Chapter 18
thrombus
A stationary clot formed in an unbroken blood vessel, usually a vein.
iron-deficiency anemia
Inadequate absorption of iron, excessive loss of iron, increased iron requirement, or insufficient intake of iron causes iron-deficiency anemia, the most common type of anemia.
White blood cell general function
Once pathogens enter the body, the general function of white blood cells is to combat them by phagocytosis or immune responses.
Monocyte
Phagocytosis (after transforming into fixed or wandering macrophages)
percentages of plasma, red blood cells, white blood cells, and platelets in whole blood
Plasma 55%, RBC 45%, WBC- 5000-10000 of the formed elements, platelets 150,000-400,000
Distinguish between monocytes and macrophages
The nucleus of a monocyte is usually kidney-shaped or horseshoe-shaped, and the cytoplasm is blue-gray and has a foamy appearance. They migrate from the bloodstream into the tissues and become macrophages.
hematocrit
The percentage of total blood volume occupied by RBCs
reticulocyte count
This is not part of a normal CBC and measures the amount of immature RBCs in the blood and indicates the bone marrow production.
universal recipient and universal donor
Universal recipient is AB Universal donor is O
How white blood cells move from within the bloodstream to infected and inflamed tissues
WBC move through emigration- WBCs leave the bloodstream by rolling along the endothelium, sticking to it, and squeezing between the endothelial cells. Adhesion molecules help WBCs stick to the endothelium.
transfusion
the transfer of whole blood or blood components (only red blood cells or plasma) into the bloodstream.
red blood cell life cycle including the fate of hemoglobin in old, worn-out red blood cells
1) Macrophages in the spleen, liver, and red bone marrow phagocytize ruptured and worn-out red blood cells, splitting apart the globin and heme portions of hemoglobin. 2) Globin is broken down into amino acids, which can be reused by body cells to synthesize other proteins. 3) Iron removed from the heme portion associates with the plasma protein transferrin, a transporter for iron in the bloodstream. 4)The iron-transferrin complex is then carried to red bone marrow, where RBC precursor cells use it in hemoglobin synthesis. Iron is needed for the heme portion of the hemoglobin molecule, and amino acids are needed for the globin portion. Vitamin is also needed for synthesis of hemoglobin. 5) Within red bone marrow, erythropoiesis (red blood cell production) releases red blood cells into the circulation. 6) When iron is removed from heme, the non-iron portion of heme is converted to biliverdin, a green pigment, and then into bilirubin, a yellow-orange pigment. Bilirubin enters the blood and is transported to the liver. Within the liver, bilirubin is secreted by liver cells into bile, which passes into the small intestine and then into the large intestine. 7) In the large intestine, bacteria convert bilirubin into urobilinogen. Excreted as waste.
embolus
A blood clot, bubble of air or fat from broken bones, mass of bacteria, or other debris or foreign material transported by the blood.
which blood types are compatible for transfusion
A can receive A, O B can receive B, O AB can receive A, B, AB, O O can receive O
how clotting is kept localized at the wound site
A clot does not extend beyond the wound site into the general circulation, in part because fibrin absorbs thrombin into the clot. This helps stop the spread of thrombin into the blood and thus inhibits clotting except at the wound site. Another reason for localized clot formation is that, because of the dispersal of some of the clotting factors by the blood, their concentrations are not high enough to bring about widespread clotting.
the chemical composition, location in blood, and function of albumin and fibrinogen
Albumin and fibrinogen are both plasma proteins. Albumin- 54% of plasma, help maintain proper blood osmotic pressure, which is an important factor in the exchange of fluids across capillary walls. Fibrinogen- 7% of plasma, a key protein in the formation of blood clots.
hemopoiesis
Blood cell production, which occurs in red bone marrow after birth.
Eosinophil
Combat effects of histamine in allergic reactions, phagocytize antigen- antibody complexes, and destroy certain parasitic worms
aplastic anemia
Destruction of red bone marrow
erythropoiesis
Erythropoiesis starts in the red bone marrow with a precursor cell called a pro erythroblast. The proerythroblast divides several times, producing cells that begin to synthesize hemoglobin. Ultimately, a cell near the end of the development sequence ejects its nucleus and becomes a reticulocyte. Loss of the nucleus causes the center of the cell to indent, producing the RBC's distinctive biconcave shape. Reticulocytes, which are about 34 percent hemoglobin and retain some mitochondria, ribosomes, and endoplasmic reticulum, pass from red bone marrow into the bloodstream. Reticulocytes develop into erythrocytes (mature RBCs) within 1 or 2 days after their release from red bone marrow.
