Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Laboratory diagnostics > 1. Isovolemia, isoosmosis, PCV, ion concentration > Flashcards

1. Isovolemia, isoosmosis, PCV, ion concentration Flashcards

1
Q

Serum vs plasma

A

Serum = plasma - clotting factors

If we add anticoagulant it’s plasma.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is common anticoagulants for haematology?

A
  • Na2- / K2- / NaK-ethylene-diamine-tetraacetic acid (EDTA) solution
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

How does EDTA work as anticoagulant?

A

by irreversibly binding calcium ions in the sample

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Are biochemistry parameters usually evaluated in plasma or in serum?

A

Mostly in serum, without adding any anticoagulant

Tho sometimes also in plasma where coagulation is blocked by heparin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

How does heparin work as anticoagulant?

A

Heparin enhances the binding of coagulation factors to antithrombin 3 -› blocks the conversion of fibrinogen to fibrin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Is heparin produced inside of the body too?

A

Yes. By mast cells. But in lab d we use synthetic heparin. Also it often has a nectotiying effect on WBCS in vitro

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Which anticoagulant is used for testing blood clotting parameters?

A

Na2-citrate (3.8 solution)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

How does Na2-citrate work as an anticoagulant?

A
  • Calcium binding but comparing to EDTA here it’s REVERSIBLE.
  • citrate causes the least damage to blood metabolism (=› blood smears, transfusion bags…)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What are clinical signs of volume disturbances?

A
  • change of capillary refill time
  • colour of mucous
  • strength of pulse, heart rate, blood pressure
  • change of skin turgor
  • sunken eyes, prolapse of third lid
  • changes of body weight
  • volume of urine production
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Up to how many % of blood loss there will be no change in blood pressure?

A

5-15%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What happens when blood loss is 15-25%?

A

• tachycardia
• vasoconstriction
• initially increase in blood pressure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What happens when blood loss is 35-45%?

A

• severe decrease of blood pressure
• oliguria/anuria
• vasodilation and shock

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Packed cell volume (PCV) - ?

A

= hematocrit
Ratio of whole blood volume to the volume of RBCs

Anticoagulated blood is needed (EDTA, heparin)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is physiological range for hematocrit?

A

35-45%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What are the ways to count hematocrit?

A
  1. Microcapillary tube method
  2. Automated cell counter
  3. HCT meter (also hemoglobin) (uses optical reflection)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

How increase and decrease of hematocrit are called?

A

Decrease - oligocythaemia/anaemia
Increase - Polycythaemia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What can be reasons of physiological polycythaemia (increased hematocrit) ?

A
  • species and breed characteristics (greyhound, whippet, borzoi, hot blooded horses)
  • newborn animals
  • long-term hypoxia (living in high altitude, regular intensive training)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What can be the reason of false polycythaemia?

A

long sample storage with EDTA. Corpuscular volume of RBCs increases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What is difference between relative and absolute polycythaemia?

A

Relative - decreased plasma volume (dehydration - lack of drinking water, vomiting, diarrhea)
Absolute - increased RBCs production

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What can be reasons of absolute polycythaemia?

A

Primary: WITHOUT increase of erythropoetin (EPO) (e.g. bone marrow neoplasia)

Secondary: due to increased EPO
a) long-term hypoxia, physiological or due to chronic respiratory or circulatory diseases (brachycephal syndrome in dogs, RAO - reaccurent airway obstruction in horses, right-left shunt)
b) without hypoxia - autonomous increase of EPO (EPO producing tumor in kidney, liver)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What is erythropoetin and what is its function?

A

Erythropoietin (EPO) – hormone that stimulates production of erythrocytes in the bone marrow. EPO is produced mainly in kidneys but also in liver. Stimulates transformation of immature cells (proerythroblasts) to mature RBCs.

If O2 delivery is decreased, production of EPO by kidneys is increased

Chronic kidney disease -› low EPO -› anemia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What is the condition of physiological oligocythaemia (anemia) ?

A

Increased plasma volume in 3d trimester of pregnancy (relative anemia)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What is relative oligocythaemia (anemia)?

A
  • due to increase of plasma volume
  • pathological: overdose in fluid therapy, terminal chronic kidney insufficiency
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Conditions of absolute oligocythaemia

A
  • several hours after bleeding (plasma is replaced much faster)
  • decreased RBCs production
    1. suppression of the bone marrow - heavy metal poisoning, mycotoxins, drugs side effect, viral infections
    2. lack of materials needed for erythropoiesis - iron, copper, B6, B12, folic acid
  • decreased life-span of RBCs (immune-mediated haemolytic anemia (IHA), parasites
  • sequestration of RBCs in the spleen due to hypersplenismus
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What is color of plasma physiologically?

