Question

1. a toxin that has been rendered harmless but still invokes an antigenic response is called:

a: toxoid b: vaccine
c: antigen d: bacteria

1. the trachea divides directly into the:

a: sinuses b: bronchioles
c: alveoli d: bronchi

1. the most commonly used local anesthetic is:

a: novacain b: lidocaine
c: carbocaine d: cocaine

1. the stability of a drug refers to:

a: how long the medication remains potent b: how the medication should be stored
c: what the medication is stored in d: shelf life

1. 650 mg equals

a: 5 grains b: 10 grains
c: 20 grains d: 15 grains

Explanation:

• Question 116: A toxoid is a toxin that has been made harmless but still elicits an antigenic response. A vaccine can contain various components (not just a modified toxin). An antigen is a broader term (any substance that can trigger an immune response, not specifically a modified toxin). Bacteria are microorganisms, not a modified toxin.
• Question 117: The trachea divides directly into the bronchi. Sinuses are air - filled cavities in the skull. Bronchioles are smaller branches that come from the bronchi. Alveoli are the tiny air - sacs at the end of the bronchioles.
• Question 118: Lidocaine is one of the most commonly used local anesthetics. Novacain (procaine) was used more in the past. Carbocaine (mepivacaine) is also a local anesthetic but not as commonly used as lidocaine. Cocaine has significant side - effects and is not a commonly used local anesthetic in modern medical practice (except in very specific, limited situations).
• Question 119: The stability of a drug refers to how long the medication remains potent. How it should be stored is related to storage conditions (a factor that can affect stability but not the definition of stability). What it is stored in is about the container. Shelf - life is related to stability (the length of time a drug remains stable is its shelf - life), but the definition of stability is about remaining potent.
• Question 120: 1 grain is approximately 65mg. So, if \(x\) is the number of grains and \(y\) is the milligrams, \(y = 65x\). When \(y = 650\)mg, then \(x=\frac{650}{65}=10\) grains.

Answer:

1. A. Toxoid
2. D. bronchi
3. B. lidocaine
4. A. how long the medication remains potent
5. B. 10 grains