Biological Sciences
Blood
Blood is a vital bodily fluid that transports oxygen and nutrients to cells and removes waste products. It consists of red blood cells, white blood cells, platelets, and plasma. Red blood cells contain hemoglobin, which binds to oxygen, while white blood cells play a key role in the immune system, and platelets are essential for blood clotting.
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11 Key excerpts on "Blood"
- Gerard J. Tortora, Bryan H. Derrickson(Authors)
- 2017(Publication Date)
- Wiley(Publisher)
584 The focus of this chapter is Blood; the next two chapters will examine the heart and Blood vessels, respectively. Blood transports various substances, helps regulate several life processes, and affords protection against disease. For all of its similarities in origin, composition, and functions, Blood is as unique from one person to another as are skin, bone, and hair. Health-care professionals routinely examine and analyze its differences through various Blood tests when trying to determine the cause of different diseases. Q Did you ever wonder how analyzing Blood can determine if we are healthy, detect a multitude of infections, and detect or rule out various diseases and injuries? 19.1 Functions and Properties of Blood OBJECTIVES • Explain the functions of Blood. • Describe the physical characteristics and principal components of Blood. The cardiovascular system (cardio- = heart; vascular = Blood or Blood vessels) consists of three interrelated components: Blood, the heart, and Blood vessels. The branch of science concerned with the study of Blood, Blood-forming tissues, and the disorders associated with them is hema- tology (hēm-a-TOL-ō-jē; hema- or hemato- = Blood; -logy = study of). Most cells of a multicellular organism cannot move around to ob- tain oxygen and nutrients or eliminate carbon dioxide and other wastes. Instead, these needs are met by two fluids: Blood and interstitial fluid. Blood is a liquid connective tissue that consists of cells surrounded by a liquid extracellular matrix. The extracellular matrix is called Blood plasma, and it suspends various cells and cell fragments. Interstitial fluid is the fluid that bathes body cells (see Figure 27.1) and is constantly renewed by the Blood. Blood transports oxygen from the lungs and nutrients from the gastrointestinal tract, which diffuse from the Blood into the interstitial fluid and then into body cells.
eBook - PDFPrinciples of Bloodstain Pattern Analysis
Theory and Practice
- Stuart H. James, Paul E. Kish, T. Paulette Sutton(Authors)
- 2005(Publication Date)
- CRC Press(Publisher)
41 3 Biological and Physical Properties of Human Blood Biological Functions of Human Blood Human Blood is a liquid connective tissue that serves two primary functions: transport and defense. The role of Blood in carrying oxygen to the cells and carbon dioxide to the lungs for disposal through respiration is probably the most well-known function. Blood is also responsible for transporting food in the form of glucose, lipids, and amino acids from the alimentary canal to the cells. It also serves as a carrying medium for hormones that are secreted directly into the Blood by the endocrine glands and electrolytes such as sodium (Na + ), calcium (Ca ++ ), and bicarbonate (HCO − 3 ) that serve a vital role in the maintenance of the proper acid-base balance needed to sustain life and neuroconduction. Blood serves a supply function, and it also plays an integral part in waste removal. Metabolism leads to the production of waste such as carbon dioxide, urea, creatinine, lactic acid, and uric acid at the cellular level. This waste is stockpiled into the tissue fluid, but it must be removed or the levels will become toxic and cause death. Blood completes this path from the cellular level to the organs of removal, usually the liver or the kidneys. In addition to delivering the basic metabolic needs, drugs and other foreign chemicals — both beneficial and detrimental — make their way from the route of ingestion to the target organ via the Bloodstream. Residual levels are then removed via the Bloodstream. Bringing essential substances to the body and then aiding in the subsequent waste removal are only parts of the role Blood serves to keep the organism alive. To thrive, an animal must also be able to adequately regulate body temperature. Extremes to either end of the spectrum could result in death. Obviously, more active regions of the body will generate more heat, but the body must be able to equalize this heat production.
