1996 NBDE Histology/Microbiology/Pathology/Physiology/Dental Occlusion

  1. Salivary gland striated ducts are composed of which of the following types of epithelium?

    • A) Simple low columnar in striated ducts
    • -modify salivary fluid by secreting HCO3-and K+ and reabsorbing Na+ and Cl- using the Na-K pump and the Cl-HCO3 pump
    • - ion pumping so it has a lot of mitochondria
    • - striated bc of basal cytoplasmic processes

    • Intercalated Duct
    • - cuboidal secretory cells

    terminal secretory unit--> intercalated duct--> striated duct
  2. It is possible to distinguish histologically between the stomach and the duodenum because of the presence of


    • Stomach:
    • - simple columnar
    • - rugae- folds in stomach that accomodate expansion
    • - produces chyme

    4 types of cells located throughout the mucosa, but not submucosa

    • 1.mucous cells
    • 2. chief cells- pepsinogen
    • 3. parietal cells- HCl and intrinsic factor
    • 4. enteroendocrine cells (APUD) cells- gastrin
  3. In a dry-heat oven, which of the following temperatures is aufficient for achieving sterilization in 1-2 hours?


    Dry Heat

    • 160 degrees C (320 degrees F) for 2 hours
    • OR 170 degrees for 1 hour

    - denatures proteins

    • Pros:
    • - doesn't corrode/dull instruments

    • Cons:
    • - ruins heat-sensitive materials; instruments must be DRY bc water interes w/ sterilization
  4. The MOST important viral cause of gastroenteritis in children less than 2 old is

    E) Rotavirus

    • "Repeat-o-virus"; a REOVIRUS= dsRNA
    • ROTA= Right Out of The Anus

    • *** MOST imp global cause of infantile gastroenteritis
    • - acute diarrhea, esp in day-care centers, kindergartens during winter
  5. Rubella and toxoplasmosis are similar in that both

    A) are prevented by vaccinations.
    B) are potentially teratogenic.
    C) can not be treated with antibiotics.
    D) primarily affect the elderly.
    E) have non-human animal reservoirs
    Maternal Infection Teratogens:

    • TORCH complex
    • 1. Toxoplasmosis- parasitic disease caused by protozoan Toxoplasma gondii
    • - primary host is cat
    • - usually from infected meat or eating infected cat feces
    • - rarely causes symptoms in healthy people--> many enter latent phase
    • - acute phase- flu-like
    • - immunocompromised: encephalitis, neurologic, heart and liver problems
    • - Most infants who are infected while in the womb have no symptoms at birth but may develop symptoms later in life

    • 2. other agents
    • 3. Rubella
    • 4. CMV
    • 5. HSV
  6. The apical cytoplasm of active serous glandular cells is typically filled with which of the following?

    C) abundance of zymogen granules

    - basal processes (closest to lumen) are rich w/ MITOCHONDRIA- provide E for ion transport
  7. What is the composition of saliva?
    • - hypotonic
    • - enzymes: 1) amylase 2) lysozyme (antibacterial
    • - antibodies (IgA mostly)
    • - inorganic ions

    - serous cells secrete fluid ISOTONIC w/ plasma
  8. Which of the following BEST characterizes the alveolar mucous membrane?

  9. The majority of cases of pharyngitis are caused by

  10. A fungus that causes systemic disease, most commonly of the lungs, and is characterized by its production of tuberculate chlamydospores in culture is


    • 4 Systemic Mycoses:
    • - dimorphic fungi (mold in soil, yeast in tissue) except coccidiodomycosis
    • - Mold= cold; Heat=yeast
    • - all can cause PNEUMONIA and DISSEMINATE
    • - SYSTEMIC MYCOSES mimics TB (granulomas)
    • Tx: fluconazole or ketoconazole

    • 1. Histoplasmosis- causes pneumonia
    • - Mississippi and Ohio R. Valleys
    • - bird or bat droppings
    • - intracellular (tiny yeast inside macrophages)
    • *** "Histo"="histiocyte" tissue macrophage

    2. Blastomycosis= Big, Broad, Budding

    • 3. Coccidiomycosis- California
    • - pneumonia and meningitis
    • - SPHERULE filled w/ endospores
    • - valley fever
  11. Each of the following is a risk factor in atherosclerosis EXCEPT one. Which one is this EXCEPTION?

