Serum vs plasma - we know this
Electrolytes - Sodium (Na), Potassium (K), Chloride (Cl), Phosphorous (P) = can use in diagnosis, ie. increased levels of K involved in contraction of the the heart muscle, - used in euthanization fluid.
Injectable bottle with black cap means it can kill you, ie. potassium.
Exocrine - delivers enzymes or chemical compounds to another part of the body via a duct. many times it's an enzyme