Biomedical Innovations Tissues of Life A Focus on Blood

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Biomedical InnovationsTissues of LifeA Focus
on Blood
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Blood Introduction

• Blood is a special Connective Tissue, and is the
  major component of the Circulatory System
• Connective tissue is a group of cells that
  collectively function to support, connect, and/or
  separate other tissues and organs.
• The Circulatory System is comprised of two
  sub-systems
• 1. Cardiovascular System
• Includes network of blood vessels, blood, and
  heart
• Major function is to transport nutrients, gases
  and hormones to cells and wastes from cells for
  excretion outside the body
• 2. Lymphatic System
• Includes network of lymph vessels, the
  lymphocyte white blood cell, and lymphoid organs
  (tonsils, spleen, thymus, bone marrow, and lymph
  nodes)
• Major functions are to return fluid that escapes
  from blood vessels back to the bloodstream AND
  fight infections and give immunity to disease

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Functions Of Blood

• 1. Transportation
• Blood transports dissolved gases, nutrients,
  hormones and metabolic wastes
• 2. Protection Clotting
• White Blood Cells (WBC) protect the body against
  foreign molecules
• Platelets (cell) and clotting proteins in blood
  minimize blood loss when a blood vessel is
  damaged (clot)
• 3. Regulation
• Blood regulates the pH and electrolyte
  composition of the interstitial fluids (fluid
  between cells)
• Blood regulates body temperature transfers heat
  via counter-current exchange

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Counter-Current Exchange
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Composition of Blood

• Contains cellular and liquid components
• Liquid Portion 55 plasma
• Cellular Portion 45 formed elements
• Normal blood pH is 7.35-7.45 (neutral)
• Blood volume
• Varies inversely with body fat
• Blood volume as body fat
• Males typically have 5 to 6 liters (10.5 to 12.5
  pints)
• Females typically have 4 to 5 liters (8.5 to
  10.5 pints)
• How can blood volume be determined?
• How much is a unit of donated blood?

• Volume
• Assess Blood pressure
• Calculate Radioactive dye
• Units
• 1 unit donated 1 pint (0.5L)
• 1 unit accepted 0.75 pint
• Packed RBC (prBC)

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Composition of Blood

• 55 Plasma
• 92 - Water
• 7 - Proteins (fibrinogen, hormones, albumins
  globulins)
• 1 - other solutes (ions, gases, nutrients,
  wastes, etc.)
• 45 Formed Elements
• 99.9 - erythrocytes (Red Blood Cells - RBCs)
• 0.1 - leukocytes (White Blood Cells - WBCs)
  thrombocytes (Platelets)

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Composition of Blood - Plasma
Figure 19.1b
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Composition of Blood Formed Elements
Figure 19.1c
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ID the Formed Elements

• Be able to identify any of the formed elements to
  RBC, WBC, or Platelet.

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Lecture 1a - Review Break

• Visualize the Composition of Blood
• Microscopy Blood Cell Identification Lab

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Lecture 1b Overview Composition of Blood

• Hematocrit or Packed Cell Volume (PCV)
• measure of RBC
• Males 47 5 Females 42 5

Figure 17.1
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Erythrocytes Red Blood Cells (RBCs)

• Oxygen-transporting cells
• 7.5 µm in diameter (diameter of capillary 8
  10µm)
• Most numerous of the formed elements
• Females 4.3 5.2 million cells/mm3
• Males 5.2 5.8 million cells/mm3
• Made in the red bone marrow in long bones,
  cranial bones, ribs, sternum, and vertebrae
• Average lifespan is 100 120 days

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RBC Structure And Function

• Have no organelles or nuclei
• Significance?
• True for all species?
• Hemoglobin oxygen carrying protein
• Each RBC has 200-300 million hemoglobin
  molecules
• Biconcave shape
• Significance?

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Hemoglobin

• Comprised of four protein chains, each called a
  globin.
• Each globin is bound to a red pigment, called a
  heme molecule.
• Contains a single Fe atom
• Each Fe atom can bind to a single O2 molecule
• How many O2 molecules can each hemoglobin combine
  with?
• What is the term for when
  hemoglobin binds with O2?
• CO2?
• Are either a reversible reaction?

