Dentosphere : World of Dentistry

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# Taste buds are predominantly located in: A. Circumvallate papilla B. Filiform papilla C. Foliate papilla D. Fungiform papilla The correct answer is A. Circumvallate papilla. # Circumvallate papilla - Present in front of the V shaped sulcus terminalis - Large in size and 8-12 in number - Contain many taste buds - Von Ebner's salivary gland ducts open into its trough # Filiform papilla/ conical papilla  - Keratinized threadlike and give the tongue a characteristic velvety appearance - Smallest and most numerous papillae - Contain no taste buds # Fungiform papillae - Mushroom shaped, numerous near the tip and margins of the tongue - contain few taste buds - Distinguished by their bright red color # Foliate papilla - Present on the lateral border of posterior parts of the tongue - Contain taste buds CLICK HERE TO VIEW ALL MCQs

 # Passavant’s muscle is formed by: A. Palatoglossus B. Palatopharyngeus C. Styloglossus D. Superior constrictor The correct answer is B. Palatopharyngeus. The upper fibres of palatopharyngeus form a sphincter internal to superior constrictor. These fibres constitute Passavant's muscle, which on contraction raises Passavant's ridge on the posterior wall of nasopharynx, but Passavant's ridge is present within Superior constrictor.  CLICK HERE FOR MORE MCQs

 # The sensory supply of soft palate is from: A. Glossopharyngeal and vagus nerve B. Maxillary nerve and mandibular nerve C. Glossopharyngeal nerve and maxillary nerve D. None of the above The correct answer is C. Glossopharyngeal nerve and maxillary nerve. General sensory nerves are derived from: a) The middle and posterior lesser palatine nerves, which are branches of the maxillary nerve through the pterygopalatine ganglion and b) from pharyngeal branch of the glossopharyngeal nerve.  CLICK HERE FOR MORE MCQs

 # Which muscles make up the pterygomandibular raphe? A. Masseter anteriorly and palatopharyngeus posteriorly B. Masseter anteriorly and middle pterygoid posteriorly C. Buccinator anteriorly and superior constrictor posteriorly D. Buccinator anteriorly and middle constrictor posteriorly The correct answer is C. Buccinator anteriorly and superior constrictor posteriorly. The pterygomandibular raphe is made up of interlacing tendinous fibres. It is attached above to the pterygoid hamulus (at the lower end of the medial pterygoid plate) and below to the posterior end of the mylohyoid line of the mandible. The raphe gives attachment anteriorly to fibres of the buccinator, and posteriorly to fibres of the superior constrictor of the pharynx.  CLICK HERE FOR MORE MCQs

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 # Floor of nasal cavity is formed by: A. Palatine process of maxilla and horizontal part of palatine bone B. Palatine process of maxilla and vertical part of palatine bone C. Maxillary process of palatine and horizontal part of maxilla D. Maxillary process of palatine and vertical part of maxilla The correct answer is A. Palatine process of maxilla and horizontal part of palatine bone. The nasal cavities contain:  Respiratory area:  The respiratory area is lined by a pseudostratified , ciliated, columnar epithelium. The epithelium contains goblet cells and a subjacent fibrous lamina propria with mixed mucous and serous glands. The Lateral walls contain conchae, which increase the surface area and promote warming of the inspired air.  Olfactory area: The olfactory area is located in the posterosuperior nasal cavity and is lined by a pseudostratified epithelium composed of bipolar neurons (olfactory cells), supporting cells, brush cells, and basal cells. The basal cel...

 # Oral diaphragm is formed by: A. Mylohyoid muscle B. Genioglossus muscle C. Buccinator muscle D. Orbicularis oris muscle The correct answer is A. Mylohyoid muscle. The mylohyoid muscle or diaphragma oris is a paired muscle running from the mandible to the hyoid bone, forming the floor of the oral cavity of the mouth. The mylohyoid muscle is flat and triangular, and is situated immediately superior to the anterior belly of the digastric muscle. It is a pharyngeal muscle (derived from the first pharyngeal arch) and classified as one of the suprahyoid muscles. Together, the paired mylohyoid muscles form a muscular floor for the oral cavity of the mouth. CLICK HERE TO VIEW MORE MCQs

