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Chapter 19 - Cardiovascular System: Blood

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Name seven functions of blood.
1) transport of gases, nutrients, and waste products
2) transport of processes molecules
3) transport of regulatory molecules
4) regulation of pH and osmosis
5) maintenance of body temperature
6) protection against foreign substances
7) clot formation
Plasma
a pale yellow fluid that consists of about 91% water and 9% other substances such as proteins, ions, nutrients, gases, and waste products
Colloid
a liquid containing suspended substances that don't settle out of solution
Albumin
makes up 58% of the plasma proteins and is important in the regulation of water movement between tissues and blood;
plays a role in maintaining blood colloid osmotic pressure;
serves as a tranport molecule for some proteins
Globulins
account for 38% of the plasma proteins;
some are part of the immune system, some are transport molecules
Fibrinogen
constitutes 4% of the plasma proteins and is responsible for the formaiton of blood clots
Formed elements
the portion of blood that is composed of cells, cell fragments, and undissolved substances
Granulocytes
white blood cells with large cytoplasmic granules and lobed nuclei;
neutrophils, basophils, eosinophils
Neutrophil
a WBC that phagocytizes microorganisms and other substances;
the most common type of WBC;
remain in the circulation for 10-12 hours
Eosinophil
a WBC that release chemicals that reduce inflammation;
attacks certain worm parasites;
stains red;
most common in tissues undergoing an allergic response
Basophil
a WBC that releases histamine, which promotes inflammation, and heparin, which prevents clot formation;
least common type of WBC
Agranulocytes
WBCs that appear to have no granules when viewed with a light microscope;
lymphocytes and monocytes
Lymphocyte
a WBC that produces antibodies and other chemicals responsible for destroying microorganisms;
contributes to allergic reactions, graft rejection, tumor control, and regulation of the immune system
Monocyte
a WBC that is phagocytic;
leaves the blood and becomes a macrophage, which phagocytizes bacteria, dead cells, cell fragments, and other debris within tissues
Hematopoiesis (hemopoiesis)
the process of blood cell production;
occurs in the embryo and fetus in tissues like the yolk sac, liver, thymus, spleen, lymph nodes, and red bone marrow; after birth occurs primarily in red bone marrow
Hemocytoblasts
blood stem cells that are capable of producing every type of blood cell;
located in the red bone marrow;
can differentiate into proerythroblasts, myeloblasts, lymphoblasts, monoblasts, or megakaryoblasts
Proerythroblast
precursor cells from which red blood cells develop
Myeloblast
precursor cells from which basophils, neutrophils, and eosinophils develop
Lymphoblast
precursor cells from which lymphocytes develop
Monoblast
precusor cells from which monoblast develop
Megakaryoblast
precursor cells from which platelets develop
Erythrocytes (red blood cells)
prominent cells of the blood, around 5 million/microL of blood;
biconcave discs filled with hemoglobin; lipids, ATP, and carbonic anhydrase;
cannot move of their own accord, have no nucleus
Hemolysis
the rupture of red blood cells;
could be caused by the combination of the antibodies with the antigens
Carbonic anyhdrase
an enzyme that catabolizes the reaction between carbon dioxide and water to form carbonic acid;
found in red blood cells
Hemoglobin
a protein molecule found within red blood cells that consists of four peptide chains and four heme groups;
functions to transport oxygen throughout the body
Globin
polypeptide chain attached to a hemoglobin
Heme
a red pigment molecule that contains one Fe atom at the center to which oxygen binds
Iron atom
found at the center of each heme group in hemoglobin;
necessary for the normal function of hemoglobin becasue each oxygen molecule that is transported is associated with an iron atom
Oxyhemoglobin
hemoglobin with an oxygen molecule attached to each heme group
Deoxyhemoglobin
hemoglobin containing no oxygen
Carbaminohemoglobin
amino groups of the globin chains in hemoglobin to which carbon dioxide attaches and is transported
Erythropoiesis
