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128 Cards in this Set
- Front
- Back
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3 circulatory system components?
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1. blood
2. heart 3. blood vessels |
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What is blood?
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tissue composed of water, solutes, cells, and formed elements
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What is the heart essentially?
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pump
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What are blood vessels essentially?
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connecting tubes
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3 types of blood vessels?
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1. arteries
2. veins 3. capillaries |
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Blood is what percentage of your total body weight?
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8%
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Approximately how much blood in women?
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5 liters
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Approximately how much blood is in men?
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5.5 liters
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5 blood functions?
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1. transports
2. fights infections 3. clotting 4. buffers internal pH 5. maintains normal body temp. |
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What does the blood transport? (2)
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1. oxygen and nutrients to cells
2. secretions and wastes away from cells |
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What are the 2 main components of blood?
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1. plasma (50-60%)
2. cells/cellular components |
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What is in the plasma of the blood?
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essentially anything water soluble
1. h2o 2. proteins 3. ions 4. glucose 5. lipids 6. aa 7. vitamins 8. globulins 9. albumin 10. hormones 11. dissolved gases |
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Albumin is a ? protein?
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carrier
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What are the 3 cells/cellular components in blood?
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1. RBC (erythrocytes)
2. WBC (leukocytes) 3. Platelets |
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Hemoglobin is used for what and what blood component is it related to?
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it is used for oxygen binding and is seen in RBCs
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What do the WBCs do?
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fight infections
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Name the 5 types of WBC?
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1. lymphocytes, T and B
2. Monocytes/Macrophages 3. Neutrophils 4. Eosinophils 5. Basophils |
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What are platelets and what are they responsible for?
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they are fragments of megakaryocytes and are used in blood clotting
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What is another name for RBCs?
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erythrocytes
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What is another name for WBCs?
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leukocytes
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Plasma is approximately what percentage of the blood in men?
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about 55%
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What is the "buffy coat"?
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blood consisting of WBC and platelets
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What percentage of blood in men is made up of the buffy coat?
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less than 1%
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What percentage of the blood in men is made up of RBC?
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about 45%
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Do women have less or more RBC then men?
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less (menstration)
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Plasma is the ? portion of blood. The ? medium?
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the liquid portion...the transport medium
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The plasma is 90% what?
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water
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What 2 general things does the plasma transport?
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1. inorganic substances
2. organic substances |
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Give 2 examples of inorganic substances transported by the plasma?
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1. Na+
2. Cl- |
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Give and example of an organic substance carried by the plasma?
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plasma proteins, which make up 6-8% of the plasma's total weight
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Name 4 plasma proteins?
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1. Albumins
2. Globulins 3. Gamma Globulins 4. Fibrinogen (there are others also) |
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What is the function of the plasma protein albumin?
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est. osmotic gradient between blood and interstitial fluid
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What is the function of the plasma protein globulin?
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(alpha, beta, and gamma) roles range from blood clotting to transport
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What is the function of the plasma protein gamma globulins?
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role in immunity as an antibody
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What is the function of the plasma protein fibrinogen?
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key factor in blood clotting
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Other than albumin, fibrinogen and gamma plasma proteins what do some other plasma proteins do?
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buffer pH changes
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Besides the plasma proteins what other substances are carried by the blood plasma?
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1. nutrients
2. waste 3. products 4. dissolved gases 5. hormones |
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What do the erythrocytes (RBC) transport?
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oxygen...and to a lesser extent carbon dioxide and hydrogen ions
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1 mL of blood is approx. how many RBCs?
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5 billion
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What does an RBC cell lack?
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a nucleus, organelles, and ribosomes
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What is the RBC mainly?
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a pkg of hemoglobin molecules
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Describe shape of RBC?
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flat, biconcave, disc...well suited for it's function...has large surface area and is thin (both are advantageous for diffusion)
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RBC plasma membranes are flexible...so what can they slide through?
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capillaries
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The 2 parts of hemoglobin?
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1. globin
2. heme |
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Describe globin part of hemoglobin?
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protein made of four highly folded polypeptide chains
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Describe heme part of hemoglobin?
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4 iron-containing, nonprotein groups
-each Fe atom is bound to one globin polypeptide and can combine with one molecule of oxygen gas -molecule is bright red when combined with oxygen -pigment |
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Besides oxygen hemoglobin can also combine with what 4 other things?
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1. CO2
2. H+ 3. CO 4. NO |
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How does hemoglobin buffer the bloods pH?