 # The action of digastric muscle is: A. Depression of mandible B. Protrusion of mandible C. Side to side movement of the mandible D. Depressing the floor of the mouth The correct answer is A. Depression of mandible. The digastric muscle is involved in any complex jaw action such as speaking, swallowing, chewing and breathing. When the digastric muscle contracts, it acts to elevate the hyoid bone. If the hyoid is being held in place (by the infrahyoid muscles), it will tend to depress the mandible (open the mouth). CLICK HERE TO VIEW MORE MCQs

 # Nasopharynx is connected to ______________ through pharyngotympanic tube. A. Middle ear B. Outer ear C. Middle meatus D. Semilunar canals The correct answer is A. Middle ear. The middle ear lies in the temporal bone, where the chain of three ear ossicles connect the tympanic membrane to the oval window. The middle ear cavity communicates with the nasopharynx via the eustachian tube, which allows air pressure to be equalized on both sides the tympanic membrane.  CLICK HERE FOR MORE MCQs

 # Nasal cavity receives blood supply from: A. Facial artery B. Maxillary artery C. Ophthalmic artery D. All of the above The correct answer is D. All of the above Nasal cavity receives blood supply from superior labial, a branch of facial artery; anterior posterior ethmoidal , a branch of ophthalmic artery; Sphenopalatine and greater palatine, a branch of maxillary artery. So, the correct answer is D. All of the above. CLICK HERE FOR MORE MCQs

 # Superior meatus of nose has opening of: A. Middle ethmoidal sinus B. Anterior ethmoidal sinus C. Posterior ethmoidal sinus D. Middle ethmoidal sinus and Anterior ethmoidal sinus The correct answer is C. Posterior ethmoidal sinus.  Meatuses are passages behind the overhanging conchae.  INFERIOR MEATUS - Largest of all three - Nasolacrimal duct opens into it. This opening is guarded by lacrimal fold or Hassner valve. - Lies underneath inferior concha MIDDLE MEATUS - Lies underneath middle concha - Most air sinuses open into it: Frontal air sinus, Maxillary Sinus, Middle ethmoidal sinus and anterior ethmoidal sinus SUPERIOR MEATUS - Below superior concha - Shallowest of all the three - Posterior ethmoidal sinus opens into it # Nasolacrimal Duct opens into Inferior meatus of nasal cavity. # The frontal paranasal sinus drains into the middle meatus of the nasal cavity. CLICK HERE FOR MORE MCQs 

 # Superior sagittal sinus continues as: A. Inferior sagittal sinus B. Straight sinus C. Right transverse sinus D. Left transverse sinus The correct answer is C. Right transverse sinus. Superior sagittal sinus continues as right transverse sinus. Inferior sagittal sinus ---> Straight sinus.  Straight sinus ---> Left transverse sinus.  Transverse sinus -----> Sigmoid sinus CLICK HERE FOR MORE MCQs

 # Cricothyroid muscle is supplied by: A. External laryngeal nerve B. Internal laryngeal nerve C. Recurrent laryngeal nerve D. A direct branch from vagus nerve The correct answer is A. External laryngeal nerve.  All the muscles of  larynx are supplied by recurrent laryngeal nerve EXCEPT Cricothyroid. Cricothyroid is supplied by External laryngeal nerve. Recurrent laryngeal nerve supplies: a) All intrinsic muscles of larynx EXCEPT Cricothyroid b) Sensory nerves to the larynx below the level of the vocal cords. c) Cardiac branches to the deep cardiac plexus. d) Branches to the trachea and oesophagus. e) Inferior constrictor CLICK HERE TO VIEW MORE MCQs

 # The space between the vocal folds is called as: A. Rima vestibuli B. Rima glottidis C. Rima laryngeus D. Rima arytenoid The correct answer is B. Rima glottidis. Within the cavity of larynx there are two folds of the mucus membrane on each side. The upper fold is the vestibular fold and the lower fold is the vocal fold.  The space between the right and left vestibular folds is the rima vestibuli; and the space between the vocal folds is the rima glottidis.  The vestibular and vocal folds divide the cavity of the larynx into three parts:  1. The part above the vestibular fold is called the vestibule of the larynx. 2. The part between the vestibular and vocal folds is called the sinus or ventricle of the larynx.  3. The part below the vocal folds is called the infraglottic part.  The sinus of Morgagni or ventricle of the larynx is a narrow fusiform cleft between the vestibular and vocal folds. The anterior part of the sinus is prolonged upwards as a diverti...

