• Human Anatomy Bones Study Guide

Blood is unique; it is the only fluid tissue in the body. Carrier of gases, nutrients, and waste products. Oxygen enters blood in the and is transported to cells. Carbon dioxide, produced by cells, is transported in the blood to the lungs, from which it is expelled. Ingested nutrients, ions, and water are carried by the blood from the digestive tract to cells, and the waste products of the cells are moved to the kidneys for elimination.

Clot formation. Proteins help stem blood loss when a blood vessel is injured. Transport of processed molecules. Most substances are produced in one part of the body and transported in the blood to another part. Protection against foreign substances. Antibodies help protect the body from pathogens. Transport of regulatory molecules. Various hormones and enzymes that regulate body processes are carried from one part of the body to another within the blood.

Maintenance of body temperature. Warm blood is transported from the inside to the surface of the body, where heat is released from the blood.

PH and regulation. Albumin is also an important blood buffer and contributes to the osmotic pressure of blood, which acts to keep water in the blood stream. Components of Blood Essentially, blood is a complex connective tissue in which living blood cells, the formed elements, are suspended. Physical Characteristics and Volume Blood is a sticky, opaque fluid with a characteristic metallic. Depending on the amount of oxygen it is carrying, the color of blood varies from scarlet (oxygen-rich) to a dull red (oxygen-poor). Blood is heavier than water and about five times thicker, or more viscous, largely because of its formed elements. Blood is slightly alkaline, with a pH between 7.35 and 7.45. Temperature.

Its temperature ( 38 degrees Celsius, or 100.4 degrees Fahrenheit) is always slightly higher than body temperature. Plasma Plasma, which is approximately 90 percent water, is the liquid part of the blood. Fresh Frozen Plasma. Dissolved substances. Examples of dissolved substances include nutrients, salts , respiratory gases, hormones, plasma proteins, and various wastes and products of cell metabolism. Plasma proteins.

Plasma proteins are the most abundant solutes in plasma; except for antibodies and protein-based hormones, most plasma proteins are made by the. Composition. The composition of plasma varies continuously as cells remove or add substances to the blood; assuming a healthy diet, however, the composition of plasma is kept relatively constant by various homeostatic mechanisms of the body.

Formed Elements If you observe a stained smear of human blood under a light microscope, you will see disc-shaped red blood cells, a variety of gaudily stained spherical white blood cells, and some scattered platelets that look like debris. Erythrocytes Erythrocytes, or red blood cells, function primarily to ferry oxygen in blood to all cells of the body.

RBCs differ from other blood cells because they are anucleate, that is, they lack a nucleus; they also contain a very few organelles. Hemoglobin. Hemoglobin, an iron bearing protein, transports the bulk of oxygen that is carried in the blood. Microscopic appearance. Erythrocytes are small, flexible cells shaped like biconcave discs- flattened discs with depressed centers on both sides; they look like miniature doughnuts when viewed with a microscope. Number of RBCs. There are normally about 5 million cells per cubic millimeter of blood; RBCs outnumber WBCs by about 1000 to 1 and are the major factor contributing to blood viscosity.

Normal blood. Clinically, normal blood contains 12-18 grams of hemoglobin per 100 milliliters (ml); the hemoglobin content is slightly higher in men (13-18 g/dl) than in women (12-16 g/dl). Leukocytes Although leukocytes, or white blood cells, are far less numerous than red blood cells, they are crucial to body defense against disease. Number of WBCs.

On average, there are 4,000 to 11,000 WBC/mm3, and they account for less than 1 percent of total body volume. Body defense.

Leukocytes form a protective, movable army that helps defend the body against damage by bacteria, viruses, parasites, and cells. Diapedesis. White blood cells are able to slip into and out of the blood vessels- a process called diapedesis. Positive chemotaxis. In addition, WBCs can locate areas of tissue damage and in the body by responding to certain chemicals that diffuse from the damaged cells; this capability is called positive chemotaxis.

Ameboid motion. Once they have “caught the scent”, the WBCs move through the tissue spaces by ameboid motion (they form flowing cytoplasmic extensions that help move them along). Leukocytosis. A total WBC count above 11, 000 cells/mm3 is referred to as leukocytosis. Leukopenia.