the process by which new red blood cells are produced;
time required for the production of a single red blood cell is 4 days
Erythropoietin
hormone released by the kidneys in response to low blood oxygen levels;
stimulates red bone marrow to produce red blood cells by increasing the number of proerythroblasts are formed and by decreasing the time required for RBCs to mature
Macrophages
cells located in the spleen, liver, and other lymphatic tissue that take up the hemoglobin released from ruptured red blood cells; the hemoglobin is then broken down and recycled
Bilirubin
the protein to which the non-iron part of the heme groups are converted;
released into the bloodstream from the macrophage, binds to albumin and is transported to the liver
Free bilirubin
bilirubin that is attached to transport molecules in the plasma that has not yet been conjugated; usually on its way to the liver
Conjugated bilirubin
bilirubin that is taken up by the liver cells and is conjugated, or joined, to glucuronic acid;
more water-soluble than free bilirubin
Bile
the fluid secreted from the liver into the small intestine;
it is in this form that bacteria interact with the conjugated bilirubin to give feces its characteristic color
Jaundice
a yellowish staining of the skin and sclerae caused by a buildup of bile pigments in the circulation and interstitial spaces
Leukocytes (white blood cells)
clear or whitish-colored cells that lack hemoglobin but have a nucleus;
protect the body against invading microorganisms and remove dead cells and debris from the body
Diapedesis
a process in which WBCs become thin and elongated and slip between or through the cells of the blood vessel walls
Chemotaxis
a means by which WBCs can attracted to foreign materials or dead cells within the tissue
Pus
the accumulation of dead white blood cells and bacteria, along with fluid and cell debris;
found at the sight of an infection
Lysozymes
a class of enzymes secreted by neutrophils that are capable of destroying certain bacteria
Histamine
a chemical released by basophils into tissue to increase inflammation
Heparin
chemical released by basophils that inhibits blood clotting
B cells
a type of lymphocyte that can be stimulated by bacteria or toxins to divide and form cells that produce antibodies
Antibodies
proteins that can attach to bacteria and activate mechanisms that result in destruction of the bacteria
T cells
a type of lymphocyte that protect against viruses and other intracellular microorganisms by attacking and destroying the cells in which they are found;
involved in the destruction of tumor cells and tissue graft rejections
Thrombocytes (platelets)
minute fragments of cells consisting of a small amount of cytoplasm surrounded by a plama membrane;
surface contains glycoproteins and proteins that allow platelets to attach to other molecules such as collagen;
plays an important role controlling blood loss
Hemostasis
the stoppage of bleeding;
very important to the maintenance of homeostasis;
Vascular spasm
an immediate but temporary constriction of a blood vessel resulting from contractions of smooth muscle within the wall of the blood vessel;
produced by nervous system reflexes and chemicals
Thromboxanes
a chemical released by platelets during the formation of a platelet plug;
derived from certain prostglandins, and thus have a relaxing effect upon smooth muscle of blood vessels
Endothelin
a chemical released from the endothelial cells of blood vessels that contribute to vascular spasms
Platelet plug
an accumulation of platelets that can seal up small breaks in blood vessels;
Platelet adhesion
occurs when platelets bind to collagen exposed by blood vessel damage;
most often mediated through von Willebrand factor (vWF)
von Willebrand factor (vWF)
a protein produced and secreted by blood vessel endothelial cells;
instrumental in platelet adhesion;
forms a bridge between collagen and platelets by binding to platelet surface receptors and collagen
Platelet release reaction
a reaction in which platelets become activated after binding to collagen fibers;
ADP, thromboxanes, and other chemicals are extruded from the platelet by exocytosis, producing a cascade resposne in surrounding tissue
Platelet aggregation
a process during which fibrinogen forms a bridge between the fibrinogen receptors of different platelets, resulting in the formation of a platelet plug
