microphages, phagocytize pathogens, dead neutrophils, and debris of dead cells. "present" antigens to activate other cells of immune system.
more actions of monocytes
emigrate from the blood into loose connective tissues and transform into macrophages. act as antigen presenting cells (APC's). LS: 10-20 hrs in the blood and possibly years in the tissues
tissue macrophages
originally monocytes, form the microphage system (refers to all the macrophages in the body) or the reticulo-endothelial system. Examples of locations: alveolar macrophages (alveoli), microglial cells (brain), dendritic cells (skin, bone marrow), reticulum cells (spleen, lymph nodes), hepatic macrophages (liver sinusoids). QUANTITATIVELY THE MOST IMPORTANT BODY DEFENSE.
lymphocytes 3 basic categories
NK (natural killer) cells (5%), T cells (80%), B cells (15%) (percentages refer to the amount of these in the blood). Function: body defense-immunity
lymphocytes
appearance: nucleus round, ovoid, or slightly dimpled on one side, of uniform dark violet color. differential count: increases in diverse infections and immune responses. functions: several functional classes usually indistinguishable by light microscopy, destroy cancer cells, cells infected with viruses, and foreign cells. "present" antigens to activate other cells of immune system. coordinate actions of other immune cells. secrete antibodies. serve in memory memory
leukopoiesis
white blood cell production; stimulated by CSF's (colony stimulating factors) and interleukins, which are secreted by mature T-cells (lymphocytes) and macrophages in response to challenges to the immune system.
red bone marrow
stores mature granulocytes and monocytes, but not RBC's
functions of platelets
platelet plug formation, phagocytize bacteria, secrete vasoconstrictors, chemotaxic substances, growth promoters, clotting factors, etc. Note: have more functions than other formed elements.
thrombopoiesis
stimulated by thrombopoietin from liver and kidneys. spleen serves as a storage site.
LS of platelets in the blood
10 days before they disintegrate
blood types and transfusion compatibility are
a matter of interactions between plasma proteins and erythrocytes.
antigens
are complex molecules such as proteins, glycoproteins, and glycolipids that are genetically unique to each individual. they occur on the surfaces of cells and enable the body to distinguish its own cells from foreign matter.
antibodies
when the body detects an antigen of foreign origin, it activates an immune response. this response consists partly of the plasma cells, secreting proteins (gamma globulins) called these. They bind to antigens and mark them, or the cells bearing them, for destruction
agglutination
one method of antibody action, in which each antibody molecule binds to two or more antigen molecules and sticks them together. repetition of this process produces large antigen-antibody complexes that immobilize the antigens until certain immune cells can break them down.
agglutinogens
blood types are based on antigens called this on the surface of RBC's.
agglutinins
blood types are based on plasma antibodies called this
ABO blood group
A, B, AB, O. Determined by the hereditary presence or absence of antigens A and B on your RBC's. Chemical basis of this is based on terminal carbs of the antigen glycolipids
anti A and B
produced in first 2-8 months from response to intestinal bacteria -max production at age 8-10.
Rh System
you either have this or you don't. Seperate from other blood typing. 6 common types of these antigens; factors C,D,E,c,d,e (over 40 total, many very rare). D factor more antigenic than other factors. If D factor present, a person is Rh positive.
transfusion reaction
the agglutinated RBC's block small blood vessels, hemolyze, and release their hemoglobin over the next few hours or days. Free hemoglobin can block the kidney tubules and cause death from acute renal failure within a week or so.
hemolytic disease of the newborn (HDN) or erythroblastoids
1st pregnancy is uneventful because the placenta normally prevents maternal and fetal blood from mixing. However, at the time of birth or if a miscarriage occurs, placental tearing exposes the mother to Rh+ fetal blood (she's Rh-) . She then begins to produce anti-D antibodies. If she becomes pregnant again with an Rh+ fetus, her anti-D antibodies may pass through the placenta and agglutinate the fetal erythrocytes. Agglutinated RBC's hemolyze, and the baby is born with a severe anemia called this
hemolyze
the rupture or destruction of red blood cells
Hemostasis
refers to the stoppage of bleeding. happens in three phases that are seperate but overlapping. Protection against blood loss.
