Blood Histology

Question 1

What is the function of blood? (3)

Answer 1

1. delivery of nutrients and oxygen, transport of wastes and CO2
2. delivery of hormones, regulatory substances, immune system cells
3. maintenance of homeostasis: buffer, coagulation, thermoregulation

Question 2

volume of RBCs in a blood sample

Answer 2

packed cell volume (PCV)

39-50% male

35-35% female

Question 3

leukocytes and platelets in a centrifuge

Answer 3

buffy coat

Question 4

• liquid extracellular material
• 90% H2O
• solvent for solutes (proteins and nutrients/electrolytes)

Answer 4

plasma

Question 5

extracellular fluid component of blood that is present after coagulation process is complete, lacks clotting factors

Answer 5

serum

Question 6

dervied from blood plasma, its electrolyte composition reflects that of blood plasma from which it is derived

Answer 6

interstitial fluid

Question 7

• type of globulin
• functional immune system molecule

Answer 7

γ-globulin

Question 8

• type of globulin
• maintain osmotic pressure within vascular walls, carrier proteins, coagulation factors

Answer 8

α-globulin and β-globulin

Question 9

• main protein constituent (50%), made in liver
• exerts conc gradient between blood and extracellular fluid
• colloid osmotic pressure, pressure on vessel walls
• carrier protein for thyroxine, bilirubin, and barbiturates

Answer 9

albumin

Question 10

• largest plasma protein, made in liver
• insoluble form is fibrin
• chains polymerize forming long fibers
• fibers become cross-linked and form an impermeable net, prevents blood loss

Answer 10

fibrinogen

Question 11

• anucleate, devoid of organelles
• disc shaped, stain uniformly (eosin), area of central palor
• histologic ruler
• biconcave disc, flexible, increases SA 20-30% vs being spherical
• bind O2 and deliver to tissues, bind CO2 and remove from tissues
• lifespan: 120 days, ~1% removed each day from spleen, BM, liver

Answer 11

erythrocytes

Question 12

dimeric, springy protein that forms a wheel-like meshwork and attach to membrane-bound hubs

Answer 12

spectrin

Question 13

What is spectrin-actin skeleton connected to cell membrane by?

Answer 13

• ankyrin band 4.2 and band 3
• protein 4.1 and glycophorin A (GP)

Question 14

• immature erythrocytes released from BM
• slighly less than 1% of circulating RBCs
• anucleate, but have mito, ribo, golgi elements, syn hemoglobin
• hallmark: RNA stains slightly basophillic (blue)
• enter circulation: lose polyribosomes and mature to erythrocytes within 48 hr

Answer 14

reticulocytes

Question 15

• decreased hemoglobin levels
• most in the reduction of RBCs due to: hemorrhage, hemolytic _____, insufficient dietary intake of Fe, vitamin B12, or folic acid
• clinical sx: weakness, fatigue, frequent HAs, difficulty conc, dizziness, palor

Answer 15

anemia

Question 16

• single point mutation (Glu > Val) β-globin chain of hemoglobin A (HbA) > sickle hemoglobin (HgS)
• erythrocytes become sickle-shaped at decreased O2 sat
• sickled RBCs = more fragile, vessel obstruction, break down ~20 days
• severe hemolytic anemia (HTC 18-30%) a/w reticulocytosis and hyperbilirubinemia

Answer 16

sickle-cell anemia

Question 17

• inherited disorder caused by intrinsic defects in RBC cell membrane
• mutations in ANK1 are responsible for ~50% of cases
• apparent on smears as small, dark staining, and lacking central pallor
• sx: reticulocytosis, mild jaundice, splenomegaly

Answer 17

hereditary spherocytosis

Question 18

• yellow appearance of sclera of eye and skin
• can be caused by destruction of circulating erythrocytes
• characteristic in many hemolytic anemias: inherited RBC defects, pathogen microbes, animal venoms, chemicals, drugs
• can occur in newborns because of inefficiency of liver

Answer 18

jaundice

Question 19

Never

Let

Monkies

Eat Bananas

Answer 19

neutrophils (50-70%)

lymphocytes (20-40%)

monocytes (2-8%)

eosinophils (1-4%)

basophils (0.5-1%)

Question 20

What is the peripheral blood leukocyte count influenced by? (4)

Answer 20

1. cell number in precursor and storage pop (BM, thymus, circ, tissue)
2. rate of release of cells from storage into circ
3. proportion of cells adhering to vessel walls (marginal pool)
4. rate of extravasation (blood into tissue)

Question 21

• most numerous circulating WBC (50-70%)
• hallmark: segmented “multi-lobed” nucleus, general lack of cytoplasmic staining
• polymorphonuclear (PMN)
• function in acute inflammation and tissue injury
• pus :)

Answer 21

neutrophils

Question 22

• type of neutrophil granule
• main active components: myeloperoxidase, neutrophil defensins
• actions: kill and degradation of engulfed microbes

Answer 22

primary granules

Question 23

• type of neutrophil granule
• main active components: lysozyme, gelatinase, collagenase, lactoferrin, cathelicidins, transobalamin I
• actions: anti-microbial substances and tissue breakdown

Answer 23

specific secondary granules

Question 24

• type of neutrophil granule
• main active components: gelatinase, adhesion molecules
• actions: matrix tissue breakdown (gel), fused into cell membrane (adh)

Answer 24

tertiary granules

Question 25

• type of neutrophil granule
• main active components: membrane proteins; enzymes, alk phos, etc
• actions: bind to endothelium (prot), tissue breakdown (enzymes)

Answer 25

secretory granules

Question 26

immature neutrophils with banded nucleus, caused by left shift

Answer 26

band cells

Question 27

• similar size to neutrophils
• bi-lobed nucleus
• hallmark: abundance of large, acidophilic granules staining intensely pink/red
• 1-4% of circ WBCs
• granule histaminase: moderates effects of inflammatory vasoactive mediators
• phagocytose antigen-ab complexes
• increased counts occur w/ allergies and parastic worms
• mediate chronic inflammation (lung tissue in asthmatics)

Answer 27

eosinophils

Question 28

• hallmark: specific granules that stain intensely purple/blue
• nucleus usually obscurred by granules
• same size as neutrophils
• least numerous <1% of WBCs
• release vasoactive agents (heparin, histamine) and supplment mast function
• severe vascular disturbances a/w type 1 hypersensitivty rxns and anaphylaxis (binds antigen-IgE complex of plasma cells, triggers exocytosis of granules)

Answer 28

basophils

Question 29

• 2-8% of circulating WBC
• hallmark: intensely staining, spherical nucleus w/ thin, pale blue rim of cytoplasm
• main functional cells of immune system
• non terminally deferentiated T cells, B cells > plasma, NK cells

Answer 29

lymphocytes

Question 30

• largest of WBCs
• 2-8% of circulating WBCs
• hallmark: indented, heart-shaped nucleus w/ paler cytoplasm, contains small, azurophilic granules
• precursor cell of macrophages: osteoclasts, Kupffer cells (liver), microglia (brain); macrophages (connective tissue, LNs, spleen, BM)
• differentiate in reponse to inflammation: monocyte leaves vasculature > macrophage > phagocytosis

Answer 30

monocytes

Question 31

• derived from megakaryocyte: large polyploid cell in bone marrow
• small bits of cytoplasm are broken off, circulate as discoid structures w/ life span of ~10 days
• hallmark: small, membrane bound, cytoplasmic fragments
• contain granules that release platelet-specific proteins, function in controlling blood loss, hemostasis
• bind to, coat, and plug damaged vessel walls and help activate blood clotting cascade

Answer 31

thrombocytes