A

Transparent, colorless-yellowish

In horses plasma is yellowish due to high level of bilirubin.
In ruminants plasma can be yellowish if there is high carotenoid content in the feedstuff

25
Q

What white, opaque plasma means?

A

Hyperlipidaemia or other lipid-metabolic disorders (DM, pancreatitis)

26
Q

At what % of dehydration decrease of skin turgor is visible?

A

5-6%

27
Q

Osmolality vs osmolarity

A

Osmolality - osmotic pressure per kg
osmolarity - osmotic pressure per liter

28
Q

How can osmolarity be measured?

A
  • mathematically ( = 2*(Na + K) + urea + glucose)
  • using osmometr
29
Q

What is mechanism of work of osmometer?

A

it measures freezing point of the sample and compares it to freezing point of water

30
Q

What is osmolar gap and what can cause it?

A

difference between calculated and measured osmolarity.
—
can be caused by ethanol, ethylene-glycol, methyl-alcohol or isopropyl-alcohol in the blood

31
Q

Main causes of hypernatremia

A
  • water loss: decreased water intake, polyuria (e.g. diabetes insipidus), vomiting or acute diarrhea, panting
  • increased Na retention in kidneys (primary hyperaldosteronism - Conn’s syndrome, secondary hyperaldosteronism - GCC therapy, liver desease, neoplasm)
  • overdose of hypertonic solution, increased salt intake
32
Q

Main causes of hyponatremia

A
  • Na loss (GIT - diarrhea, renal loss - hypoaldosteronism (Addison’s desease), sweating (horses), sequestring in body cavities (ascites)
  • excessive fluid intake, retention of water
33
Q

How aldosterone affects K⁺ concentration ?

A

Excretion of K⁺ increases under aldosterone effect in the epithelial cells of the distal tubules via regulation of Na⁺/K⁺/-ATPase -› decrease of plasma K⁺ conc

34
Q

How does insulin affect K concentration?

A

Insulin -> increased work of Na+/H+ anti porter -> increase of IC Na+ -> increased work of
Na+/K+/ ATPase -> increase of IC K+ = decrease of plasma K+

Insulin shifts potassium into cells by stimulating the activity of Na+-H+ antiporter on cell membrane, promoting the entry of sodium into cells, which leads to activation of the Na+-K+ ATPase, causing an electrogenic influx of potassium. IV insulin leads to a dose-dependent decline in serum potassium levels

35
Q

Main causes of hypokalemia

A
  • decreased intake (anorexia)
  • long term polyuria, loop-diuretic drugs (furosemide)
  • diarrhoea, enteral bleeding
  • hyperaldosteronism (primary or secondary)
  • alkalosis
  • insulin (it induces cotransport with glucose into the cells)
36
Q

Main causes of HYPERkalemia

A
  • increased per os intake, overdose of potassium containing fluids
  • acute kidney failure
  • rupture of urinary bladder
  • hypoaldosteronism (Addison’s disease)
  • acidosis
  • cell injury
37
Q

When pseudohyperkalemia may occur?

A

In case of damage of tissue cells or RBCs (IC conc of potassium is high)

38
Q

Alsosterone, its function and its effect on plasma electrolyte concentration

A

Aldosterone – steroid hormone produced by zona glomerulosa of adrenal gland and it acts on distal consulates tubule and collecting duct, stimulating expression of Na⁺/K⁺/-ATPase on the basolateral surface of the cells (pumping Na⁺ to the blood and K⁺ to the lumen) -› increased water reabsorption -› increased blood pressure, decrease of plasma K⁺ and increase of plasma Na⁺

39
Q

Consequence of change in plasma potassium concentration

A
  • change in either direction influences the conduction of neural stimuli. Muscle weakness
  • muscle spasm can occur in case of hyperkalemia due to secondary hypocalcaemia
  • hypokalaemia -> decreased neuromuscular irritability, paresis, glucose intolerance, decreased insulin secretion, decreased conductance of electrical stimuli in the heart, bradycardia, polyuria, polydipsia, sodium retention, alkalosis
40
Q

What is reference range for plasma chloride?

A

100-125 mmol/l

41
Q

Main reasons of hyperchloremia

A
  • “salt poisoning”
  • overdose in fluid therapy
  • decreased excretion (hypoaldosteronism = Conn’s syndrome)
42
Q

Main reasons of hypochloremia

A
  • vomiting, diarrhoea
  • sweating (horse)
  • abomasal displacement
43
Q

Role of calcium in the body

A
  • maintenance of neuromuscular irritability
  • initiation of muscle contraction
  • regulation of cell permeability and irritability
  • blood clotting process (factor 4)
  • building and stabilising of bones and teeth
44
Q

In what form Calcium is present in the body?