Step 1 of hemostasis
vascular spasm and vasoconstriction. Caused by local myogenic spasm (muscle reflexes), vasoconstrictors, and nervous reflexes. Reduces the amount of blood loss but doesn't stop it. The vascular spasm is maintained long enough for the other two hemostatic mechanisms to come into play.
step 2 of hemostasis
platelet plug formation. Occurs when a vessel is broken, however, collagen fibers of the wall are exposed to the blood. Contact with collagen or other rough surfaces, platelets grow long spiny pseudopods that adhere to the vessel and to other platelets; the pseudopods then contract and draw the walls of the vessel together. the mass of platelets are called a platelet plug. As platelets aggregate, they undergo degranulation (the exocytosis of their cytoplasmic granules and release factors that promote hemostasis).
ADP
part of step 2 of hemostasis. One of the chemical messengers released during degranulation (the exocytosis of their cytoplasmic granules and release factors that promote hemostasis). attracts platelets
serotonin
part of step 2 of hemostasis. One of the chemical messengers released during degranulation (the exocytosis of their cytoplasmic granules and release factors that promote hemostasis). attracts platelets and is a vasoconstrictor
thromboxane A2
part of step 2 of hemostasis. One of the chemical messengers released during degranulation (the exocytosis of their cytoplasmic granules and release factors that promote hemostasis). A vasoconstrictor, promotes degranulation, and promotes aggregation (the "GLUE" that makes the platelets stick together). Approx. 1 min to plug formation.
prostacyclin (PGI2)
platelets normally repulsed due to this molecule that prevents blood clot reaction without blood loss. Making it possible that all the hemostasis reactions don't occur without the loss of blood.
step 3 of hemostasis
blood clotting or coagulation. last but most effective defense against bleeding.
blood clotting times
begins in 15 to 120 sec., 3 to 6 min. for clot to form, 20 to 60 min. for clot to retract
blood clotting's objective
to convert the plasma protein fibrinogen into fibrin, a sticky protein that adheres to the walls of a vessel. As blood cells and platelets arrive, they stick to the fibrin like insects in a spider web. the resulting mass of fibrin, blood cells, and platelets ideally seals the break in the blood vessel.
extrinsic and intrinsic mechanisms
two reaction pathways to coagulation
extrinsic mechanism
one of the two reaction pathways to coagulation. Initiated by clotting factors released by the damaged blood vessel and perivascular tissues. Note: name refers to the fact that these factors come from sources other than the blood itself. However, both systems work simultaneously to contribute to hemostasis.
intrinsic mechanism
one of the two reaction pathways to coagulation. Its name refers to the fact that its clotting factors come from the blood itself. However, both systems work simultaneously to contribute to hemostasis.
extrinsic and intrinsic mechanisms
2 pathways that lead to activation of prothrombin activator and a cascade of enzymes
3 steps that occur with extrinsic and intrinsic mechanisms
1. tissue is damaged>prothrombin activated. 2. prothrombin (inactive) changed into thrombin (active) 3. thrombin will convert fibrinogen into fibrin. Fibrin (little threads) that form longer threads which are fibrin polymers
fibrinogen
origin: is from the liver. Precursor of fibrin.
prothrombin
origin: liver. Precursor: thrombin
procoagulants
proteins produced by the liver. they are always present in the plasma in inactive form, but when one factor is activated, it functions as an enzyme that activates the next one in the pathway. Ex: fibrinogen and prothrombin. they are numbered I to XIII (and beyond) in order of discovery (not function)
clot retraction
platelets adhere to the fibrin polymers and contract by means of contractile proteins (actomyosins)
platelet's also release
platelet derived growth factors (PDGF's) or mitotic stimulants for tissue repair
Enzyme amplification
occurs in blood clotting, leading to the production of fibrin
anticoagulant heparin
secreted by basophils and mast cells: activates antithrombin III, a plasma protein (secreted by the liver) that combines with and inactivates thrombin, this interferes with the prothrombin activator formation . Note: thrombin absorbed into fibrin polymers, thus preventing enlargement of the clot
Mechanism for dissolving a blood clot
Prekallikrein is converted to kallikrein. Kallikrien is an enzyme that catalyzes the formation of plasmin from its inactive form Plasminogen. Plasmin is an enzyme that dissolves the blood clot. Prekallikrien>Kallikrien>Plasminogen>Plasmin
Fibrinolysis
the dissolution of a clot. Is achieved by a small cascade of reactions with a positive feedback component. BEGINS IN 2 DAYS
Kallikrien
plasma enzyme involved in the dissolving of a clot.
Plasmin
a fibrin-dissolving enzyme that breaks up the clot
Sets found in the same folder