 # The tympanic membrane is supplied by the following nerves EXCEPT : A. Auriculotemporal B. Vagus C. Glossopharyngeal D. Chorda tympani The correct answer is D. Chorda tympani. The tympanic membrane is a thin, translucent partition between external acoustic meatus and the middle ear. It forms an obtuse angle with the floor of the external auditory meatus. It is oval in shape and measures 9*10 mm. It is placed obliquely at an angle of 55 degrees with the floor of the meatus. It faces downwards, forwards and laterally. The inner surface is convex. Its outer surface is concave. The inner surface provides attachment to handle of the malleus which extends upto its center. The point of maximum convexity lies at the tip of the handle of the malleus and is called the umbo.  The outer surface of the tympanic membrane is supplied by the auriculotemporal nerve and the auricular branch of the vagus. The inner surface is supplied by the glossopharyngeal nerve through the tympanic plexus....

 # Which of the following about external acoustic meatus is correct? A. External acoustic meatus is purely cartilaginous in nature B. External acoustic meatus is totally bony in nature C. Medial side is bony in nature, whereas lateral side is cartilaginous in nature D. Medial side is cartilaginous in nature, whereas lateral side is bony in nature The correct answer is C. Medial side is bony in nature, whereas lateral side is cartilaginous in nature External ear consists of auricle and the external acoustic meatus.  External acoustic meatus is 24 mm long, of which medial two thirds (16 mm) are bony and lateral one third (8 mm) is cartilaginous. It can be examined by pulling the pinna upwards, backwards and outwards. The skin  lining the anterior half of the meatus is supplied by the auriculotemporal nerve and lining the posterior half by the auricular branch of the vagus. External auditory meatus contains modified sebaceous glands. Its floor is longer than its roof. It is ...

# In detachment of retina, the separation is between the: A. Choroid and retina B. Pigmented layer and layer of rods and cornea C. Layer of rods and cones and external limiting membrane D. Layer of nerve fibres and internal limiting membrane   The correct answer is B. Pigmented layer and layer of rods and cones. In detachment of the retina, the outer pigmented layer remains attached to the choroid, but the remaining layers of the retina separate from the pigmented layer and are displaced inwards.  Most of the eye's interior is filled with vitreous. There are millions of fine fibres intertwined within the vitreous that are attached to the surface of the retina. As we age, the vitreous slowly shrinks or liquifies, and these fibres pull on the retinal surface. Usually the fibres break, allowing the vitreous to separate and shrink from the retina. This is a vitreous detachment which occurs towards inside.  CLICK HERE FOR MORE MCQs

 # Snyder's test tell us the: (AIPG-96) a) Exact nature of microorganisms b) Combined acidogenic nature of microorganisms c) Enamel dissolving capacity of saliva d) All of the above The correct answer is B. Combined acidogenic nature of microorganisms Snyder test measures the ability of the salivary microorganisms to form organic acids from a carbohydrate medium. In this test the glucose agar medium contains an indicator dye "Bromocresol green" which changes color from green to yellow in the range of PH 5.4 to 3.8   Colour observations in snyder test:-  24 hrs 48 hrs 72 hrs If yellow marked caries susceptibility If yellow  definate caries susceptibility If yellow  limited caries susceptibility If green continue to incubate and observe at 48 hrs If green continue to incubate and observe at 72 hrs If green caries inactive CLICK HERE FOR MORE MCQs

