NBDE 1998 Anatomy and Biochemistry

  1. Antidiuretic hormone is PRODUCED by cells that reside in which of the following structures, cells or areas?A) Pars intermedia
    B) Acidophils of the pars distalis
    C) Pars nervosa
    D) Supraoptic nucleus of the hypothalamus
    E) Basophils of the pars distalis
    D
  2. The pyramids contain




    D)
  3. Which of the following anterior primary rami form the medial cordof the brachial plexus?




    D)
  4. Preganglionic sympathetic fibers to the head have their cell bodies in the




    E)
  5. In the photomicrograph below of a ground section of a tooth viewed by transmitted light, some dentinal tubules appear black because they





    E)
  6. Fiber tracts passing from the thalamus to the cortex are found in which of the following?




    C)
  7. Which of the following is the MOST numerous cell type in the normal dental pulp?




    E)
  8. Which of the following represents the MOST vascular portion of the articular disc of the temporomandibular joint?



    C)
  9. Which of the following organs is the NEAREST to the right kidney?




    D)
  10. The prochordal plate consists of



    .D) embryonic endoderm, mesoderm, and ectoderm.
    E) a circular area anterior to the notochord in which the endoderm is fused to the embryonic mesoderm.
    A)
  11. Which group of fibers of the periodontal ligament offer the MOSTresistance to movement of the tooth in an apical direction?




    C) Oblique resists intrusive movements and rotational forces

    In the APICAL direction
  12. On a comparative basis, bone and cellular cementum are similar in that both



    A)
  13. The core of a microvillus consists of which of the following?




    A)
  14. The blood-testis barrier is maintained by




    E)
  15. Oxyphil cells are present in which of the following?




    D)
  16. Which of the following is the nerve that supplies the mimetic muscles?




    A) mimetic muscles= facial muscles
  17. Which of the following is the posterior limit of the vestibular side of the cheek?




    A)
  18. Para-keratinized oral mucosa is often found on which of the following?




    A) attached gingiva
  19. Which of the following represents a popular theory for the force that is considered to be the MOST responsible for active tooth eruption?




    C)
  20. Which of the following ligaments helps resist posterior movement of the mandibular condyles?A) Temporomandibular
    B) Anterior cruciate
    C) Sphenomandibular
    D) Stylomandibular
    E) Pterygomandibular raphe
    A)
  21. Which of the following structures runs directly adjacent to, and parallel with, the median nerve in the arm?A) Brachial artery
    B) Ulnar artery
    C) Radial artery
    D) Medial brachial cutaneous nerve
    E) Cephalic vein
    A
  22. Structure of Thymus
    • - made up of lobules held together by areolar tissue
    • - enclosed by capsule
    • - each follicle has:
    • Illu thymus.jpg
    • 1. cortex- mainly lymphoid cells; earliest T cell dev (thymocyte)
    • 2. medulla - Hassall's corpuscle (remains of the epithelial tubes from 3rd branchial pouch)
    • - less lymphoid cells
    • *** Thymus and spleen only have efferent lymphatic vessels

    • 2 origins of thymus:
    • - endoderm (3rd branchial pouch)
    • - hematopoeitic stem cells
  23. Which of the following represents the normal substrate of thrombin?




    A)

    Substrate= the substance on which an enzyme acts

    Prothrombin--> thrombin converts fibrinogen--> fibrin in the clotting cascade
  24. Epinephrine causes an elevation in cAMP levels in muscle cells which in turn activate




    D) glycogen phosphorylase
  25. Which of the following noncollagenous protein components BESTcharacterizes dentin matrix?




    • E)
    • - one of the proteins formed from dentin sialophosphoprotein
    • - MOST ACIDIC protein ever discovered
    • - aa sequence makes it HIGHLY (-)--> attracts A LOT of Ca2+ for dentin

    • - dentin sialphosphoprotein- only protein produced uniquely by odontoblasts; non collagenous protein broken into:
    • 1. dentin phosphoprotein
    • 2. dentin sialoprotein
    • 3. dentin glycoprotein
  26. Intravenous injections of KCl solution would increase the secretion of which of the following?




    E) Aldosterone- uptake of Na+ from DCT of nephron
  27. The movement of Ca++ across a membrane is characterized by which of the following?



    C)
  28. Which of the following is necessary for de novo synthesis of cholesterol?




