Ch. 10 Review

Parts and Classification of Blood:

Blood

• Fluid tissue in the human body 

  • Blood & lymph are the only fluid tissues in the body 

• Classified as a connective tissue 

  • Has a non-living matrix 

• Contains fibrin (tiny fibers that help make clots) 

Components of Blood 

1. Formed elements (non-fluid components) 

• Living cells (or cell fragments) 

• Erythrocytes (RBC’s) 

• Leukocytes (Platelets) 

  • Cell fragments 

2. Non-living matrix

• Plasma 

• If blood is centrifuged 

• Forced separation 

• By density 

• Plasm rises to the top (55%) of blood 

• Buffy coat is a thin, whitish layer between the erythrocytes & plasma 

  • Buffy coat contains leukocytes and platelets (less than 1% of blood) 

• Erythrocytes sink to the bottom 

  • 45% of blood, a percentage known as the hematocrit 

Characteristics of Blood:

Physical characteristics of Blood: 

• Color range 

  • Oxygen-rich blood is scarlet red 

  • Oxygen-poor blood is dull red 

• pH must stay between 7.35-7.45

• Blood temperature is slightly higher than body temperature @ 100.4 F °

• In a healthy man, blood volume 

  • 5-6 liters 

  • A little less than 6 quarts 

  • 1.5 gallons

• Blood makes up 8% of total body weight 

Plasma Characteristics:

Blood Plasma: 

• Composed of approximately 90% water 

• Includes many dissolved substances 

  • Nutrients Salts (electrolytes) 

  • Respiratory gases 

  • Hormones 

  • Metabolic waste products 

  • Plasma proteins 

  Plasma Proteins: 

  • The most abundant solutes in plasma 

  • Most plasma proteins are made by liver 

  • Examples: 

    • Albumin regulates osmotic pressure 

      • The movement of water across a membrane 

    • Clotting proteins - help to stop blood loss from damaged blood vessels. 

      • Antibodies

        • Help protect the body from pathogens (disease causing microorganisms) 

          • Help identify pathogens by bonding  

Formed Elements: 

Erythrocytes: 

• Transport oxygen 

• Anucleates 

  • No nucleus 

  • Very few organelles 

  • Follow the current blood circulation 

  • Flexible, flattened discs w/ depressed centers 

    • Increased surface area for gas exchanges 

• Hemoglobin 

  • Molecules contained in RBCs 

  • Iron - containing proteins 

  • Chemically binds, strongly but reversibly, to oxygen 

  • Each hemoglobin molecules has 4 oxygen binding sites 

  • Each RBC has 250 million hemoglobin molecules 

  • Normal blood contains 12-18 grams 

•  Homeostatic imbalance of RBCs 

  • Anemia 

    • Any decrease in the oxygen-carrying ability of the blood (decrease in RBCs or low hematocrit) 

  • Polycythemia 

    • An excessive or abnormal increase in the number of erythrocytes 

• Leukocytes (white blood cells or WBCs) 

  • 4,000 to 11,000 cm WBC per cubic millimeter of blood 

  • Crucial in the body’s defense against disease 

  • Complete cells w/ a nucleus & organelles Able to move into & out of blood vessels (diapedesis) 

  • Attracted to chemicals released by damaged tissues (chemotaxis) 

    • Can move by amoeboid motion

    • Phagocytosis - “engulfing” 

  • Phagocyte - any cell capable 

  • Macrophage - large phagocyte 

  • Types of leukocytes 

    • Granulocytes 

      • Granules in their cytoplasm can be stained 

      • Possess lobed nuclei 

      • Include neutrophils, eosinophils, & basophils 

    • A? Granulocytes 

      • w/o visible granules 

      • Large nuclei; spherical, oval, or kidney - shaped 

      • Include lymphocytes & monocytes 

    • List of the WBSs from most to least abundant 

      • Neutrophils Never

      • Lymphocytes Let

      • Monocytes Monkeys

      • Eosinophils Eat 

      • Basophils Bananas 

Hematopoiesis and Cell Differentiation:

• Blood cell formation 

  • Occurs in red bone marrow & lymphatic tissues 

  • All blood cells are derived from a common stem cell (hemocytoblast)

Erythrocytes: 

• Unable to divide, grow, synthesize proteins 

• Wear out every 100 to 200 days 

Control of Erythrocytes Production (Erythropoiesis): 

• Rate is controlled by a hormone (erythropoietin) 

• Kidneys produce most erythropoietin as a response to reduced oxygen levels in the blood

Formation of White Blood Cells & Platelets: 

• Controlled by hormones 

• Secreted proteins & signal molecules prompt bone marrow to generate leukocytes 

• Thrombopoietin stimulates production of platelets 

  • Produced by liver & kidneys 

•  Form from large multinucleate cells called megakaryocytes 

Hemostasis Steps

• Step 1: Vascular spasms 

  • Vasoconstriction causes blood vessel to spasm 

    • Smooth muscle tissue 

  • Spasms narrow the blood vessels, decreasing blood loss 

• Step 2: Platelet Plug Formation 

  • Collagen fibers are exposed by a break in a blood vessel 

  • Platelets become “sticky” & cling to fibers & trap RBCs 

  • Anchored platelets release chemicals to attract more platelets 

  • Platelets pile up to form a temporary platelet plug 

• Step 3: Coagulation 

  • Injured tissues, inside & outside the vessels, release tissue factors (TF) 

