NBDE 1996 anatomy/physiology/tooth anatomy

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NBDE 1996 anatomy/physiology/tooth anatomy
2010-03-01 19:07:54
NBDE 1996 anatomy physiology tooth anatomy

NBDE 1996 anatomy/physiology/tooth anatomy
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  1. In a cervical cross section, which premolar(s) sometimes exhibit a root outline and a pulp chamber floor outline that are both kidney-shaped?
    A) All premolars
    B) Maxillary second
    C) Mandibular second
    D) Maxillaryfirst
    E) Mandibular first
    • D. maxillary 1st premolar
    • - has 2 roots
    • - kidney shaped bc interradicular groove on the mesial
  2. Ketone Bodies
    • Synthesis of ketone bodies in liver when E stores are low
    • - VERY IMPORTANT for brain in starved state bc brain only uses glucose for E

    • - in LIVER: free FA's and amino acids metabolized to form ketone bodies
    • - beta oxidation of alpha-keto acids derived from amino acids
    • - occurs in mitochondrial matrix of hepatocytes (liver)
    • - acetyl-coA--> ketone bodies in starved state

    • Process:
    • acetyl CoA-- (cholesterol)--(HMG COA synthase= RLS)> acetoacetate--> beta-hydroxybutyrate (both can be reconverted back to acetyl-CoA and used in TCA cycle in other tissues)
    • - 3 ketone bodies: acetoacetate, beta-hydroxybutyrate, acetone (acetone not used for E bc can't be reconverted in other tissues back to acetyl-CoA to be used in TCA cycle)--> excreted in urine; causes fruity breath)

    - Ketosis= ketone bodies accumulate (get ketoacidosis and diabetic coma)
  3. In cervical cross-section, the root of a mandibular canine is described as
    A) broader mesiodistally on the lingual than on the facial.
    B) flattened in a mesiodistal direction.
    C) triangular.
    D) roughly conical.
    B) flattened in the mesiodistal direction
    (this multiple choice question has been scrambled)
  4. Which of the following is characteristic of primary maxillary canines?
    A) Cusp is low and rounded.
    B) The mesioincisal cusp ridge is shorter than the distoincisal cusp ridge.
    C) The mesioincisal cusp ridge is longer than the distoincisal cusp ridge.
    D) Crown height < mesiodistal width.
    From the facial aspect:

    In the permanent max canine, the mesial cusp ridge is shorter than the distal

    • In the primary max canine, the mesialincisal slope is longer than the distoincisal
    • - longer and sharper cusp than permanent max canine
  5. Frequency of impulse activity in the afferent nerve from a muscle spindle (Group a afferent fibers) is increased by a (an)
    (a) relaxation of intrafusal muscle fibers;
    (b) increased activity in gammaefferent fibers;
    (c) passive stretch of the muscle.

    A) (c) onlyB) (b) onlyC) (b) and (c)D) (a) and (c)E) (a) onlyF) (a) and (b)
    • B and C
    • Gamma motorneuron - A muscle spindle, with γ motor and Ia sensory fibers
    • A stretch reflex is a muscle contraction in response to stretching within the muscle. It is a monosynaptic reflex which provides automatic regulation of skeletal muscle length.

    - 1a afferent sensory fiber (proprioception) are parallel to contractile muscle fibers so they respond to length and stretch

    • - fusimotor system= muscle spindles and gamma motoneurons--> the system the CNS uses to control and modify spindle activity; proprioceptive info
    • - gamma motoneurons regulate gain of stretch reflex by adjusting level of tension in intrafusal muscle fibers of muscle spindle
  6. Which of the following substances represents an unsaturated fatty acid?A) CholineB) OleateC) PalmitateD) StearateE) Cholesterol
    B) Oleate
  7. Each of the following is involved in gene cloning EXCEPT one. Which one is this EXCEPTION?

