Physical%20Characteristics%20of%20Blood

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Physical Characteristics of Blood

• Thicker (more viscous) than water and flows more
  slowly than water
• Temperature of 100.4 degrees F
• pH 7.4 (7.35-7.45)
• 8 of total body weight
• Blood volume
• 5 to 6 liters in average male
• 4 to 5 liters in average female
• hormonal negative feedback systems maintain
  constant blood volume and osmotic pressure

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Blood components

• 55 plasma mainly water
• 7 to 8 dissolved substances (sugars, amino
  acids, lipids vitamins), ions, dissolved gases,
  hormones
• most of the proteins are plasma proteins provide
  a role in balancing osmotic pressure and water
  flow between the blood and extracellular
  fluid/tissues
• loss of plasma proteins from blood decreases
  osmotic pressure in blood and results in water
  flow out of blood into tissues ? swelling
• most common plasma proteins albumin, globulins,
  clotting proteins (fibrin)

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Blood Cellular elements

• 45 of blood is the cellular elements or formed
  elements
• 99 of this (44.55 of total blood) is
  erythrocytes or RBCs
• formed by differentiation of hematopoietic stem
  cells (HSCs) in the red bone marrow of long bones
  and pelvis makes about 2 million per second!
• made from an immature cell reticulocyte
• as they mature in the marrow they lose most
  organelles and its nucleus
• lives only about 120 days destroyed by the
  liver and spleen
• liver degrades the hemoglobin to its globin
  component and the heme is degraded to a pigment
  called bilirubin - bile
• Iron(Fe3)
• transported in blood attached to transferrin
  protein
• stored in liver, muscle or spleen
• attached to ferritin or hemosiderin protein
• in bone marrow being used for hemoglobin
  synthesis

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-1 found in the Buffy coat -leukocytes (WBCs)
and platelets (thromobocytes) -neutrophils
phagocytic properties -release agents which
destroy/digest bacteria -eosinophils parasitic
defense cells -also involved in the
allergic response -release histaminase to slows
down inflammation caused by basophils -basophils
release heparin, histamine serotonin
-heighten the inflammatory response and account
for hypersensitivity (allergic)
reaction -monocytes enter various tissues and
differentiate into phagocytic
macrophages -lymphocytes T and B cells
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Hematopoiesis
HSC
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Hematocrit

• Percentage of blood occupied by cells
• female normal range
• 38 - 46 (average of 42)
• male normal range
• 40 - 54 (average of 46)
• testosterone
• Anemia
• not enough RBCs or not enough hemoglobin
• Polycythemia
• too many RBCs (over 65)
• dehydration, tissue hypoxia, blood doping in
  athletes

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Blood Groups and Blood Types

• RBC surfaces are marked by genetically determined
  glycoproteins glycolipids
• agglutinogens or isoantigens
• distinguishes at least 24 different blood groups
• ABO, Rh, Lewis, Kell, Kidd and Duffy systems

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RH blood groups

• Antigen was discovered in blood of Rhesus monkey
• People with Rh agglutinogens on RBC surface are
  Rh. Normal plasma contains no anti-Rh
  antibodies
• Antibodies develop only in Rh- blood type only
  with exposure to the antigen
• transfusion of positive blood
• during a pregnancy with a positive blood type
  fetus
• Transfusion reaction upon 2nd exposure to the
  antigen results in hemolysis of the RBCs in the
  donated blood

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Hemolytic Disease of Newborn

• Rh negative mom and Rh fetus will have mixing of
  blood at birth
• Mom's body creates Rh antibodies unless she
  receives a RhoGam shot soon after first delivery
• can lead to miscarriage or spontaneous abortion
  of future Rh children
• RhoGam binds to loose fetal blood and removes it
  from body before she reacts
• In 2nd child, hemolytic disease of the newborn
  may develop causing hemolysis of the fetal RBCs

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Anemia

• Symptoms
• oxygen-carrying capacity of blood is reduced
• fatigue, cold intolerance paleness
• lack of O2 for ATP heat production
• Types of anemia
• iron-deficiency lack of absorption or loss of
  iron
• type of nutritional anemia
• failure to take in essential raw ingredients not
  made by the body
• pernicious lack of intrinsic factor for vitamin
  B12 absorption from the digestive tract
• B12 is essential for normal RBC formation and
  maturation
• binding of B12 to intrinsic factor allows its
  absorption
• intrinsic factor synthesized by the small
  intestine
• hemorrhagic loss of RBCs due to bleeding
  (ulcer)
• hemolytic defects in cell membranes cause
  rupture
• rupture of too many RBCs by external factors such
  as malaria (normal RBCs) or genetic disorders
  like sickle cell anemia (defective RBCs)
• thalassemia hereditary deficiency of hemoglobin
• aplastic destruction of bone marrow
  (radiation/toxins)
• failure of the bone marrow to produce enough RBCs
  