- Angela L. Williams(Author)
- 2019(Publication Date)
- Omnigraphics(Publisher)
Part One Understanding the Blood and Circulatory System 3 Chapter 1 Blood Function and Composition Blood is a connective tissue, and as a connective tissue, it consists of cells and cell fragments (formed elements) that are suspended in an intercellular matrix (plasma). Blood is the only liquid tissue in the body that measures about five liters in the adult human and accounts for eight percent of body weight. The body consists of metabolically active cells that need a continu-ous supply of nutrients and oxygen. Metabolic waste products need to be removed from the cells to maintain a stable cellular environment. Blood is the primary transport medium that is responsible for meeting these cellular demands. Blood cells are formed in the bone marrow, the soft, spongy center of bones. New (immature) Blood cells are called “blasts.” Some blasts stay in the marrow to mature. Some travel to other parts of the body to mature. The activities of the Blood may be categorized as transportation, regulation, and protection. These functional categories overlap and interact as the Blood car-ries out its role in providing suitable conditions for cellular functions. This chapter includes text excerpted from “Anatomy,” Surveillance, Epidemi -ology, and End Results Program (SEER), National Cancer Institute (NCI), April 28, 2009. Reviewed June 2019.
No longer available |Learn more- Ann Scott, Elizabeth Fong(Authors)
- 2016(Publication Date)
- Cengage Learning EMEA(Publisher)
It carries nutrients from the digestive tract to the cells, oxygen from the lungs to the cells, waste products from the cells to the various organs of excretion, and hormones from secreting cells to other parts of the body. It aids in the distribution of heat formed in the more active tissues (such as the skeletal muscles) to all parts of the body. Blood also helps regulate the acid-base balance and protect against infection. Consequently, Blood is a vital fluid to our life and health (Table 12-1). Blood Composition Blood is made up of plasma (PLAZ-mah), the liquid portion of Blood without its cellular elements. Serum is the name given to plasma after a Blood clot is formed: serum 5 plasma 2 (fibrinogen 1 prothrombin). Blood also contains cellular elements, including erythrocytes (eh-RITH-roh-sights) or red Blood cells (RBCs), leukocytes (LOO-koh-sights) or white Blood cells (WBCs), and thrombocytes (THROM- boh-sights) or platelets (Figure 12-1). Blood Plasma Plasma is a straw-colored, complex liquid, comprising about 55% of the Blood volume and containing the following six substances in solution: 1. Water—Water makes up about 92% of the total volume of plasma. This percentage is maintained by the kidneys and by water intake and output. 2. Plasma proteins —These three proteins are the most abundant of those found in plasma: fibrinogen, serum albumin, and serum globulin. a. Fibrinogen (figh-BRIN-oh-jen) is necessary for Blood clotting. Without fibrinogen, the slightest cut or wound would bleed profusely. It is synthesized in the liver. b. Albumin (al-BYOO-men) is the most abun- dant of all the plasma proteins. A product of the liver, albumin helps maintain the Blood’s osmotic pressure and volume. It provides the “pulse pressure” needed to hold and pull water from the tissue fluid back into the Blood vessels. Normally, plasma proteins do not pass through the capillary walls, because their molecules are relatively large.
eBook - PDF- Gerard J. Tortora, Mark Nielsen(Authors)
- 2016(Publication Date)
- Wiley(Publisher)
The extracellular fluids that nourish, protect, and exchange materials with every cell of the body are derived from the Blood, renewed by the Blood, and returned to the Blood. Based on these relationships, Blood has three general functions: 1. Transportation. Blood transports oxygen from the lungs to the cells of the body and carries carbon dioxide from the body cells to the lungs for exhalation. It carries nutrients from the gastrointestinal tract to body cells and hormones from endocrine glands to cells throughout the body. Blood also transports heat and waste products to the lungs, kid- neys, and skin for elimination from the body. 2. Regulation. Circulating Blood helps maintain homeostasis in all body fluids. Blood plays a role in the regulation of pH through buffers. (Buffers are chemicals that convert strong acids or bases into weak ones.) It also assists in the adjustment of body tem- perature; the heat-absorbing and coolant properties of the water in Blood plasma and its variable rate of flow through the skin allow excess heat to be lost from the Blood to the environment. Blood osmotic pressure also influences the water content of cells, mainly through interactions of dissolved ions and proteins. 3. Protection. Blood can clot (become gel-like), which protects against its excessive loss from the cardiovascular system after an injury. In addition, white Blood cells protect against disease Blood samples for laboratory testing may be obtained in several ways. The most common procedure is venipuncture (ve ¯n′-i-PUNK- chur), withdrawal of Blood from a vein using a needle and collecting tube, which contains various additives. A tourniquet is wrapped around the arm above the venipuncture site, which causes Blood to accumu- late in the vein. This increased Blood volume makes the vein stand out. Opening and closing the fist further causes it to stand out, making the venipuncture more successful.
