Chapter 17: Blood Flashcards
What are the three main functions of blood?
transport, regulation and protection
Transport Function
distribute o2, nutrients, and hormones to cells and metabolic wastes (co2 and nitrogenous wastes) to elimination sites
Regulation Function
maintains normal body temp, pH of body fluids and fluid volume in blood vessles
Protection Function
prevents blood loss and defends body against invading microorganisms
Characteristics of Blood
sticky, viscous fluid with a metalic taste (due to iron); color ranges from bright red (o2 rich, arteries) to dark red (o2 poor, veins); pH ranges from 7.35-7.45 (blood is slightly basic); volume varies by sex (5-6L in adult male and 4-5L in adult female)
Composition of Blood
consists of plasma (liquid portion) and 3 formed elements: erythrocytes, leukocytes, and platelets; components can be separated by centrifugation (WBC is the buffy coat); hematocrit values- healthy male 42-52%, healthy females 37-47%
Plasma
90% water and 10% solutes
What are the solutes found in plasma?
electrolytes (ions, na, k, ca, cl, hco3- bicarbonate); plasma proteins (albumin, globulins, fibrinogen, and most produced by liver); nitroginous substances (urea, uric acid, creatinine); nutrients (glucose, amino acids, fatty acids and glycerol, vitamins); respiratory gases (o2 and co2); hormones (steroids and TH transported by plasma protein)
Structure of Erythrocytes
biconcave disc (~7.5 micrometer diameter); at maturity lack a nucleus (anucleate) and mitochondria (so they only produce ATP by glycolysis); packed with hemoglobin molecules; each of which contains 4 heme hroups and 4 globin chains; life span about 120 days (filtered and recycled by spleen)
Function of Erythrocytes
transports respiratory gases; 98% of o2 transported from lungs to tissues is bound to the iron atom of heme; 20% of co2 transported from tissues to lungs is bound to globin (carbaminohemoglobin)
Erythropoiesis
RBC production; occurs in red bone marrow; derived from hematopoietic stem cell (aka heocytoblasts) (all blood cells come from this); mostly in axial skeleton
Phases of Erythropoiesis
hematopoietic cells to myoblast to proerythroblast (once at this phase it is committed to forming a RBC); phase 1- ribosome synthesis; phase 2- hemoglobin accumulation then phase 3- ejection of nucleus then a reticulocyte and then it enters the blood; whole process takes 15 days; process requires nutrients, vit. b12, folic acid, adnd iron
What regulates erythropoiesis?
erythropoietin (EPO) hormone synthesized by the kidney
Erythropoietin Mechanism
1) stimulus- hypoxia (inadequate o2 delivery) due to decreased RBC, decreased hemoglobin, decreased availability of o2; 2) kidney releases erythropoietin; 3) stimulates red marrow; 4) enhanced erythropoiesis increases RBC; 5) o2 carrying ability of blood rises
Fate of RBCs
aged and damaged red blood cells are engulfed by macropahges of spleen, liver, and bone marrow; hemoglobin is broken down; iron and amino acids are recycled; bilirubin is a waste product that the liver uses to make bile
Erythrocyte disorders are classified as either….
anemia or polyathemia
Anemia
reduced o2 carrying capacity of blood caused by blood loss, insuffience RBC production, or excessive destruction of RBC
Hemorrhagic Anemia
may be acute (rapid blood loss) or chronic (slow and persistent)
Iron Deficiency Anemia
inadequate intake or malaabsorption of iron
Pernicious Anemia
autoimmune disease; imune cells attack stomach mucosa cells that produce intrinsic factor (required for intestinal cells to absorb b12); mostly seen in elderly
Renal Anemia
lack of EPO (erythropoietin)
Aplastic Anermia
destruction or inhibition of red bone marrow; one of the reasons they do cancer treatments in cycles and not continuous
Thalassemias
genetic; one of the 2 beta globulin chain is absent or defective resulting in fragile RBC that rupture prematurely
Sickle Cell Anemia
genetic; beta globulin gene corder for production of beta globulin chains that have 1 amino acid substitution (val is swapped for glu at position 6); RBC rupture prematurely
Polycythemia
abnormal excess of RBCs caused by polycethemia vera; seondary polycythemia
Polycythemia Vera
bone marrow cancer
Secondary Polycythemias
occur as a result of elevated EPO production or hypoxia (decrease in o2 availability due to living at high altitudes or smoking)
Blood Doping
injecting EPO or harvesting and storing RBCs; artificially induced polycythemia
Characteristics of Leukocytes
WBC; nuceleate; less numerous than RBCs’ exit capillaries via diapedesis; exhibits amoeboid movement in tissues and postive chemtaxis (move towards certain chemicals); protective functions
What are the two major types of leukocytes?
granulocytes and agranulocytes
Saying to remember the order of leukocytes by amount (from highest to lowest)
Never Let Monekys Eat Bananas; neutrophils, lymphocytes, monocytes, eosinophiles, and basophiles
Granulocytes
spherical; larger and have shorter life span that RBCs; multilobed nucleus; cytoplasmic granules
Neutrophils
granulocyte; multilobed; kinda big; not very noticable granules; 3000-7000; takes about 14 days to develop; life span of 6 hrs to a few days; phagocytize bacteria
Eosinophil
bilobed; granulocyte; definitive granules; 100-400; about 14 days to make; life span about 5 days; kills parasitic worms and complex role in allergy and asthma
Basophil
granulocyte; bilobed; really dark granules; 20-50; takes 1-7 days to make and life span of a few hrs to a few days; release histamine and other mediators of ifalmmation contain heparin, an anticoagulant; also involved in allerfica reactions
Agranulocytes
spherical; spherical or kidney shaped nucleus; lack visible cytoplasmic granules
Lymphocyte
agranulocyte; large circular nucleus; little cytoplasm seen; 1500 - 3000; takes days to week to make and life span of hours to years; mount immune response by direct cell attack of via antibodies
B Cells
type of lymphocyte; form antibody producting plasma cells; made in bone marrow
T Cells
type of lymphocyte; attack viral infected cells and tumor cells; made in thymus
Monocyte
usually the largest; typically ‘U’ shaped nucleus; light cytoplasm; 100-700; developed in 2-3 days and life span of months; phagocytosis; develop into macrophages in the tissues
Leukopoesis
WBC production; occurs in red bown marrow; derived from hematopoietic cells (aka hemocytoblasts); regulated by interleukins and colony stimulating factors
What do myoblasts lead to?
eosinophils, basophils, neutrophils and monocytes
Leukocytic Disorder
involve over or underprodcution of WBCs
Leukopenia
underproduction; abnormally low number of WBCs in blood; usually induced by glucocorticoids or anticancer drugs
Leukemias
overproduction (aka leukocytosis) of abnormal WBCs; crowd out other cell lines; acute forms advance rapidly (more serious primarily affect kids); chronic form advances slowely (primarily affect elderly)
Myeloid Leukemia
involves myeoblast descendants (neutrophils, eosinophils, basophils)
Lymphocytic Leukemia
involves lymphoblast descendant (B and T cells)
Infectious Mononucleosis
aka mono; overproduction of abnormal WBCs; caused by epstein bar virus
Characteristics of Platelets
anucleate cytoplasmic fragments; have granules containing substances involved in clotting (ADP, serotonin, Ca2, enzymes , fibrinogen, platelet derived growth facotr; seal small tear in blood vessels istrumental in blood clotting
Thrombopoiesis
platelet production; occurs in red bone marrow; derived from hematopoietic stem cells; regulated by thrombopoietin (hormone produced by liver and kidney)
ADD HEMATOPOIESIS SUMMARY
Hemostasis
process that stopes blood loss from a damaged blood vessel; rapid; localized; triggered by injury to blood vessels; inactive platelets circulate in blood
Events of Hemostasis
vascular spasm then platelet plus formation; then coagulation
Vascular Spasm
vascular smooth muscle contracts (vasoconstriction)
Platelet Plug Formation
platelets activated; stick to exposed collagen fibers and each other creaing a temporary plug
Coagulation
clotting; reinforces platelet plug with fibrin threads; requires cloting factors, CA2 and vit K
ADD CLotting FACTORS
What are the three phases of coagulation?