hemorrhagic anemia
Excessive loss of RBCs through bleeding resulting from large wounds, stomach ulcers, or especially heavy menstruation
Platelet
Form platelet plug in hemostasis; release chemicals that promote vascular spasm and blood clotting
Red blood cell
Hemoglobin within RBCs transports most oxygen and part of carbon dioxide in blood
diagnostic significance of a high white blood cell count and a low white blood cell count
High count- infection, allergic reaction, leukemias or other cancers low count- stress, drug toxicity, shock, radiation
regulation of erythropoiesis
If the oxygen-carrying capacity of the blood falls because erythropoiesis is not keeping up with RBC destruction, a negative feedback system increases RBC production. The controlled condition in this particular feedback loop is the amount of oxygen delivered to the kidneys (and thus to body tissues in general). Cellular oxygen deficiency, called hypoxia, may occur if too little oxygen enters the blood. Hypoxia stimulates the kidneys to increase the release of the hormone erythropoietin. Erythropoietin circulates through the blood to the red bone marrow, where it speeds the development of proerythroblasts into reticulocytes. As the number of circulating RBCs increases, more oxygen can be delivered to body tissues.
adverse consequences from incompatible blood transfusion
In an incompatible blood transfusion, antibodies in the recipient's plasma bind to the antigens on the donated RBCs, which causes agglutination, or clumping, of the donated RBCs. Clumping of RBCs can block small blood vessels, preventing blood flow to essential tissues. Agglutination is an antigen-antibody response in which RBCs become cross-linked to one another. Formation of these antigen-antibody complexes causes hemolysis or rupture of the RBCs and the release of hemoglobin into the plasma.
pernicious anemia
Insufficient hemopoiesis resulting from an inability of the stomach to produce intrinsic factor, which is needed for absorption of vitamin in the small intestine
which dietary nutrients are needed for red blood cell production to occur
Iron, folic acid, protein, vitamin B12
Basophil
Liberate heparin, histamine, and serotonin in allergic reactions that intensify overall inflammatory response
Lymphocyte
Mediate immune responses, including antigen-antibody reactions
neutrophil
Phagocytosis, destruction of bacteria
hemolytic anemia
RBC plasma membranes rupture prematurely
where formed elements are produced
Red bone marrow becomes the primary site of hemopoiesis in the last three months before birth, and continues as the source of formed elements after birth and throughout life.
ABO and Rh blood groups
The ABO blood group is based on two antigens called A and B. People whose RBCs display only antigen A have type A blood. Those who have only antigen B are type B. Individuals who have both A and B antigens are type AB, and those who have neither antigen A nor antigen B are type O. People whose RBCs have Rh antigens are designated Rh+ (Rh positive); those who lack Rh antigens are designated Rh− (Rh negative).
sickle-cell disease
The RBCs of a person with sickle-cell disease (SCD) contain Hb-S, an abnormal kind of hemoglobin. When Hb-S gives up oxygen to the interstitial fluid, it forms long, stiff, rodlike structures that bend the erythrocyte into a sickle shape. The sickled cells rupture easily. When red blood cells sickle, they break down prematurely (sickled cells die in about 10 to 20 days). This leads to anemia, which can cause shortness of breath, fatigue, paleness, and delayed growth and development in children. The rapid breakdown and loss of blood cells may also cause jaundice, yellowing of the eyes and skin. Sickled cells do not move easily through blood vessels and they tend to stick together and form clumps that cause blockages in blood vessels.
Describe the functions of blood
Transportation. Blood transports oxygen from the lungs to cells throughout the body and carbon dioxide from body cells to the lungs for exhalation. It also carries nutrients from the gastrointestinal tract to body cells, hormones from endocrine glands to other body cells, and heat and waste products away from cells to various organs for elimination from the body. Regulation. Circulating blood helps maintain homeostasis of all body fluids. Blood helps regulate pH through the use of buffers (chemicals that convert strong acids or bases into weak ones). It also helps adjust body temperature through the heat-absorbing and coolant properties of the water in blood and blood's variable rate of flow through the skin, where excess heat can be lost from the blood to the environment. Also, blood osmotic pressure influences the water content of cells, mainly through interactions of dissolved ions and proteins. Protection. Blood can clot in response to an injury, which protects against its excessive loss from the cardiovascular system. Blood's white blood cells protect against disease by carrying on phagocytosis. Several types of blood proteins, including antibodies, interferons, and complement, also help protect against disease.
vascular spasm
When arteries or arterioles are damaged, the smooth muscle in their walls contracts immediately. Vascular spasm reduces blood loss for several minutes to several hours, during which time the other hemostatic mechanisms begin to operate.
platelet plug formation
When platelets come into contact with parts of a damaged blood vessel, their characteristics change drastically and they quickly come together to form a platelet plug that helps fill the gap in the injured blood vessel wall.
anemia
a condition in which the oxygen-carrying capacity of blood is reduced. All of the many types of anemia are characterized by reduced numbers of RBCs or a decreased amount of hemoglobin in the blood. The person feels fatigued and is intolerant of cold, both of which are related to lack of oxygen needed for ATP and heat production. Also, the skin appears pale, due to the low content of red-colored hemoglobin circulating in skin blood vessels.
describe the differential white blood cell count
a count of each of the five types of WBCs, to detect infection or inflammation, determine the effects of possible poisoning by chemicals or drugs, monitor blood disorders (such as leukemia) and the effects of chemotherapy, or detect allergic reactions and parasitic infections. Differential white blood cell counts measure the number of each kind of WBC in a sample of 100 WBCs.
leukemia
a group of red bone marrow cancers in which abnormal white blood cells multiply uncontrollably. The accumulation of the cancerous white blood cells in red bone marrow interferes with the production of red blood cells, white blood cells, and platelets. As a result the oxygen-carrying capacity of the blood is reduced, an individual is more susceptible to infection, and blood clotting is abnormal.
