Chapter 17: Blood Flashcards

1
Q

Functions of Blood

A
  • distribution
  • regulation
  • protection
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2
Q

Functions of Blood: Distribution

A

Distribution of:

  • O2 and nutrients to body cells
  • metabolic wastes to the lungs and kidneys for elimination (spleen too)
  • hormones from endocrine organs to target organs
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3
Q

Functions of Blood: Regulation

A

Regulation of:

  • body temperature by absorbing and distributing heat
  • maintain normal pH (7.35-7.45) using buffers*
  • adequate fluid volume in the circulatory system- we need fluid volume for blood pressure
  • homeostasis- blood uses positive feedback
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4
Q

Functions of Blood: Protection

A

Protection against:

  • blood loss- plasma proteins and platelets initiate clot formation
  • infection:
  • antibodies
  • complement proteins
  • WBCs defend against foreign invaders
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5
Q

Blood Composition

A
  • blood is a fluid connective tissue composed of:
    1. plasma (55%)
    2. formed elements (45%)
    • erythrocytes (RBCs)- most abundant formed element
    • leukocytes (WBCs)
    • platelets
  • pH 7.35-7.45 (slightly basic)
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6
Q

Erythrocytes

A
  • RBCs
  • hematocrit
  • percent of blood volume that is RBCs
  • 47% +- 5 for males
  • 42% +- 5% for females
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7
Q

Hematocrit (Hct)

A

= RBC / total blood volume

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8
Q

Centrifuging Blood

A
  • plasma layer on top- 55% of whole blood, least dense component
  • buffy coat- leukocytes and platelets, 1% of whole blood
  • erythrocytes- 45% of whole blood, most dense component
  • separates plasma from formed elements
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9
Q

Hemopoiesis

A
  • blood cell formation
  • occurs in red bone marrow of axial skeleton, gridles and proximal epiphyses of humerus and femur
  • most commonly in upper form of lower limbs
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10
Q

hemocytoblasts (hematopoietic stem cells)

A
  • give rise TO ALL FORMED ELEMENTS

- hormones and growth factors push the cell towards a specific pathway of blood cell development

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11
Q

How long does it take for blood to circulate to the body and back to the heart

A

-20-60 seconds

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12
Q

Erythropoiesis

A
  • red blood cell production
  • goes from hemocytoblast -> erythrocyte
  • takes 15 days
  • color changes from blue of ribosomes to pink of hemoglobin
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13
Q

CBC

A
  • complete blood cell count

- measure RBCs, leukocytes, platelets, hematocrit

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14
Q

reticulocyte

A
  • immature RBC

- sometimes bones push out reticulocytes to increase blood volume to aid mature RBCs in oxygen delivery

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15
Q

regulation of erythropoiesis

A
  • too few RBCs leads to tissue hypoxia
  • too many RBCs increases blood viscosity- blood moves slower and RBCs may be less effective
  • balance between RBC production and destruction depends on hormonal controls and adequate supplies of iron, amino acids, and B vitamins
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16
Q

erythropoietin (EPO)

A
  • hormone that stimulates erythropoiesis
  • released by the kidneys in response to hypoxia
  • many of the hematopoietic hormones (EPO) are used with cancer or AIDS patients to stimulate bone marrow
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17
Q

effects of EPO

A
  • increases production of RBCs
  • testosterone also enhances EPO production, resulting in higher RBC counts in males (Lance Armstrong)
  • Dietary Requirements:
  • nutrients
  • iron
  • vitamin B12
  • folic acid
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18
Q

Negative Feedback Cycle

A
    1. stimulus- hypoxia due to decreased RBC count, decreased amount of hemoglobin, decreased availability of O2
      1. kidney (and liver to a smaller extent) releases erythropoietin
      2. erythropoietin stimulates red bone marrow
      3. enhanced erythropoiesis increases RBC count
      4. O2 carrying ability of blood increases
  • homeostasis- normal blood oxygen levels
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19
Q

Erythropoietin (EPO) in the blood would rise due to all the following except

A
  • during anemia
  • at high altitudes
  • as a consequence of hemorrhage
  • due to infection
  • when blood flow to the kidney is disrupted
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20
Q

Leukopoiesis

A
  • production of WBCs
  • stimulated by chemical messengers from bone marrow and mature WBCs
  • all leukocytes originate from hemocytoblasts
  • there are 5 main types of WBCs
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21
Q

5 types of leukocytes

A
  • all come from a hemocytoblast
  • immature WBC- bands ** (in the marrow) -> if someone has bands in their blood it is called left shift
  • eosinophils- granular
  • basophils- granular
  • neutrophils- granular
  • monocytes- agranular
  • lymphocytes- agranular
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22
Q

