Blood Flashcards
What is blood?
Blood is the internal transport system of the body.
What is the composition of blood?
Blood is composed of blood plasma and formed elements.
What are the formed elements of blood?
The formed elements of blood include erythrocytes, leukocytes, and platelets.
What is the function of erythrocytes?
Erythrocytes are responsible for carrying oxygen to the body’s tissues.
What is the function of leukocytes?
Leukocytes are responsible for fighting infections and diseases.
What is the function of platelets?
Platelets are responsible for blood clotting.
What happens when a blood vessel breaks?
When a blood vessel breaks, platelets form a clot to stop the bleeding.
How is blood replaced in an emergency?
Blood is replaced in an emergency through blood transfusions.
What can the study of blood tell us about a patient?
The study of blood can help clinicians determine the cause of disease in their patients.
What are the protective functions of blood?
Preventing blood loss and preventing infection.
What are the transport functions of blood?
Delivering oxygen and nutrients to body cells, transporting metabolic waste products from cells to elimination sites, and transporting hormones from endocrine organs to their target organs.
What are the regulatory functions of blood?
Maintaining appropriate body temperature, maintaining normal pH in body tissues, and maintaining adequate fluid volume in the circulatory system.
What is the composition of whole blood?
Living blood cells called formed elements suspended in a nonliving fluid matrix called plasma.
55% Plasma
45 % RBC
<1% buffy Coat (Leukocytes & Platelets)
What is plasma?
The liquid component of blood that makes up 55% of whole blood and contains dissolved fibrous proteins.
What are the formed elements in blood?
Erythrocytes (red blood cells), leukocytes (white blood cells), and platelets.
What is the function of erythrocytes?
Transporting oxygen.
What is the buffy coat in blood?
A thin, whitish layer at the erythrocyte-plasma junction that contains leukocytes and platelets.
Why is blood classified as a connective tissue?
Because it contains living blood cells suspended in a nonliving fluid matrix.
What are the three formed elements of blood?
Erythrocytes, leukocytes, and platelets.
What is the hematocrit?
The percentage of erythrocytes in a blood sample, which is normally about 45%.
What is the normal hematocrit range for healthy males and females?
Males: 47% ± 5%, Females: 42% ± 5%.
What is blood plasma?
A straw-colored, sticky fluid that makes up about 55% of whole blood and contains over 100 different dissolved solutes.
What are the major plasma components?
Water, electrolytes, plasma proteins, nonprotein nitrogenous substances, nutrients, respiratory gases, and hormones.
What is the most abundant plasma protein and what is its function?
Albumin, which accounts for 60% of plasma protein, acts as a carrier to shuttle certain molecules through the circulation and is the major blood protein contributing to the plasma osmotic pressure.
What is the normal blood volume in healthy adult males and females?
Males: 5-6 L, Females: 4-5 L.
What happens when the number of red blood cells increases or decreases beyond the normal range?
When the number of red blood cells increases beyond the normal range, blood becomes more viscous and flows more slowly. When the number of red blood cells drops below the lower end of the range, the blood thins and flows more rapidly.
What are the three types of formed elements in human blood?
Erythrocytes, leukocytes, and platelets.
What is the structure of erythrocytes?
They are small, disc-shaped cells with a biconcave shape.
What is the function of erythrocytes in the blood?
They play a crucial role in oxygen and carbon dioxide transport.
What is the chemical composition of hemoglobin?
Hemoglobin is a protein that contains iron and binds to oxygen in the lungs and releases it in the tissues.
What are some disorders caused by abnormalities of erythrocytes?
Examples include anemia, sickle cell disease, and polycythemia.
What is hematocrit?
Hematocrit is the percentage of blood volume occupied by erythrocytes. The normal value is around 45% for men and 40% for women.
What problems would reduced synthesis of plasma proteins cause in a patient with liver failure due to chronic alcoholism?
Reduced synthesis of plasma proteins can cause fluid accumulation in the tissues, leading to edema and ascites.
What is the shape of erythrocytes and what gives them their shape?
Erythrocytes are biconcave disc-shaped cells, and their shape is maintained by a network of proteins, especially spectrin, attached to the cytoplasmic face of RBC plasma membranes.
What is the function of hemoglobin in erythrocytes?
Hemoglobin binds easily and reversibly with oxygen, and most oxygen carried in blood is bound to hemoglobin. It transports respiratory gases (oxygen and carbon dioxide).
What is the normal range of hemoglobin in adult males and females?
The normal range of hemoglobin is 13-18 grams per 100 milliliters of blood (g/100 ml) in adult males, and 12-16 g/100 ml in adult females.
How many hemoglobin molecules are present in a single red blood cell and how much oxygen can they transport?
A single red blood cell contains about 250 million hemoglobin molecules, and each of these tiny cells can transport about 1 billion molecules of oxygen.