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by binding H+
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Out of all the things that bind with hemoglobin which are the only two that compete for the same binding site? Which has the greater affinity?
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CO and O2...CO has greater affinity
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What is erythropoiesis?
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production of new RBCs
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If a cell has no nucleus it has no cellular what?
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division
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RBCs in circulation cannot what?
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divide
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How long is the avg. lifespan of a RBC?
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120 days
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Where is the site of the final demise of old erythrocytes?
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spleen
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RBCs do not do what to reproduce?
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divide
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Where is the site of erythrocyte production in children and adults?
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bone marrow
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What do pluripotent stem cells in the red marrow do?
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differentiate into all the different types of blood cells
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What do regulatory factors do during erythropoiesis?
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act on hemopoietic (blood producing) red marrow to govern the type and # of cells produced and discharged into the circulation
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How many RBCs do we replace per second?
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2-3 million
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Why does the number of erythrocytes usually remain constant?
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it is highly regulated
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A low level of oxygen delivery to tissues (including the kidney) stimulates what?
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an increased rate of erythrocyte production
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The process of erythropiesis is controlled by what hormone? Where is this produced?
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erythropoietin (epo) produced in the kidneys
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In general what is anemia?
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reduction below the normal capacity of blood to carry oxygen
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Name 6 different kinds of anemia?
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1. nutritional anemia
2. pernicious anemia 3. aplastic anemia 4. renal anemia 5. hemorrhagic anemia 6. hemolytic anemia |
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What causes nutritional anemia?
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dietary deficiency of a factor needed for erythropoiesis (ex. iron)
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What causes pernicous anemia?
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an inability to absorb adequate amounts of vitamin B12 from the digestive tract
-low absorption of B12 due to lack of "intrinsic factor" |
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What causes aplastic anemia?
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a failure of bone marrow to make adequate number of RBCs
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What cause renal anemia?
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kidney disease
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What causes hemorrhagic anemia?
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due to loss of significant amounts of blood
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What causes hemolytic anemia?
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due to the rupture of many RBCs
-sickle cell disease can make red cells fragile and vulnerable to hemolysis |
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What is polycythemia?
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excess circulating RBCs
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Polycythemia does what to hematocrit?
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elevates it
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What is primary polycythemia caused by?
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tumorlike condition in the bone marrow...produces more than 2X the number of RBCs
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Primary polycythemia increases ? ? up to 7X normal.
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blood viscosity
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Primary polycythemias increase in blood viscosity may lead to what?
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it may reduce O2 delivery to tissues and increase TPR(temp,pulse,respiration)
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What is secondary polycythemia?
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erythropietin-induced adaptive (appropriate) mechanism to improve the oxygen-carrying capacity in the blood to the tissue
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Besides primary and secondary polycythemia are there other conditions that can elevate the hematocrit? Give some examples.
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Yes, but they are not true polycythemia
ex. dehydration due to heavy sweating ex. diarrhea |
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What is a normal hematocrit?
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about 45% RBCs 55% plasma
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What is the range for an anemic hematocrit?
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30% RBCs 70% plasma
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What is the range of hematocrit for polycythemia?
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70% RBCs and 30% plasma
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What is the hematocrit for dehydration?
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70% RBCs 30% plasma (but there is less overall of both than seen in polycythemia)...there is a decrease in plasma
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What are platelets aka?
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thrombocytes
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Where are platelets stored and how are they secreted?
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stored in spleen and secreted by SNS stimulation
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Describe structure of platelets? (2)
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1. lack nuclei, but have organelles and cytosolic enzymes
2. synthesize and store secretory products |
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What do platelets synthesize and store?
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secretory products
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What is the most important function of platelets?
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function in homeostasis = arrest of bleeding
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What is the trigger for making more platelets?
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thrombopoetin (increases megakaryote number)
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What is hemostasis?
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arrest of bleeding from damaged blood vessels
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Name the three steps of hemostasis?
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1. vascular spasm
2. platelet plugging 3. blood coagulation |
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Describe the 1st step of hemostasis; vascular spasm?
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vascular constriction, reduces blood flow through damaged blood vessel
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Describe the 2nd step of hemostasis; platelet plugging?
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-platelet aggregation forms plug, sealing vessel
1. platelets aggregate on contact with exposed collagen in damaged wall of vessel 2. stimulated by ADP 3. Other substances from blood vessels endothelium inhibit platelet aggregation, keeping the process under control |
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Hemostasis involves what kind of mechanism?
