Intro to Blood

Question 1

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

Answer 1

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

Question 2

How can the components of blood be blood separated?

Answer 2

Separated into by centrifugation to:

1. Plasma
2. Serum

Question 3

What is the difference between plasma and serum?

Answer 3

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)

Question 4

What are the components of plasma?

Answer 4

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

Question 5

List the blood cells:

Answer 5

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

Question 6

What is a **complete blood count **(CBC)?

What is a differential blood count?

Answer 6

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

Question 7

What are the normal differential count values (%)?

Answer 7

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

Question 8

What are the normal CBC values for:

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

Answer 8

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%

Question 9

Erythrocytes:

Morphology

Answer 9

• 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

Question 10

What do the erythrocytes carry for respiration?

Answer 10

hemoglobin

Question 11

What is the appearance of hemoglobin (stain)?

How is hemoglobin structured?

Answer 11

• 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

Question 12

What is the role of carbonic anhydrase?

Answer 12

carbonic anhydrase: CO₂ ⇒ carbonic acid ⇒ HCO₃^-

Question 13

Describe the red blood cell plasma membrane:

Answer 13

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

Question 14

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

Answer 14

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

Question 15

Describe the anitgens in the RBC outer membrane:

Answer 15

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

Question 16

ABO blood groups:

Answer 16

Question 17

What is the normal lifespan of a RBC?

Answer 17

120 days

Question 18

What is the indication of abnormal RBC values?

Answer 18

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

Question 19

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

Answer 19

• 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)

Question 20

What is the function and location of leukocytes?

Answer 20

• **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

Question 21

What are granulocytes?

What sets them apart from other leukocytes?

Answer 21

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

Question 22

Define neutrophils:

Answer 22

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

Question 23

Neutrophils:

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

Answer 23

• % 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

Question 24

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

Answer 24

persistent bacterial infections

Question 25

**Define Eosinophils:**

Answer 25

* 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**

Question 26

**Eosinophils****:** * % of WBCs: * Size: * Major function: * Lifespan:

Answer 26

* % 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

Question 27

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

Answer 27

**parasitic infections **and **asthma**

Question 28

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

Answer 28

* 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

Question 29

**Define basophils:**

Answer 29

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

Question 30

**Basophils:** * % of WBCs: * Size: * Lifespan:

Answer 30

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

Question 31

How are basophils similar to mast cells?

Answer 31

**Basophil/mast cell function:** 1. An **antigen invades**… 2. …causing a plasma cell to make **immunoglobulin E** (IgE) 3. **IgE binds to the IgE-Receptor** on the basophil/mast cell membrane, where it remains, until… 4. …later in life, when the **same antigen is re-introduced**, it immediately binds the IgE on the basophil/mast cell membrane. 5. **releases** its specific granules – **histamine** 6. **releases leukotrienes:** * rapidly causes BV leakiness, which can cause circulatory shock, and bronchiolar constriction, causing respiratory insufficiency

Question 32

**Monocytes:** * % of WBCs: * Size: * Nucleus: * Major function: * Lifespan:

Answer 32

* % of WBCs: **5 - 12%** * Size: ~ 15 µm * Nucleus: **indented, horseshoe-shaped** * Major function: * migrate into tissue ⇒ **differentiate into macrophages** ⇒ phagocytosis * Macrophages known as **antigen-presenting cells** ‘present’ phagocytosed antigens to lymphocytes during an immune response * Lifespan: **several months**

Question 33

Which tissues are these cells in? * dust cell ⇒ * histiocyte ⇒ * Kupffer cell ⇒ * microglia ⇒ * osteoclast ⇒ * sinusoidal lining cell ⇒

Answer 33

* dust cell ⇒ **lung** * histiocyte ⇒ **CT** * Kupffer cell ⇒ **liver** * microglia ⇒ **CNS** * osteoclast ⇒ **bone** * sinusoidal lining cell ⇒ **spleen** Note: these are all macrophages

Question 34

**Lymphocytes:** * % of WBCs: * Size: * Types: * Major function:

Answer 34

* % of WBCs: **19 - 53%** * Size: variable depending on level of activity * most in **peripheral blood** are **\< 10 µm** * Types: **B & T lymphocytes** * Major function: * complementary function, **defending against foreign invaders and cancer cells** * These cells have **immunologic memory** * **​**each responds to only 1 single antigen

Question 35

**Lymphocytes** * _____ predominant in peripheral blood (~80%) * _____ differentiate into plasma cells ⇒ \_\_\_\_\_\_\_\_

Answer 35

* **T cells** predominant in peripheral blood (~80%) * **B cells** differentiate into plasma cells ⇒ **antibodies**

Question 36

What eventually turn into **platelets**?

Answer 36

**megakaryocytes**

Question 37

**Platelets:** * Size: * Morphology: * Major function:

Answer 37

* Size: small, ~ 2 µm; 300,000/µl (mcL) * **granulomere** = dark central region with granules containing **clotting factors** and **growth factors** such as platelet-derived growth factor (PDGF) * **hyalomere** = peripheral light region with parallel microtubules * platelet membrane has receptors

Question 38

**Thrombocytopenia** means ....

Answer 38

**too few platelets** (\< 50,000/µL)

Question 39

What is this?

Answer 39

**Lymphocyte**

Question 40

What is this?

Answer 40

**Eosinophil**

Question 41

What is this?

Answer 41

**Neutrophil**

Question 42

What is this?

Answer 42

**Monocyte**

Question 43

What is this?

Answer 43

**Basophil**

Question 44

What is this?

Answer 44

**Platelet**