    A) Restriction nucleasesB) DNA ligaseC) Reverse transcriptaseD) DNA polymerase IE) RNA polymerase
    E) RNA polymerase
  8. From the incisal aspect, the crown of a maxillary canine normally exhibits which of the following?
    A) A distal portion that displays some concavity in its facial outline
    B) A trapezoidal outline
    C) Less faciolingual thickness than the crown of a mandibular canine
    D) A mesial portion that is thinner faciolingually than the distal portion
    E) Symmetry between its mesial and distal portions
    • A)
    • very prominent distal concavity from distal contact--> CEJ
  9. During swallowing, muscular contraction results in movements that seal off the oropharynx from the nasopharynx. Which of the following muscles cause movements that result in a fold in the posterior wall of the pharynx?
    A) Palatopharyngeus
    B) Levator veli palatini
    C) Palatoglossus
    D) Tensor veli palatini
    E) Musculus Uvulae
    A) Palatopharyngeus
    (this multiple choice question has been scrambled)
  10. Which of the following primary teeth would exhibit a prominent cervical ridge on both the facial and lingual surfaces?

    A) T
    B) L
    C) A
    D) J
    E) F
    E) F

    maxillary central incisor
    - no mamelons
    - prominent facial and lingual cervical ridges
    (this multiple choice question has been scrambled)
  11. Which of the following explains why enamel is harder than bone?
    A) Enamel contains more collagen.
    B) Enamel contains amelogenins in its organic matrix.
    C) Enamel crystals have more surface area.
    D) Enamel crystals are larger and more firmly packed.
    E) Enamel contains more magnesium and carbonate.
    (this multiple choice question has been scrambled)
  12. in an aqueous solution at pH 7, a peptide containing 1 amino group side chain and 2 carboxyl group side chains would have which of the following net charges?
    A) 1-B) 2-C) 1+D) 0E) 2+
    A) -1

    pKa of amino= 9 (+1 in this situation)

    pKa of carboxyl group= 4.4 (-2 in this situation)
  13. In which of the following teeth is the mesial portion MOST distinctly separated from the remainder of the occlusal table by a transverse ridge?
    A) Mandibular second premolar
    B) Primary maxillary first molar
    C) Mandibular first molar
    D) Primary mandibular second molar
    E) Primary mandibular first molar
    • E) primary 1st molar
    • - has prominent transverse ridge that connects MB and ML cusps
    • - most unique tooth
    • - most difficult primary tooth to restore
    • - no central fossa; only mesial and distal triangular fossae
    • - prominent buccal cervical ridge
    • - well developed mesial marginal ridge
    • - 4 cusps; MB largest; ML sharpest
  14. On permanent teeth, the greatest incisal curvature of a cervical line is on which surface of which incisor? (surface --> incisor)
    A) Distal surface --> Mandibular central
    B) Distal surface --> Maxillary lateral
    C) Mesial surface --> Maxillary central
    D) Mesial surface --> Mandibular lateral
    E) Mesial surface --> Mandibular central

    most contoured CEJ on mesial
    (this multiple choice question has been scrambled)
  15. Which of the following enzymes converts trypsinogen to trypsin?

    A) Peptidase B) Secretin C) Pepsin D) Enterokinase
    D) Enterokinase/Enteropeptidase

    • - produced by duodenum wall (Crypts of Lieberkuhn) whenever ingested food enters duodenum
    • - converts trypsinogen to active form, indirectly activating of pancreatic digestive enzymes
  16. From the facial view, the maxillary first molar has its lingual root apex in line with which of the following?A) Mesiofacial cusp tip
    B) Mesiodistal diameter midpoint
    C) Distofacial line angle
    D) Distofacial cusp tip
    E) Facial groove
    E) facial groove
  17. Peripheral (lower motor neuron) lesions of cranial nerve VII will cause which of the following?
    A) An ipsilateral flaccid paralysis of the facial musculature
    B) A contralateral paralysis of only the upper facial muscles
    C) An ipsilateral flaccid paralysis of only the lower facial muscles
    D) A contralateral paralysis of only the lower facial muscles
    E) A contralateral paralysis of the facial musculature

    LMN lesion- ipsilateral paralysis of upper and lower face; loss of corneal reflex= Belly's Palsy