    • B) NAPH (reduced)
    • - used in anabolic processes (steroid and FA synthesis) as a supply of reducing equivalents

    • RLS in synthesis of cholesterol: HMG CoA Reductase
    • -converts HMG-CoA--> mevalonate

    - 2/3 plasma cholesterol is esterified by LCAT (lecithin-cholesterol acyltransferase)
  29. The enzyme catalyzing the rate-controlling step in the de novosynthesis of fatty acids is regulated allosterically by the positive modulator

    A) cyclic AMP.
    B) ATP.
    C) oxaloacetate
    .D) citrate.
    E) NADPH.
    D) citrate

    • - citrate builds up in TCA when have a high E state- want to make FAs when have excess E
    • - citrate also inhibits glycolysis
  30. Which of the following controls the excitability of the muscle spindle?



    • D) gammer efferent
    • - stretch reflex
    • - muscle spindle= sensory receptor in belly of extrafusal fibers (muscle)
    • - length of muscle

    • - afferent Ia and II
    • - 3 types of intrafusal fibers:
    • 1. nuclear bag (length and tension)- dynamic fast type Ia
    • 2. nuclear bag- static
    • 3. nuclear chain fibers (length and tension)- slow type II afferent
    • - muscle spindles receive efferent= gamma innervation--> causes shortening of muscle spindle
  31. Under strict anaerobic conditions, the catabolism of one glucose molecule would yield a net of



    D)

    • ANAEROBIC- Lactic fermentation:
    • - pyruvate converted to lactic acid via LACTATE DEHYDROGENASE
    • - need to convert NADH--> NAD+ so glycolysis can continue
    • - MUSCLE TISSUE (working out) and some BACTERIA
  32. Which of the following represents a polyunsaturated fatty acid that is commonly found in animal cell membranes?





    E)

    • #C's Common Name
    • 12Lauric acid
    • 14Myristic acid
    • 16Palmitic acid

    • Unsaturated- drop in MP
    • 18Stearic acid
    • 18 Oleic acid
    • 18Linoleic acid
    • 18alpha-linolenic acid
  33. GABA increases the permeability of postsynaptic membranes to which of the following ions?




    • A) Cl-
    • - most abundant inhibitory NT
  34. Formation of Microfilaments
    • - G-actin= globular actin (individual subunits of actin)
    • - F-actin= G-actin subunits assemble into filamentous polymers
    • - 2 parallel f-actin strands make up a microfilament (of cytoskeleton)
    • - requires ATP to transform G-actin--> f-actin
  35. Which of the following sweeteners is non-nutritive as well as non-cariogenic?




    C)

    • - artificial sweetener
    • - gives no food E
  36. If the pH becomes lower than the isoelectric point of a protein, then how will the protein respond in an electrophoretic system? It will
    A) migrate to the positive pole
    .B) separate into its different monomeric forms.
    C) remain stationary and unchanged.
    D) migrate to the negative pole.
    E) become denatured.
    D)

    IP= pH at which the protein is neutral
  37. Sodium fluoride inhibits glycolysis by affecting which of the following?



    C) enolase
  38. Insulin INCREASES the activity of which of the following?




    A)

    - high E state, insulin stimulates synthesis of ATP from glucose
  39. When arterial pressure increases, pressoreceptors discharge and



    A)
  40. The level of nonprotein nitrogen in the blood is due principally to the level of which of the following?A) Arginine
    B) Creatine
    C) Uric acid
    D) Ammonia
    E) Urea

    After prolonged acidosis, which of the following represents the nitrogenous product that is excreted in high amounts in the urine?




    • A) Urea
    • E) ammonia
  41. Which of the following are the immediate effects of calcitonin on serum levels of calcium and phosphate?A) Serum calcium decreases, Serum phosphate has no change
    B) Serum calcium has no change, Serum phosphate increases
    C) Serum calcium increases, Serum phosphate increases
    D) Serum calcium decreases, Serum phosphate decreases
    E) Serum calcium increases, Serum phosphate decreases
    D) calcium and phosphate are put back into bone
  42. Most endogenous cholesterol in the liver is usually converted into which of the following?




    B) Cholic acid

    • cholic acid= bile acid
    • - produced by liver from cholesterol
    • - derivatives are made from cholyl-CoA which forms a conjugate with either glycine, or taurine, yielding glycocholic and taurocholic acid respectively.
    • - Cholic acid and chenodeoxycholic acid are the most important human bile acids
  43. The ability to concentrate urine varies among animal species. The maximum urine concentration that can be produced by an animal isMOST closely related to which of the following?




    A)
  44. In relative insulin insufficiency, acetyl CoA is usually channeled into




    • A)
    • - insulin insufficiency indicates a post-absorptive state (low serum glucose)
    • - Diabetes pts- low insulin--> get diabetic ketoacidosis bc form ketone bodies for E
Author
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Card Set
NBDE 1998 Anatomy and Biochemistry
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NBDE 1998 Anatomy and Biochemistry
Updated