The opposite condition, leukopenia, is an abnormally low WBC count. Granulocytes. Granulocytes are granule-containing WBCs; they have lobed nuclei, which typically consist of several rounded nuclear areas connected by thin strands of nuclear material, and includes neutrophils, eosinophils, and basophils. Neutrophils. Neutrophil are the most numerous of the WBCs; they have a multilobed granules and very fine granules that respond to acidic and basic stains; neutrophils are avid phagocytes at sites of acute infection, and are particularly partial to bacteria and. Eosinophils.

Eosinophils have blue red nucleus that resembles an old-fashioned telephone receiver and sport coarse, lysosome-like, brick-red cytoplasmic granules; their number increases rapidly during allergies and infections by parasitic worms or entering via the skin. Basophils, the rarest of the WBCs, contain large, histamine-containing granules that stain dark blue; histamine is an inflammatory chemical that makes blood vessels leaky and attracts other WBCs to the inflammatory site.

Agranulocytes. The second group of WBCs, the agranulocytes, lack visible cytoplasmic granules; their nuclei are closer to the norm- that is, they are spherical; they are spherical, oval, or -shaped; and they include and monocytes. Lymphocytes have a large, dark purple nucleus that occupies most of the cell volume; they tend to take up residence in tissues, where they play an important role in the immune response. Monocytes are the largest of the WBCs; when they migrate into the tissues, they transform into with huge appetites; macrophages are very important in fighting chronic infections. Platelets are not cells in the strict sense; they are fragments of bizarre multinucleate cells called megakaryocytes, which pinch off thousands of anucleate platelet “pieces” that quickly seal themselves off from surrounding fluids; platelets are needed for the clotting process that occurs in plasma when blood vessels are ruptured or broken.

Hematopoiesis Blood cell formation, or hematopoiesis, occurs in red bone marrow, or myeloid tissue. Hemocystoblast. All the formed elements arise from a common type of stem cell, the hematocystoblast. Descendants of hemocystoblasts.

The hemocystoblast forms two types of descendants- the lymphoid stem cell, which produces lymphocytes, and the myeloid stem cell, which can produce all other classes of formed elements. Formation of Red Blood Cells Because they are anucleate, RBCs are unable to synthesize proteins, grow, or divide. As they age, RBCs become more rigid and begin to fragment, or fall apart, in 100 to 120 days. Lost cells are replaced more or less continuously by the division of hemocystoblasts in the red bone marrow. Immature RBCs. Developing RBCs divide many times and then begin synthesizing huge amounts of hemoglobin.

Human Anatomy Bones Study Guide

Reticulocyte. Suddenly, when enough hemoglobin has been accumulated, the nucleus and most organelles are ejected and the cell collapses inward; the result is the young RBC, called a reticulocyte because it still contains some rough endoplasmic reticulum (ER). Mature erythrocytes. Within 2 days of release, they have rejected the remaining ER and have become fully functioning erythrocytes; the entire developmental process from hemocystoblast to mature RBC takes 3 to 5 days. Erythropoietin.

The rate of erythrocyte production is controlled by a hormone called erythropoetin; normally a small amount of erythropoeitin circulates in the blood at all times, and red blood cells are formed at a fairly constant rate. Control of RBC production. An important point to remember is that it is not the relative number of RBCS in the blood that controls RBC production; control is based on their ability to transport enough oxygen to meet the body’s demands.

Formation of White Blood Cells and Platelets Like erythrocyte production, the formation of leukocytes and platelets is stimulated by hormones. Colony stimulating factors and. These colony stimulating factors and interleukins not only prompt red bone marrow to turn out leukocytes, but also marshal up an army of WBCs to ward off attacks by enhancing the ability of mature leukocytes to protect the body. Thrombopoeitin. The hormone thrombopoeitin accelerates the production of platelets, but little is known about how that process is regulated. Hemostasis The multistep process of hemostasis begins when a blood vessel is damaged and connective tissue in the vessel wall is exposed to blood.

Vascular spasms occur. The immediate response to blood vessel injury is vasoconstriction, which causes that blood vessel to go into spasms; the spasms narrow the blood vessel, decreasing blood loss until clotting can occur. Platelet plug forms. Injury to the lining of vessels exposes collage fibers; platelets adhere to the damaged site and platelet plug forms.

Coagulation events occur. Option C: Hematopoiesis is the process of blood cell production or the formation of blood cellular components.

