Lecture 1 Flashcards
(126 cards)
1
Q
what is anatomical pathology?
A
diagnosis of disease based on gross and microscopic examination of the body, organs and tissue
2
Q
What is clinical pathology?
A
the diagnosis of disease based on examination of body tissues and fluid
3
Q
What tubes do we use for a biochemical profile test?
A
green if doing in house, red/orange if sending out
4
Q
What does EDTA do to the blood?
A
it binds calcium
5
Q
what 4 things are included in quality assurance program?
A
- periodic monitoring of all lab equipment
- monitoring of reagent inventory and expiration dates
- controls for each test performed
- Log
6
Q
What 5 things does quality control asses?
A
- technician
- analyzer (equipment)
- reagents
- test procedure
- accuracy of results
7
Q
what are quality control sera?
A
freeze dried and reconstituted for use
8
Q
what can quality control sera be divided into?
A
aliquots… and frozen for future controls
9
Q
what are trends in terms of quality control?
A
a gradual change in control values (increased or decreased) over a certain period
10
Q
what is precision?
A
the ability to obtain results time after time (reproducibility)
11
Q
what is accuracy?
A
measurement agrees with known value of the quantity measured
12
Q
what is reliability?
A
the ability to be both accurate and precise
13
Q
what is sensitivity?
A
the ability of the test to correctly identify those patients with the disease (tests with low sensitivity = increased number of false positives)
14
Q
what is false positive?
A
the patient does not have the disease but the test is positive
15
Q
what is a false negative?
A
the patient has the disease but the test is negative
16
Q
what are references intervals?
A
calculated from a set of lab results from a group of clinically healthy animals that conform to a group of stated selection criteria
17
Q
True or False, every lab has their own reference intervals?
A
true
18
Q
what are 6 selection criteria for reference intervals?
A
- clinical parameters used to select animals for reference values
- population parameters
- environmental and physiological conditions
- specimen collecting and handling
- analytic method
- statistical method used to determine reference values
19
Q
young animals have low __ and __ until about 6 months old?
A
iron and hematocrit
20
Q
what are 4 population parameters?
A
- species
- breed
- age
- sex
21
Q
what gender has a higher hematocrit?
A
males
22
Q
which dogs have a higher hematocrit?
A
athletic dogs
23
Q
what is a normal PCV for dogs?
A
37-55%
24
Q
what is a normal PCV in cats?
A
30-45%
25
What are the 5 environmental and physiological conditions in regard to reference intervals?
1. diet
2. fasting
3. excitement
4. body condition
5. medications
26
urea is a byproduct of diet ___
breakdown
27
what medications can increase ALP in dogs?
corticosteroids
28
What blood chemistry level will be higher in well muscled animals?
creatinine
29
what type of diet will have a higher BUN concentration?
high protein diet
30
Why would an excited cat have a higher PCV?
because the spleen is not contracting and releasing more RBC's into circulation
31
Pending time of day, what do thyroid hormones do?
they go up and down
32
what are 5 specimen collecting and handling considerations in terms of reference intervals?
1. collection site
2. anticoagulants used
3. sampling time
4. interval between collecting and testing
5. storage conditions including freezing and thawing
33
what is the difference between plasma and serum?
plasma has fibrinogen
34
what is the composition of plasma?
90% water 10% proteins, carbohydrates, vitamins, hormones, enzymes, lipids, salts, minerals, antibodies
35
what factors of a difficult venipuncture can alter coagulation results?
-speed of blood flow
- needle size too small
- bent needle
36
what is a common coagulopathy in cats and dogs?
rodenticide, factor 8 deficiency
37
how can you minimize hemolysis when collecting blood?
use the gauge needle possible to reduce turbulence
38
how should you transfer collected blood into a collection tube?
remove the tube cap, dont try to force blood into the tube by poking into the cap
39
why is it important to recap the blood sample?
evaporation
40
what values in the blood are altered when the cap is left off the blood tube?
- gasses in the blood (CO2 or O2 diffusion)
- glucose
41
when and what is a heparin tube used for?
blood gasses and tests done right away in house
42
how much blood should you collect?
enough to run the test twice
43
how long must a sample sit for in order to get a clot?
30 minutes
44
how long and what RPM do you centrifuge serum or plasma sample?
2000-3000 RPM for 10 minutes
45
if the clot site with the serum, RBC's use __ at a rate of ___ which gives a ___in low concentration
blank 1= glucose
blank 2= 10% per hour
blank 3= false decrease
46
what are the 2 most common problems encountered when running samples?
lipemia and hemolysis
47
what are cells doing during hemolysis?
RBC are releasing their content (mostly water)
48
what happens to the value of hematocrit if there is hemolysis?
it decreases
49
can hemolysis cause potassium to be low?
no, it can cause it to be high
50
how can we prevent lipemia?
1. fasting
51
what does lipemia promote?
hemolysis
52
how does hemolysis interfere with test results?
- diluting normal substances in aqueous component of serum
- interferes with spectrophotometer assays
53
why would you put a lipemic sample in the fridge?
because fat rises so the lipid will float to the top and you can take it off
54
what is a reagent that some labs add to clear lipemic serum sample?
lipoclear
55
what type of centrifuge can external labs use with lipemic sample?
ultra centrifugation
56
What things can hemolysis falsely increase (there are 8)
1. iron
2. AST
3. LDH
4. Potassium
5. Phosphorus
6. creatine kinase
7. total protein
8. magnesium
57
what 1 thing can hemolysis falsely decrease?
lipase
58
where is lipase produced?
the pancreas
59
how can we avoid hemolysis? (there are many)
- dont use a moist needle
- dont mix blood vigorously
- dont force blood through the needle
- dont freeze blood sample
- dont use excessive alcohol
- dont use a needle that is too small
- dont under fill the collection tube
60
can icteric be minimized by proper patient preparation or a change in sample handling?
no
61
does icteric interfere with spectrophotometric assays?
yes
62
how long can serum/plasma be stored in the fridge?
