Haematology

Question 1

Haematology is…

Answer 1

the study of blood and blood disorders

Question 2

Haematopoeisis

Answer 2

formation of blood cells - platelets, WBCs, RBCs
occurs in bone marrow
maturation and activation of lymphoid cells in spleen, thymus, and lymph nodes
RBCs in liver and spleen

Question 3

erythropoeisis

Answer 3

RBC formation
stimulated by low oxygen levels
especially in kidneys - erythropoeitin - kidney disease –> anemia

Question 4

myelopoeisis

Answer 4

production of WBCs
bone marrow
stimulated by variety of factors
trigger differentiation to myeloblasts
increased production with inflammation

Question 5

thrombopoeisis

Answer 5

production of platelets
bone marrow - from megakaryocytes
stimulated by thrombopoietin - produced in liver

Question 6

leukocytes - neutrophils

Answer 6

first response
acute inflammation
bacterial infection
granulated
phagocytosis

Question 7

leukocytes - eosinophils

Answer 7

pink granules
parasitic infection
allergic response

Question 8

leukocytes - basophils

Answer 8

usually don’t see
parasitic and allergy (with eosinophils)
histamine release

Question 9

lymphocytes

Answer 9

adaptive immune response
b and t cells
b - humoral, antibody
t - cell mediated
natural killer - innate immune response

Question 10

leukocytes - monocytes

Answer 10

biggest leukocytes
larger than neutrophils, greyer cytoplasm
cytokine release
become macrophages in tissue

Question 11

regenerative vs non-regenerative anemia

Answer 11

regenerative - will see immature RBCs (reticulocytes/polychromatophils) - regenerating the lost RBCs
non-regenerative - cells largely same size

Question 12

Spherocytes

Answer 12

RBCs with no central pallor - indicate immune mediated hemolytic anemia

Question 13

rouleux vs agglutination

Answer 13

agglutination - RBCs stick together - grapes - IMHA
rouleux - stack of coins - increased blood protein

Question 14

hypochromia

Answer 14

pale staining, increased central pallor of RBCs
iron deficiency

Question 15

left shift

Answer 15

release of granulocyte precursors from marrow
increased neutrophil
inflammation/infection

Question 16

CBC Parameters

Answer 16

measured:
haemoglobin
red blood cell concentration
mean cell volume - average size of RBCs

calculated:
hemocrit -how likely they are anemic (MCV*RBC)
mean corpuscular hemoglobin
mean corpuscular hemoglobin concentration

Also:
red cell distribution width
reticulocyte % - measure of regeneration
reticulocyte hemoglobin concentration
plateletcrit - indicative of number of platelets

Question 17

Packed cell volume

Answer 17

blood in capiliary tube
split into red cells, buffy coat, plasma
visual indication of % of each - eg. more buffy coat –> high WBCs

Question 18

RBC morphological abnormalities - spherocytes

Answer 18

small, dark, no central pallor
agglutination - IMHA
rouleux - high protein

Question 19

RBC morphological abnormalities - heinz bodies and eccentrocytes

Answer 19

oxidative injury
hemoglobin pushed to cell margin
toxins

heinz bodies - look like tiny head snowmen
eccentrocytes - darker ring around edge of cell

Question 20

RBC morphological abnormalities - acanthocytes

Answer 20

alterations ti lipid metabolism of rbc membranes
wobbly shape

Question 21

RBC morphological abnormalities - schistocytes

Answer 21

rbc fragments - secondary to being pushed through abnormal blood vessels or being fragile

Question 22

RBC morphological abnormalities - hypochromic RBCs

Answer 22

increased central pallor
iron deficiency

Question 23

Anemia

Answer 23

reduced RBCs
evidenced by - reduced hb, packed cell volume, hemocrit, rbc count
normal variation by breed and age
influenced by some drugs

Question 24

Anemia - compensatory mechanisms (4)

Answer 24

increased oxygen delivery
increased cardiac output
increased rbc production
vasoconstriction

Question 25

Anemia - clinical signs

Answer 25

pale mm
lethargy
exercise intolerance
tachycardia
tachypnoea
collapse
icterus
melaena - blood loss from GIT
pica

Question 26

Anemia - classification

Answer 26

severity
rbc indices
regenerative vs non-regenerative

Question 27

Anemia - causes

Answer 27

regenerative -
hemorrhage
hemolysis
IMHA

non-regenerative (marrow diseases) -
chronic inflammation
endocrinopathies - hypothyroidism, hypoadrenocorticism
chronic renal failure

Question 28

Polycythemia (erythrocytosis)

Answer 28

opposite of anemia - increased RBC
rarer
primary - neoplastic conditions of bone marrow, blood too thick to get around vessels, low erythropoietin (rare)
secondary - hypoxia (increased erythropoetin production –> increased RBCs), tumours

Question 29

blood film examition

Answer 29

total WBC count
differential count - proportions of different WBCs
morphological assessment

Question 30

neutrophilia

Answer 30

increased neutrophils
to meet demand - infection, immune mediated disease, inflammation, neoplasia
persistence in circulation - chronic stress, glucocorticoid effect (steroids)
redistribution - shift from marginating (on walls of blood vessels) to circulating pool, excitement (increased epinephrine - stress), increased blood pressure

Question 31

neutropenia

Answer 31

increased demand - migration to tissue quicker than production, bacterial sepsis, abscess, endotoxemia, tumour necrosis
decreased production - bone marrow disease, drugs
redistribution - in response to demand
increased destruction - immune mediated

Question 32

band neutrophils

Answer 32

released with increased demand
horseshoe shape
found in peripheral blood
released earlier than they would be otherwise

Question 33

toxic neutrophils

Answer 33

more severe indicator of increased demand
maturation defects
dohle bodies
foamy cytoplasm
blueish cytoplasm tinge

Question 34

lymphocytosis

Answer 34

increased production of lymphocytes due to increased demand
increased production without demand
redistribution - excitement/acute stress, hypoadrenocorticism

Question 35

lymphopenia

Answer 35

decreased lymphocytes
loss of lymphocytes
decreased production - viral infections, chemo
redistribution - stress, trapped in lymph nodes

Question 36

monocytosis

Answer 36

increased monocytes
increased production with demand - infection, immune mediated, inflammation, necrosis, sepsis, neoplasia
without demand - leukemia
redistribution - stress or steroids
(opposite is monocytopenia - not clinically significant)

Question 37

eosinophilia

Answer 37

increased production of eosin to demand - parasites, allergy, paraneoplastic, inflammation of mast cell rich tissue
without demand - noplasia, hypereosinophilic syndrome

Question 38

basophilia

Answer 38

usually goes along with high eosinophilia
increased demand - hypersensitivity, parasites, inflammation
without demand - paraneoplastic, basophilic leukemia

Question 39

stress leukogram

Answer 39

leukocyte pattern due to increased cortisol
neutrophilia with or without monocytosis
absent in addisons - would be expected when sick but doesn’t show up - good indicator

increased neutrophilia, decreased lymphocytes and eosinophils

Question 40

Blood tubes

Answer 40

EDTA - Anticoagulant - removes calcium and lead
Heparin - anticoagulant - stablises blood cell membrane, reduces lysis
Serum gel - separates blood cells from serum so can centrifuge to test separately
Serum clot activator - promotes clotting, used to collect serum

Question 41

vacutainer colours

Answer 41

yellow - serum gel - serology and biochem tests (not anticoagulant)
green - heparin - biochem
purple - EDTA - hematology, hemoparasite screens, cytology and fibrinogen
red - serum clot activation - serum collection for select tests