Option A: Erythroblastosis fetalis is a serious medical condition that most commonly results from maternal-fetal blood type (Rh factor) incompatibility. Option B: Hemochromatosis is an inherited disorder characterized by abnormally high absorption of iron by the intestinal tract, resulting in excessive storage of iron, particularly in the liver, skin, pancreas, heart, joints, and testes. Option D: Megakaryocytosis is the presence of megakaryocytes in the blood or of excessive numbers in the bone marrow. Option E: Thrombocytosis is a disorder in which the body produces too many platelets (thrombocytes), which play an important role in blood clotting. Option C: Basophil releases histamine, which promotes inflammation, and heparin, which prevents clot formation. Option A: Monocyte is a phagocytic cell in blood; leaves the blood and becomes a macrophage, which phagocytizes bacteria, dead cells, cell fragments, and other debris within tissues.

Option B: Lymphocyte produces antibodies and other chemicals responsible for destroying microorganisms; contributes to allergic reactions, graft rejection, tumor control, and regulation of the immune system. Option D: Eosinophil releases chemicals that reduce inflammation; attacks certain worm parasites.

Option E: Neutrophil phagocytize microorganisms and other foreign substances. Option E: After a clot has formed, it begins to condense into a more compact structure by a process known as clot retraction. Retraction of the clot pulls the edges of the damaged blood vessel together, helping to stop the flow of blood, reducing the probability of infection, and enhancing healing. The damaged vessel is repaired by the movement of fibroblasts into the damaged area and the formation of new connective tissue. In addition, epithelial cells around the wound divide and fill in the torn area.

Clots are dissolved by a process called fibrinolysis. Option C: Hematopoiesis is the process of blood cell production or the formation of blood cellular components. Option A: Erythroblastosis fetalis is a serious medical condition that most commonly results from maternal-fetal blood type (Rh factor) incompatibility. Option B: Hemochromatosis is an inherited disorder characterized by abnormally high absorption of iron by the intestinal tract, resulting in excessive storage of iron, particularly in the liver, skin, pancreas, heart, joints, and testes. Option D: Megakaryocytosis is the presence of megakaryocytes in the blood or of excessive numbers in the bone marrow.

Option E: Thrombocytosis is a disorder in which the body produces too many platelets (thrombocytes), which play an important role in blood clotting. Option C: Basophil releases histamine, which promotes inflammation, and heparin, which prevents clot formation. Option A: Monocyte is a phagocytic cell in blood; leaves the blood and becomes a macrophage, which phagocytizes bacteria, dead cells, cell fragments, and other debris within tissues.

Option B: Lymphocyte produces antibodies and other chemicals responsible for destroying microorganisms; contributes to allergic reactions, graft rejection, tumor control, and regulation of the immune system. Option D: Eosinophil releases chemicals that reduce inflammation; attacks certain worm parasites. Option E: Neutrophil phagocytize microorganisms and other foreign substances. Option E: After a clot has formed, it begins to condense into a more compact structure by a process known as clot retraction. Retraction of the clot pulls the edges of the damaged blood vessel together, helping to stop the flow of blood, reducing the probability of infection, and enhancing healing. The damaged vessel is repaired by the movement of fibroblasts into the damaged area and the formation of new connective tissue. In addition, epithelial cells around the wound divide and fill in the torn area.

Clots are dissolved by a process called fibrinolysis. Text Mode: All questions and answers are given on a single page for reading and answering at your own pace. Be sure to grab a pen and paper to write down your answers. What is the normal pH of the blood?

7.35–7.45. Option B: The normal blood pH is tightly regulated between 7.35 and 7.45. The major component of plasma is: A. Water. Option E: Plasma is a pale yellow fluid that consists of about 91% water; 7% proteins; and 2% other substances, such as ions, nutrients, gases, and waste products.

The most common formed elements in the blood are: A. Leukocytes (white blood cells) D. Erythrocytes (red blood cells) E. Thrombocytes (platelets) 3. Erythrocytes (red blood cells). Option D: About 95% of the volume of the formed elements consists of red blood cells (RBCs), or erythrocytes. The remaining 5% of the volume of the formed elements consists of white blood cells (WBCs), or leukocytes, and cell fragments called platelets, or thrombocytes.

Hematopoiesis is: A. a serious medical condition that most commonly results from maternal-fetal blood type (Rh factor) incompatibility B. An abnormally high absorption of iron by the intestinal tract, resulting in excessive storage of iron, particularly in the liver, skin, heart, joints, and testes C. The process of blood cell production or the formation of blood cellular components D. the presence of megakaryocytes in the blood or of excessive numbers in the bone marrow E. a disorder in which the body produces too many platelets (thrombocytes), which play an important role in blood clotting 4.