Blood Plasma

A
  • 55% of blood
  • 90-92% water
  • plasma proteins- contribute to osmotic pressure, most column is albumin
  • nitrogenous byproducts of metabolism- lactic acid, urea, creatinine
  • nutrients- glucose, lipids, amino acids, vitamins
  • electrolytes- Na, K, Ca, Mg, Cl, HCO3- most abundant
  • respiratory gases- O2, CO2
  • hormones
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23
Q

Formed Elements

A
  • RBC, WBC, platelets
  • RBC majority of formed elements (99%)
  • RBCs have no nuclei or organelles
  • only WBCs are complete cells
  • platelets are cell fragments
  • most blood cells originate in bone marrow and do not divide
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24
Q

Erythrocyte structure and function

A
  • RBCs are dedicated to respiratory gas transport
  • biconcave
  • no nucleus
  • no organelles
  • hemoglobin binds reversibly with oxygen
  • iron atom in each heme can bind to one O2 molecule
  • each Hb molecule can transport four O2
  • one RBC contains about 250 million hemoglobin molecules so each RBC can transport about 1 billion molecules of O2
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25
Q

Life of RBC

A
  • birth in red bone marrow
  • 15 days to grow in the bone marrow
  • lives for about 120 days
  • dies in the spleen, macrophages destroy old and damaged RBCs
  • hemoglobin is broken down and parts are either recycled or excreted
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26
Q

Erythrocyte disorders

A
  • anemia

- polycythemia

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27
Q

anemia

A
  • low oxygen carrying capacity

- causes- blood loss, low RBCs produced, abnormal RBC

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28
Q

polycythemia

A
  • excess of RBC (increases viscosity)
  • bone marrow cancer
  • secondary polycythemia- when less O2 is available (high altitude) or when EPO production increases
  • blood doping- can increase risk of MI, stroke, or blood clots
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29
Q

causes of anemia (dont study crazy)

A
    1. blood loss- hemorrhagic anemia
    1. not enough RBC produced:
  • pernicious anemia- vitamin B12 intrinsic factor
  • aplastic anemia- destruction of bone marrow by drugs
    1. RBC destroyed or abnormal hemoglobin:
  • hemolytic anemia- mismatched blood
  • thalassemia’s- genetic disease of Mediterranean ancestry
  • sick cell anemia- abnormal hemoglobin
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30
Q

sick-cell disease

A
  • normal erythrocyte has normal hemoglobin amino acid sequence in the beta chain
  • sickled erythrocyte results from a single amino acid change in the beta chain of hemoglobin
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31
Q

RBCs are efficient oxygen transport cells. Of the following characteristics, which is the major contributor to the significant oxygen-carrying capacity of a RBC

A
  • RBC lack mitochondria
  • RBC dont divide
  • RBC are biconcave discs***
  • RBC contain myoglobin
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32
Q

oxygen binds to the _________ portion of hemoglobin

A
  • globin
  • oxyhemoglobin
  • iron atom**
  • amino acid
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33
Q

leukocytes

A
  • make up <1% of total blood volume
  • can leave capillaries via diapedesis*
  • move through tissue spaces by ameboid motion and positive chemotaxis* (follow trail released by damaged cells)
  • leukocytosis- WBC count over 11,000/mm3- normal response to bacterial or viral invasion
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34
Q

Never Let Monkeys Eat Bananas

A
  • neutrophils (50-70%)- most abundant
  • lymphocytes (25 - 45%)- immune
  • monocytes- (3-8%) largest in size
  • eosinophils
  • basophils
35
Q

Granulocytes

A
  • neutrophils
  • eosinophils
  • basophils
  • cytoplasmic granules stain specifically with Wright’s stain
  • larger and shorter lived than RBCs
  • lobed nuclei
  • 1st stand during an infection they attack in large numbers and eat until they die -> “phagocytic”
36
Q

Neutrophils

A
  • BACTERIA slayers- phagocytic
  • most numerous
  • multilobed nucleus
  • granulocyte- WBC
37
Q

eosinophils

A
  • digest PARASITIC worms
  • elevated with ALLERGIES
  • also phagocytic
  • bilobed nucleus
  • red cytoplasmic granules
  • granulocyte- WBC
38
Q

basophils

A

contains HISTAMINE

  • promotes inflammation
  • bilobed nucleus purplish-black cytoplasmic granules
  • granulocyte WBC
39
Q

