Blood Part 1 (4) - Week 3 PDF

1 Chapter 18: BLOOD © 2019 McGraw-Hill Education  2 BLOOD Continuously regenerated connective tissue...

1 Chapter 18: BLOOD © 2019 McGraw-Hill Education  2 BLOOD Continuously regenerated connective tissue Moves gases, nutrients, wastes, and hormones Transported through cardiovascular system Heart pumps blood Arteries transport blood away from heart Veins transport blood toward heart Capillaries allow exchange between blood and body tissues © 2019 McGraw-Hill Education  3 Functions of Blood Explained © 2019 McGraw-Hill Education  Physical Characteristics of Blood 4 High O2 – Bright red COLOR Low O2 – Dark red VOLUME ~ 5,000 cc (5 liters) normal adult Thick. High erythrocyte = high VISCOSITY viscosity [PLASMA] Solutes concentration determines direction of osmosis TEMPERATU One degree Celsius higher than body RE temp 7.35 to 7.45. Slightly alkaline. Crucial pH for plasma protein integrity © 2019 McGraw-Hill Education  5 Whole Blood Separation and Composition Figure 18.1 © 2019 McGraw-Hill Education  6 Hematocrit Percentage of volume of all formed elements Clinical definition: percentage of only erythrocytes Adult males: 42–56%; females 38–46% Testosterone causes more erythropoietin secretion by kidney Blood smear Thin layer of blood placed on microscope slide and stained Formed elements differ in appearance Erythrocytes are most numerous - pink, anucleate, biconcave discs Leukocytes - larger than erythrocytes, varied in form, noticeable nucleus Platelets - small fragments of cells © 2019 McGraw-Hill Education  7 Ask Yourself: What did you learn? 1. What are some of the materials that blood transports? 2. How does blood help regulate body temperature and fluid levels in the body? 3. Will blood be able to properly carry out its functions if blood pH is significantly altered? Explain why? 4. What are the three components visible in a centrifuged blood sample? 5. How does hematocrit vary among adult men and women, and how may dehydration affect hematocrit? © 2019 McGraw-Hill Education  8 Composition of Blood - Plasma © 2019 McGraw-Hill Education  9 Plasma Proteins Acts as a transport protein for some lipids, hormones and ions LDL and HDL are common transports proteins Includes enzymes and hormones Blood is also considered a solution Contains dissolved organic and inorganic molecules and ions Include electrolytes, nutrients, gases, waste products Polar or charged substances dissolve easily Nonpolar molecules require carrier proteins © 2019 McGraw-Hill Education  10 Plasma Proteins and Osmotic Pressure 5 Plasma proteins exert colloid osmotic pressure (Albumin is the most abundant) Prevents loss of fluid from blood as it moves through capillaries Helps maintain blood volume and blood pressure Can be decreased with diseases, resulting in fluid loss from blood and tissue swelling E.g., liver diseases that decrease production of plasma proteins © 2019 McGraw-Hill Education  11 Ask Yourself: What did you learn? 6. How are plasma protein levels related to colloid osmotic pressure? 7. What is the most abundant type of plasma protein, and what are its two primary functions? 8. What are the main dissolved substances found in plasma? © 2019 McGraw-Hill Education  12 Hematopoie Production of formed sis elements (blood cells) Occurs in red bone marrow of certain bones Erythropoiesis: red blood cell production Leukopoiesis: production of leukocytes Thrombopoiesis: platelet production © 2019 McGraw-Hill Education  13 Platelet Formation Figure 18.4 © 2019 McGraw-Hill Education (a) ©McGraw-Hill Education/Al Telser  14 Erythrocytes and Their Structure Small, flexible formed elements Lack nucleus and cellular organelles; packed with hemoglobin Have biconcave disc structure Transport oxygen and carbon dioxide between tissues and lungs © 2019 McGraw-Hill Education  15 Hemoglobin Red-pigmented protein Transports oxygen and carbon dioxide Termed oxygenated or deoxygenated Each hemoglobin molecule is composed of four globins Two alpha chains and two beta chains Each chain has a heme group: a porphyrin ring with an iron ion in its center Oxygen binds to the iron ion, so each hemoglobin can bind four oxygen molecules © 2019 McGraw-Hill Education  16 Erythropoiesis: Erythrocyte Production Figure 18.7 © 2019 McGraw-Hill Education  17 Erythropoietin Testosterone also stimulates EPO production, so males typically have a higher erythrocyte count Environmental factors such as altitude influence EPO levels How might EPO be used by endurance athletes as a form of blood doping? © 2019 McGraw-Hill Education  18 Fate and Destruction of Erythrocytes © 2019 McGraw-Hill Education  19 BLOOD TYPES © 2019 McGraw-Hill Education  20 ABO Blood Types Figure 18.9a © 2019 McGraw-Hill Education  21 Rh Positive or Negative The Rh blood group was named after the Rhesus monkey. If the Rh factor surface protein is present on red blood cells, the blood is Rh positive; otherwise it is Rh negative. Presence of the Rh agglutinogens on RBCs is indicated as Rh+. Anti-Rh antibodies are not spontaneously formed in Rh– individuals. However, if an Rh– individual receives Rh+ blood, anti-Rh antibodies form. A second exposure to Rh+ blood will result in a typical transfusion reaction © 2019 McGraw-Hill Education  22 Rh Positive or Negative © 2019 McGraw-Hill Education  23 Erythrocytes Clinical considerations If someone receives an incompatible transfusion agglutination occurs. Recipient’s antibodies bind to transfused erythrocytes and clump them together Can block blood vessels and prevent © 2019 McGraw-Hill Education  24 Agglutination Test Figure 18.10b © 2019 McGraw-Hill Education ©Jean Claude Revy/ISM/Medical Images  25 Clinical View: Rh Incompatibility and Pregnancy © 2019 McGraw-Hill Education