The process of blood cell production or the formation of blood cellular components. Option C: Hematopoiesis is the process of blood cell production or the formation of blood cellular components. Option A: Erythroblastosis fetalis is a serious medical condition that most commonly results from maternal-fetal blood type (Rh factor) incompatibility. Option B: Hemochromatosis is an inherited disorder characterized by abnormally high absorption of iron by the intestinal tract, resulting in excessive storage of iron, particularly in the liver, skin, pancreas, heart, joints, and testes. Option D: Megakaryocytosis is the presence of megakaryocytes in the blood or of excessive numbers in the bone marrow. Option E: Thrombocytosis is a disorder in which the body produces too many platelets (thrombocytes), which play an important role in blood clotting. Each hemoglobin molecule: A.

Contains 1 iron atom. Contains red-pigmented globin molecules. Consists of 4 protein chains and 4 heme groups.

Can carry 1 oxygen molecule. Is bluish in color when bound to oxygen 5. Consists of 4 protein chains and 4 heme groups. Option C: Hemoglobin is the protein that makes blood red. It is composed of four protein chains, two alpha chains and two beta chains, each with a ring-like heme group containing an iron atom.

Erythrocytes: A. Are biconvex disks. Have several nuclei in each cell.

Divide frequently. Contain large quantities of hemoglobin.

Have all these properties. Contain large quantities of hemoglobin. Option D: Red blood cells (RBCs) or erythrocytes are biconcave disks; no nucleus; contain hemoglobin, which color the cells red; 6.5–8.5 μm in diameter. Which of these leukocytes is NOT correctly matched with its function or description? Monocytes — become macrophages B. Lymphocytes — vital in immune response C.

Basophils — synthesize or produce antibodies D. Eosinophils — reduce inflammation E.

Neutrophils — phagocytize microorganisms and other foreign substances 7. Basophils — synthesize or produce antibodies. Option C: Basophil releases histamine, which promotes inflammation, and heparin, which prevents clot formation.

Option A: Monocyte is a phagocytic cell in blood; leaves the blood and becomes a macrophage, which phagocytizes bacteria, dead cells, cell fragments, and other debris within tissues. Option B: Lymphocyte produces antibodies and other chemicals responsible for destroying microorganisms; contributes to allergic reactions, graft rejection, tumor control, and regulation of the immune system. Option D: Eosinophil releases chemicals that reduce inflammation; attacks certain worm parasites. Option E: Neutrophil phagocytize microorganisms and other foreign substances. Granulocytes are so called because these cells have granules of enzymes which help to digest the invading microbes. Granulocytes account for about 60% of our white blood cells. The white blood cells called granulocytes are: A.

Erythrocytes, thrombocytes, and megakaryocytes. Monocytes, macrophages, and neutrophils. Neutrophils, basophils, and eosinophils. Lymphocytes and monocytes. Thrombocytes, monocytes, and macrophages. Neutrophils, basophils, and eosinophils.

Option C. Granulocytes are a category of white blood cells characterized by the presence of granules in their cytoplasm. Neutrophils, basophils, and eosinophils are categorized as granulocytes. Option D: Agranulocytes, also known as mononuclear leukocytes, are white blood cells with a one-lobed nucleus.

Lymphocytes and monocytes are considered agranulocytes. Which of the following does not help to prevent blood loss? Formation of a network of fibrin B. Formation of a platelet plug C. Synthesis of thromboxanes D.

Release of heparin E. Blood vessel constriction 9. Release of heparin. Option D: Heparin acts as an anticoagulant, preventing the formation of clots and extension of existing clots within the blood. It is contraindicated in those with risk of (especially in people with uncontrolled, liver disease, and ), severe liver disease, or severe.

The healing process after clot formation involves: A. Clot retraction B. Repair of the damaged vessel by fibroblasts C. Repair of the wound by division of epithelial cells D.

Clot dissolution E. All of these 10. All of these. Option E: After a clot has formed, it begins to condense into a more compact structure by a process known as clot retraction.

Retraction of the clot pulls the edges of the damaged blood vessel together, helping to stop the flow of blood, reducing the probability of infection, and enhancing healing. The damaged vessel is repaired by the movement of fibroblasts into the damaged area and the formation of new connective tissue.

In addition, epithelial cells around the wound divide and fill in the torn area. Clots are dissolved by a process called fibrinolysis. See Also Other anatomy and physiology study guides:. Further Reading.