General ChemPath Flashcards
What is the ratio of intracellular to extracellular fluid?
2:1
Name 3 locations of the extracellular fluid
Intersitial, intravascular, transcellular
Which is the largest component of extracellular fluid?
Interstitial
Name the 6 main physiological determinants of osmolarity
Sodium, potassium, chloride, bicarbonate, urea, glucose
What is the equation to determinate osmolarity?
2(Na + K) + urea + glucose
What is the normal range for serum osmolality?
275-295mmol/kg
Define osmolarity and osmolality
Osmolarity = total number of particles in 1kg of solvent (mmol/kg), calculated Osmolarity = total number of particles in 1L of solvent (mmol/l), measured
What causes osmolarity to be lower than osmolality?
Extra unmeasured solutes
What is the serum marker of acute pancreatitis?
Amylase - usually >10x normal
What is the serum marker of muscle damage?
Creatine kinase (CK)
State a physiological cause of raised CK
Afro-Caribbean ethnicity (<5x normal)
State four pathological causes of raised CK
Duchenne muscular dystrophy (>10x normal), myocardial infarction (>10x normal), statin related myopathy, rhabdomyolysis
State two physiological causes of raised alkaline phosphatase
Pregnancy, childhood growth spurt
State four pathological causes of raised CK >5x normal
Paget’s disease of bone, osteomalacia, cholestasis, cirrhosis
State four pathological causes of raised CK <5x normal
Bone malignancy, fractures, osteomyelitis, infiltrative liver disease, hepatitis
Where is brain natriuretic hormone primarily released from?
Ventricles of the heart
Which has greater prognostic value, NT-proBNP or BNP - and which disease do they indicate?
NT-proBNP
Heart failure
How long after myocardial injury does troponin remain elevated?
3-10 days
What is an international unit of an enzyme?
The quantity of enzyme that catalyses 1uMol of substrate in 1 minute at a given temperature and pH
