Biochemistry

Question 1

Serum vs Plasma

Answer 1

both are fluid part of blood after cells have been removed
plasma contains all clotting factors including fibrinogen
serum is fluid part after clot formation

Question 2

collecting serum

Answer 2

collect blood in tubes without anticoagulant
serum tube have red or brown tops
serum separator tubes with layer of gel which separates serum from cells

Question 3

separation of serum

Answer 3

allow blood to clot and remove supernatant 
centrifuge
serum separator tubes (gel)
separate immediately if possible
store at 4oC

Question 4

total protein

Answer 4

measured on serum or plasma
made up of albumin and globulins
measure by refractometer or colorimetric method
falsely increased by icterus, severe haemolysis + lipemia

Question 5

increased protein?

Answer 5

dehydration
inflammation
neoplasia

Question 6

decreased protein?

Answer 6

loss
decreased synthesis
dilution

Question 7

albumin

Answer 7

dye binding method of measuring albumin
increased albumin - dehydration
decreased albumin - increased loss (renal, haemorrhage, GI), decreased synthesis (liver), third spacing (effusions)

Question 8

globulins

Answer 8

calculated
different types that can be separated by electophoresis
selective increase - infl, neoplasia

Question 9

evaluating the liver

Answer 9

enzymes
metabolites
function tests

Question 10

pancreas

Answer 10

amylase and lipase
from pancreas and other sources - not specific
increases seen in dogs with pancreatitis
renal insufficiency also causes increases

Question 11

urinary system evaluation

Answer 11

look at both serum/plasma chemistry + urine
urea + creatinine both indicators of glomerular filtration
urea made in liver via urea cycle and excreted by kidney
cratinine derived from creatine in muscle

Question 12

azotemia

Answer 12

increase nitrogenous waste in circulation

Question 13

azotemia - causes

Answer 13

pre-renal - dehydration
renal - renal disease
post-renal - obstruction
check urine specific gravity (USG) - measure of kidneys ability to concentrate urine
compare with serum/plasma urea + creatinine

Question 14

urine specific gravity (USG)

Answer 14

1030 dog
1035 cat
1025 horse or ruminant
if USG less then there’s decreased concentrating ability + renal failure is present

Question 15

urea

Answer 15

in ruminants is not reliable indicator of renal disease - use creatinine only
urea levels influenced by protein intake + may be increased by high protein meal or GI bleeding

Question 16

sodium

Answer 16

main ion in extracellular fluid
regulated by kidney
increased sodium may be due to increased intake, water loss or decreased water intake
decreased sodium may be increased loss or increased water intake

Question 17

potassium

Answer 17

main ion in intracellular space
acid-base change will effect levels
regulated by intake + renal
increase - renal failure, hypoadrenocorticism + leakage from cells
decrease - loss (vomit/diarrhoea) + intake

Question 18

chloride

Answer 18

usually changes with sodium
interference with bromide + iodine salts
changes with acid-base status or vomiting/abomasal displacement

Question 19

calcium

Answer 19

free calcium - active
bound calcium - bound to albumin
affected by albumin levels
if increased - check free Ca levels seperately
regulated by PTH and calcitonin

Question 20

phosphorus

Answer 20

regulated by PTH and calcitonin
increase often associated with renal disease
increase often seen in young growing animals with increased calcium + ALP

Question 21

Urinalysis

Answer 21

gross appearance
chemical analysis - specific gravity + urine strip
sediment - cellular elements, crystals, casts others