  • Trigger a clotting cascade

    • Series of events to produce fibrin (clotting proteins) 

    • Ultimately, thrombin (an enzyme) joins fibrinogen 

Proteins into hair-like molecules of insoluble fibrin

• Fibrin forms a meshwork

• Blood usually clots within 3 to 6 minutes 

• The clot remains as endothelium regenerates 

• The clot is broken down after tissue repair 

Undesirable Clotting:

• Thrombus 

  • A clot in an unbroken blood vessel 

  • Can form in deep veins in the legs (DVT) but can be deadly in areas like the heart 

  • Treatment involves anticoagulants (to prevent clotting) 

  • Embolus 

    • Any material that flows through vessels w/ the potential to form a blockage 

    • Can be critical areas such as the brain, heart, lungs or retina. 

      • Brain embolism 

      • Cardiac embolism 

      • Pulmonary embolism 

      • Retinal embolism 

• A thrombus can break away & float freely into the bloodstream 

Blood Types & Transfusions:

• Large losses of blood have serious consequences 

  • Loss of 15-30% causes weakness/dizziness 

  • Loss of over 35% causes shock, which can can be fatal 

• Transfusions are the only way to replace blood fast 

• A person can receive blood from a donor, successfully if the donor’s blood does not have RBC antigens matching the recipient’s plasma antibodies 

• Whole blood (all formed elements & plasma) is not used for standard transfusions 

  • Only RBC content is used 

    • To avoid antibodies from donor’s plasma 

  • If plasma is transfused: 

    • 1. Only a small amount of antibodies are present in the donated plasma. 

    • 2. Donor antibodies are diluted w/ transfusions in recipient’s circulation

      Blood Type Matching: 

      • If a person receives blood w/ antigens that the recipients has antibodies for, the recipients blood will “attack” the RBCs of the donated blood 

      • Rapid intravascular hemolysis?

      • Disseminated intravascular coagulation 

        • Blood clots abnormally form & use up body’s clotting resources

      • Deadly in places like the lungs, heart, brain 

      • Shock

        • Blood flow disturbance 

      • Acute renal failure 

        • Sudden Kidney failure 

      • Death  

Blood Typing Process:

• 4 Blood samples, 3 are separately mixed w/ serums that each contain one type of antibody; one if left as a control 

  • Anti-A, Anti-B, & Anti-D (for Rh antibody) serum 

• When antibodies recognize their specific antigen, visible agglutination occurs

  • RBCs are clumped together 

  • If agglutination occurs, the blood is a type that belongs to that antigens blood group (has that antigen on its RBCs) 

Rh Factor & inheritance: 

• The only antibodies that are inherited from parents are A & B antibodies 

• The first time an Rh person receives Rh+ blood (has Rh factor / antigen - no reaction) 

• If the same person receives Rh+ blood a 2nd time, his or her body has then produced RH antibodies → transfusion reaction 

  • Best to avoid 

Dangers during Pregnancy: 

• Mother’s & baby’s blood are separated by the placenta wall 

• Danger occurs when the mother is Rh- & the father is Rh+ & the child inherits the Rh+ factor (antigen)`

• Some of baby’s blood can get into mother’s circulation during tramas 

• Mother will then produce Rh antibodies from 1st pregnancy that can pass to the baby of the 2nd pregnancy & destroy the baby’s RBCs 

• Mother will then produce Rh antibodies from 1st pregnancy, that can pass the baby to the baby of the 2nd pregnancy & destroy the baby RBCs 

Antigens & Antibodies: 

• Antigens 

  • A substance the recognizes as foreign on the structures of: 

    • Viruses 

    • Bacteria 

    • Also may exist on the surface of the RBC’s 

  • May cause cells/virus to be attacked by the immune system 

• Antibodies

  • “Y” shaped proteins that recognize & work to neutralize structures that have specific/recognized antigens

  • Can exist in the blood plasma 

Human Blood Groups: 

• There are 30 common red blood cell antigens 

• The most vigorous transfusion reactions are caused by ABO & Rh blood group antigens 

  • Based on the presence or absence of 3 Antigens on the 

RBC’s:

• A, B, Rh 

• An individual may have: 

  • One of the antigens 

  • Two of the antigens 

  • All three of the antigens 

  • None of the antigens 

Human Blood Groups:

• A or B is in the blood type if either of those antigens are present on the RBCs

• AB is the blood type if both antigens are present 

• O means neither A or B antigens are present 

• The absence of any one of the antigens on the RBCs means that the antibodies for the missing antigen(s) will exist in the individual’s plasma 

Disorders and Conditions:

Bleeding Disorder: 

• Thrombocytopenia 

  • Platelet deficiency 

  • Normal movements can cause bleeding 

  • Bleeding into the skin resulting in small reddish spots (petechiae)

  • Hemophilia 

    • Hereditary bleeding disorder 

    • Normal blood clotting causes are missing