Ch. 18 - Blood Flashcards
Blood
continuously regenerated CT that moves gases, wastes, and hormones. Transported through cardiovascular system
Arteries transport blood
away from the heart
Veins transport blood
towards the heart
Capillaries
very small vessels that allow for exchange between blood and body tissues.
General Composition of blood
Blood is made up of formed elements and plasma. Formed elements include erythrocytes, leukocytes, and thrombocytes.
Erythrocytes
red blood cells that transport respiratory gases in the blood. It is small and flexible. Lacks a nucleus or organelles and is just packed with hemoglobin. biconcave disc and can stack in a single file called Rouleau.
Leukocytes
white blood cells that defend against pathogens. Contain a nucleus and organelles; no hemoglobin. Motile and flexible. Most are in tissues, not blood. 5 types divided into 2 classes.
Thrombocytes
platelets; help form clots to prevent blood loss
Plasma
fluid portion of the blood; contains plasma proteins and dissolved solutes.
Functions of Blood
transportation, protection, regulation of body conditions
Transportation
blood transports formed elements, dissolved molecules, and ions. Carries o2 and co2 and transports nutrients, hormones, heat, and waste
Protection
leukocytes, plasma protein, and other molecules protect against pathogens. platelets and certain plasma proteins protect against blood loss
Regulation of body conditions
regulates body temp by absorbing heat from body cells and releasing it at dermal capillaries. Regulates pH by absorbing acid and bases from body and neutralizing it using buffers. Regulates fluid balance by adding water by GI tract, losing it through urine, respiration, and skin. blood proteins help maintain osmotic balance.
Color of Blood
Oxygen rich is bright red and o2 poor is dark red
Volume of Blood in average adult
5 liters
Viscosity of blood
about 4-5 times thicker than water. Depends on amount of dissolved and suspended substances. Viscosity increases with # of RBCs and if fluid amount decreases.
Osmosis of Blood
plasma concentration determines the direction of osmosis across capillary walls. During dehydration plasma becomes hypertonic and fluid is drawn from tissues
Blood Temp
blood is 1C higher than body temp and warms areas through which it travels
Blood pH
slightly alkaline; between 7.35-7.45. Crucial for normal plasma protein shape (avoiding denaturation)
Centrifuged blood
whole blood (plasma and formed elements) separated into parts by a centrifuge.
Erythrocytes are lower red layer (44%)
Plasma is straw colored at top of sample (55%)
Buffy coat
very thin 1% middle layer with gray-white color. Composed of leukocytes and platelets.
Hematocrit
percentage of volume of all formed elements. clinical def: % of only erythrocytes. 42-56% of adult males and 38-46% for females. Testosterone causes more erythropoietin secretion by kidney.
Medical vs. Clinical definition of hemocrit
medical: percentage of all formed elements
clinical: percentage of erythrocytes
colloid
blood is a colloid or a substance microscopically dispersed evenly throughout another substance. Contains dispersed plasma proteins that exert colloid osmotic pressure.
Plasma proteins
dispersed in plasma; most produced in the liver or leukocytes. Includes albumin, globulins, fibrinogen and more
Colloid Osmotic Pressure
Prevents loss of fluid from blood as it moves through capillaries to maintain volume and bp. Can be decreased with diseases resulting in fluid loss from blood and tissue swelling. For example liver diseases can decrease production of plasma proteins and kidney diseases can increase their elimination.
Albumins
smallest and most abundant group of plasma proteins 58%. Exerts greatest colloid osmotic pressure (cop) and acts as transport proteins for lipids, hormones, and ions.
Globulins
second largest group of plasma proteins 37%. Smaller alpha-globulins & larger beta-globulins. Transport some water-insoluble molecules, hormones, metals. Gamma-globulins (immunoglobulins or antibodies) aid in body defense.
Fibrinogen
4% of plasma proteins, soluble. Contributes to blood clots where it is converted to insoluble fibrin strands.
Serum
plasma with clotting proteins removed
Regulatory proteins
<1% of plasma proteins. includes enzymes and hormones.
nonpolar molecules require
carrier proteins
____ substances dissolve easily in blood
polar/charged
Hemopoiesis
production of formed elements. Occurs in red bone marrow of certain bones.
Hemocytoblasts
stem cells
pluripotent
an immature or stem cell that can differentiate into many types of cells. Produces 2 different lines: myeloid line and lymphoid line
Myeloid line
forms erythrocytes, all leukocytes except lymphocytes, and megakaryocytes (cells that produce platelets)
Lymphoid line
forms only lymphocytes (type of pluripotent cells)
Colony-stimulating factors (CSFs)
stimulates hemopoiesis
Erythropoiesis
red blood cell production. This process requires: iron, b vits., amino acids. Begins with myeloid stem cell that responds to multi-CSF. Forms progenitor cells, then proerythroblasts. Proerythroblasts become erythroblasts, then normoblasts, then reticulocytes, and then an erythrocyte.
proerythroblast
a large nucleated cell that forms from progenitor cells during erythropoiesis.