• may selectively destroy the ability to produce
  RBCs only

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Sickle-cell Anemia (SCA)

• Genetic defect in hemoglobin molecule (Hb-S) that
  changes 2 amino acids in the globin protein
• at low very O2 levels, RBC becomes deformed by
  changes in hemoglobin molecule within the RBC
• sickle-shaped cells do not pass through
  capillaries well and get stuck causing
  occlusions and decreased blood flow to organs
• also rupture easily causing anemia clots
• Found among populations in malaria belt
• Mediterranean Europe, sub-Saharan Africa Asia
• Person with only one sickle cell gene
• increased resistance to malaria because RBC
  membranes leak K lowered levels of K kill the
  parasite (Plasmodium) infecting the red blood
  cells

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Blood Clotting

• in a test tube blood separates into liquid
  (serum) and a clot of insoluble fibers (fibrin)
  in which the cells are trapped
• in the body the clot plugs damaged blood
  vessels and initiates healing
• ultimate step is conversion of fibrinogen
  (soluble plasma protein) into insoluble fibrin
• Substances required for clotting are Ca2,
  enzymes synthesized by liver cells (clotting
  factors and plasma proteins) and substances
  released by platelets or damaged tissues
• thrombin released by damaged cells, catalyzes
  the conversion of fibrinogen to fibrin
• 12 clotting factors involved
• Clotting is a cascade of reactions in which each
  clotting factor activates the next in a fixed
  sequence resulting in the formation of fibrin
  threads
• prothrombinase Ca2 convert prothrombin into
  thrombin
• thrombin converts fibrinogen into fibrin threads

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Overview of the Clotting Cascade
-may be triggered through two possible paths 1.
extrinsic pathway 2. intrinsic pathway -both
pathways result in the release and activation of
specific clotting factors -either path leads to
activation of the common pathway -common pathway
results in the formation of prothrombinase
(clotting factors X and V) -prothrombinase
activates thrombin -thrombin cleaves fibrinogen
to form fibrin
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The Bodys Response to Infection The Immune
System

• Three lines of defense

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The Bodys Response to Infection First Line of
Defense

• 1. Skin
• Sheds, takes pathogens with it
• Has low pH, repels microorganisms
• Glands in skin secrete chemicals to slow
  bacterial growth
• 2. Mucous membranes
• Mucous traps pathogens
• Can be sneezed, coughed away

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The Bodys Response to Infection Second Line of
Defense

• 1. White blood cells production
• A. macrophages and other phagocytes
• Engulf and digest invasive organisms
• Also digest old red blood cells and cellular
  debris
• Can release chemicals to stimulate production of
  more white blood cells like T and B cells
• B. White blood cells natural killer cells
• Attack tumor cells and virus-infected cells
• Release chemicals that break apart the cell
  membranes of infected cells or tumor cells

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The Bodys Response to Infection Second Line of
Defense Inflammation

• 2. Inflammation response which produces redness,
  warmth, swelling, and pain
• After tissue injury, damaged cells release
  histamine
• Histamine causes vasodilation which increases
  blood flow
• this will increase more WBCs into the infected
  area
• brings more O2 and nutrients
• BUT also brings in more fluid some fluid gets
  pushed out into the surrounding tissues Swelling

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The Bodys Response to Infection Second Line of
Defense Defensive Proteins

• 3. Interferons are produced by infected cells
• bind to healthy cells
• stimulate production of anti-viral chemicals
• 4. Complement proteins are made in response to
  inflammation and infection
• are a class of about 20 different proteins
• can coat surface of bacteria to facilitate
  phagocytosis
• can make holes in bacterial membrane ? BOOM!

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The Bodys Response to Infection Second Line of
Defense Fever

• 5. Fever temperature above range of 97-99º F
• macrophages can release pyrogens
• which causes temperature of tissue to increase
• increased temperature inhibits bacterial growth
• increases metabolism of healthy cells promotes
  mitosis and tissue repair
• large-scale production of pyrogens can increase
  overall body temperature Fever
• also increases the efficiency of immune cells

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The immune system

• Cells of the immune cells (macrophages, T cells,
  B cells) are found in specific locations called
  lymphatic tissues

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The Bodys Response to Infection Third Line of
Defense Lymphocytes

• Lymphocytes are a specific defense because they
  recognize specific antigens
• antigen cell-surface protein that identifies
  the type of cell bearing it
• also distinguishes it from antigens in another
  organism
• when your immune system is developing your
  lymphocytes learns what antigens belong to you
  and what dont
• develop self-tolerance
• examples of non self-tolerant, foreign antigens
  proteins found on or in viruses, bacteria, fungi,
  protozoans and worms.
• Lymphocytes travel throughout the body in spaces
  between the cells and are carried in the blood
  and lymphatic system.

