1. In gate control therapy of pain, pain is mainly modukated by

A. Substantia gelatinosa
B. B fibres
C. C fibres
D. Transmission system

Ans. A

2. Non myelinated axons differ from myelinated ones in that the

A. Are more excitable
B. Lack nodes of ranvier
C. Are not capable of regeneration
D. Are not assosciated with schwann cells

Ans. B
* Impulse transmission is by saltatory conduction in myelinated nerve fibres.
* Here impulse jumps from one node to other node(nodes of ranvier)
* Non myelinated nerve fibres do not have these nodes and thus there is a slow transmission of impulse.

3. Sensitivity to local anaesthetics is greater in

A. Type B fibres
B. Type C fibres
C. Type A delta fibres
D. Fibres supplying the muscle spindles

Ans. B
Small diameter C fibres are not susceptible to action of local anesthetics.

4. The first sensation to be lost following administration of local anesthetic is

A. Proprioception
B. Pain
C. Touch
D. Temperature

Ans. B
In local anesthetics, the loss of function will be in the following order.  ie, pain, temperature, touch, proprioception and skeletal muscle tone. The return of sensation is in the reverse order. When blocking a nerve containing both motor and sensory fibres, the last functional property list is proprioception.

5. To give field block the LA should be deposited near

A. Main trunk
B. Large branch of peripheral nerve
C. Small nerve endings
D. Periodontal ligament

Ans. B

6. Of the following which tooth is most difficult to anesthetize by infiltration technique alone
A. Maxillary canine
B. Maxillary central incisors
C. Maxillary first molar
D. Maxillary first premolar
Ans. C
Because of thick cortical plate, zygoms infiltration technique is difficult on the buccal aspect of maxillary first molar.infiltration is easily achieved  on the lateral aspect of lower anterior teeth.

7. In case of Gow gates technique the target area is

A. Neck of condyle
B. Head of the condyle
C. Medial side of the ramus
D. Lateral side of the condyle
Ans. A

8. Technique contraindicated in primary teeth

A. Periodontal injection
B. Intraseptal injection
C. Intrapulpal injection
D. Intraosseous injection

Ans. A

9. Last resort for local anesthetic injection is

A. Intrapulpal
B. Intraliganentary
C. Intraosseous
D. Field block

Ans. A
Intrapulpal injections are given in endodontic procedures. On occasion, the IO and PDL injections, even when repeated, do not produce profound anesthesia, and pain persists when the pulp is entered. These cases can be considered for intrapulpal injection.

10. For extraction of mandibular molar, anesthesia is given to act on

A. Inferior alveolar nerve
B. Buccal nerve
C. Lingual nerve
D. Masseteric nerve

Ans. A