 # The valuable test for evaluating caries activity in very young children: (KCET-10) a) Lactobacillus colony count test b) Swab test c) Alban test d) Colorimetric Snyder test The correct answer is B. Swab Test. Swab test was developed by Grainger et al. It has an advantage over the other tests in that no collection of saliva is necessary . So it is valuable in evaluating caries activity in very young children .   Procedure: The oral flora is sampled by swabbing the buccal surfaces of the teeth with a cotton applicator, and the sample is subsequently incubated in the medium. The change in pH following a 48-hour incubation period is either read on a pH meter or read by the use of a color indicator.   Principle: Same as Snyder test INTERPRETATION pH Caries activity  <= 4.1  Marked caries activity 4.2 to 4.4  Active 4.5 to 4.6  Slightly active > 4.6  Caries inactive CLICK HERE FOR MORE MCQs

 # The visual sense has maximum acuity at : A. Ora serrata B. Optic disc C. Macula lutea D. Fovea centralis The correct answer is D. Fovea Centralis. At the posterior pole of the eye, 3 mm lateral to the optic disc there is another depression of similar size called the macula lutea. It is avascular and yellow in color. The center of the macula is further depressed to form the fovea centralis. This is the thinnest part of the retina. It contains cones only and it is the site of maximum visual acuity.  The rods and cones are the light receptors of the eye. The rods contain a pigment called visual purple. They can respond to dim light (Scotopic vision). The periphery of the retina contains only rods, but the fovea centralis contains no rods. The cones can only respond to bright light (photopic vision) and are sensitive to color. The fovea centralis has only cones.  CLICK HERE TO VIEW MORE MCQs

 # The aqueous humor is secreted from: A. Scleral spur B. Sinus venosus sclerae C. Ciliary processes D. Suprachoroid lamina The correct answer is C. Ciliary processes. Aqueous humor is a clear fluid which fills the space between the cornea in front and the lens behind in the anterior segment. This space is divided by the iris into anterior and posterior chambers which communicates freely with each other via pupil. The aqueous humor is secreted into the posterior chamber from the capillaries in the ciliary processes. It passes into the anterior chamber through the pupil. From the anterior chamber it is drained into the anterior ciliary veins through the iridocorneal angle or angle of anterior chamber located between the fibres of the ligamentum pectinatum and the canal of Schlemm. Interference with the drainage of the aqueous humor into the canal of Schlemm results in an increase of intraocular pressure (glaucoma). This produces cupping of the optic disc and pressure atrophy o the r...

 # The cornea is nourished by: A. Aqueous humor B. Lymphatic fluid C. Lacrimal fluid D. All of the above The correct answer is B. Lymphatic fluid. The cornea is more convex than the sclera, but the curvature diminishes with age. It is separated from the iris by a space called the anterior chamber of the eye. The cornea is avascular and is nourished by lymph which circulates in the numerous corneal spaces. Pain is the only sensation aroused from the cornea.  CLICK HERE TO VIEW ALL MCQs

 # Medial squint may be the result of a lesion involving: A. III cranial nerve B. IV cranial nerve C. VI cranial nerve D. Optic nerve The correct answer is. C. VI cranial nerve. Medial squint is the result of palsy of lateral rectus of eye. All the extraocular muscles are supplied by the third cranial nerve (Oculomotor nerve) EXCEPT Lateral rectus which is supplied by sixth cranial nerve (Abducent nerve) and Superior Obique which is supplied by fourth cranial nerve (Trochlear nerve).  CLICK HERE FOR MORE MCQs

 # Superior rectus helps in all of the following movements EXCEPT: A. Upward rotation B. Lateral rotation C. Intorsion D. Medial rotation The correct answer is B. Lateral rotation.  All the rectus muscles are involved in medial rotation of eye except the lateral rectus. Lateral rectus is the only rectus muscle involved in lateral rotation.  CLICK HERE FOR MORE MCQs

 # Which of the following group of muscles is involved in elevation of the eyeball? A. Superior rectus and inferior oblique B. Inferior rectus and Superior oblique C. Superior Oblique and superior rectus D. Inferior oblique and Inferior rectus The correct answer is : A. Superior rectus and inferior oblique Action of Individual Muscles: Levator Palpebrae superioris - Elevation of upper eyelid Superior rectus - Upward rotation, medial rotation and intorsion Inferior rectus- Downward rotation, medial rotation and extorsion Medial rectus- Medial rotation Lateral rectus- Lateral rotation Superior oblique- Downward rotation, lateral rotation and intorsion  Inferior oblique- Upward rotation and extorsion Single movements of eyeball and muscles involved: Upward rotation (Elevation)- Superior rectus and inferior oblique Downward rotation (Depression)- Inferior rectus and Superior oblique Medial rotation (Adduction)- Medial rectus, Superior rectus and Inferior rectus Lateral rotation (A...