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The Lymphatic System

• Lymphocytes travel throughout the body in spaces
  between the cells and are carried in the blood
  and lymphatic system.
• the lymphatic system system of lymphatic
  vessels lymph nodes lymphatic tissues
  (spleen, thymus, tonsils) that filter lymph and
  circulate WBCs
• lymph yellow-colored fluid that is produced
  from your blood plasma
• produced when plasma filters out of your blood
  and into your tissues
• some of that filtrate becomes lymph

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The Lymphatic System

• Lymph comes from your blood plasma but is
  returned to you blood stream
• along the way it flows through lymph nodes which
  house lymphocytes and macrophages
• these immune cells clean the lymph of bacteria
• so what gets returned to your blood is cleaned
• lymph is the way we launder our blood

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The Bodys Response to Infection Third Line of
Defense Lymphocytes

• Two types of Lymphocytes
• A. T cells
• B. B cells

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Lymphocytes

• Lymphocytes are produced from stem cells in the
  red bone marrow.
• they are named by the location where they were
  first identified
• B cells develop in the bone marrow
• T cells develop in the thymus
• thymus disappears over time

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T and B Lymphocytes

• B cells
• Recognize small organisms such as bacteria by
  producing antibodies
• antibodies small proteins that bind foreign
  antigens and target the foreign cell for
  destruction by the hosts immune system
• can respond to viruses if helped by T cells

• Antibody
• abbreviated as Ig
• made up of four protein chains
• two light chains
• two heavy chains determine the type of antibody
• ends of the antibody are specific for the
  foreign antigen Antigen-binding Site

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T and B Lymphocytes

• T cells
• Respond to larger organisms (e.g. fungus),
  viruses, and body cells that have gone awry (e.g.
  tumor cells)
• also attack transplanted tissues!
• if they attack normal cells Auto-immune disease
• Attack the antigen-bearing cell directly by
  secreting chemicals that kill it
• help B cells and teach them what antibodies to
  make
• can bind a foreign protein and then interact with
  a B cell
• B cell then makes antibodies to that foreign
  protein

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T and B Lymphocytes

• B and T cells display cell-surface proteins that
  bind to foreign antigens
• called antigen receptors
• once they bind the T and B cells are called
  activated
• activated T cells help B cells by physically
  binding them
• the B cell then begins to make antibodies

• B and T cells have a Memory
• once the infection is cleared, there are a small
  number of T and B cells that remember the
  infection
• will become activated if the foreign antigen
  re-appears
• faster activation than the 1st time

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Types of Immunity Antibody and Cell-Mediated
Immunity

• B cell mediated immunity is called Antibody
  mediated immunity
• B cells exposed to foreign antigens rapidly
  divide clonal expansion
• most B cells develop into plasma cells that make
  the antibodies
• Rest of B cells become memory cells to provide
  long term immunity

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Antibody and Cell-Mediated Immunity

• T cell mediated immunity is called Cell-mediated
  immunity
• T cells divide exposed to foreign antigens divide
  and develop into different types of cells
• depends on the foreign antigen
• if its a bacterial antigen ? helper T cells
• help B cells make antibodies
• if its a viral or tumor antigen ? cytotoxic T
  cells
• secrete chemical to directly kill the pathogen
• e.g. interferons
• some stay as memory T cells

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Cell-Mediated Immunity

• T cells need help learning what a foreign
  antigen is
• the are presented the foreign antigen by
  another cell Antigen-Presenting cell
• the APC internalizes the foreign invader and
  displays foreign antigens on its surface
• the T cell binds the APC and learns what the
  foreign antigen looks like
• the T cell is now activated and can develop
  either into helper or cytotoxic T cells

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Types of Immunity

• immunity can also be classified into
• Passive Immunity short-term immunity, lasts as
  long as the antibodies are in bloodstream.
• can be passed on via fluids
• e.g. antibodies found in breast milk
• Active Immunity long-term, caused by exposure
  to antigen and production of B and T cells.
• basis for immunity from vaccinations

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Vaccinations

• Vaccinations attempt to take advantage of
  long-term immunity through exposure to parts of
  antigens.
• Produces population of memory cells
• Some antigens, such as flu, mutate quickly and
  require frequent vaccinations
• Some antigens are difficult to make vaccines for

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The Bodys Response to Infection The Immune
System Allergy

• Allergy immune response that occurs even though
  no pathogen is present
• Body reacts to a non-harmful substance as if it
  were pathogenic
• called an allergen
• immune cells called mast cells produce large
  amounts of histamine and leukotrienes ?
  inflammation
• Common allergies include ragweed pollen and
  peanuts
• Asthma might be caused by allergy