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Flashcards in Intro to Blood Deck (44)
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1

  1. What is the function of blood?
  2. What is blood comprised of?

  1. Function: blood conveys
    • nutrients and waste
    • hormones (endocrine)
    • gases: O2 and CO2
  2. Blood is comprised of:
    • ~5% body weight = ~5 L
    • specialized connective tissue (CT)
      • extracellular matrix component = plasma
      • cellular component = RBCs, WBCs, platelets

2

How can the components of blood be blood separated?

Separated into by centrifugation to:

  1. Plasma
  2. Serum 

3

What is the difference between plasma and serum?

  1. Plasma:
    • fluid supernatant phase after centrifugation in the presence of heparin (to prevent clotting)
  2. Serum: 
    • It is the fluid supernatant phase remaining after clotting, followed by centrifugation to remove clotting factors and blood cells (aka formed elements)

4

What are the components of plasma?

  1. water ~ 90%
  2. protein ~ 10%
    • albumin: keeps blood volume via colloid osmotic pressure
    • globulins: α and β transporters; γ = antibodies
    • clotting proteins, complement, lipoproteins
  3. salts and gases

5

List the blood cells:

  • Erythrocytes (RBCs)
  • Leukocytes (WBCs)
    • Granulocytes
      • neutrophils
      • eosinophils
      • basophils
    • Agranulocytes
      • monocytes
      • lymphocytes

6

What is a complete blood count (CBC)?

What is a differential blood count?

 

  1. complete blood count (CBC):
    • total RBCs and WBCs + additional blood components
  2. differential blood count: 
    • ​​describes relative numbers of leukocytes

7

What are the normal differential count values (%)?

  • Neutrophils ⇒ 34-71%
  • Lymphocytes ⇒ 19-53%
  • Monocytes ⇒ 5-12%
  • Eosinophils ⇒ 0-7%
  • Basophils ⇒ 0-1%

8

What are the normal CBC values for:

  1. RBC
  2. WBC
  3. HGB
  4. HCT

  1. RBC ⇒ 4.6 - 6.1 x 106/µL
  2. WBC ⇒ 4.0 - 10.0 x 103/µL
  3. HGB ⇒ 13.7 - 17.5 g/dL
  4. HCT ⇒ 40 - 51%

9

Erythrocytes:

Morphology

  • Size: 7.5 µm diameter = “the internal standard size”
  • biconcave disk ⇒ increased surface area for respiration
  • nucleus: mature RBCs have no nucleus
  • cytoplasm: no organelles

10

What do the erythrocytes carry for respiration?

hemoglobin

11

What is the appearance of hemoglobin (stain)? 

How is hemoglobin structured?

 

  • hemoglobin (Hb) = 33% = intense eosinophilia
  • tetramer: α, β, χ, δ subunits
    • fetal = HbF = α2χ2 (until end of pregnancy)
    • adult = HbA = α2β2
  • oxyhemoglobin = Hb + O2
  • carboxyhemoglobin = Hb + CO2

12

What is the role of carbonic anhydrase?

carbonic anhydrase: CO2 ⇒ carbonic acid ⇒ HCO3- 

13

Describe the red blood cell plasma membrane:

The RBC plasma membrane is well-characterized

  • integral proteins: span the lipid bilayer
    • band 3: anion transporter which exports HCO3- and binds ankyrin
      • to maintain biconcave shape by ‘anchoring’ to the subplasmalemmal network
  • RBC’s outer membrane contains antigens

14

What is the consequence of mutations in RBC plasma membrane proteins?

  • Mutations in proteins that maintain the biconcave shape of RBCs cause spherocytosis
    • RBCs are spherical, causing problems in RBC distribution and turnover

15

Describe the anitgens in the RBC outer membrane:

constitute blood group systems:

  • common ABO blood group is conferred by
    carbohydrate antigens A and B
  • Rh group is conferred by presence (+) or absence
    (-) of RH protein

16

ABO blood groups:

17

What is the normal lifespan of a RBC?

120 days

18

What is the indication of abnormal RBC values?

  • A lower than normal RBC count ⇒ anemia
  • An hematocrit value >55% indicates:
    • polycythemia (increased RBC #) 
    • erythrocytosis (increased RBC mass)

19

What is the consequence of a mutation in the β-chain of hemoglobin?

  • β thalassemia: 
    • β chain gene is mutated and protein is hence not made; affected adults have HbF instead of HbA
  • sickle cell anemia:
    • β-globin mutation: glutamic acid (GAA) ⇒ valine (GTA)

20

What is the function and location of leukocytes?

  • Location: 
    • pass thru peripheral blood toward their working destination which is in the tissue spaces of the body.
  • Leukocytes:
    • move thru tissues via diapedesis
    • function to defend against foreign invaders
    • adult number = 4.0-10 x 103/µl in peripheral blood; higher at birth

21

What are granulocytes?

What sets them apart from other leukocytes?

  • All cells have ‘granules’, usually granules are lysosomes
  • Granulocytes, in addition, have “specific”granules   
    • specific granules denote the names of the granular leukocytes

22

Define neutrophils:

  • syn = polymorphonuclear leukocytes
  • specific granules have ‘neutral’ staining
    • neither eosinophilic or basophilic
  • Nucleus is segmented

23

Neutrophils:

  • % of WBCs:
  • Size:
  • Major function:
  • Lifespan:

  • % of WBCs: 34 - 71%
  • Size: ~12 µm diameter
  • Major function: kill bacteria
    • release of specific granules ⇒ degrade the extracellular matrix ⇒ ultimately degrade the bacteria
    • phagocytize the bacteria
    • Neutrophils kill bacteria by releasing hydrolytic enzymes to create a respiratory burst, initiated by NADPH oxidase
  • Lifespan:
    • few days

24

What is the consequence of a mutation in the NADPH oxidase gene?

persistent bacterial infections

25

Define Eosinophils:

  • Specific granules are reddish (i.e. eosinophilic) and large (~1.0 µm), with a crystalloid center that contains major basic protein
  • Nucleus is bi-lobed

26

Eosinophils:

  • % of WBCs:
  • Size:
  • Major function:
  • Lifespan:

  • % of WBCs: 0 - 7%
  • Size: > 12 µm diameter
  • Major function:
    • kill parasites via major basic protein
    • phagocytize Ab:Ag complexes
    • secrete leukotrienes
  • Lifespan: ~2 weeks

27

There is a high incidence of eosinophils in ....

parasitic infections and asthma

28

What is the contribution of eosinophils to symptoms in an asthmatic patient?

  • In asthma, leukotrienes recruit eosinophils to the lungs and induce them to manufacture more leukotrienes, which in turn causes:
    1. blood vessel leakiness ⇒ edema
    2. bronchiolar cells ⇒ constriction of airway
    3. mucous glands ⇒ mucus buildup

29

Define basophils:

  • Nucleus is irregular, obscured by granules.
  • Basophil specific granules contain heparin and histamine

30

Basophils:

  • % of WBCs:
  • Size:
  • Lifespan:

  • % of WBCs: ~0 - 1% 
  • Size: > 12 µm diameter
  • Lifespan: long-lived, few years (memory)