    D) Alcoholism

    Risks for atherosclerosis:

    • 1. Smoking
    • 2. Men and postmenopausal women (low estrogen)
    • 3. HTN
    • 4. heredity
    • 5. nephrosclerosis (secondary HTN)
    • 6. Diabetes
    • 7. Hyperlipidemia (higher LDL= bad)

    • - most common sites:
    • - CAD (heart)
    • - abdominal aorta
  12. Cementum differs from dentin in that cementum


    B is incorrect because dentin is 70% inorganic and enamel is 55% inorganic (mineralized)
  13. Excessive deposits of copper in liver cells, degenerative changes in the brain, and a greenish-brown ring at the outer margin of the cornea characterize which of the following?

    A) Diabetes mellitus
    B) Tay-Sachs disease
    C) Phenylketonuria
    D) Wilson's disease
    E) Galactosemia
    Wilson's Disease

    • - autosomal recessive- mutations in wilson disease protein
    • - Cu accumulates in tissues
    • - hepatolenticular degeneration
    • - liver disease
    • - neurological symptoms
    • -Cu in LIVER and BRAIN
  14. Which of the following represents the major pathway for metabolism of excessive intraneuronal free norepinephrine?

  15. A subject consumes 250 ml of oxygen per minute with a tidal volume of 400 ml and a respiratory rate of 18 per minute. Which of the following represents this subject's respiratory minute volume in liters?
    A) 5.4
    B) 7.2
    C) 10.0
    D) 1.8
    E) 4.5
    B. 7.2

    respiratory minute volume= 0.4 L x 18 breaths/min= 7.2
  16. Which of the following types of tissues can be demonstrated on the posterior slope of the articular eminence?A) Fibrocartilage
    B) Fibrous connective tissue
    C) Elastic cartilage
    D) Hyaline cartilage
    E) Articular cartilage
    B) fibrous connective tissue
  17. MOST fluid reabsorption by the kidney occurs in which of the following?

    C) Proximal Tubule
  18. A hemorrhagic tendency is seldom seen in which of the following conditions?
    A) Hepatic insufficiency
    B) Secondary thrombocytopenia
    C) Acute leukemia
    D) Renal insufficiency
    E) Scurvy
    • A) hepatic insufficiency- bc it makes clotting factors
    • B) low platelets= increase bleeding time
    • C) acute leukemia= pancytopenia; low platelets increase bleeding time
    • E) Scurvy- Vit C deficiency; get bleeding esp gums
  19. The finding of yeast cells and chlamydospores in the oral mucosa suggest which of the following?

    D) Candida Albicans

    - chlamydospore- thick-walled big resting spore of several kinds of fungi. It is the life-stage which survives in unfavourable conditions, such as dry or hot seasons.
  20. Streptococcus pyogenes, group A, is subdivided into specific antigenic types principally on the basis of immunologic differences in its

    C) M Protein
  21. Which of the following are MOST antigenic?

    E) Proteins

    Hapten- "half an antigen"- a small molecule that can elicit immune response only when attached to a larger carrier (like a protein)
  22. Which of the following represents a DNA gyrase inhibitor with a broad spectrum of activity?

    B) Ciprofloxacin/Ofloxacin

    • - 2nd gen Fluoroquinolone class
    • - It kills bacteria by interfering with the enzymes that cause DNA to rewind after being copied, which stops DNA and protein synthesis (DNA gyrase/topoisomerase)
    • - Bactericidal
    • - AEROBIC/facultative gram + and - and mycobacteria; NOT ANAEROBES
  23. A 6-year-old boy has minute white specks on the oral mucosa adjacent to his first molars. A bluish-red ring surrounds these spots. He appears to have a cold and his eyes are red and runny. There is a blotchy reddish rash behind his ears and on his face. This child has which of the following?

    A) MeaslesB) ChickenpoxC) Scarlet feverD) Eczema
    A) Measles/Rubeola- a Paramyxovirus

    • - Koplik spots- red spots with white centers on buccal mucosa
    • - rash
    • 3 C's of Measles:
    • 1. cough
    • 2. coryza- inflammation of mucous membranes
    • 3. conjunctivitis
  24. What condylar movement is performed as the mandible moves from a pure protrusive movement from maximum intercuspal position to a maximum protruded position?

    C) Translation
  25. The absolute refractory period of a nerve action potential is determined by the duration of which of the following?


    • 3 phases of Na+ gate:
    • - deactivated (closed)- blocked on their intracellular side by an "activation gate", which is removed in response to stimulation that opens the channel.
    • - activated (open)
    • - inactivated (closed)

    - local anesthesia favors activated and inactivated states--> rapidly firing
  26. In an ideal intercuspal relation, the oblique ridge of the maxillary first molar opposes which structure of the mandibular molar?

  27. In anemia resulting from drug-induced bone marrow suppression, the peripheral blood smear shows erythrocytes to be

  28. In protrusive movement, the mandibular canines in a Class II occlusal relationship articulate with which of the following maxillary teeth?

