Parasympathetic Cranial nerves

# # All of cranial nerve have parasympathetic outflow except :
A. 5th nerve
B. 7th nerve
C. 3rd neve
D. 9th nerve

The correct answer is A. 5th nerve

Cranial nerves having parasympathetic now are 3,7,9 and 10.

Preganglionic parasympathetic neuron cell bodies are located in certain cranial nerve nuclei of the brain stem and in the grey matter of the second to fourth sacral segments of the spinal cord. Efferent fibres, which are myelinated, emerge from the CNS only in cranial nerves III, VII, IX, and X and in the second to fourth sacral spinal nerves. Preganglionic parasympathetic neurons are cholinergic. 

The only cranial nerve which arises on the dorsal aspect   -       Trochlear

The cranial nerve with longest intracranial coarse              -        Abducent

The cranial nerve with longest coarse                                 -       Vagus

The cranial nerve involved in raised intracranial tension   -       Abducent nerve

Cranial nerve carrying parasympathetic fibres                      -       3,7,9,10

Commonest cranial nerve affected in spinal anesthesia     -       Abducent nerve

Cranial nerve involved in Bell's palsy                                 -       VII Nerve

Cranial nerve involved in Ramsay Hunt Syndrome             -       VII nerve

Cranial nerve arising from the pons                                    -     V, VI, VII, VII nerves

Pure sensory nerves                                                          -       1,2,8

Branchiomeric nerves                                                       -       5.7.9,10,11

Referred pain in Orofacial region:

# ___________most often refer pain to the temporal region,
while _________most often refer pain the ear.
A. Maxillary second premolars, mandibular molars
B. Maxillary molars, mandibular molars
C.  Maxillary second premolars, mandibular premolars
D. Maxillary molars, mandibular premolars

The correct answer is A. Maxillary second premolars, mandibular molars.

If careful diagnosis does not reveal the affected tooth, other teeth and related anatomic structures

become suspect. Pulpitis in one tooth may cause pain in other areas - the pain is referred.

Site of Pain Referral                             Pulp of Tooth Causing Pain

Forehead region                                    Maxillary incisors

Nasolabial area                                      Maxillary canines. premolars

Temporal region                                     Maxillary second premolars

Ear. angle of jaw, or posterior                 Mandibular molars

regions of neck

Mental region of mandible                        Mandibular incisors, canines. and premolars

Zygomatic, parietal, and occipital              Maxillary molars

regions of head

Opposing quadrant or to other                      Maxillary and mandibular molars

teeth in the same quadrant

Important: The nerve endings of cranial nerves VII, IX, and X are widely distributed within the subnucleus caudalis of the trigeminal (V) nerve. A profuse intermingling of these nerve fibers creates the potential for the referral of dental pain to many sites.

Orofacial pain can be the clinical manifestation of a variety of diseases involving the head and neck region. The cause of the pain must be differentiated between odontogenic and nonodontogenic.

Characteristics of nonodontogenic involvement:

• Episodic pain with pain-free remissions

• Trigger points

• Pain travels and crosses the midline of the face

• Pain that surfaces with increasing stress

• Pain that is seasonal or cyclic

• Pain accompanied by paresthesia

Hydrolysis of Lactose, Maltose and Sucrose

# Which of the following statements is TRUE? (MAN-95)
a) The hydrolysis of lactose yields glucose and galactose
b) The hydrolysis of maltose yields glucose and fructose
c) The hydrolysis of sucrose yields only glucose
d) All of the above statements are true

The correct answer is A. The hydrolysis of lactose yields glucose and galactose

Carbohydrate	Products
Maltose	2 glucose units
Sucrose	1 glucose + 1 fructose
Lactose	Galactose + glucose
Starch	Water soluble amylose and a water soluble amylopectin
Inulin	Polymer of fructose

Chromic gut Suture vs Plain gut Suture

# Advantage of chromic gut over plain is:
A. Delayed resorption
B. Increased strength
C. Less irritation
D. Less tissue reaction

The correct answer is A. Delayed resorption.

• Chromic gut sutures consist of the plain gut that has been treated with chromium trioxide. This results in a delay in the absorption rate.

• Because retention of sutures beyond a few days is not recommended in endodontic surgery, the use of chromic gut sutures offers no advantage.

• Also, evidence indicates that plain gut is more biocompatible with oral soft tissues than is the chromic gut. The gut suture material is marketed in sterile packets containing isopropyl alcohol.

• When removed from the packet, the suture is hard and non-pliable because of its dehydration. Before using gut sutures should be hydrated by placing them into sterile, distilled water for 3 to 5 minutes.

• After hydration, the gut suture material will be smooth and pliable with manipulative properties similar to silk.

# Benzodiazepine antagonist is:

# Benzodiazepine antagonist is:
A. Flumazenil
B. Naloxone
C. Furazolidone
D. Dapsone

The correct answer is A. Flumazenil

Benzodiazepine act by enhancing presynaptic or postsynaptic inhibition through a specific receptor which is integral part of gabba receptor Cl-channel complex.

Flumazenil is a BZD analogue which has little intrinsic activity but it competes with BZDs as well as inverse agonists for BZD receptor and reverses their depressant or stimulant effects respectively. Flumazenil is the drug of choice for benzodiazepine overdose.

# To prevent sensitivity caused by acid etching and to protect pulp in deep cavities, which of the following should be used?

# To prevent sensitivity caused by acid etching and to protect pulp in deep cavities, which of the following should be used?
A. Calcium hydroxide liner
B. ZnO liner
C. Light cure GIC liner
D. Lining with varnish

The correct answer is A. calcium hydroxide liner

Deep caries excavation close to the pulp, which may result in either an undetected pulpal exposure or a visible pulpal exposure, should be covered with a calcium hydroxide liner that can stimulate formation of dentin bridges (reparative dentin) over the exposure.

For amalgam restorations, deep excavations not encroaching on the pulp should be covered with a glass-ionomer material that will contribute to thermal protection and provide mechanical protection from amalgam condensation forces at thicknesses of I to 1.5 mm or greater.

Bonding of Composite resin to tooth

# Bonding of composite resins to tooth structure is by: (KAR-01)
a) Covalent bond
b) Ionic bond
c) Mechanical
d) Vander waal forces

The correct answer is C. Mechanical

Bonding of composites to tooth structure occurs by micromechanical retention. Acid etching creates micro porosities into which the resin penetrates resulting in resin tag formation. These tags penetrate to a depth of 5 - 10 µm but their lengths are dependent on the enamel etching time.