 # Nasolacrimal duct is directed: A. Downward, medially, backwards B. Downward, laterally, backwards C. Downward, laterally, forward D. Downward, medially, forward The correct answer is: B. Downward, laterally, backwards Nasolacrimal duct: The groove for nasolacrimal duct is located medially near the orbital margin. It is a membranous passage of 18 mm length. It begins at the lower end of the lacrimal sac, runs downwards, backwards and laterally, and opens into the inferior meatus of the nose. A fold of mucous membrane called the valve of Hasner forms an imperfect valve at the lower end of the duct.  CLICK HERE FOR ALL MCQs

 # Stapedius muscle has its nerve supply from: A. Trigeminal nerve B. Facial nerve C. Glossopharyngeal nerve D. Stato-acoustic nerve The correct answer is: B. Facial nerve Stapedius muscle along with the tensor tympani are muscles of ossicles of middle ear. Stapedius is supplied by facial nerve, whereas tensor tympani is supplied by mandibular nerve. Stapedius and tensor tympani both act simultaneously to damp down the intensity of high pitched sound waves, thus protecting the internal ear. In paralysis of the muscle even normal sounds appear too loud, which is known as "hyperacusis".  CLICK HERE FOR MORE MCQs

 # The lower one-third of pinna is supplied by: A. Auriculotemporal nerve B. Great auricular nerve C. Lesser occipital nerve D. Vagus nerve The correct answer is: B. Great Auricular Nerve. Greater auricular nerve supplies lower one third of both lateral and medial surface of pinna. Auriculotemporal nerve supplies upper 2/3rds of lateral surface of pinna. Lesser occipital supplies upper 2/3rds of medial surface of pinna. Vagus nerve supplies root of the pinna. Facial nerve supplies muscles of pinna.  CLICK HERE TO VIEW MORE MCQs

 # Which of the following areas are regarded as the ‘dangerous area’ of the face? A. Chin and lower lips B. Lower and upper lips C. Upper lip and lower part of the nose D. Upper part of nose and forehead The correct answer is C. Upper lip and lower part of the nose. The dangerous area of the face is drained by the facial vein. Deep connections of the facial vein with cavernous sinus includes: i. A communication between the supraorbital and superior ophthalmic veins.  ii. Another with the pterygoid plexus through the deep facial vein which passes backwards over the buccinator. The pterygoid venous plexus in turn communicate with the cavernous sinus through an emissary vein. The veins of the dangerous area of face are valveless. Movements of the facial muscles and absence of valves in the facial vein might facilitate retrograde flow of blood. This allows retrograde infection, which is carried by facial, angular and nasofrontal veins and superior ophthalmic veins into cavernous s...

 # The branch of facial artery that crosses the submandibular region, runs anteriorly over mylohyoid muscle and divides into two branches, a deep branch and a superficial branch, is: A. Submental artery B. Tonsillar artery C. Superior labial artery D. Retromandibular artery The correct answer is A. Submental artery. Submental artery: The largest cervical branch, it arises as the facial artery emerges out from the submandibular gland, turning forwards on the mylohyoid below the mandible. It supplies the surrounding muscles and anastomoses with a sublingual branch of the  lingual and mylohyoid branch of the inferior alveolar arteries; at the chin it ascends the mandible, dividing into superficial and deep branches, which anastomose with the inferior labial and mental arteries, supplying the chin and lower lip.  CLICK HERE FOR MORE MCQs 

 # Which of the following muscles of the face is not supplied by facial nerve? A. Levator palpebrae superioris B. Procerus C. Platysma D. Buccinator The correct answer is: A. Levator palpebrae superioris Levator palpebrae superioris (an extraocular muscle), is supplied by the third cranial nerve.  CLICK HERE TO VIEW ALL MCQs