Hematopoiesis I: Blood

Question 1

hematopoiesis

Answer 1

formation of blood and its components (RBCs, WBCs, megakaryocytes/platelets)

Question 2

hematopoietic tissues during gestation

Answer 2

yolk sac: 0-3 months of gestation liver: main hematopoietic organ from 2-7 months of gestation spleen: small amt. of hematopoiesis from 3-6 months of gestation bone marrow: starts hematopoiesis during 4th month, becomes primary source during 7th month of gestation

Question 3

primary hematopoietic tissues in adulthood

Answer 3

vertebra, sternum, rib

Question 4

primary hematopoietic tissues from birth till around 25 years old

Answer 4

tibia and femur

Question 5

formed element

Answer 5

solid components of blood, includes RBCs, WBCs, platelets

Question 6

percentages of formed blood elements

Answer 6

RBCs: 41-53% in males, 36-46% in females WBCs and platelets: about 1% (buffy coat)

Question 7

plasma

Answer 7

liquid extracellular component of blood

Question 8

discuss the contents of plasma (w/ percentages)

Answer 8

water: 90% protein: 7% (albumin, globulins-alpha, beta, gamma, fibrinogen, prothrombin) inorganic ions: 0.9% the rest is composed of nutrients, blood gases, hormones etc.

Question 9

serum

Answer 9

clear, yellow supernatant after blood coags. like plasma but w/o clotting factors, platelets, cells. contains factors released from platelets (e.g. growth factors)

Question 10

function of erythrocytes

Answer 10

transport O2 and CO2

Question 11

lifespan of erythrocyte

Answer 11

~120 days

Question 12

reticulocyte

Answer 12

immature RBC, still has some ribosomes, normally 1-2% of erythrocytes, stain blue

Question 13

microcyte

Answer 13

erythrocytes that are too small, <6 micron, due to low iron

Question 14

macrocyte

Answer 14

erythrocytes that are too large >9microns in diameter, due to low B12 and folic acid

Question 15

morphology of erythrocytes

Answer 15

anucleate, lack many organelles, biconcave discs, ~7.5micron diameter, flexible

Question 16

oxyhemoglobin

Answer 16

hemoglobin bound to O2

Question 17

carboxyhemoglobin

Answer 17

hemoglobin bound to CO, irreversible binding, leads to CO poisoning

Question 18

carbaminohemoglobin

Answer 18

hemoglobin bound to CO2

Question 19

sickle cells

Answer 19

mutated hemoglobin aggregates and distorts cell shape, cells are rigid fragile, short-lived

Question 20

what are the two major classes of leukocytes

Answer 20

1. granulocytes: PMNs (polymorphonuclear) 2. agranulocytes: mononuclear

Question 21

what are the three types of granulocytes?

Answer 21

granulocytes are one of the two classes of leukocytes. 1. neutrophil 2. eosinophil 3. basophil

Question 22

what are the three types of agranulocytes?

Answer 22

agranulocytes are one of the two classes of leukocytes. 1. lymphocyte (become B and T cells) 2. monocyte

Question 23

what is the suffix that denotes whether a cell is a granulocyte? agranulocyte?

Answer 23

granulocyte: -phil (because it’s FILLED w/ granules) agranulocyte: -cyte

Question 24

what is the concentration and percentage of leukocytes in the blood?

Answer 24

4,400-11,000 leukocytes/microleter of blood ~0.1% of blood cells

Question 25

what is the concentration and percentage of neutrophils?

Answer 25

1,800-7,700/microleter 50-70% of leukocytes

Question 26

what is the concentration and percentage of lymphocytes?

Answer 26

1,000-4,8000/microleter 18-42% of leukocytes

Question 27

function of neutrophils

Answer 27

first leukocytes to extravasate; phagocytose bacteria and other small particles

Question 28

respiratory burst

Answer 28

burst of O2 consumption by neutrophils during phagocytosis- leads to formation of toxic superoxide anions and hydrogen peroxide that helps degrade bacteria in tissues

Question 29

what is the purpose of lactoferrin and which leukocyte uses lactoferrin?

Answer 29

binds iron which is a crucial element in bacterial nutrition, released from granules present in neutrophils

Question 30

what is the purpose of lysozyme?

