80. Which of the following hormones is secreted by anterior pituitary cells that stain with acidic dyes?

A. ACTH B. FSH
C. LH D. Prolactin

E. TSH

ANS. D. The cells of the anterior pituitary can be classified as chromophils (stain
with dyes) or chromophobes (do not stain with dyes). The chromophils can be further divided inacidophils (stain with acidic dyes) and basophils (stain with basic dyes). The acidophils include thesomatotrophs, which secrete growth hormone, and the mammotrophs, which secrete prolactin.The basophils include the corticotrophs, which secrete ACTH (choice A), the gonadotrophs, which secrete FSH and LH (choices B and C), and the thyrotrophs, which secrete TSH (choice E).

FOR MORE IN DENTISTRY: VISIT

RxDENTISTRY
LOVEHUES
DENTAL MATRIX

78.The major structural component of the sperm flagellum is the:

A. microtubule
B. microfilament
C. actin filament
D. mysosin filament
E. ciliary body

ANS A. This is a basic histological question of a type found commonly on NBDE, which asks about basic cellular organelles and structures. The sperm cell flagellum is notable for a “9+2” arrangement of fibers formed from microtubules. The 9 single fibers form a circular ring in cross section around the 2 doubled fibers in the center. One of the significant facts about the fibers is
that they are composed of microtubules, made up of tubulin. The other significant fact is that all eucaryotic flagella and cilia have this same structure (for example, cilia form the tracheal lining). Note that procaryotic (bacterial) flagellea do NOT share this structure.


FOR MORE IN DENTISTRY: VISIT

RxDENTISTRY
LOVEHUES
DENTAL MATRIX

76.Damage to which of the following structures might produce hair cell loss?

A.Basilar membrane B.Organ of Corti
C.Reissner's membraneD.Scala tympani
E.Scala vestibuli

ANS B.

Hearing is the detection of sound, which consists of pressure waves

conducted through air or water. The receptors of the cochlear duct provide us with a sense of hearing

that allows us to detect the quietest whisper and yet remain functional in a crowded, noisy

environment. The organ of Corti contains hair cells from the cochlear branch of the vestibulocochlear

nerve (CN VIII). These cells rest on the basilar membrane (choice A), which separates the scala

tympani (choice D) from the scala media. The hair cells are embedded in the tectorial membrane,

and movement of the basilar membrane below the cells causes the hairs to bend, which generates

action potentials. The tectorial membrane that lies on the hair cells does not form a boundary between

the different scala; the membrane separating the scala media from the scala vestibuli (choice E) is

Reissner's (vestibular) membrane (choice C).

1H

FOR MORE IN DENTISTRY: VISIT

RxDENTISTRY
LOVEHUES
DENTAL MATRIX

75.Which cusp of the maxillary molar is NOT part of the trigon (primitive cusp triangle)?

A. Mesiolingual    B. Mesiobuccal

C. Distolingual     D. Distobuccal

ANS> C. In evolution, three cusps of the maxillary molar are considered to be the 

primary cusp triangle, and the original three cusps of the evolving molar. They form the trigon, and are 

the MB, ML, and DB cusps. The fourth cusp, the DL, is the smallest, is considered to be a minor cusp, 

and is known evolutionarily as the talon, or talon cusp. This cusp is less conspicuous as you go from 

first to second to third maxillary molar. 

FOR MORE IN DENTISTRY: VISIT

RxDENTISTRY
LOVEHUES
DENTAL MATRIX

74. At which of the following ages does fetal movement first occur?

A. 1 month B. 2 months

C. 4 months D. 6 months E. 7 months


The correct answer is B. Neuromuscular development is sufficient to allow fetal movement in the

eighth week of life. Other features of Week 8 include the first appearance of a thin skin, a head as

large as the rest of the body, forward-looking eyes, appearance of digits on the hands and feet,

appearance of testes and ovaries (but not distinguishable external genitalia), and a crown-rump length

of approximately 30 mm. By the end of the eighth week, nearly all adult structures have at least begun to 

develop, and the fetus "looks like a baby." 

FOR MORE IN DENTISTRY: VISIT

RxDENTISTRY
LOVEHUES
DENTAL MATRIX

73. Mosquito borne transmission appears to be the method of spread in:

a. St. Louis encephalitis   b. Histoplasmosis

c. Typhus  d. Toxoplasmosis

ANS.  A



FOR MORE IN DENTISTRY: VISIT

RxDENTISTRY
LOVEHUES
DENTAL MATRIX

72. Which cusp on the primary mandibular first molar is highest and sharpest?

A. Mesiobuccal       B. Distobuccal

C. Mesiolingual        D. Distolingual



ANS.  C. The primary first mandibular molar is a highly unusual tooth. It is molar-like

in form, with two roots (mesial and distal), but has a very pronounced mesial development of the

crown. The mesial section comprises two-thirds of the crown, and the distal portion is much reduced.

The mesiolingual cusp is the highest and sharpest, although the mesiobuccal is overall largest as

viewed from the occlusal. It is followed in size by the ML, DB, and DL cusps.

FOR MORE IN DENTISTRY: VISIT

RxDENTISTRY
LOVEHUES
DENTAL MATRIX

63.Injury at the lower border of a rib will most likely damage which structure?

A. intercostal a. B. intercostal n.
C. intercostal v. D. internal intercostal muscle

ANS>B. The three structures in the intercostal space are, from superior to inferior, the intercostal vein, artery, and nerve. The proper site for insertion of an intercostal drain is superior to a rib, not directly at the level of the superior border but slightly higher to avoid the collateral branches of the nerve, artery, and vein. The nerve is the most inferior structure and thus most likely to be damaged by the drain (producing an anesthetic dermatome). In addition, the nerve is the least protected by the costal groove.

The intercostal artery (choice A) is the middle structure and thus is not the most likely to be damaged.

The intercostal vein (choice C) is the most superior structure and is thus the least likely to be damaged. In addition, the vein is the structure best protected by the costal groove (the further superior the structure, the more protected by the costal groove).

The internal intercostal fibers (choice D) will tend to be separated by the drain. In addition, the internal intercostal muscle is membranous (internal intercostal membrane) posteriorly, from the neck of the rib to its angle; therefore, many drains, when inserted, will not even pass through a layer of internal intercostal muscle.


FOR MORE IN DENTISTRY: VISIT

RxDENTISTRY
LOVEHUES
DENTAL MATRIX

62.A trauma patient is bleeding in the casualty. The immediate measure of management would be:

1.Suture the tongue with silk 2.Use towel clip

3.Oro-pharyngeal airway 4.Definite airway

ANS.4

FOR MORE IN DENTISTRY: VISIT

RxDENTISTRY
LOVEHUES
DENTAL MATRIX