Plasma
a liquid extracellular fluid that contains dissolved substances, and formed elements, which include cells and cell fragments.
the structure and function of hemoglobin
a pigment that gives whole blood its red color. A hemoglobin molecule consists of a protein called globin, composed of four polypeptide chains; a ringlike nonprotein pigment called a heme is bound to each of the four chains. At the center of the heme ring is an iron ion that can combine reversibly with one oxygen molecule, allowing each hemoglobin molecule to bind four oxygen molecules. Each oxygen molecule picked up from the lungs is transported bound to an iron ion within the heme ring. As blood flows through tissue capillaries, hemoglobin releases oxygen, which diffuses first into the interstitial fluid and then into cells.
function of hemostasis
a sequence of responses that stops bleeding when blood vessels are injured. When blood vessels are damaged or ruptured, the hemostatic response must be quick, localized to the region of damage, and carefully controlled in order to be effective.
the diagnostic value of the complete blood count
a very valuable test that screens for anemia and various infections. Usually included are counts of RBCs, WBCs, and platelets per of whole blood; hematocrit; and differential white blood cell count. The amount of hemoglobin in grams per milliliter of blood also is determined.
hemophilia
an inherited deficiency of clotting in which bleeding may occur spontaneously or after only minor trauma. Hemophilia is characterized by spontaneous or traumatic subcutaneous and intramuscular hemorrhaging, nosebleeds, blood in the urine, and hemorrhages in joints that produce pain and tissue damage.
red blood cell anatomy
biconcave (concave on both sides) discs with a simple structure; they lack a nucleus and other organelles and can neither reproduce nor carry on extensive metabolic activities. The cytosol of erythrocytes contains hemoglobin molecules, which were synthesized before loss of the nucleus during RBC production. Essentially, erythrocytes consist of a plasma membrane enclosing a cytosol rich with hemoglobin. The RBC plasma membrane is both strong and flexible, which allows the cells to deform without rupturing as they squeeze through narrow capillaries
blood clotting
blood remains in its liquid form as long as it stays within its vessels. If it is withdrawn from the body, however, it thickens and forms a gel. Eventually, the gel separates from the liquid. The straw-colored liquid, called serum, is simply plasma minus the clotting proteins. The gel is called a clot and consists of a network of insoluble protein fibers called fibrin in which the formed elements of blood are trapped
platelet development
hemopoietic stem cells also differentiate into cells that produce platelets. Under the influence of the hormone thrombopoietin, myeloid stem cells develop into precursor cells called megakaryoblasts. Megakaryoblasts transform into megakaryocytes, huge cells that splinter into 2000-3000 fragments in the red bone marrow and then enter the bloodstream. Each fragment, enclosed by a piece of the plasma membrane, is a platelet, or thrombocyte.
formed elements
include red blood cells (RBCs), white blood cells (WBCs), and platelets
How white blood cells accomplish their functions
many WBCs leave the bloodstream and collect at sites of pathogen invasion or inflammation. Once granular leukocytes and monocytes leave the bloodstream to fight injury or infection, they never return to it. Lymphocytes, on the other hand, continually recirculate—from blood to interstitial spaces of tissues to lymphatic fluid and back to blood.
Compare the structure of reticulocytes and erythrocytes
reticulocytes are round with a nucleus and organelles. Erythrocytes are biconcave with no nucleus or organelles.
procedure for typing ABO blood
single drops of blood are mixed with different antisera, solutions that contain antibodies. One drop of blood is mixed with anti-A serum, which contains anti-A antibodies that will agglutinate red blood cells that possess A antigens. Another drop is mixed with anti-B serum, which contains anti-B antibodies that will agglutinate red blood cells that possess B antigens. If the red blood cells agglutinate only when mixed with anti-A serum, the blood is type A. If the red blood cells agglutinate only when mixed with anti-B serum, the blood is type B. The blood is type AB if both drops agglutinate; if neither drop agglutinates, the blood is type O.
function of clot retraction
the consolidation or tightening of the fibrin clot. Platelets trapped around the fibrin threads contract, pulling on the fibrin threads and tightening the clot. Because the fibrin threads are attached to the damaged surfaces of the blood vessel, as the clot retracts, it pulls the edges of the damaged blood vessel closer together, decreasing the risk of further damage. Permanent repair of the blood vessel can then take place.
erythropoietin
the hormone that stimulates production of RBCs
polycythemia
the percentage of RBCs is abnormally high, and the hematocrit may be 65 percent or higher. This raises the viscosity of blood, making the blood more difficult for the heart to pump.