erythroblast
smaller cell that produces hemoglobin; formed from proerythroblast in erythropoiesis.
normoblast
smaller than erythroblast, more hemoglobin, anucleate. erythropoiesis process.
reticulocyte
what normoblasts become, lacks organelles except ribosomes that make hemoglobin
erythrocyte
come from reticulocytes; ribosomes have degenerated
Leukopoiesis
production of leukocytes; involves maturation of granulocytes, monocytes, lymphocytes. Multi-CSF and GM-CSF cause myeloid stem cell to form progenitor cell.
granulocytes include
neutrophils, basophils, and eosinophils
Leukopoiesis of Lymphocytes
Lymphocytes derived from lymphoid stem cells that differentiate into b-lymphoblasts and t-lymphoblasts that mature into lymphocytes. Some differentiate directly into natural killer cells
Leukopoiesis of granulocytes
Multi-CSF and GM-CSF cause myeloid stem cell to form progenitor cell. Progenitor cells become myeloblasts that becomes a granulocytes
Leukopoiesis of monocytes
monocytes also derived from myeloid stem cells. M-CSF promotes progenitor cell to become monoblast. Monoblast becomes promonocytes, then monocyte.
Thrombopoiesis
megakaryoblast is produced from myeloid stem cell. This forms a megakaryocyte (large sized and multi-lobed nucleus) b/c of thrombopoietin. 1 megakaryocyte produces thousands of platelets by producing proplatelets. Proplatelets are long extensions that extend through blood vessel wall and into bloodstream. The blood flow slices off fragments making platelets.
Rouleau
erythrocytes that are in a stack in a single file
Hemoglobin
a red-pigmented protein that transports 02 and C02. It is oxygenated when it is fully loaded with oxygen and deoxygenated when not. Each hemoglobin is composed of 4 globins (2 alpha & 2 beta chains). Each chain has a heme group with iron in its center. Oxygen binds to iron, C02 binds to globin protein.
How many 02 molecules can Hemoglobin carry at once?
4, one for each heme group
Erythropoietin (EPO)
increases erythropoiesis. It is produced in kidney and secreted when blood oxygen is low. It stimulates red marrow myeloid cells to make more RBCs to increase o2 carrying capacity. Testosterone stimulates EPO, so males have a higher erythrocyte count and higher hematocrit.
Blood Doping
increasing erythrocytes in blood to enhance athletic performance. Can be done naturally (high-altitude), self-donation, or pharmaceutically. Increases blood viscosity making the heart work harder.
Erythrocyte destruction/removal
erythrocytes cannot synthesize proteins for repair w/o organelles. Max lifespan= 120 days. old erythrocytes are phagocytized in spleen or liver. Globins and membrane proteins –> amino acids for protein synthesis
Iron –> transported by transferrin proteins to liver to be stored in ferritin and hemosiderin cells.
Heme group –> converted to green pigment biliverdin, then to yellowish bilirubin. Then transported by albumin to liver and becomes part of bile.
What makes feces brown?
bilirubin is converted to urobilinogen in small intestine and continues through intestine. Is converted to sterocobilin by bacteria and is expelled as brown pigment.
What makes pee yellow?
bilirubin is converted to urobilin and is excreted as yellow pigment.
Anemia
% of erythrocytes in low or o2 carrying capacity is reduced.
Aplastic anemia
defective red marrow due to poison, toxin, radiation.
Congenital hemolytic anemia
genetic defect; erythrocytes destroyed
Erythroblastic anemia
large # of immature cells due to accelerated cell maturation
Hemorrhagic anemia
due to blood loss
pernicious anemia
failure to absorb Vit. b12 due to lack of intrinsic factor
sickle-cell anemia
genetic; abnormal hemoglobin.
ABO blood group
depends on surface antigens. A and B antigens are membrane glycoproteins
type O blood
has neither a or b antigen; Has both anti-a and anti-b antibodies. o neg is universal donor.
AB blood
has both surface antigens and no antibodies. Universal recipient.
Rh factor
Rh positive can receive neg. blood, but neg. blood cant have Rh pos. anti-d antibodies (antibodies to Rh factor) only appear after Rh neg. has been exposed to Rh positive blood.
agglutination
when antibodies bind to transfused RBC causing a clump. prevents normal circulation. can cause hemolysis, rupture of RBCs or organ damage.
Rh Incompatibility and pregnancy
a neg. mom that has been exposed to Rh+ blood through first childbirth will have anti-d antibodies. These antibodies may destroy fetal RBCs in future pregnancies resulting in hemolytic disease of the newborn. Treated with immunoglobulins.
Erythroblastosis fetalis
hemolytic anemia in the fetus due to Rh incompatibility with mother.
diapedesis
process of squeezing through blood vessel wall
chemotaxis
attraction of leukocytes to chemicals at an infection site.
two classes of leukocytes
granulocytes (have visible granules and consist of neutrophils, eosinophils, and basophils) B.E.N.
agranulocytes (have smaller granules not visible by light microscope; includes lymphocytes and monocytes)
5 types of lymphocytes
Neutrophils, basophils, eosinophils, monocytes, and lymphocytes
Neutrophils
most numerous leukocytes in blood. Have a multiobed nucleus and pale granules (when stained). Enters tissue spaces and phagocytizes infectious pathogens. In chronic bacterial infections, #’s rise dramatically
Eosinophils
1-4%of leukocytes. bilobed nucleus connected by thin strand. Cytoplasm has reddish granules. Phagocytize antigen-antibody complexes or allergens; active in cases of parasitic worm infection.
Basophils
0.5-1% of leukocytes. bilobed nucleus; cytoplasm has blue-violet granules with histamine and heparin. Histamine release causes increase in blood vessel diameter and capillary permeability. Haparin release inhibits blood clotting and keeps fluids leaking out of capillaries. (allergies and inflammation)
Lymphocytes
reside in lymphatic organs and structures. 20-40% of blood leukocytes. round nucleus. Has 3 catergories: t-lymphocytes that manage immune response, lymphocytes that become plasma cells and produce antibodies, and NK(natural killer) cells that attack abnormal/infected tissue.
Monocytes
c-shaped nucleus, 2-8% of blood leukocytes. take residence in tissues. Transform into large phagocytic cells, and macrophages that eat bacteria, viruses and debris.
Leukopenia
reduced number of leukocytes; increases risk of infection
Leukocytosis
elevated leukocyte count; may be due to infection or stress
Differential Count
measures amount of each type of leukocyte and whether and are immature.
Neutrophilia
increase in neutrophils- associated with bacterial infections, stress, and tissue necrosis.
Left-shifted differential
immature neutrophils enter circulation. Named for way lab results were printed
Neutropenia
decreased neutrophil count. Common with anemia, and drug or radiation therapies.
Monocyte count changes
increases in response to chronic inflammatory disorders or TB. Decreases in response to acute allergic and stress reactions.
Basophil count changes
increases in response to myeloproliferative disorders (overproduction of bone marrow) and decreases in response to acute allergic and stress reactions.
Lymphocyte count changes
Increase caused by viral infections, chronic bacterial infections, some leukemias, and multiple myeloma. Decreases with HIV, some leukemias, and sepsis.
Eosinophil count increasing
due to allergic reactions, parasitic infections, and some autoimmune diseases.
Leukemia
malignancy in leukocyte-forming cells. Abnormal development and proliferation of leukocytes. Increase in leukocytes and decrease in erythrocytes and megakaryocytic lines. Results in anemia and bleeding, pallor, and bruising.
Acute leukemia
rapid progression. Death typically within months in children/young adults
Chronic leukemia
slower progression, in middle-aged and older individuals.
Platelets
small, membrane enclosed cell fragments with no nucleus. Break off of megakaryocytes in red marrow and have important role in blood clotting. 150-400k per cubic mm. 30% is stored in speen. Circulates for 8-10 days and then recycled
Hemostasis
stopping of bleeding. Has 3 overlapping phases: vascular spasm, platelet plug formation, and coagulation
Step 1: Vascular spasm
blood vessel constriction to limit blood leakage during blood vessel injury. Lasts many minutes. Platelets and endothelial cells release chemicals that stimulate further constriction.
Step 2: platelet plug formation
Vessels endothelial wall is covered with prostacyclin (an eicosanoid that repels platelets). When damaged, collagen fibers in vessel wall are exposed and platelets stick to them with help of von Willebrand factor. Closes off injury.
Platelet activation
platelet plug forms in 1 min and prevented from getting too large by prostacyclin secretion of healthy cells. platelets cytosol degranulates and releases chemical serotonin and thromboxane A2 that cause prolonged vascular spasms. ADP and thromboxane A2 attract other platelets and facilitate their degranulation. Procoagulants stimulate coagulation and mitosis stimulating substances trigger repair of vessel.
Step 3: Coagulation Phase
network of fibrin forms a mesh (precursor to fibrinogen). Mesh traps erythrocytes, leukocytes, platelets, plasma proteins to form clot. Clotting requires calcium, clotting factiors, platelets, and vit. k.
Clotting factors
inactive enzymes produced in liver. Named in order of discovery (factor 1= fibrinogen, factor 2= prothrombin) Some are proteases that make other factors into active forms
Vitamin K
a fat-soluble coenzyme required for synthesis of clotting factors II, VII, IX, X.
Coagulation pathways
if greater than 10% blood is lost, sympathetic NS increases vasoconstriction, hr, and force of heart contraction and blood is redistributed to heart and brain. Effective in maintaining bp until 40% loss.
Hemolysis
Breaking down of ruptured erythrocytes
Hypoxia
Insufficient oxygen in tissue
Apoxia
No oxygen
Diapedesis
Process of squeezing through blood vessel wall
Agglutination
Clumping from incompatible transfusion. Antibodies bind to RBCS
Chemotaxis
Attraction of leukocytes to chemicals released at infection site.
Thrombin turns _________ into __________
Fibrinogen into fibrin
All coagulation pathways require
Calcium