A
  • bound to proteins (albumin)
  • 45-50% free ionised form (Ca⁺⁺)
  • chelated with organic acids
45
Q

Reference range for calcium

A

2,1 - 3,0 mmol/l (Ca⁺⁺ is 45-50% of this).
In poultry laying eggs tCa (total Ca) can be even double (~5,8 mmol/l) but ionised fraction will be decreased

46
Q

Main reasons of hypocalcaemia

A
  • insuff. intake or absorption (vit D deficiency or its decreased activation can cause decreased absorption)
  • hypofunction of parathyroid gland
  • lactation
  • toxicosis of calcium binding substances (citrate, oxalate, ethylene-glycol)
  • alkalosis (Ca⁺⁺ decreases due to increased binding to albumin)
47
Q

Main causes of hypercalcemia

A
  • excessive Ca or vit D intake
  • hyper A vitaminosis in cats
  • hyperfunction of parathormone (also can be due to inflam. or neoplastic processes)
48
Q

Role of magnesium in the body

A
  • ATP metabolism (ATP is bound to Mg⁺⁺ within cells forming a complex)
  • actin-myosin activator - maintains neuromuscular irritability
  • catalysator for more than 300 enzymes
  • facilitates synthesis and breakdown of acetylcholine
  • antagonises acetylcholine receptors at the neuromuscular junction and blocks the sarcomere
49
Q

Indications to check magnesium

A
  • hypocalcemia of unknown origin (deficiency of Mg blocks PTH production and activity)
  • hypokalemia which is resistant to supplementation
  • DKA (diabetic keto-acidosis)
  • muscle weakness of unknown origin
  • tremor, seizure, arrhythmia
50
Q

Reference range for magnesium

A

0,8 - 1,5 mmol/l

51
Q

Main causes of hypomagnesemia

A
  • decreased intake (grass tetany in cattle and sheep)
  • lactation
  • absorption disturbances or increased excretion
52
Q

Role of inorganic phosphate in the body

A
  • participant of many reactions (ATP, synthesis of sugar phosphates, freeing glucose from glucose-6-phosphate, phosphorolytic processes)
  • buffer-system
53
Q

Parathyroid hormone and its effect on concentration of electrolytes

A

Increased Ca⁺⁺ plasma level and decreased phosphate plasma level
1. Increased mobilisation of Ca⁺⁺ and Pi from bones
2. Increased Pi excretion (PCT, Na⁺/phosphate cotransporter) and Ca⁺⁺ reabsorption (DCT, principal cells, Na⁺/Ca⁺⁺) from kidneys
3. Helps to convert Cholecalciferol (precursors of vit D) to its active form vit D (Calcitriol) -› calcitriol acts on digestive system increasing Ca⁺⁺ absorption

54
Q

Calcitonin and its effect of electrolytes plasma concentration

A

Calcitonin is hormone produced by parafollicular cells (C-cells) of thyroid hormone. Calcitonin decreases blood calcium in 2 ways
1. Inhibits octeoclasts -› decrease of plasma calcium concentration
2. Decrease of calcium and phosphate reabsorption by the principal cells in DCT (Na⁺/Ca⁺⁺ channels) -› increased phosphate and calcium excretion

decreased Ca⁺⁺ and phosphate plasma conc

55
Q

Possible reasons for HYPOvolemic NORMOcythaemia?

A

Blood loss

56
Q

Possible reasons for HYPERvolemic NORMOcythaemia

A
  • chronic stress
  • overdose on a full blood transfusion
57
Q

How blood pH influences concentration of K+?

A
  • more acidic pH increases potassium reabsorption as H+ ions get pumped out to antagonise the acidosis. higher the ph, higher K+ conc
  • in alkaline environment hypokalemia may occur
58
Q

How much of K+ is reabsorbed in kidneys usually?

A

90%

59
Q

How much of Na+ is reabsorbed in kidneys usually?

A

60%

60
Q

Grass tetany is related to deficiency of which ion?

A

Magnesium

61
Q

Reasons of decreased blood phosphate concentration

A
  • liver dysfunction
  • hyperparathyroidism (PTH causes Ca absorption and phosphate excretion)
  • calcitonin
  • low pH (phosphate decreases, calcium increases)

Laboratory diagnostics (14 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions