Cardiovascular System

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Cardiovascular System

• Anatomy and Physiology
• Liberty Senior High

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Whats the purpose of the cardiovascular
system?Do all organisms have one?

• Lets model!

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Why we need a cardiovascular system!

• Human embryos before 3 weeks are so small,
  materials are transported by simple diffusion.
• At third week (few mms in length), heart begins
  beating- first system to function.
• Supplies nutrients to all 75 trillion cells in
  the body.

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What is the cardiovascular system?

• Three parts
• Blood a circulating fluid. (Chapter 19).
• Heart a pump. (Chapter 20).
• Blood vessels the conducting pipes (Chapter 21)

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Cardiovascular Lymphatic Systems

• Fluid leaves the vessel and enters the tissues-
  interstitial fluid.
• Eventually returns to the vessels.
• Lymphatic system has its own vessels.
• Used to transport antibodies, white blood cells,
  and monitor for infection and cancer.
• Cardiovascular Lymphatic Circulatory System.

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What is blood?

• Specialized connective tissue with cells in a
  fluid matrix.

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Functions of the Blood

• Transport dissolved gases, nutrients, hormones,
  and metabolic wastes.
• Regulation of the pH and electrolytes of
  interstitial fluid. Neutralizes the acids
  created by metabolism (lactic acid).
• Restricts fluid losses through damaged vessels or
  at injury sites- blood clots.

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Functions of the Blood

• Defense against toxins and pathogens- transports
  white blood cells that migrate into tissue to
  fight infection and remove debris. Also, deliver
  antibodies.
• Stabilize body temperature- absorbs heat from
  active muscles and distributes to other tissues.
  Also brings heat to the surface of the skin to
  lose heat.

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Composition of Blood

• It is a fluid connective tissue with an
  extracellular matrix- plasma formed elements
  (cells and cell fragments) whole blood.
• Plasma Formed Elements Whole Blood.

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Whole Blood After Centrifugation
Plasma
White Blood Cells Buffy Coat
Red Blood Cells
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Whole Blood
37-54
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Centrifuge and Separate
Formed Elements
Plasma
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Plasma
1 Electrolytes and other Solutes
7 Plasma Proteins
92 Water
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Plasma- The Fluid of Life!

• Plasma Plasma Proteins a Ground Substance
  (Serum).
• Plasma Proteins
• Albumin- transport fatty acids, maintain
  isotonic solution.
• Globulin- immunoglobulin (antibodies).
• Fibrinogen- form blood clots becomes fibrin- an
  insoluble protein.

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Plasma
Globulin
Serum
Albumin
Fibrinogen
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Plasma- The Fluid of Life!

• Plasma that has been allowed to clot will lose
  its fibrin and other salts like Ca2.
• Plasma without its fibrin Serum.

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Formed Elements

• Formed Elements Blood Cells Fragments
  suspended in the plasma.
• Erythrocytes (Red Blood Cells) most abundant
  (99.9 of all cells) transport of oxygen and
  carbon dioxide.
• Leukocytes (White Blood Cells) bodys defense
  cells. (0.1 of cells).
• Thrombocytes (Platelets) small, membrane- bound
  packets of cytoplasm that contain enzymes for
  blood clot formation.

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Erythrocyte
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A Normal Blood Smear
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Collecting and Analysis of Blood

• Blood usually collected at a vein-venipuncture.
• Venipuncture- veins are easy to locate, walls of
  vein are thinner, pressure is lower? heals
  easier.
• Peripheral capillaries- tip of finger, earlobe
  oozing small drop for blood smear.
• Arterial Puncture- check for effeciency of gas
  exchange.

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Properties of Blood

• Temperature- 38 C or 100.4 F.
• Viscosity- has a great deal of dissolved proteins
  in plasma ? more viscous than water.
• pH 7.35-7.45 slightly alkaline.

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Erythrocytes (RBCs)

• erythros- red cyte- cell.
• RBCs are the most abundant blood cell (99.9). 25
  trillion in average adult. Takes 1 min. to
  travel circuit.
• Hematocrit- percentage of formed elements in a
  sample of whole blood. of cells / microliter of
  whole blood.
• Has a red pigment-hemoglobin- gives whole blood
  its color.

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RBCs Structure and Function

• Highly specialized cell to transport gases.
• Cell structure is a biconcave disc.

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EM of RBCs
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RBCs Structure and Function

• Shape provides the RBC with a large surface area.
• Exchange of O2 with the surrounding plasma must
  be quick larger surface area? faster the
  exchange.
• Total surface of all RBCs is 3800 m2 compared to
  1.9 m2 of the whole human body.

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RBCs Structure and Function

• Biconcave shape allows them to form stacks
  (dinner plates) rouleaux inside narrow blood
  vessels.
• Rouleaux permit the cells to pass through blood
  vessels without bumping along the walls.
• Do not form logjams or clogs in the narrow
  capillary.

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Rouleaux in a Blood Smear
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Rouleaux in Bone Marrow
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RBCs Structure and Function

• Biconcave shape allows the RBCs to bend and flex
  when entering capillaries.
• May pass through capillaries ½ the RBCs
  diameter.

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RBCs are Highly Specialized Cells

• Have lost all organelles- lack nuclei,
  mitochondria, and ribosomes.
• Lost these structures to allow more space for
  hemoglobin and oxygen transport.
• Downside RBCs unable to divide or repair
  themselves. Made in bone marrow.
• Short lifespan- 120 days and then must be broken
  down.