4-7 days
63
what should you do with frozen plasma/serum?
return to room temp before testing
64
what are the 5 types of automated analyzers?
1. photometry
2. end point assay
3. kinetic assay
4. ion selective electrode
5. electrochemical methods
65
what does photometry do?
its a light reflectance
66
what does spectrophotometer do?
measures the amount of light transmitted through or reflected by the sample
67
what does colorimeter do?
uses a filter to select the appropriate wavelength of light that will have the maximum absorbance by the sample (increased accuracy)
68
what does reflectometer do?
decrees light that is reflected from substances being tested
69
what does beers law state?
that the absorbance is directly proportional to the concentration of solution
70
end point assays= sample and reagent reach a ____
stable end point
71
what does analyzers use to calculate the results?
- one point calibration or an internal standard curve
72
what do kinetic assays mainly used to determine?
enzyme activity
73
enzymes induce a chemical change in what?
a substrate
74
why must kinetic assays be read at a specific time?
because they do not reach a stable end point
75
what is often used to measure electrolytes?
ion selective electrode analyzers
76
what are 2 automatic analyzers?
1. dry chemistry technology
2. liquid chemistry technology
77
what does dry chemistry technology measure?
light reflected from the slides or pads or cartridges
78
what does liquid chemistry technology measure?
uses light to measure the absorbance and transmittance of light
79
what is the most common example of liquid chemistry technology?
rotor technology
80
how much water is in the body?
60%
81
water in the body is divided into 2 subcategories. what are they?
1. intracellular fluid
2. extracellular fluid
82
in large animal, where is the most water found?
rumen
83
what can extracellular fluid be further divided into?
1. blood
2. intercellular fluid
3. third space fluid
4. GI trat in large animal
84
where are electrolytes found?
intracellular and extracellular
85
what electrolytes (2) are highest concentration in extracellular fluid?
sodium and chloride
86
what electrolytes are highest concentration in intracellular fluid?
potassium, calcium, magnesium, phosphorus
87
what units are electrolytes measured in?
mol/L (SI)
mEq/L (American)
88
electrolytes are critical in allowing cells to do what?
1. generate energy and
2. maintain the stability of their cell membranes
89
what do electrolytes generate?
electricity, contract muscles, move water and fluids within the body, participate in many other activities
90
what monitors changes in blood pressure and the amount of sodium, potassium, and water
kidney
91
where is renin?
juxtaglomerular cells of the kidney
92
where is angiotensin?
lung, brain, heart
93
where is aldosterone?
adrenal gland
94
where is anitdiuretic hormone?
pituitary gland
95
what hormones maintain electrolyte balance normal limits?
renin, angiotensin, aldosterone, ADH
96
what measures all electrolytes?
io selective electrodes
97
what is the most abundant cation?
sodium
98
where is sodium filtered?
by the glomeruli and reabsorbed through renal tubules in exchange for hydrogen as needed
99
what does sodium help maintain?
BP, blood volume, normal muscle and nerve function
100
what is hypernatremia?
increased concentration of serum sodium
101
hypernatremia is usually associated with what?
dehydration
102
what is hyponatremia?
decrease in concentration of serum sodium
103
what are some causes of hyponatremia? (6)
1. diarrhea
2. over hydration
3. renal failure
4. hypoadrenocorticism (Addisons disease)
5.hemolysis
6. CHF
104
what % of potassium is intracellular?
90%
105
____ has a very narrow reference range for maintaining normal neuromuscular and cardia function
potassium
106
What 2 electrolytes help maintain potassium balance?
sodium and magnesium
107
what type of cell is high in potassium?
reticulocyte
108
what can increase serum potassium?
hemolysis or prolonged contact between serum and RBCs
109
RBCs of which species (3) are high in potassium?
pigs, horses, primates
110
what is hyperkalemia?
increased potassium levels
111
what are reasons (8) for hyperkalemia?
1. diarrhea (calves)
2. diabetes melitus
3. massive tissue necrosis
4. marked muscle excretion
5. Madison's disease
6. post renal obstruction
7. renal failure
8. ruptured bladder
112
what is hypokalemia?
low potassium levels
113
reasons for hypokalemia (7)
1. insulin therapy
2. diarrhea (especially horses)
3. renal loss
4. prolonged exercise (horse, dog)
5. anorexia (especially in herbivores)
6. abomasa stasis
7.profuse sweating (horses)
114
what is the cause of cervical ventroflexion (cats) and inability to raise or lift head (cow)?
hypokalemia
115
when would we often see hyperkalemia and why?
in blocked cats because the urine is building up in the body and potassium is not being excreted in the urine (this is an emergency)
116
what is the only way you can get potassium?
from eating
117
when is hypokalemia usually seen?
renal failure as the animal is not eating
118
what can a back up of urine lead to?
heart failure
119
how do you calculate the sodium to potassium ratio?
divide sodium by potassium
120
what is the most abundant extracellular anion?
chloride
121
what 2 electrolytes have a close relationship?
chloride and sodium
122
what is an important component for maintaining acid base balance?
bicarbonate
123
what does bicarb do?
help buffer the acids that build up as normal by products of metabolism
124
what do the lungs regulate?
the amount of CO2
125
what do the kidneys (renal tubules) regulate?
bicarb
126
what is a normal pH level?
7.35-7.45