    C) Canines and lateral incisors
  29. In an ideal intercuspal relation, the mesiofacial cusps of the mandibular second molars contact the maxillary molars in (on) the

  30. The growth rate in the cartilage of the epiphyseal plate of a long bone is markedly retarded when there is a lack of hormone from which of the following?

    D) hypophysis= pituitary gland!

    • - adenohypophysis= anterior pituitary
    • -->B-FLAT (basophophils) and GH, Prolactin, endorphins (acidophils)

    • - neurohypophysis= posterior pituitary
    • --> oxytocin and ADH/vasopressin
  31. Regulation of each of the following mechanisms is associated with the hypothalamus EXCEPT one. Which one is this EXCEPTION?

  32. Which of the following is an antimicrobial agent that primarily inactivates cellular DNA

    • D) Ethylene oxide gas
    • - sterilization method
    • - sterilization is slow 10-16 hours
    • - inactivates DNA and proteins

    • Pros:
    • - used mostly in HOSPITALS for heat-sensitive materials

    • Cons:
    • - long time
    • - VERY TOXIC and flammable; need good ventilation

    • A. chlorhexidine- inhibits plaque gingivitis (most potent inhibitor)
    • - Peridec, Perioguard
    • - stains teeth, alters taste perception

    • B. Glutaraldehyde (2%)- sterilization
    • - alkylates nucleic acids and proteins
    • - takes 10 hours--> used for respiratory equipment
    • - most potent CHEMICAL germicide
    • - associated w/ HYPERSENSITIVITY
  33. Which of the following BEST describes the Curve of Spee?

  34. Which of the following has a high affinity for binding calcium and collagen in the calcifying matrix?

    E) Osteonectin

    • - glycoprotein in bone that binds calcium and has high affinity for collagen
    • - secreted by osteoblasts during bone formation
    • - vital in bone mineralization, cell matrix interactions, collagen binding
    • - increases activity of matrix metalloproteinases (imp for invading cancer cells in bone)
    • - overexpressed in many cancers (e.g. breast, prostate, colon)
  35. In a Class II occlusal relationship, the tip of the facial cusp of a mandibular first premolar lies directly below the contacting area between which maxillary teeth?

  36. Which of the following represents a striated muscle that contains transverse tubules, a slow rate of calcium sequestration, and is inhibited by acetylcholine?


    • T-tubules are less developed
    • - slow rate of Ca2+ sequestration to ensure ventricles can fill up
    • - Ach parasympathetics decrease its activity
    • - sympathetics (Epinephrine) increases activity
  37. Which of the following causes activation of the pyloric pump, relaxation of the pylorus, and contraction of the lower esophageal sphincter?

    • C) gastrin
    • - increases HCl secretion; stimulates parietal cells
    • - increases growth of gastric mucosa
    • - increases gastric motility

    • - increased by stomach distention, amino acids, peptides, vagal stimulation
    • - decreased by stomach pH <1.5

    Ach- from vagal stimulation stimulates gastric parietal cell
  38. Hypersensitivity to M. Tuberculosis is manifested by which of the following?

    C) necrosis
  39. Dentinal tubules are S-shaped in the crown of the tooth due to the

  40. Which group of fibers of the periodontal ligament is the first to offer resistance to movement of the tooth in an occlusal direction?

    C) apical

    - apical fibers are at the apex of the root
  41. In a newly erupted tooth, the junction between tooth surface and the crevicular epithelium consists of which of the following?

    • C) Basal-lamina like structure btwn enamel and epithelium- forms epithelial attachment
    • - secreted by epithelial cells; epithelial cells on top of an ECM often confused as basement membrane

    • - Basal lamina:
    • 1. lamina lucida
    • 2. lamina densa- electron dense

    • Basement membrane:
    • 1. lamina lucida
    • 2. lamina densa
    • Lamina reticularis
  42. Which of the following is a function of the enterogastric reflex?

    • A)
    • Enterogastric reflex- one of 3 reflexes in GI tract

    • + stimulation:
    • - acid in duodenum
    • - stomach pH < 1.5

    • Results in:
    • - inhibit gastrin from G-cells in antrum of stomach
    • - inhibit gastric motility and HCl secretion

    - purpose: shuts off stomach motility when there is chyme in duodenum
  43. Vascular smooth muscle relaxes in response to

    B) adenosine

    - G-protein coupled receptors

    • adenosine imp in:
    • 1. E transfer (e.g. ATP,ADP)
    • 2. signal transduction (e.g. cAMP)
    • 3. inhibitory NT- promote sleep and arousal
    • 4. causes endothelial dependent relaxation of smooth muscle and is found inside artery walls
  44. Buerger's Disease
    aka Thomboangiitis obliterans

    • -recurring inflammation and thrombosis of small and medium arteries of hands and feet
    • - main symptom= PAIN in affected areas
    • - complications= ulcerations and gangrene of extremities--> need amputation
    • - strongly associated with tobacco products, esp smoking

    • Etiology:
    • - MEN in 20-40s (like Warthin's Tumor)
  45. A 53-year-oid patient has an indurated, chronic ulcer near the inner canthus. The MOST likely diagnosis is

    • A) basal cell carcinoma- most common skin malignancy
    • - never metastasizes
    • - malignant bc destroys surrounding tissues
  46. The oral lesions of herpangina can often be distinguished from hand-foot-and-mouth disease by which of the following?