eBook - PDF- Gerard J. Tortora, Bryan H. Derrickson(Authors)
- 2016(Publication Date)
- Wiley(Publisher)
In an arterial stick, Blood is withdrawn from an artery; this test is used to determine the level of oxygen in oxygen- ated Blood. Components of Blood Whole Blood has two components: (1) Blood plasma, a watery liquid extracellular matrix that contains dissolved substances, and (2) formed elements, which are cells and cell fragments. If a sample of Blood is centrifuged (spun) in a small glass tube, the cells (which are more dense) sink to the bottom of the tube while the plasma (which is less dense) forms a layer on top (Figure 19.1a). Blood is about 45% formed elements and 55% Blood plasma. Normally, more than 99% of the formed elements are cells named for their red color—red Blood cells (RBCs). Pale, colorless white Blood cells (WBCs) and platelets occupy less than 1% of the formed elements. Because they are less dense than red Blood cells but more dense than Blood plasma, they form a very 19.1 Functions and Properties of Blood OBJECTIVES • Explain the functions of Blood. • Describe the physical characteristics and principal components of Blood. The cardiovascular system (cardio- = heart; vascular = Blood or Blood vessels) consists of three interrelated components: Blood, the heart, and Blood vessels. The branch of science concerned with the study of Blood, Blood-forming tissues, and the disorders associated with them is hematology (hēm-a-TOL-ō-jē; hema- or hemato- = Blood; -logy = study of). Most cells of a multicellular organism cannot move around to ob- tain oxygen and nutrients or eliminate carbon dioxide and other wastes. Instead, these needs are met by two fluids: Blood and intersti- tial fluid. Blood is a liquid connective tissue that consists of cells sur- rounded by a liquid extracellular matrix. The extracellular matrix is called Blood plasma, and it suspends various cells and cell fragments. Interstitial fluid is the fluid that bathes body cells (see Figure 27.1) and is constantly renewed by the Blood.
eBook - PDF- Gerard J. Tortora, Bryan H. Derrickson(Authors)
- 2020(Publication Date)
- Wiley(Publisher)
696 CHAPTER 19 The Cardiovascular System: The Blood The focus of this chapter is Blood; the next two chapters will examine the heart and Blood vessels, respectively. Blood trans- ports various substances, helps regulate several life processes, and affords protection against disease. For all of its similarities in origin, composition, and functions, Blood is as unique from one person to another as are skin, bone, and hair. Health-care professionals routinely examine and analyze its differences through various Blood tests when trying to determine the cause of different diseases. Refer to Section 19.1, Clinical Connection: Blood Tests to find out why THERE ARE MANY IMPORTANT REASONS FOR HAVING Blood TESTS DONE. Horacio Villalobos/Getty Images Blood and Homeostasis Blood contributes to homeostasis by transporting oxygen, carbon dioxide, nutrients, and hormones to and from your body’s cells. It also helps regulate body pH and temperature, and provides protection against disease through phagocytosis and the production of antibodies. 19.1 Functions and Properties of Blood 697 19.1 Functions and Properties of Blood OBJECTIVES • Explain the functions of Blood. • Describe the physical characteristics and principal components of Blood. The cardiovascular system (cardio- = heart; vascular = Blood vessels) consists of three interrelated components: Blood, the heart, and Blood vessels. The branch of science concerned with the study of Blood, Blood-forming tissues, and the disorders as- sociated with them is hematology (hēm-a-TOL-ō-jē; hema- or hemato- = Blood; -logy = study of). Most cells of a multicellular organism cannot move around to obtain oxygen and nutrients or eliminate carbon dioxide and other wastes. Instead, these needs are met by two fluids: Blood and interstitial fluid. Blood is a liquid con- nective tissue that consists of cells surrounded by a liquid extracellular matrix.
