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67 Cards in this Set
- Front
- Back
How does blood circulate?
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-blood leaves heart via arteries --> capillaries
-O2 + nutrients diffuse to tissues, CO2 + waste move into blood -O2 deficient blood goes capillaries -->veins --> heart(release CO2 + picks up O2 at lungs) |
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What is blood made of?
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-fluid tissue
-liquid(plasma) -formed elements |
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What are the formed elements?
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-erythrocytes(RBCs)
-leuocytes(WBCs) -platelets |
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What is heatocrit?
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% of blood volume that is RBCs
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What percentage is blood?
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-plasma - 55%
-buffy coat(leuk,plate) - <1% -erythrocytes - 45% |
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Characteristics of Blood
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-sticky, opaque fluid
-metallic taste -scarlet(o2 rich) to dark red(o2 poor) -pH ranges from 7.35 to 7.45 -normal temp 38 deg C -approx 8% of body weight |
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Avg volume of blood
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men: 5-6 L
women: 4-5 L |
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What are the 3 functions of blood?
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1)distribution
2)regulation 3)protection |
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Distribution
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-delivers O2 + nutrients
-transports metabolic wast + hormones |
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Regulation
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maintains body temp, normal pH, adequate fluid volume
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Protection
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prevents blood loss + infection
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Blood plamsma contains:
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-is 90% water
-proteins -non-protein nitrogenous substances(lactic acid, urea, creatine) -electrolytes -respiratory gases |
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what are the characteristics of formed elements?
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-WBC are complete cells
-RBC have no nuclei or organelles -platelets are just cell fragments |
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How long do formed elements survive?
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short time, a few days
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What are blood cells replaced by?
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cells in bone marrow
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What is the structure and characteristics of RBCs?
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-biconcave discs
-anucleate -no organelles |
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What does RBC contain?
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hemoglobin (97%)
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What is the importance of RBC's structure?
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It can change shape if necessary
structure drives function -> greater surface area to volume, can carry more oxygen -also don't consume the O2 they transport |
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What is hemoglobin composed of?
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- 2 a and 2 b globin chains which are each bound to a heme group
-each heme grp contains iron -each Hb can transpor for O2s |
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For respiratory gas transport, what does Hb bind to?
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the iron
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What is MCHC?
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Mean Corpusculal Hb Concentration
-avg conc. of Hb in a RBC normal range: 31-37 g/dl |
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O2 + O2 Carrying Capacity of Hb
3 Stages |
1)oxyhemoglobin - bound to O2 (O2 loading takes place in lungs)
2)deoxyhemoglobin - unbound (after O2 diffuses into tissue) 3)carbaminohemoglobin - bound to CO2 (CO2 loading in tissues, eliminated in lungs) |
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3 Steps of producing erytrocytes
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hematopoiesis, circulating RBC, erythropoiesis
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What is hematopoiesis and where does it take place?
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blood cell formation, occurs in bone marrow (WBC and RBC)
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What does circulating RBCs do?
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-remain constant, show balance b/w RBC production + destruction
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What is the result of too few RBC?
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hypoxia- low oxygen
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What is the result of too many RBC?
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increased blood viscosity
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What does erythropoiesis depend on?
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-it's hormonally controlled
-depends on adequate supplies of Fe2+, AA, + Vit B |
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erythropoietin(EPO) release by kidneys:
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-hypoxia due to decreased RBC
-decreased O2 avail -increased tissue demand for O2 |
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eryhropoiesis increases what?
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RBC count and O2 carrying ability of blood
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What is the main function of hormones?
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negative feedback system
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Steps of Negative feedback mechanism
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1)imbalance in normal blood O2 levels
2)reduces O2 levels in blood 3)kidney(and kinda liver) releases erythropoietin 4)stimulates red bone marrow 5)enhanced erythropoiesis increases RBC count 6)increases O2-carrying ability of blood |
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What does erythropoiesis require?
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-proteins, lipids carbs
-Fe2+, vit B12, folic acid -vit C |
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Which foods are high in Fe2+?
What inhibits absorption? |
-meats, dark green veg, clams, beans, molasses, oysters
-tea inhibits absorption |
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Where is iron stored?
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Hb(65%), liver, spleen, bone marrow
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What is the life span of an RBC?
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100 - 120 days
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How do RBC's die?
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-become rigid + fragile
-Hb begins to degenerate -dying erythrocytes engulfed by macrophages -heme + globin separate -Fe kept for reuse -heme grp is degraded to bilirubin |
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What is a eryhrocyte disorder?
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anemia - abnormally low O2 carrying capacity
- blood o2 levels can't support metabolism |
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What are the symptoms?
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-fatigue
-paleness -shorness of breath -chills |
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Causes of anemia
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-insufficient erythrocytes
-dec. Hb content -abnormal Hb |
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insufficient erythrocytes: 3 types
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hemorrhagic
hemolytic aplastic |
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hemorrhagic anemia
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result of acute or chronic blood loss
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hemolytic anemia
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prematurely ruptured erythrocytes
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aplastic anemia
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destruction/inhibition of bone marrow
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decreased Hb content: 2 types
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iron-deficiency anemia
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iron-deficiency anemia
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inadequate intake or absorption
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pernicious anemia
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deciency of vit B12
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abnormal Hb?
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sickle-cell anemia
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what is sickle cell anemia?
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-single amino acid substitution in the B chain
-causes sickle shape after O2 is released to tissue -RBC become rigid + stick in blood vessels |
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vaso-occlusive crisis
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-tissue hypoxia
-sever pain + organ damage |
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more rapid destruction of RBCs:
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fatigue
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What is the advantage of sickle-cell anemia?
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survival against malaria
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What ethnicity grp has the most cases of sickle-cell?
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blacks
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What is polycythemia?
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excess RBC increases blood viscosity
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3 types of polycythemia
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1)polycythemia vera - bone marrow cancer
2)secondary polycythemia - high altitude living 3)blood doping - artificially induced |
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What is leukocytosis?
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-increased production of WBC
-count over 11,000 WBC/ ul of blood |
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Which blood cells are crucial to defense against disease?
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WBC - leukocytes
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Characteristics of WBCs
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-larger, shorter-lived than RBC
-lobed nuclei -phagocytic cells(ingest material) -diapedesis |
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what is diapedesis?
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ability to "leap across" the capillary membrane to infected tissues
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What are the types of WBCs?
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Granulocytes
a)neutrophils b)eosinophils c)basophils Agranulocytes d)lymphocytes e)monoytes |
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Neutrophils
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~50-70%
eliminates body's bacteria |
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Eosinophils
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~2-4%
leads the body's attack against parasite lessen the severity of allergies |
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basophils
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0.5%
contain histamine |
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Lymphocytes
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25-45%
found mostly in lymph(some circulate in blood) |
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What are the 2 types of lymphocytes?
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T cells- immune response
B cells - give rise to plasma cells which produce antibodies |
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Monocytes
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3-8%
largest WBC enter tissue, differentiate into macrophages activate lymphocytes to mount an immune response |
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Look at table for info on WBCs
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look
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