What are the three structural characteristics that contribute to erythrocyte gas transport functions?
The small size and shape of erythrocytes provide a huge surface area relative to volume, erythrocytes are over 97% hemoglobin, and they lack mitochondria and generate ATP by anaerobic mechanisms, making them very efficient oxygen transporters.
What is the process of oxygen loading and unloading in the body?
Oxygen loading occurs in the lungs and oxygen-deficient blood moves through the lungs, where oxygen diffuses from the air sacs of the lungs into the blood and then into the erythrocytes, where it binds to the iron in hemoglobin. In body tissues, oxygen detaches from iron, hemoglobin resumes its former shape, and the resulting deoxyhemoglobin, or reduced hemoglobin, becomes dark red. The released oxygen diffuses from the blood into the tissue fluid and then into tissue cells.
What is hematopoiesis?
Hematopoiesis is the process of blood cell formation.
Where does hematopoiesis occur in the body?
Hematopoiesis occurs in the red bone marrow.
What is the function of erythrocytes?
The function of erythrocytes is to transport oxygen from the lungs to the body tissues and to transport carbon dioxide from the body tissues to the lungs.
What is the lifespan of erythrocytes?
The lifespan of erythrocytes is about 120 days.
What is the final stage of erythropoiesis?
The final stage of erythropoiesis is the reticulocyte, which is essentially a young erythrocyte that still contains a scant reticulum of clumped ribosomes.
What is the function of reticulocytes?
The function of reticulocytes is to enter the bloodstream and mature into erythrocytes.
What is the average amount of new blood cells produced by the red bone marrow every day?
The red bone marrow turns out some 30 ml of new blood containing 100 billion new cells every day.
What triggers the synthesis and release of erythropoietin?
The drop in normal blood oxygen levels.
What are the possible causes of reduced blood oxygen levels that trigger EPO formation?
Reduced numbers of red blood cells due to hemorrhage or excessive RBC destruction, insufficient hemoglobin per RBC, reduced availability of oxygen.
What happens when there are too many erythrocytes or excessive oxygen in the bloodstream?
Erythropoietin production is depressed.
What controls the rate of erythropoiesis?
The ability of erythrocytes to transport enough oxygen to meet tissue demands.
How does bloodborne erythropoietin stimulate red marrow cells?
It causes them to mature more rapidly.
What is the role of kidneys in erythropoietin production?
They play the major role in EPO production.
What happens when kidney cells become hypoxic?
Oxygen-sensitive enzymes are unable to carry out their normal functions of degrading an intracellular signaling molecule called hypoxia-inducible factor (HIF).
What is the consequence of abusing recombinant EPO?
It can cause thick, sticky ‘sludge’ that can cause clotting, stroke, or heart failure.
What stimulates the kidneys to produce erythropoietin?
Low O2 levels in blood.
What is the function of erythropoietin in the blood?
To promote erythropoiesis in red bone marrow.
Where are aged and damaged red blood cells engulfed and broken down?
By macrophages of spleen, liver, and bone marrow.
What happens to the hemoglobin of dying erythrocytes?
It is split off from globin, and its core of iron is salvaged and stored for reuse.
What is bilirubin and how is it eliminated from the body?
Bilirubin is a yellow pigment that is released to the blood and eliminated from the body in feces as stercobilin.
What are the raw materials required for erythropoiesis?
Nutrients (amino acids, lipids, and carbohydrates), vitamin B12, folic acid, and iron.
What is the average lifespan of red blood cells?
100 to 120 days.
What happens to the protein (globin) part of hemoglobin?
It is metabolized or broken down to amino acids, which are released to the circulation.
Define anemia.
Anemia is a condition in which the blood’s oxygen-carrying capacity is too low to support normal metabolism.
What are the three groups of causes of anemia?
Blood loss, not enough red blood cells produced, or too many of them destroyed.
What is hemorrhagic anemia?
Hemorrhagic anemia is caused by blood loss.
What is iron-deficiency anemia?
Iron-deficiency anemia is a result of inadequate intake of iron-containing foods or impaired iron absorption.
What is pernicious anemia?
Pernicious anemia is an autoimmune disease that most often affects the elderly.
What is renal anemia?
Renal anemia is caused by the lack of EPO, the hormone that controls red blood cell production.
What is aplastic anemia?
Aplastic anemia may result from destruction or inhibition of the red marrow by certain drugs and chemicals, ionizing radiation, or viruses.
What is hemolytic anemia?
Hemolytic anemia is a condition in which erythrocytes rupture, or lyse, prematurely.
What are thalassemias?
Thalassemias are a group of genetic disorders in which one of the globin chains is absent or faulty, and the erythrocytes are thin, delicate, and deficient in hemoglobin.