Answer 30

cleaves bonds in cell wall of some gram-positive bacteria

Question 31

discuss the morphology of neutrophils

Answer 31

has a 2-5 lobed nucleus, linked by threads of chromatin, relatively few mitochondria (allows cell to live in poorly oxygenated tissues-i.e. inflamed, necrotic), granules are difficult to see

Question 32

discuss the life cycle of neutrophils

Answer 32

produced in the sinusoids of the bone marrow, short-lived, half-life of 6-7 hours in blood, 1-4 days in connective tissue, die by apoptosis

Question 33

granule contents of neutrophils

Answer 33

granules contain lysozyme, lactoferrin to help degrade bacteria via phagocytosis

Question 34

granule contents of eosinophils

Answer 34

5'nucleotidase, elastase, collagenase, myeloperoxidase, lysozyme, cationic antibacterial proteins, phospholipase, RNase, eosinophilic peroxidase

Question 35

discuss the location of neutrophils in the body

Answer 35

circulate in the blood, extravasate when prompted by infection/inflammation

Question 36

function of collagenase

Answer 36

degrades extracellular matrix, neutrophil and eosinophil granules release this in order to move freely through tissues

Question 37

band neutrophils (percentage, origin)

Answer 37

2-5% of neutrophils are immature (band neutrophils), infections and leukemia may increase number of band neutrophils; originate in the bone marrow, then released in blood stream

Question 38

structure of eosinophils

Answer 38

usually bilobed nucleus, granules stain blue, do not overlie nucleus

Question 39

function of eosinophils

Answer 39

kill parasites and tone down immune response, phagocytize antigen-antibody complexes

Question 40

granule contents of eosinophils

Answer 40

histaminase (anti-histamine), collagenase, cathepsin (proteinase), arylsulfatase

Question 41

where are eosinophils found in the body?

Answer 41

connective tissue underlying epithelia of bronchi, GI, uterus, vagina (they are found in normal tissues)

Question 42

what might cause an increase in eosinophils in the blood (eosinophilia) indicate?

Answer 42

allergic rxn, parasitic (helminthic) infections

Question 43

what compounds (found in eosinophil granules) inactivate leukotrienes and histamine?

Answer 43

arylsulfatase and histaminase

Question 44

structure of basophils

Answer 44

irregular, lobed nucleus, large granules that overlie nucleus, nucleus stains pink

Question 45

function of basophils

Answer 45

nonphagocytic granulocytes; functionally similar to mast cells, promote allergic rxns, bind IgE antibodies for allergen specificity

Question 46

granule contents of basophils

Answer 46

eosinophilic chemotactic factor, heparine, histamine, peroxidase, leukotrienes

Question 47

what type of leukocyte has a horseshoe shaped nucleus when not fully developed?

Answer 47

neutrophil

Question 48

structure of monocytes

Answer 48

large, oval, horseshoe, kidney shaped nucleus, less condensed chromatin, cytoplasm stains blue

Question 49

function of monocytes

Answer 49

monocyte-derived cells (e.g. macrophages) involved in innate and adaptive immune response, bacterial phagocytosis, wound healing, bone resorption, debris removal

Question 50

MPS

Answer 50

mononuclear phagocytic system, monocytes are precursor cells to this system (e.g. turn into macrophages, big part of MPS)

Question 51

lifespan of monocytes

Answer 51

in blood ~3 days

Question 52

lifespan of platelets

Answer 52

~10 days

Question 53

what are the three types (an percentages) of lymphocytes

Answer 53

T lymphocytes (60-80%) B lymphocytes (20-30%) natural killer cells (\>10%)

Question 54

what is the role of T lymphocytes?

Answer 54

involved in cell mediate immunity, activate B cells, macrophages, cytotoxic T cells

Question 55

what is the role of B lymphocytes?

Answer 55

involved in humoral immunity, precursors to Ab-producing plasma cells

Question 56

what is the role of NK cells?

Answer 56

kill certain virus-infected cells and some tumor cells

Question 59

percentage of eosinophils

Answer 59

1-3% of leukocytes

Question 60

percentage of monocytes

Answer 60

2-8% of leukocytes