Biochemistry Flashcards
Enzymes released in haemolysis
AST
LDH
Enzymes released when liver cells die
AST
ALT
Enzymes stimulated by the presence of disease in the biliary tract
Gamma GT
Alkaline Phosphatase
Enzymes released in acute and chronic pancreatitis
Amylase
Lipase
Enzyme release by muscle
CK
AST
Enzyme released by heart
Troponin
AST
LDH
Enzyme release by bone
Alk Phos.
True positive test result
Test is abnormal in person with the disease
True negative result
Test is normal in person without the disease
False positive test result
Abnormal test result, disease absent
False negative test result
Normal test result, disease present
Sensitivity
The percentage of people with the disease who have a positive (abnormal) test result
Specificity
The percentage of people without disease who have a normal (negative) test
(How good a test is at correctly identifying health or absence of disease)
Positive predictive value
The likelihood of disease in people with a positive test
Also known as post-test probability of disease
Negative predictive value
The likelihood of health in someone with a negative (normal) test result.
Or post-test probability of health
Prevalence
A measure of how common the disease is in the population of people who’ve been tested
Pre-test probability of disease
As prevalence falls, PPV falls and NPV rises
Volume of hydrogen ions produced by metabolism daily
60millimol
Concentration of hydrogen ions in body
35 to 45 nanomol/L
Bicarbonate buffer system of H+
(H+) + (HCO3-) H2CO3 CO2 + H2O
Hemoglobin buffer system of H+
(H+) + (Hb-) HHb
Acidosis
An increase in [H+] or a process tending to cause an increase in [H+]
Alkalosis
A decrease in [H+] or a process tending to cause a decrease in [H+]
Acidaemia
Increase in [H+]
Alkalaemia
Decrease in [H+]
The respiratory component
PCO2
The metabolic component
HCO3-
Respiratory acidosis
Increase in [H+] due to increase in pCO2
Respiratory alkalosis
Decreased [H+] due to decreased pCO2
Metabolic acidosis
Increase in [H+] due to decrease in HCO3-
Metabolic alkalosis
Decrease in [H+] due to increase in HCO3-
Respiratory compensation for metabolic acidosis
Primary problem is too much H+
Compensate by blowing off CO2
Metabolic compensation for respiratory acidosis
Primary problem is too much CO2
Compensate by excreting more H+
Causes of respiratory acidosis
Choking
Bronchopneumonia
COPD
Causes of respiratory alkalosis
Hysterical over breathing
Mechanical over-ventilation
Raised intracranial pressure
Causes of metabolic acidosis
Impaired H+ excretion
Increased H+ production and ingestion
Loss of HCO3-
Metabolic alkalosis
Loss of H+ in vomit
Alkali ingestion
Potassium deficiency
Arterial blood gases
H+
PCO2
HCO3-
pO2