phase 1: intrinsic/extrinsic pathway; phase 2: common pathway; Phase 3: common pathway
Phase 1: Intrinsic/Extrinsic Pathways
slowest of the three phases; results in the formation of prothrombin activator (required for phase 2); involves two pathways
Intrinsic Pathway
all factors needed for clotting found WITHIN blood; triggered by negatively charged surfaces (activated platelets, collagen, glass); many steps therefore slower than extrinsic pathway
Extrinsic Pathway
one factor needed for clotting (tissue factor) which is found outside the blood; tissue factor is a membrane cound glycoprotein found in subendothelial tissues; fewer steps therefore faster than intrinsic
Phase 2: Common Pathway
prothrombin activator catalyzes conversion of prothrombin II to thrombin (required for pahse 3)
Phase 3: Common Pathway
thrombin catalyzes conversion of soltuble fibronogen I to insoluble fibrin threads XIII to bind fibrin threads tightly forming a fibrin mesh
How long does it take the clotting process to be complete?
3-6 mins
Clot Retraction
stabilizes clot; platelets contract to compact clot; platelets release plateltet derived growth factor which stimualtes blood vessel repair
Fibrinolysis
degrades clot; endothelial cells in area of clot secrete tissue plasminogen in clot to plasmin (fibrin digesting enzyme that dissolves fibrin mesh)
Thromboemolytic Disorders
cause undesirable clotting
Thrombus
clot that develops and persists in an unbroken vessel
Embolus
clot traveling through bloodstream; may cause embolism
What do you use to help prevent undesirable clotting?
use anticoagulants; aspirin, heparin, warfarin
Bleeding Disorders
prevent normal clottig
Thrombocytopenia
deficiency of platelets; results in formation of petechiae on skin
Impaired Liver Function
deficiency of clotting factors due to lack of vit. K, hepatitis, or cirrhosis
Hemophilias
genetically inherited deficiency
Hemophilia A
lacking factor VIII; most common type; x linked
Hemophilia B
lacking factor IX; sex linked
Hemophilia C
lack factor XI; rarest; autosomal
Type A Blood
exhibits A antigens; has anti B antibodies in plasma
Type B Blood
exhibits B antigens; has anti A antibodies in plasma
Type AB Blood
has both A and B antigens; NO antibodies
Type O Blood
NO antigens; BOTH A and B antibodies
Order of blood types from most common to least common
O, A , B , AB
Rh Blood Groups
based on the presence of absence of 1 antigen (D or Rh antigen); Rh+ have D antigen; Rh - (do not have D antigens)
Rh-
anti-Rh antibodies do NOT form in the plasma of Rh- individuals UNLESS they have been EXPOSED to the D antigen; like a transfusion or birth
Hemolytic Disease of the Newborn
aka erythroblastosis fetialis; occurs when an Rh- women is pregnant with her SECOND Rh+ child; reason why Rh- women given RhoGAM shot before or shortly after birth, miscarraige or abortion it blocks the production of anti Rh antibodies
Transfusion Reactions
occur when receipients antibodies attack the transfused fonors RBCs causing them to aggulinate (clump)
How to Blood Type
use of anti A, B, D sera to determine the blood group of donor and receipinet BEFORE blood is transfused
Differential White Blood Count
count 100 WBC and identify/categorize
Prothrombin Time (test)
amount of time it takes for blood to clot
Platelet Count
you actually count the platelets
Comprehensive Metabolic Panel
tests basically everything
Complete Blood Count
counts all formed elements in blood