Agranulocytes

A
  • no granules
  • lymphocytes
  • monocytes
40
Q

lymphocytes

A
  • mostly in lymph tissue
  • crucial to immunity
  • T cells and B cells
41
Q

Monocytes

A
  • largest WBC
  • big eaters against viruses and bacteria
  • becomes macrophage when it leaves bloodstream
42
Q

What response would you expect after traveling to high altitude for two weeks

A
  • blood levels of oxygen would remain depressed for the duration
  • a surge in iron release from the liver would occur
  • the kidneys would secrete elevated amount of erythropoietin
  • there would be no change in blood composition***
43
Q

leukopenia

A
  • penia = poverty
  • abnormally low WBC count
  • drug induced (usually anti-cancer drugs)
44
Q

leukemias

A
  • cancerous conditions involving overproduction of WBCs
  • WBC are nonfunctional and cannot defend body
  • treatments include irradiation, antileukemic drugs (destroys the rapidly dividing cell), and stem cell transplants
45
Q

platelets

A
  • small fragments of megakaryocytes
  • NOT cells
  • originate from hemocytoblasts -> fragments
  • formation is regulated by thrombopoietin (hormone)
  • granules contain many chemicals that aide in clotting process (serotonin, Ca, enzymes, ADP, and platelets derived growth factor
  • forms a temporary plug in a broken blood vessel
46
Q

hemostasis

A
  • fast series of reactions for stoppage of bleeding
    1. vascular spasm
    1. platelet plug formation
    1. coagulation (blood clotting)
47
Q

vascular spasm

A
  • vasoconstriction of damaged blood vessel
  • constricted blood vessel reduces blood loss allowing time for next 2 steps
  • triggers:
  • direct injury
  • chemicals released by endothelial cells and platelets
  • pain reflexes
48
Q

platelet plug formation

A
  • positive feedback cycle
  • at site of blood vessel injury. platelets
  • stick to exposed collagen fibers with the help of clotting factors (a plasma protein)
  • positive feedback cycle as more platelets stick together, increase in chemical released and more platelets arrive
49
Q

coagulation

A
  • intrinsic and extrinsic pathways
  • set of reactions in which blood is transformed from a liquid to a gel
  • reinforces the platelet plug with fibrin threads, molecular glue
  • has 3 stages that use clotting factors made in liver
  • clotting factors are numbered from 1 to 13
50
Q

three phases of coagulation

A
    1. prothrombin activator is formed (intrinsic and extrinsic pathways) -> begins with activation of factor X
    1. prothrombin is converted into thrombin
    1. thrombin catalyzes the joining of fibrinogen to form a fibrin mesh
  • starts with clotting factors and ends with fibrin mesh
51
Q

clot retraction

A
  • actin and myosin in platelets contract within 30-60 minutes
  • draws ruptured edges of blood vessel more closely together
  • platelets pull on the fibrin stands
  • squeezing serum from the clot
52
Q

clot repair

A
  • platelet derived growth factor (PDGF) stimulates division of smooth muscle cells and fibroblasts to rebuild blood vessel wall
  • growth factors stimulates endothelial cells to multiply and restore the endothelial lining
  • new cells grow to repair wound site
53
Q

fibrinolysis

A
  • begins within two days, removes unneeded clots
  • plasminogen in clot is converted to plasmin by tissue plasminogen activator (tPA), factor XII, and thrombin
  • plasmin is a fibrin-digesting enzyme
  • tPA is used for immediate treatment of heart attacks and strokes
  • needs to be given within 12 hours of first signs of MI (heart attack) and within 3 hours of beginning of stroke
  • not to be given if questionable bleeding
54
Q

Clotting overview

A
    1. hemostasis- stops bleeding:
      - vascular spasm
      - platelet plug
      - coagulation: formation of prothrombin activator (intrinsic/extrinsic), prothrombin to thrombin, fibrinogen to fibrin mesh
    1. clot retraction- draws edges of blood vessel together
    1. clot repair- rebuild vessel wall
    1. fibrinolysis- plasmin digests fibrin
55
Q

factors limiting clot growth or formation

A
  • homeostatic mechanisms prevent clots from becoming large
  • swift removal and dilation of clotting factors (swift blood flow)
  • inhibition of activated clotting factors:
  • most thrombin is bound to fibrin threads, and prevented from acting elsewhere -> fibrin acts as an anticoagulant (keeps thrombin local)
  • heparin, another anticoagulant, also inhibits thrombin activity
  • NEED TO INHIBIT OR INACTIVATE THROMBIN
56
Q

