Chapter 4 Flashcards
Measurement Systems, Units, and Equivalencies
What are the three main measurement systems used in medicine?
Household (U.S. Customary) System
Metric (International) System
Apothecary System
What is the basic unit of volume in the metric system?
Liter (L)
How many milliliters (mL) are in 1 liter (L)?
1,000 mL
What is the basic unit of weight in the metric system?
Gram (g)
Convert 1 kilogram (kg) to grams (g).
1 kg = 1,000 g
How many grams (g) are in 1 milligram (mg)?
1,000 mg = 1 g
What is the smallest unit of measurement in the metric system used in pharmacy?
Microgram (mcg or µg)
How many micrograms (mcg) are in 1 milligram (mg)?
1,000 mcg = 1 mg
In the household system, how many teaspoons (tsp) are in one tablespoon (Tbsp)?
3 tsp = 1 Tbsp
Convert 1 cup (c) to ounces (oz) in the household system.
1 cup = 8 oz
What is the abbreviation for tablespoon in the household system?
Tbsp or T
What is the basic unit of length in the metric system?
Meter (m)
Convert 1 meter (m) to centimeters (cm).
1 m = 100 cm
What is the household abbreviation for pound?
lb
How many ounces (oz) are in one pound (lb) in the household system?
16 oz = 1 lb
In the apothecary system, what is the basic unit of weight?
Grain (gr)
What is the apothecary unit of volume?
Fluid dram (fl ʒ)
How many fluid drams (fl ʒ) are in one fluid ounce (fl ℥)?
8 fluid drams = 1 fluid ounce
What are milliequivalents (mEq) used for in pharmacy?
To express the concentration of electrolytes (e.g., sodium, potassium, calcium).
What is the meaning of the abbreviation “IU” in pharmacy?
International Unit – used to measure the potency of biologics like insulin or vitamins.
What are some common abbreviations used in the household system?
Teaspoon = tsp
Tablespoon = Tbsp
Ounce = oz
Pound = lb
Cup = c
Pint = pt
Quart = qt
Gallon = gal
What are the key rules for expressing measurements in the metric system?
Use decimals, not fractions (e.g., 1.5 mL, not 1½ mL).
Always include a leading zero for values less than 1 (e.g., 0.25 mg).
Do not include trailing zeros (e.g., 2.5 mL, not 2.50 mL).
How many milliliters (mL) are in one cubic centimeter (cc)?
1 mL = 1 cc
What is the standard abbreviation for milliliter?
mL (Note: cc is not recommended for use due to potential for error).