DENT5315 Oral Histology/Embryology/Genetics EXAM 1 (February 6th 2007) NAME: ______________________________ ID#: _________________________________ MULTIPLE CHOICE QUESTIONS. Choose ONE BEST answer for each of the following questions. CAUTION: Read all questions carefully! 1. What are the four layers in order from the oral cavity to internal, of the masticatory mucosa? A. Stratum corneum, spinosum, basale, and granulosum B. Stratum granulosum, spinosum, basale, and corneum C. Stratum corneum, granulosum, spinosum, and basale* D. Stratum basale, spinosum, granulosum, and corneum E. Stratum corneum, granulosum, basale, and spinosum 2. Which germ layers are present at the end of week 3 of development? A. Epiblast only B. Epiblast and hypoblast C. Ectoderm and endoderm D. Ectoderm, mesoderm and endoderm* E. Epiblast, mesoderm and hypoblast 3. The __________________ layer of masticatory mucosa is mitotically active and provides new cells replenish the cells that are continuously shed: A. Stratum basale* B. Stratum granulosum C. Stratum spinosum D. Stratum corneum E. Stratum superficiale 4. The _________________ surface of the tongue is covered with specialized mucosa, and the ventral surface of the tongue is covered with _____________ mucosa: A. Ventral, masticatory B. Dorsal, lining* C. Dorsal, masticatory D. Ventral, lining E. Ventral, specialized 5. Which statement best describes the development of the neural tube? A. It develops directly from the primitive streak. B. It develops directly from the notochord. C. It develops from the ectoderm immediately dorsal to the notochord* D. It develops from the ectoderm immediately dorsal to the primitive streak. E. None of the above. THE EXAMINATION CONTINUES IN THE NEXT PAGE 1 6. Your first patient presents with a chief complaint of pale yellow spots in the buccal mucosa near the angle of the mouth. You suspect these to be ectopic sebaceous glands. What condition does the patient have? A. Von Ebners’s disease B. Fordyce’s disease* C. Circumvallate papillae D. Mucous cells E. None of the above 7. Which of the following is true about fungiform papilla? A. They constitute majority of the papillae B. They are the only papillae that does not contain any taste buds C. Constitute about 10 to 14 in number and present distributed in “V”-shaped pattern between the base and the body of the tongue D. Contains taste buds and present interspersed between the filiform papillae and usually appears red round structures due to increased blood supply* E. Present on the lateral margins of the posterior tongue as parallel ridges 8. Alteration of the vasculature in the lamina propria and submucosa will most likely result in a clinically apparent alteration in the oral mucosa’s: A. Texture B. Surface C. Integrity D. Color* E. None of the above 9. Keratohyaline granules are seen in the granular cell layer of: A. Orthokeratinizing oral epithelium* B. All oral epithelium C. Parakeratinizing oral epithelium D. Epithelium with significant numbers of melanocytes E. Epithelium that is acanthotic 10. Which of the following areas of the oral mucosa has keratinized epithelium: (1) Gingiva (2) Buccal mucosa (3) Tongue (4) Hard Palate A. B. C. D. E. (1) and (3) (1) and (4)* (2) and (3) (2) and (4) (3) and (4) THE EXAMINATION CONTINUES IN THE NEXT PAGE 2 11. The following are true about junctional epithelium EXCEPT: A. Attached to the tooth surface cervical to the gingival sulcus and continuous with the sulcular epithelium B. Has a high rate of cell division C. Readily regenerates from the sulcular epithelium if it is damaged D. Comprised of orthokeratinized stratified squamous epithelium* E. Derived from reduced enamel epithelium 12. Which of the answers below correctly describe the number of cervical sclerotomes, vertebrae, and spinal nerves, respectively? A. 8, 8, and 8 B. 8, 7, and 8* C. 7, 7, and 7 D. 8, 8, and 7 E. 7, 8, and 7 13. Which ONE of the following statements is TRUE about the parotid gland? A. Derived from ectoderm* B. Comprised predominantly of mucous cells C. Starts forming around the 8th week of embryonic development D. Forms without input from ectomesenchyme E. Considered a mixed (both mucous-serous) gland 14. The dorsal muscle mass in the lower limb forms what type of muscles? A. Extensors and abductors* B. Extensors