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Leukocytes White Blood Cells (WBCs)

• Protect the body from
• infectious microorganisms
• Cancerous cells
• Foreign particles
• Typically, function outside the bloodstream in
  loose connective tissue
• Diapedesis - circulating leukocytes leave the
  capillaries and enter the interstitial fluid
• Exception?
• WBCs have a nucleus and are larger than RBCs
• Most produced in bone marrow
• Exception?
• Lifespan of 12 hours to several years

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Leukocytes White Blood Cells (WBCs)

• Two types of leukocytes
• Granulocytes
• Agranulocytes
• Relative WBC Count
• Never
• Let
• Monkeys
• Eat
• Bananas

Figure 17.5
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White Blood Cells
Type Of White Blood Cells By Volume Of WBC Description Function
Neutrophils 60 70 Nucleus has many interconnected lobes blue granules Phagocytize and destroy bacteria most numerous WBC
Eosinophils 2 4 Nucleus has bilobed nuclei red or yellow granules containing digestive enzymes Play a role in ending allergic reactions
Basophils lt 1 Bilobed nuclei hidden by large purple granules full of chemical mediators of inflammation Function in inflammation medication similar in function to mast cells
Lymphocytes (B Cells and T Cells) 20 25 Dense, purple staining, round nucleus little cytoplasm the most important cells of the immune system effective in fighting infectious organisms act against a specific foreign molecule (antigen)
Monocytes 4 8 Largest leukocyte kidney shaped nucleus Transform into macrophages phagocytic cells
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Lymphocyte

• Compose 20 45 of WBCs
• The most important cells of the immune system
• Nucleus stains dark purple
• Effective in fighting infectious organisms
• Act against a specific foreign molecule (antigen)
• Two main classes of lymphocyte
• T cells attack foreign cells directly
• Active in cell mediated immune response
• B cells multiply to become plasma
  cells that secrete antibodies
• Active in the humoral immune response

Figure 17.4d
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Platelets

• Structure
• Small, nearly colorless bodies appearing as
  irregular spindles or oval disks (2-4 µm)
• originate in bone marrow from giant cell
  megakaryocyte
• Functions
• Hemostasis
• Regulation of blood flow
• Coagulation, or blood clotting

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Summary of Formed Elements
Table 17.1
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Review Activity Break

• Blood Disorders
• Blood Types
• Review for Quiz 1
• Basics
• Disorders
• Typing

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Blood Cell Formation

• Hematopoiesis process by which blood cells are
  formed
• 100 billion new blood cells formed each day
• Takes place in the red bone marrow of the
  humerus, femur, sternum, ribs, vertebra and
  pelvis
• Red marrow actively generates new blood cells
• Contains immature erythrocytes
• Remains in epiphyses, girdles, and axial skeleton
• Yellow marrow dormant (can become active if
  needed)
• Contains many fat cells
• Located in the long bones of adults

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Cell Lines in Blood Cell Formation

• All blood cells originate in bone marrow
• All originate from one cell type
• Blood stem cell (pluripotential hematopoeitic
  stem cell)
• Lymphoid stem cells - give rise to lymphocytes
• Myeloid stem cells - give rise to all other blood
  cells

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Cell Lines in Blood Cell Formation

• Genesis of erythrocytes (erythropoiesis)
• Committed cells are proerythroblasts
• Remain in the reticulocyte stage for 12 days in
  circulation
• Loss of nucleus
• Formation of leukocytes (leukopoiesis)
• Granulocytes form from myeloblasts
• Monoblasts enlarge and form monocytes
• Platelet formation (thrombopoiesis)
• Form from megakaryoblasts
• break apart into platelets

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The Blood Throughout Life

• First blood cells develop with the earliest blood
  vessels
• Late in the second month the liver and spleen
  take over blood formation
• Bone marrow becomes major hematopoietic organ at
  month 7

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RBC life span and circulation

• Replaced at a rate of approximately 3 million new
  blood cells entering the circulation per second
• Damaged or dead RBCs are recycled by phagocytes
• Components of hemoglobin individually recycled
• Heme stripped of iron and converted to
  biliverdin, then bilirubin
• Iron is recycled by being stored in phagocytes,
  or transported throughout the blood stream bound
  to transferrin

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Red Blood Cell Turnover
Figure 19.5
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Clotting Mechanisms

• Know the general stages of blood clotting
• Stage 1 Source of damage
• Stage 2 prothrombin ? thrombin
• Calcium, prothrombin activator
• Stage 3 fibrinogen ? fibrin
• Calcium, thrombin
• Be able to identify the key difference between
  intrinsic and extrinsic pathways
• Stage 1

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Clotting Cont.

• What two conditions increase clotting?
• What two conditions decrease clotting?
• How are clots removed?
• Fibrinolysis

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Review Activity Break
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You should be able to

• Identify and describe the following blood
  disorders/conditions

• Identify and describe
• The different types of tissues
• Functions of the blood
• Blood composition
• Plasma Formed Elements
• Hematocrit
• Blood Cell Formation
• The process of clotting
• Blood type based on tests and genetic inheritance
• Antigen vs. antibody
• Coagulation vs. agglutination

• Leukemia
• Leukopenia
• Leukocytosis
• Anemia
• Polycythemia
• Blood doping
• Sickle-cell anemia
• Embolus
• Thrombus
• Erythroblastosis fetalis