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positive feedback (homeostasis platelet plugging)
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Describe diagram of hemostasis process?
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1. exposed collagen at site of vessel injury
2. aggregating platelet plugging occurs on exposed collagen 3. plugged platelets produce ADP (which causes the platelets to become sticky and results in more ADP being produced) 4. ADP also acts on normal/uninjured endothelium to produce prostacyclin and nitric oxide which prevents sticking |
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What is coagulation aka? What does it do?
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aka clotting...reinforces platelet plugging and converts blood to a gel in area of vessel damage
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What is the ultimate step in clot formation?
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the conversion of fibrinogen (large, soluble plasma protein) into fibrin (thread-like protein that makes mesh over damaged area)
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What is the conversion of fibrinogen to fibrin catalyzed by?
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thrombin
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How do fibrin threads form a clot?
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trap RBCs
-clot is a meshwork strengthened by cross-linkage from factor XIII (fibrin stabilizing factor) |
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If ? is dysfunctional you will have problems with clotting.
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liver
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Thrombin is formed from what precursor?
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prothrombin
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Thrombin is formed from it's precursor, prothrombin, via what?
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factor X
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The conversion of prothrombin to thrombin via factor X involves what?
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the clotting cascade
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4 functions of thrombin?
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1. converting fibrinogen to fibrin
2. activating factor XIII 3. facilitating its own formation via positive feedback 4. enhancing platelet aggregation |
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Thrombin is a central player in ? formation?
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clot
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What is the clotting cascade in general?
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series of steps involving twelve clotting factors...lead to final conversion of fibrinogen to fibrin
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What are the clotting factors?
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proteolytic (protein splitting) enzymes in series of reactions (the clotting sequence)
-one factor in sequence activated, which in turn activates another factor, an so on |
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Name the last two steps in the clotting cascade?
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1. prothrombin converted to thrombin (from the positive feedback)
2. fibrinogen converted to fibrin |
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What are the two different pathways involved in the clotting cascade?
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1. intrinsic : seven steps where all elements needed are found in the blood
2. extrinsic : shortcut of four steps, factors are external to blood |
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The extrinsic pathway of the clotting cascade begins (is stimulated) by what?
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external influence such as tissue damage
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Where does the external and intrinsic pathway of the clotting cascade adjoin?
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at factor X...then they go on to complete the last two steps of the cascade (prothrombin to thrombin, and fibrinogen to fibrin)
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After clot is formed what occurs?
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Clot retraction : contraction of platelets in clot causes fibrin mesh to shrink and fluid (serum) to be squeezed from clot
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What is amplification as it relates to blood clotting?
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it occurs in the clotting process, one molecule can activate one hundred molecules in the next step, and these can each go on to activate 100 more, etc...this is an advantage of clotting being a multi-step process
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Clotting is a short term solution. What is a long one?
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fibroblasts form scar tissue for vessel repair
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What 2 main things occur during clot dissolution?
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1. the clot is slowly dissolved by the enzyme plasmin
2. phagocytic WBCs remove products of dissolving clot |
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The plasmin, an enzyme involved in clot dissolution, is made where and how?
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in the liver as an inactive precursor, plasminogen
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In what fashion is plasminogen activated?
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in a cascade fashion
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What factor involved in the cascade of plasminogen is also involved in clot formation?
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Factor XII (Hageman factor)
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What part of the clot is broken down by activated plasmin?
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it slowly breaks down fibrin mesh (but it acts more slowly than clot formation)
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TPA is aka what?
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tissue plasminogen activator
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What does TPA prevent?
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inappropriate clot formation
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Where is TPA derived from?
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tissues
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What can inappropriate clotting produce?
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thromboembolism
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Hemophilia is a condition that causes what?
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excessive bleeding
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What is hemophilia due to?
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a deficiency of any factor in the clotting cascade
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80% of all hemophiliacs are deficient of which factor in the clotting cascade?
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Factor VIII
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Platelet deficiency is aka what?
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thrombocytopenia purpura
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What does thrombocytopenia purpura (platelet deficiency) cause?
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hundreds of small, confined hemorrhagic areas in body
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Deficiency of what vitamin can cause a bleeding deficiency?
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vitamin k (it is reqd to produce many of the cascading factors in the liver)
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Which med inhibits the synthesis of vitamin k?
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warfarin
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