and supinators C. Flexors and pronators D. Flexors and adductors 15. All major salivary glands are ectodermal in origin: A. True B. False* 16. The femur bone develops from which of the following? A. Somite mesoderm B. Somatopleuric mesoderm* C. Intermediate mesoderm D. Splanchnopleuric mesoderm E. Sclerotome mesoderm 17. Which one of the following is TRUE about myoepithelial cells: A. Modify the secretory product by secreting sodium B. Function as muscle cell by squeezing the acinus and facilitating secretion* C. Secrete high amounts of IgA D. Are rich in rough endoplasmic reticulum E. Is increased in number as one ages THE EXAMINATION CONTINUES IN THE NEXT PAGE 3 18. Which of the following are pure serous glands? A. Sublingual glands B. Palatine glands C. Glands of Von Ebner* D. Submandibular glands E. Glands of Blandin-Nuhn 19. Each of the following develops as an outpocketing of the gut tube EXCEPT one. Which one is the EXCEPTION? A. Lung B. Liver C. Spleen* D. Pancreas E. Gallbladder 20. Saliva becomes hypertonic after passing through the striated ducts: A. True B. False* 21. The terminal portion of the salivary ductal system that are in contact with serous cells is called: A. Intercalated duct* B. Excretory duct C. Striated duct D. Stensons duct E. None of the above 22. Passage of urine through the umbilicus reveals which of the following conditions? A. Omphalocele B. Gastroschisis C. Anal agenesis D. Meckel’s diverticulum E. Patent urachus* 23. Oncocytes are common feature noted in older individuals: A. True* B. False 24. The following statements are TRUE about striated ducts EXCEPT: A. Comprised of columnar cells B. Ductal cells contain prominent striations C. Saliva become hypertonic after passing through the striated ducts* D. Saliva becomes hypotonic after passing through the striated ducts E. The striated ducts lead to terminal excretory duct THE EXAMINATION CONTINUES IN THE NEXT PAGE 4 25. The ureteric bud gives rise to the: A. Collecting duct system* B. Nephrons C. Collecting duct system and nephrons D. None of the above 26. Salivary glands are normally found in: (1) Buccal mucosa (2) Free gingiva (3) Upper lip (4) Anterior hard palate A. B. C. D. E. (1) and (2) (2) and (4) (1) and (4) (3) and (4) (1) and (3)* 27. The paraxial mesoderm of the head and the trunk areas breaks up into segmented blocks called _____________________ and _______________________ respectively: A. Somites and somatomeres B. Somatomeres and somites* C. Rhombomeres and somites D. Somites and rhombomeres E. Somatomeres and rhombomeres 28. What hormone induces the formation of the prostate gland and what is the embryological origin of the glandular portion of the prostate? A. Testosterone, endoderm B. Testosterone, mesoderm C. SRY, endoderm and mesoderm D. Dihydrotestoterone, endoderm* E. Dihydrotestoterone, mesoderm 29. As demonstrated by the pattern of MOTOR innervation, which one of the following is involved in development of the tongue? A. First branchial arch only B. First and third branchial arch C. Occipital somites* D. Second branchial arch only E. Third branchial arch only THE EXAMINATION CONTINUES IN THE NEXT PAGE 5 30. The following statements are true about Meckel’s cartilage EXCEPT: A. Completely converts to form the mandible by endochondral ossification* B. It is the cartilage of the first branchial arch C. The malleus and incus develop from the dorsal aspect of this cartilage D. Is innervated by trigeminal nerve E. Is in close relationship with the developing mandible but does not contribute to it 31. The septation of the left and right atrium is completed: A. Prior to birth via the cardiac neural crest B. At birth independent of the cardiac neural crest* C. Prior to birth independent of the cardiac neural crest D. At birth via the cardiac neural crest E. None of the above. 