    A) Coxsackie A virus- picoRNA, ssRNA, non-enveloped

    • Herpangina- self limited
    • - tonsillar pillars and soft palate, pharyngitis
    • - malaise, fever, dysphagia
    • - outbreaks in summer: fecal/oral, contaminated saliva

    • Hand-foot-mouth
    • - airborne/ fecal-oral
    • - oral lesions favor palate, tongue, buccal mucosa
    • - mostly in children
    • - fever, malaise, sore mouth, lymphadenopathy
  47. The submucosa is present in each of the following EXCEPT one. Which one is this EXCEPTION?A) Jejunum
    B) Colon
    C) Duodenum
    D) Stomach
    E) Gallbladder
    E) Gall Bladder

    • - non-vital organ
    • - stores bile

    • Histology:
    • - simple columnar epithelial lining
    • - Aschoff's recesses- pouches inside the lining
    • - lamina propria- connective tissue
    • - smooth muscle (muscularis externa)- contracts in response to CCK from duodenum to release bile
    • - NO SUBMUCOSA btwn mucosa and adventitia; just thin muscular layer that prevents infection
  48. Which of the following is the site of oxidative phosphorylation in bacteria?

    B) cell membrane
  49. Each of the following develops as an outpocketing of the gut tube EXCEPT one. Which one is this EXCEPTION?

    • D) SpleenImage Upload 1
    • - like thymus, contains only EFFERENT vessels
    • - forms w/in and from the dorsal mesentery (DERIVED FROM MESENCHYMAL tissue)
    • - mesenchyme- reticular connective tissue derived from all 3 germ layers
    • - can dev into cartilage, lymphatic system, circulatory, connective tissue

    • - holds reserve of RBCs in case of hemorrhagic shock
    • - recycles iron
    • - removes old RBCs

    • white pulp
    • - synthesis Ab's
    • - removes Ab-coated bacteria and Ab-coated blood cells
    • - removal leads to increase infections

    *** All the rest are derived from gut tube (endoderm)
  50. Which of the following bacterial exotoxins converts plasminogen to plasmin?

    E) streptokinase

    - inexpensive blood-clotting medication
  51. Which of the following conditions predisposes to lung cancer by causing squamous metaplasia of bronchial epithelium?

    • C) Chronic Bronchitis (COPD)--> Cigarette smoking
    • - increase lung cancer- squamous metaplasia from chronic inflammation
    • - blue bloaters- early cyanosis; late dyspnea
    • - productive cough, noisy chest
    • - chronic cough 3 months in 2 yrs
    • - increase reid index- mucosal gland thickness: smooth muscle
  52. Which of the following represents the MOST frequent cause of a clinically palpable breast mass in an adult woman?

    A) fibrocystic disease- normal collagen buildup; benign

    - fibroadenoma- most common in younger than 25 yrs

    • - Invasive ductal= most common malignant breast tumor; worst and most invasive
    • - firm, fibrous mass, small, glandular, duct-like cells
  53. Which of the following conditions increase the risk of developing osteosarcoma?

    • C) Osteitis deformans= Paget's disease
    • - uncontrolled osteoclast/osteoblast activity
    • - increase in size of head; enlarged and deformed bones
    • - bone is weak - arthritis, fractures
    • - Men>women; less than 40s

    • a) osteoblastoma- benign tumor found in vertebral column - trabeculae and woven bone surrounded by osteoblasts
    • b) osteogenesis imperfecta- Type I collagen deficiency
    • - autosomal dominant- aa substitituion of glycine by a bulkier one
    • - blue sclera, bone fractures, hearing loss (bony ossicles malformed), dentin malformation
    • d) osteoporosis- esp in post-menopausal women (decrease in estrogen); decrease in bone density
    • e) osteomalacia- softening of bones; vit D deficiency in adults
Card Set
1996 NBDE Histology/Microbiology/Pathology/Physiology/Dental Occlusion
1996 NBDE Histology/Microbiology/Pathology/Physiology/Dental Occlusion