Coagulation
blood clotting;
part of the healing process when a blood vessel is severly damaged;
involved three stages
Blood clot
a network of fibrin, trapping blood cells, platelets, and fluid
Coagulation factors
proteins found within the plasma that influence the formation of a blood clot;
normally stored in an inactive form and don't cause clotting;
factors are activated after a clot
Stage one of coagulation
consists of the formation of prothrombinase
Stage two of coagulation
conversion of prothrombin to thrombin by prothrombinase
Stage three of coagulation
the conversion of soluble fibrinogen to insoluble fibrin by thrombin
Extrinsic clotting pathway
clotting pathway that begins with chemicals that are outside of blood;
damaged tissues release a mixture of lipoproteins and phospholipids called thromboplastin
Intrinsic clotting pathway
clotting pathway that begins with chemicals that are inside of the blood
Anticoagulants
molecules contained within the blood that prevent coagulation factors from being activated;
only when coagulation factor concentrations exceed a given threshold in a local area does coagulation occur
Antithrombin
an anticoagulant;
a plasma protein produced by the liver;
slowly inactivates thrombin
Haparin
an anticoagulant produced by basophils and endothelial cells;
increases the effectiveness of antithrombin because heparin and antithrombin together rapidly inactivate thrombin
Prostacyclin
a prostaglandin derivative produced by endothelial cells;
counteracts the effects of thrombin by causing vasodialation and by inhibiting the release of coagulation factors from platelets
Clot retraction
a process through which a clot begins to condense into a denser, compact structure;
Serum
plama from which fibrinogen and some of the clotting factors have been removed
Fibrinolysis
a process by which a clot dissolves, usually within a few days after formation
Plasmin
formed from inactive plasminogen;
aids in the process of fibrinolysis by hydrolyzing fibrin
Transfusion
the transfer of blood or blood components from one individual to another;
utilized when large quantities of blood are lost and red blood cells must be replaced so that the oxygen-carrying capacity of the blood is restored
Infusion
the introduction of a fluid other than blood, such as a saline or glucose solution, into the blood;
utilized when it is necessary to return blood volume back to a range in order to prevent shock
Antigens (agglutinogens)
molecules that exist on the surface of RBCs that determine the person's blood type
Antibodies (agglutinins)
very specific molecules that combine to foreign antigens
Agglutination
clumping of RBCs;
forms as a result of incompatible blood; antibodies form molecular bridges that connect or clump multiple blood cells;
these clumps of cells might clog vessels resulting in ischemia
Blood groups
different types of blood that are categorized by the different antigens presnt on the surface of the RBCs;
more than 35 blood groups exist
ABO blood group
the most common type of categorization used to classify blood;
type A has A antigen, type B has B antigen, and type AB has both
Rh blood group
first studied in rhesus monkeys;
people are positive if they have Rh antigens and negative if they lack the Rh antigens on the surface of the RBCs;
antibodies against the Rh antigen do not develop unless an Rh negative person is expose to Rh positive blood
Erythroblastosis fetalis
an Rh compatibility problem that may result during pregnancy;
if the mother has Rh negative blood and the baby has Rh positive blood, the mother could be exposed to the fetus' blood and begin producing antibodies that can pass through the placental barrier and cause agglutination in the fetus' blood
Blood typing
a diagnostic test to determine the ABO and Rh blood groups of the blood sample
Complete blood count (CBC)
an analysis of the blood that consists of RBC count, hemoglobin and hematocrit measurements, a white blood count, and a differential white blood count
Red blood count (RBC)
the number of red blood cells per, expressed in millions per microliter of blood
Erythrocytosis
an overabundance of RBCs
Hemoglobin measurement
determines the amount of hemoglobin in a given volume of blood;