eBook - PDF- Gerard J. Tortora, Mark Nielsen(Authors)
- 2020(Publication Date)
- Wiley(Publisher)
443 Mark Nielsen Steve Gschmeissner/Science Source 444 CHAPTER 12 The Cardiovascular System: Blood 12.1 Functions of Blood OBJECTIVES • Define cardiovascular system. • Outline the functions of Blood. The cardiovascular system (cardio- = heart; vascular = Blood or Blood vessels) consists of three interrelated components: Blood, the heart, and Blood vessels. The branch of science con- cerned with the study of Blood, Blood-forming tissues, and the disorders associated with them is hematology (hēm-a-TOL- ō-jē; hema- or hemato- = Blood; -logy = study of). Blood is a liquid connective tissue composed of cells and a liquid extracellular matrix and is closely related to other body fluids. In fact, many of the extracellular body fluids (including interstitial fluid, lymph plasma, cerebrospinal fluid, and aque- ous humor) arise from the Blood during development and are continually replenished by it. The extracellular fluids that nourish, protect, and exchange materials with every cell of the body are derived from the Blood, renewed by the Blood, and returned to the Blood. Based on these relationships, Blood has three general functions: 1. Transportation. Blood transports inhaled oxygen from the lungs to the cells of the body and carries carbon dioxide from the body cells to the lungs for exhalation. It carries nutrients from the digestive canal to body cells and hor- mones from endocrine glands to cells throughout the body. Blood also transports heat and waste products to the lungs, kidneys, and skin for elimination from the body. 2. Regulation. Circulating Blood helps maintain homeosta- sis in all body fluids. Blood plays a role in the regulation of pH through buffers. (Buffers are chemicals that convert strong acids or bases into weak ones.) It also assists in the adjustment of body temperature; the heat-absorbing and coolant properties of the water in Blood plasma and its variable rate of flow through the skin allow excess heat to be lost from the Blood to the environment.
- Gerard J. Tortora, Bryan H. Derrickson, Brendan Burkett, Gregory Peoples, Danielle Dye, Julie Cooke, Tara Diversi, Mark McKean, Simon Summers, Flavia Di Pietro, Alex Engel, Michael Macartney, Hayley Green(Authors)
- 2021(Publication Date)
- Wiley(Publisher)
Table 19.1 describes the chemical composition of Blood plasma. Pdf_Folio:860 860 Principles of anatomy and physiology FIGURE 19.1 Components of Blood in a normal adult. Blood is a connective tissue that consists of Blood plasma (liquid) plus formed elements (red Blood cells, white Blood cells, and platelets). Plasma (55%) Buffy coat, composed of white Blood cells and platelets Red Blood cells (45%) (a) Appearance of centrifuged Blood Other fluids and tissues 92% PLASMA 55% Proteins 7% ALBUMINS 54% GLOBULINS 38% FIBRINOGEN 7% All others 1% Water 91.5% Other solutes 1.5% Electrolytes Nutrients Gases Regulatory substances Waste products PLASMA (weight) Solutes Whole Blood 8% FORMED ELEMENTS 45% PLATELETS 150,000–400,000 WHITE Blood CELLS 5000–10,000 RED Blood CELLS 4.8–5.4 million Body weight Volume FORMED ELEMENTS (number per μL) Neutrophils 60–70% WHITE Blood CELLS Lymphocytes 20–25% Monocytes 3–8% Eosinophils 2–4% Basophils 0.5–1.0% (b) Components of Blood FUNCTIONS OF Blood 1. Transports oxygen, carbon dioxide, nutrients, hormones, heat, and wastes. 2. Regulates pH, body temperature, and water content of cells. 3. Protects against Blood loss through clotting, and against disease through phagocytic white Blood cells and proteins such as antibodies, interferons, and complement. ....................................................................................................................................................................................... QUESTION If you were dehydrated, how would you expect your haematocrit to refect this condition? TABLE 19.1 Substances in Blood plasma Constituent Description Function Water (91.5%) Liquid portion of Blood. Solvent and suspending medium. Absorbs, transports, and releases heat. Plasma proteins (7%) Most produced by liver. Responsible for colloid osmotic pressure. Major contributors to Blood viscosity. Transport hormones (steroid), fatty acids, and calcium.