What is sickle-cell anemia?
Sickle-cell anemia is a genetic disorder in which the globin part of hemoglobin is abnormal, causing the erythrocytes produced to be fragile and rupture prematurely.
What is polycythemia?
An abnormal excess of erythrocytes that increases blood viscosity, causing it to flow sluggishly.
What is blood doping?
Artificially induced polycythemia, practiced by some athletes competing in aerobic events.
How does blood doping work?
Some of the athlete’s red blood cells are drawn off and stored. The body quickly replaces these erythrocytes because removing blood triggers the erythropoietin mechanism. Then, when the stored blood is reinfused a few days before the athletic event, a temporary polycythemia results.
What are the risks associated with blood doping?
The risk of stroke and heart failure due to high hematocrit and high blood viscosity.
What is sickle-cell anemia?
A genetic disorder caused by a single amino acid change in the beta chain of hemoglobin, resulting in sickled erythrocytes.
How is sickle-cell anemia treated?
Hydroxyurea, a drug used to treat chronic leukemia, switches the fetal hemoglobin gene back on. This drug dramatically reduces the excruciating pain and overall severity and complications of sickle-cell anemia (by 50%). In children who are severely affected, bone marrow stem cell transplants offer a complete cure, but carry high risks.
What is diapedesis?
The process by which white blood cells slip out of the capillary blood vessels and enter areas of the body where they mount inflammatory or immune responses.
What are the signals that prompt WBCs to leave the bloodstream at specific locations?
Cell adhesion molecules displayed by endothelial cells.
What are neutrophils and what percentage of WBC population do they account for?
Neutrophils are the most numerous white blood cells and account for 50-70% of the WBC population.
What is the size of neutrophils compared to erythrocytes?
Neutrophils are about twice as large as erythrocytes.
What is the color of neutrophil cytoplasm and why are they called neutral-loving?
Neutrophil cytoplasm has a lilac color due to the presence of granules that take up both basic and acidic dyes. They are called neutral-loving because of this property.
What is the role of neutrophils in the body?
Neutrophils are our body’s bacteria slayers and their numbers increase explosively during acute bacterial infections. They are chemically attracted to sites of inflammation and are active phagocytes.
What is the process of respiratory burst and how do neutrophils kill bacteria?
Respiratory burst is a process during which neutrophils metabolize oxygen to produce potent germ-killer oxidizing substances such as bleach and hydrogen peroxide. Defensin-containing granules merge with the microbe-containing phagosome and form peptide ‘spears’ that pierce holes in the membrane of the ingested bacteria, causing it to lyse.
What are eosinophils and what percentage of leukocytes do they account for?
Eosinophils account for 2-4% of all leukocytes.
What is the role of eosinophils in the body?
The most important role of eosinophils is to lead the counter-attack against parasitic worms that are too large to be phagocytized. They also have complex roles in many other diseases including allergies and asthma.
What are granulocytes and what are the types of granulocytes?
Granulocytes are a type of leukocyte that contain obvious membrane-bound cytoplasmic granules. The types of granulocytes are neutrophils, eosinophils, and basophils.
What is leukocytosis and when does it occur?
Leukocytosis is a condition in which the white blood cell count is over 11,000 cells/μl and it occurs as a normal response to an infection in the body.
What are the two major categories of leukocytes and how are they grouped?
The two major categories of leukocytes are granulocytes and agranulocytes. They are grouped on the basis of structural and chemical characteristics.
What is the relative percentage of leukocytes in normal blood and what is the order of leukocytes from most abundant to least abundant?
Leukocytes and platelets together account for the remaining 21% of formed elements in normal blood. The order of leukocytes from most abundant to least abundant is neutrophils, lymphocytes, monocytes, eosinophils, and basophils.
What are the three sizes of leukocytes based on their diameter?
Small (5-8 μm), medium (10-12 μm), and large (14-17 μm).
What is the function of T lymphocytes (T cells)?
Acting directly against virus-infected cells and tumor cells in the immune response.
What do B lymphocytes (B cells) give rise to?
Plasma cells, which produce antibodies (immunoglobulins) that are released to the blood.
What is the average diameter of monocytes?
18 μm.
What happens to circulating monocytes when they leave the bloodstream and enter the tissues?
They differentiate into highly mobile macrophages with prodigious appetites.
What is the function of macrophages?
They are actively phagocytic and are crucial in the body’s defense against viruses, certain intracellular bacterial parasites, and chronic infections such as tuberculosis.
What is leukopoiesis?
The production of white blood cells.
What is the function of basophils?
They contain histamine, an inflammatory chemical that acts as a vasodilator and attracts other white blood cells to the inflamed site.
What is the most numerous leukocyte in the blood?
Neutrophils.
What is the second most numerous leukocyte in the blood?
Lymphocytes.