    UMN lesion (central lesion to facial motor nucleus from stroke)- contralateral lower face weakness only
    - can still raise eyebrows on affected side bc bilateral innervation to upperface muscles
    (this multiple choice question has been scrambled)
  18. Which of the following represents the location of the cell bodies of pain fibers in the glossopharyngeal nerve?A) Trigeminal (semilunar) ganglion
    B) Superior ganglion of cranial nerve IX
    C) Spinal nucleus of cranial nerve V
    D) Nucleus ambiguous
    E) Otic ganglion
    - sensory fibers of CN IX are located in the superior ganglion (jugular foramen) and inferior petrosal ganglion (jugular foramen)
  19. Which of the following maxillary teeth has the largest cervico-occlusal crown height?
    A) First molar
    B) First premolar
    C) Second molar
    D) Second premolar

  20. The midroot cross-sectional diagram illustrates the root of which maxillary molar?
    A) Left third
    B) Right third
    C) Left first
    D) Right first
    D) right 1st
    (this multiple choice question has been scrambled)
  21. Which of the following teeth is MOST likely to have a distal coronal concavity that can pose special problems in matrix placement?
    A) Maxillary first molar
    B) Mandibular first premolar
    C) Mandibular first molar
    D) Maxillary first premolar
    (this multiple choice question has been scrambled)
  22. Calcification of the mandibular third molars generally begins at
    A) 11-13 years.
    B) 8-10 years.
    C) 3-4 years.
    D) 5-7 years.
    E) 14-16 years.
    B) 8-10 yrs
    (this multiple choice question has been scrambled)
  23. Which of the following nerves is the MOST likely to become injured in fractures of the mid-humeral shaft?A) Radial
    B) Musculocutaneous
    C) Ulnar
    D) Median
    E) Axillary
    A) radial, extrinsic extensors of wrists and hands, cutaneous supply to back of hand

    • supplies triceps brachii
    • -originates from the posterior cord of the brachial plexus with roots from C5, C6, C7, C8 & T1.
    • - The radial nerve divides into a deep branch (which becomes the posterior interosseous nerve), and continues as the superficial branch which goes on to innervate the dorsum (back) of the hand.
    • - After giving off branches to the long and medial heads of the triceps brachii, it enters a groove on the humerus, the radial sulcus.
  24. The lymph vessels that drain both dental arches connect directly with which of the following nodes?

    A) Sublingual B) Retropharyngeal C) Superficial cervical D) Submandibular E) Deep cervical
    D) Submandibular
  25. From a proximal view, which of the following describes the crown outline on a mandibular posterior tooth?A) It is designed to allow for a minimum amount of chewing effficiency on the coronal surface of the tooth.
    B) It is usually rhomboidal and has a design flaw that encourages cusp fracture.
    C) It is usually trapezoidal and has a design flaw that encourages cusp fracture.
    D) It is designed to protect against root fracture by having the crown structure serve as root support
  26. Alpha-ketoglutarate, oxygen, and ascorbic acid are essential for which of the following processes?
    A) Incorporation of proline
    B) Hydroxylation of proline
    C) Gamma-Carboxylation of proline
    D) Activation of procollagen peptidase
    E) Oxidative deamination of lysine
    (this multiple choice question has been scrambled)
  27. Which of the following teeth have long axes positioned with their root apices facial and their crowns lingual?

    A) Mandibular incisors
    B) Maxillary incisors
    C) Maxillary premolars
    D) Mandibular molars
    E) Maxillary molars
    D) mandibular Molars
    (this multiple choice question has been scrambled)
  28. A derivative of vitamin K is the coenzyme for which of the following?
    A) Cross-linking of fibrinogen
    B) Hydrolysis of peptide bonds
    C) Esterification of retinol
    D) Carboxylation of glutamate side chains
    E) Production of menadiol

    Vit K needed to carboxylate glutamate residues to form gamma-carboxyglutamate residues--> allows them to bind Ca2+ needed in blood coagulation (Factors II, VII, IX, X. protein C and S)
    (this multiple choice question has been scrambled)