eBook - PDFFundamentals of Children's Anatomy and Physiology
A Textbook for Nursing and Healthcare Students
- Ian Peate, Elizabeth Gormley-Fleming(Authors)
- 2014(Publication Date)
- Wiley-Blackwell(Publisher)
Figure 8.2 Composition of Blood in percentages. Source: Tortora and Derrickson (2009), Figure 19.1, p. 691. Reproduced with permission of John Wiley and Sons, Inc. Plasma (55%) Buffy coat, composed of white Blood cells and platelets Red Blood cells (45%) Table 8.1 Haematological values for infants and children. Age Haemoglobin (g/dL) Packed cell volume (% of Blood that is made up of red cells) Mean cell volume (fL) Mean cell haemoglobin concentration (%) White cell count (×10 9 /L) Neutrophil count a Cord Blood 13.5–20 50–56 110–128 29.5–33.5 9–30 2 weeks 14.5–18 50–55 100–120 30–34 6–15 6 months 10–12.5 33–38 80–96 32–36 6–15 2.3–6.9 1–5 years 10.5–13 36–40 6–15 2.3–6.9 5–10 years 11–14 37–42 5–15 2.0–8.0 10–15 years 11.5–14.5 38–42 4–13 2.0–8.0 a See section on white Blood cells for more details on neutrophil count. 171 Blood Chapter 8 • Regulation: – maintaining body temperature – maintaining acid–base balance – regulation of fluid balance. • Protection against infection. Transportation Blood vessels form a huge interlinking network of transportation routes within the body. They carry: • Oxygen (O 2 ) from the lungs to the tissues, and carbon dioxide (CO 2 ) from the tissues to the lungs for removal by exhalation. O 2 is transported by haemoglobin (Hb) in red Blood cells and as a dissolved substance in Blood plasma. Most of the CO 2 is transported by bicarbonate ions in the Blood plasma. • Nutrients, such as glucose and amino acids, from the gastrointestinal tract (stomach and intestines) to the cells so they can carry out their cellular functions (Nair, 2011). • Waste products of metabolism; for example, urea and uric acid – transported by Blood for elimination. • Hormones – from the endocrine glands to other cells in the body where they are needed. • Enzymes – secreted by some organs to other parts of the body for cellular function (Nair, 2011).
eBook - PDF- David Ucko(Author)
- 2012(Publication Date)
- Academic Press(Publisher)
T h e y destroy or inactivate microorganisms and foreign protein molecules known as antigens. T h e protein fibrinogen in b l o o d plasma is n e e d e d for b l o o d clot formation. Clotting is the chemical defense against loss of Blood. It results from the con-version of fibrinogen to fibrin, the substance that forms the jellylike clot. Nu-merous chemical substances affect the clotting time. T h e major role o f the erythrocytes, the red b l o o d cells, is the transport of 0 2 and C 0 2 . Oxygen is carried b y binding to the iron of h e m e groups in the pro-tein hemoglobin. Carbon dioxide is transported as bicarbonate ion in the plasma or as carbamate groups on the hemoglobin chains. Certain conditions result in overproduction of the erythrocytes, known as polycythemia. Anemia results from a deficiency of red b l o o d cells. T h e membranes o f the erythrocytes contain chemical groups that divide them into b l o o d group substances. Four different b l o o d types exist—Α, Β, AB, and O. Antibodies in die plasma (anti-A, anti-B) can react with antigens of an-other Blood type. T h e leukocytes, or white b l o o d cells, are part of the body's protective system. T h e y are formed in the b o n e marrow or lymph nodes and are carried to areas of inflammation. T h e number o f leukocytes rises during infections. In addition to plasma, other specialized fluids are n e e d e d for normal func-tioning of the b o d y . These include the interstitial fluid, lymph, aqueous humor, cerebrospinal fluid, tears, digestive tract secretions such as saliva, and sweat. Milk, secreted by the mammary glands of a mother at the end of preg-nancy, is one o f the most complete natural foods. Urine is the fluid separated from the b l o o d plasma b y the kidney. It con-tains waste products from metabolism as well as any other substances present in excess amounts that must b e eliminated. T h e volume voided varies from 600 to 2500 ml in 24 hours.
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