factors preventing undesirable clotting

A
  • platelet adhesion is prevented by:
  • smooth endothelial lining of blood vessels
  • antithrombic substances nitric oxide and prostacyclin secreted by endothelial cells
  • vitamin E, which acts as a potent anticoagulant
57
Q

the cascade of reactions leading to the formation of a fibrin mesh is called

A
  • vascular spasm
  • clot retraction
  • coagulation**
  • fibrinolysis
58
Q

plasmin is an enzyme that

A
  • converts fibrinogen to fibrin and forms a fibrin mesh
  • causes platelets adhesion via a positive feedback cycle
  • digests fibrin and dissolves a clot*
  • assist in coagulation via the intrinsic pathway
59
Q

thromboembolic disorders

A
  • undesirable clot formation
  • thrombus- stationary clot- DVT
  • embolus- travelling clot- PE -> becomes an embolism if it wedges in a vessel
  • prevented by: blood thinners (anticoagulants)
60
Q

bleeding disorders

A
  • abnormalities that prevent normal clot formation
  • thrombocytopenia- decreased # of platelets
  • hemophilia- hereditary bleeding disorders
61
Q

history of transfusion (not on tests)

A
  • 1667- jean baptist denis (france)- animal to human transfusion
  • 1825- james blundell (british obstetrician)- human to human transfusion
  • 1900- karl landsteiner (australia)- discovered blood groups
62
Q

human blood groups

A
  • humans have 30 varieties of naturally occurring RBC antigens
  • antigens of the ABO and Rh blood groups cause vigorous transfusion reactions
  • Rh factor- type of protein on surface of RBC
  • 85% of people of Rh +
63
Q

ABO blood groups

A
  • types A, B, AB, O
  • based on the presence or absence of two agglutinogen (A and B) on the surface of the RBCs
  • blood may contain anti-A or anti-B antibodies (agglutinins) that act against transfused RBCs with ABO antigens not normally present
  • anti-A or anti-B form in the blood at about 2 month of age
64
Q

hemolytic disease of the newborn

A
  • also called erythroblastosis fetalis
  • mother is Rh neg and father is Rh + -> baby will be Rh +
  • Rh- mother becomes sensitized when exposure to Rh+ blood during delivery and produces anti-Rh antibodies
  • during 2nd pregnancy, antibodies cross the placenta and destroy the RBCs of an Rh+ baby
65
Q

transfusion reactions

A
  • occur if mismatched blood is infused
  • donor cells:
  • are attacked by the recipients plasma agglutinins (antibodies)
  • agglutinate and clog small vessels
  • rupture and release free hemoglobin into the bloodstream
  • symptoms- skin flushing, fever, pain
  • results in:
  • diminished oxygen carrying capacity
  • hemoglobin in kidney tubules and renal failure
66
Q

restoring blood volume

A
  • death from shock may result from low blood volume
  • volume must be replaced immediately with:
  • normal saline or multiple electrolyte solution that mimics plasma electrolyte composition
  • plasma expanders:
  • mimic osmotic properties of albumin (pulls water in)
  • more expensive and may cause significant complications
67
Q

suppose your blood is AB positive. This means that…

A
  • agglutinogen A and B are present on your RBCs
  • there are no anti-A or anti-B antibodies in your plasma
  • your blood is Rh+
  • all of the above
68
Q

a clot that develops and persists in an unbroken blood vessel is called…

A
  • embolus
  • platelet
  • fibrin
  • thrombus
69
Q

hematocrit

A

-oxygenation status

70
Q

blood glucose test

A
  • metabolic function
  • increased levels in diabetics
  • hemoglobin A1C
71
Q

differential WBC count

A

-increased with infection

72
Q

prothrombin time and platelet count

A
  • assess hemostasis

- clotting mechanism

73
Q

SMAC

A

-blood chemistry profile (sequential multiple analysis with computer)

74
Q

complete cell count (CBC)

A

-counts of different formed elements, hematocrit, hemoglobin content and size of RBC

75
Q

Rh factor is not blood type

A
  • true
  • something on your blood cells that is positive or negative
  • only important for delivery a baby or transfusion
76
Q

Blood Type A

A
  • has antigen A

- antibody anti-B

77
Q

Blood type B

A
  • has antigen B

- antibody anti-A

78
Q

blood type AB

A
  • have both antigen A and B

- no anti-A or anti-B antibodies in the plasma

79
Q

Blood type O

A
  • no antigen on the cell
  • antibody anti-A and anti-B present
  • universal donor
80
Q

precursor for platelets

A

-megakaryocyte

81
Q

plasma

A

-produces antibodies

82
Q

universal donor

A

O

83
Q

universal recipient

A

AB