expressed in grams of hemoglobin per 100mL of blood
Anemia
a reduced number of RBCs per 100mL of blood or a reduced amount of hemoglobin in each RBC
Hematocrit
the percentage of total blood volume composed of RBCs
Buffy coat
a thin whitish layer found above the RBCs in a hematocrit containing WBCs
Normocytes
normal sized red blood cells
Microcytes
RBCs that are smaller than normal size
Macrocytes
RBCs that are larger than normal size
White blood count (WBC)
a test that measures the total number of white blood cells in the blood
Leukopenia
a lower-than-normal white blood count;
can indicate depression or destruction of the red bone marrow by radiation, drugs, tumor, or a deficiency of vitamin B12 or folate
Leukocytosis
an abnormally high WBC
Leukemia
a cancer of the red marrow;
often results in leukocytosis
Differential white blood count
a diagnostic test that determines the percentage of each of the five kinds of white blood cells;
neutrophils, 60-70%
lymphocytes, 20-30%
monocytes, 2-8%
eosinophils, 1-4%
basophils, 0.5-1%
Platelet count
the number of platelets per microliter of blood
Thrombocytopenia
a condition in which the platelet count is greatly reduced, resulting in chronic bleeding through small vessels and capillaries
Prothrombin time measurement
a measure of how long it takes for the blood to start clotting;
determined by added thromboplastin to whole plasma;
normal range is 9-12 seconds
What are the three main ways that carbon dioxide is transported in the blood?
1) 7% is transported as CO2 dissolved in the plasma;
2) 23% is transported in combination with the globin portion of hemoglobin; and
3) 70% is transported in the form of bicarbonate ion
What are the two ways in which oxygen is transported in the blood?
1) 98.5% is transported in combination with hemoglobin, and
2) 1.5% is transported as oxygen dissolved in the blood plasma
What vitamins and minerals are most important for erythrocyte development?
folate and B12 for DNA sysnthesis; iron for hemoglobin synthesis
List the steps involved in the formation of a platelet plug.
1) platelet adhesion to collagen occurs,
2) the binding of platelets to collagen activates the platelets, causing them to release ADP, thromboxanes, and other chemicals; this is called the platelet release reaction
3) platelet aggregation occurs as platelets begin to change shape and express fibrinogen receptors on their surface; multiple platelets can bind to a single fibrinogen
4) the activated platelets express platlet factor III and coagulation factor V, which are important in clot formation
Thrombus
a clot that has formed and is attached to the wall of the heart or a vessel
Embolus
a clot that has formed and subsequently broken away from its site of formation and is flowing with the circulation; dangerous because it may block the circulation
How does the anticoagulant coumadin work?
Coumadin works by suppressing the production of vitamin K-dependent coagulation factors by the liver
What is a transfusion reaction?
A reaction that occurs within an individual as a result of a transfusion with blood that is incompatible with the individual's blood type; results in agglutination of blood cells; usually results in clotting within blood vessels, kidney damage, and even death
What is the approximate distribution of ABO and Rh blood groups in American Caucasians? African Americans?
ABO GROUPS
Caucasian: O-47%, A-41%, B-9%, AB-3%
African American: O-46%, A-27%, B-20%, AB-7%
RH GROUPS
Caucasian: (+)-85%
African American: (+)-88%
What is RhoGAM and what is it used for?
an Rh antibody preparation that is used to prevent hemolytic disease of the newborn (erthroblastosis fetalis); can be administered before, during, or after each pregnancy or abortion; drug prevents sensitization of the mother who is Rh- to Rh antigens
What is the normal percentage composition of WBCs in a normal, healthy person?
Neutrophils: 60-70%
Lymphocytes: 20-30%
Monocytes: 2-8%
Eosinophils: 1-4%
Basophils: 0.5-1%
What is a normal platelet count?
250,000-400,000/uL blood
What is a hematocrit for a normal, healthy individual?
in males, RBCs account for 40-50% of blood volume; in females, RBCs account for 38-47% of total blood volume
where rh found?
on monkey

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