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Hemoglobin (Hb)

• Accounts for 95 of proteins inside the RBC.
• 280 million Hbs in each RBC.
• Hb binds to and transports O2 and CO2.

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Hb Molecule

• Each Hb molecule four protein chains 2 alpha
  chains 2 beta chains of polypeptides.
• Each chain is a globular subunit and has a heme
  group.
• Heme a porphyrin which is a ring compound with
  an iron in the center.
• Iron has a charge and can bind to O2 (negative).

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Hb Molecule

• When hemoglobin binds to O2 it becomes
  oxyhemoglobin.
• Very weak interaction easy to separate.
• Fetus uses a fetal hemoglobin- more readily binds
  to O2 for more efficient uptake from mothers
  RBCs.

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Hb Molecule

• Alpha and Beta chains bind to CO2 at other sites
  and transport to lungs.
• If hematocrit is low or the amount of Hb in RBCs
  is low than normal activity cannot be sustained
  in tissue- anemia.

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Sickle Cell Anemia

• Mutations in the beta chains of the Hb molecule.
• When the blood contains abundant O2, the Hb and
  RBCs are normal.
• But when the defective Hb loses its O2,
  neighboring Hb molecules interact and change the
  shape of the cell- curved and stiff.
• Cannot form rouleaux and may form clots.

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Sickle Cell Mutation
Sickle Cell Mutation
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Sickle Cell Anemia
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Iron-Deficiency Anemia
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Malaria in an RBC
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Leukocytes (WBCs)

• General Properties
• 1. Help defend against pathogens, toxins, and
  damaged cells.
• 2. They have nuclei and other organelles.
• 3. Are made in bone marrow, thymus, spleen, and
  other lymphatic tissue.

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Two Major Groups of WBCs

• Granulocytes- WBCs with darkly-staining vesicles
  and lysosomes inside.
• a. Neutrophils
• b. Eosinophils
• c. Basophils

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Two Major Groups of WBCs

• Agranulocytes- do not stain darkly on their
  interior have very small vesicles and lysosomes.
• a. Monocytes
• b. Lymphocytes

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Leukocytes

• Most WBCs are not in the circulatory system, but
  in tissues or organs of the lymphatic system.
• Circulate for only a short time in vessels.

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Characteristics of WBCs

• Move along the capillaries by amoeboid movement.
• Detect chemicals from injured cells.
• Leave the capillary by squeezing through cells
  diapedesis.
• Are positively chemotactic in the tissue.
• Can destroy things by phagocytosis.

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Infected Cell
White Blood Cell
Diapedesis
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Neutrophils

• Most abundant of WBCs.
• Granules are neutral. Filled with toxins.
• Have a dense, segmented nucleus of 2 to 5 lobes-
  Polymorphonulear (PMNs).
• Very mobile and arrive at site of infection first.

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Neutrophils

• Phagocytize tagged bacteria.
• Breakdown bacteria with their toxic granules.
• Also, release chemicals to call WBCs to the site-
  interleukins.

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Neutrophils
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Eosinophiles

• Granules stain with eosin- a red dye.
• Only amount 2-4 of the WBCs.
• Have a bilobed nucleus.
• Phagocytize bacteria and cell debris.
• Use exocytosis to release toxins onto the surface
  of large parasites.
• Release chemicals that cause allergic reactions.

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Eosinophil
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Neutrophil and Eosinophil
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Basophiles

• Stain very darkly. Very small cells.
• Very rare in circulation. Usually in tissue.
• Release granules of histamine and heparin.
• Histamine permeability of capillaries.
• Heparin blood clotting.
• Do not phagocytize.

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Basophil
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Monocytes

• Larger cells with oval nuclei.
• Circulate throughout the blood stream.
• Leave the vessel and become macrophages.
• Macrophages phagocytize bacteria, cell debris,
  and other foreign elements.
• Also, release chemical messengers.

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Monocyte
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Lymphocytes

• Larger than RBCs and lack deeply-stained
  granules. Single, large nucleus.
• Abundant in blood. Migrate from blood ? to
  tissue? through lymph? return to blood.
• Most are not found in blood at any one time.

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Lymphocyte
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3 Kinds of Lymphocytes

• T Cells cellular immunity against foreign tissue
  and cells infected with viruses have killer T
  cells and helper T cells (CD-4 and CD-8).
• B cells humoral immunity, produce antibodies
  (globulin proteins).Also memory cells.
• NK cells (Natural Killers) large granules of
  toxin that destroy cancerous cells and some
  virally-infected cells.

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Leukemia
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Platelets

• Thrombocytes (nonmammalian)
• Circulates for 9-12 days
• Cell fragments

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Platelet Function

• Transport of chemicals important to the clotting
  process

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Platelet Function

• Formation of a temporary patch in the walls of
  damaged blood vessels
• Forms a platelet plug slows the rate of blood
  loss while clotting continues

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Platelet Function

• Active contraction after clot formation has
  occurred
• Contain actin myosin
• After clot forms contraction shrinks clot
  reduces size of break in vessel wall

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Blood Clot
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Platelet Production

• Thrombocytopoiesis occurs in the bone marrow
• Bone marrow contains Megakaryocytes enormous w/
  large nuclei

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Platelet Production

• Megakaryocytes make proteins, enzymes,
  membranes.
• Shed cytoplasm in small membrane-enclosed
  packets Platelets that enter circulation
• Mature megakaryocyte produces 4000 platelets

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Megakaryocyte