32. Name the structures that originate from the 1st branchial arch: (1) Stapes (2) Masseter (3) Buccinator (4) Incus A. B. C. D. E. (1) and (2) (1) and (4) (2) and (3) (2) and (4)* (3) and (4) 33. All of the following are major sites of hematopoiesis EXCEPT the: A. Outer layer of the yolk sac wall B. Kidney* C. Spleen D. Liver 34. Name the structures that originate from the 2nd branchial arch: (NOT SCORED) (1) Stapes (2) Masseter (3) Buccinator (4) Incus A. B. C. D. E. (1) and (2) (1) and (4) (2) and (3) (2) and (4) (3) and (4) THE EXAMINATION CONTINUES IN THE NEXT PAGE 6 35. The blood vessels in the 3rd branchial arch become the: A. B. C. D. E. Pulmonary circulation Common carotid arteries* Dorsal aorta All of the above None of the above 36. Please refer to the sketch below in which is illustrated the head and neck region of a human embryo. The facial process labeled B gives rise to which of the following? For orientation the structure labeled C gives rise to the hyoid bone. A. Secondary palate and nasal septum B. Mandible and lower lip* C. Maxilla and middle portion of the upper lip D. Secondary palate and lateral portion of upper lip E. Maxilla and primary palate 37. All of the following are true about the stomatodeum EXCEPT: A. It is separated from the gut by the buccopharyngeal membrane B. Surfaced by ectoderm C. Surfaced by endoderm* D. Limited superiorly by the frontal prominence and inferiorly by the developing heart (cardiac bulge) E. All of the statements are true 38. The ureteric bud and mesonephric duct originate from: A. Splanchnopleuric mesoderm B. Somatopleuric mesoderm C. Intermediate mesoderm* D. A & C THE EXAMINATION CONTINUES IN THE NEXT PAGE 7 39. The structures derived form the 2nd branchial arch are innervated by: A. Cranial nerve IX B. Cranial nerve X C. Cranial nerve V D. Cranial nerve XII E. Cranial nerve VII* 40. Which of the three primary germ layers forms the histologically definitive endocardium of the adult heart? A. Ectoderm B. Endoderm C. Mesoderm* D. Epiblast E. Hypoblast 41. The following statements are true about development of pituitary gland EXCEPT: A. It is ectodermal in origin B. Rathke’s pouch (hypophysial diverticulum) is an upgrowth from the roof of the stomatodeum C. The adenohypophysis and the neurohypophysis portions develop from different sources D. A downgrowth from the diencephalon contributes to the development of neurohypophysis E. Rathke’s pouch (hypophysial diverticulum) contributes to the development of neurohypophysis* 42. The uterine tubes of the adult female are derived embryologically from which of the following? A. The mesonephric duct B. The mesonephric tubules C. The paramesonephric duct* D. The paramesonephric tubules E. The uterovaginal primordium 43. In the fetal heart, the foramen ovale connects the: A. Pulmonary artery and the aorta. B. Right and the left atria, permitting the flow of blood from right to left.* C. Right and the left atria, permitting the flow of blood from left to right. D. Right and the left ventricles, permitting the flow of blood from right to left. E. Right and the left ventricles, permitting the flow of blood from the left to right. 44. Abnormalities of the superior and inferior parathyroid glands indicate abnormal development of which of the following pharyngeal pouches? A. 1st only B. 1st and 2nd C. 2nd and 3rd D. 3rd only E. 3rd and 4th * THE EXAMINATION CONTINUES IN THE NEXT PAGE 8 45. All of the following statements concerning the cochlear duct are correct EXCEPT: A. It arises from the otic vesicle B. It is of ectodermal origin C. It contains the spiral organ of Corti D. It contains perilymph* 46. All of the following statements concerning the tympanic cavity are correct EXCEPT: A. It is of mesodermal origin* B. It develops from the tubotympanic recess C. The malleus and incus develop from pharyngeal arch 1 D. The stapes develops from pharyngeal arch 2 47. The surface ectoderm gives rise to the: A. Dilator pupillae muscle B. Retina C. Lens* D. Sclera E. Choroid 48. All of the following statements concerning the otic vesicle are correct EXCEPT: A. It gives rise to the membranous labyrinth B. It develops from the neuroectoderm* C. It is found adjacent to the hindbrain D. It gives rise to the endolymphatic duct E. It gives rise to the cochlear duct 49. Pharyngeal cleft 1 gives rise to the: A. Internal auditory meatus B. External auditory meatus* C. Eustatchian tube D. Cervical sinus E. Primary tympanic cavity 50. What pharyngeal arch gives rise to muscles that are innervated by the trigeminal cranial nerve (V)? A. Pharyngeal arch 1* B. Pharyngeal arch 2 C. Pharyngeal arch 3 D. Pharyngeal arch 4 E. Pharyngeal arch 6 THIS IS THE END OF THE EXAMINATION THE EXAMINATION CONTINUES IN THE NEXT PAGE 9