Study Guide for dental students and dentists

This is a comprehensive study guide for dental students and dentists. On this site you will Histology of the Human Eye for UCLA Dental Students. In addition there is a comprehensive study guide for the Systemic Pathology.

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Sunday, February 26, 2006

Sample Test for Dental students

Here are some sample test questions to help you understand the depth to which you will be examined. Click on what you think is the right answer to confirm. If you think this test is too simple or too difficult let me know by email.

1. Which of the following is least true of the boney walls that surround the eye?
a. the frontal bone forms a portion of the orbital roof
b. the ethmoid bone is thin and prone to sinus infection
c. the lacrimal gland lies in a fossa of the lacrimal bone
d. the floor of the orbit is prone to fracture from trauma
e. the zygomatic bone forms part of the lateral wall of the orbit

2. Which structure is most correctly listed with their functions?
a. lacrimal gland- responsible for secreting lipid to cover the tear film
b. goblet cell- secrete copious amounts of aqueous for the tear film
c. Meibomian gland- secrete mucins to lubricate the eye
d. Gland of Kraus- secrete proteins to prevent infection
e. levator muscle- responsible for closing the eyelds

3. A patient had complications from a recent operation that was performed so he would not need glasses (a LASIK procedure). However, there was a complication and the cornea was made too thin by the laser. During the procedure a laser obliterates tissue from the center of the cornea after a flap is made to peel back the anterior portion (100 microns) of the cornea (normally about 500 microns in central thickness). Given the patient had normal corneal anatomy prior to the operation and knowing the patient's cornea did not rupture, the complication was likely due to overzealous treatment of the:
a. epithelium
b. Bowman's layer
c. epithelial basement membrane
d. stroma
e. Descemet's membrane
f. endothelium

4. Which of the following is least likely to be traversed by a photon traveling to initiate a visual response in the brain?
a. lens nucleus
b. ganglion cell
c. Bowman's layer
d. Bruch's membrane
e. vitreous
f. aqueous

5. A patient has glaucoma because aqueous outflow is slow. A structure adjacent to or connected to the normal pathway has impeded the flow. The LEAST likely cause of the obstruction of aqueous based on anatomic considerations:
a. the peripheral iris became adherent to the cornea.
b. the ciliary body rotated and pushed the lens against the iris.
c. flow across Bruch's membrane was impeded by adjacent abnormal retinal pigment epithelium
d. flow thru the aqueous veins was diminshed by a tumor

6. The cell with the longest axon is the:
a. ganglion cell
b. Muller cell
c. cone
d. rod
e. amacrine cell

7. The vitreous is most firmly attached at the:
a. optic nerve (Bergmeister's papilla)
b. ora serrata (vitreous base)
c. lens (posterior capsule)
d. pars plicata (ciliary processes)

8. The structure in which nuclei are most abundant in the normal adult:
a. anterior lens capsule
b. posterior lens capsule
c. lens nucleus
d. lens equator

9. The structures shown at the tips of the arrows in the photomicrograph function mainly to
a. modulate fluid (aqueous) transfer
b. regulate an aperature
c. control focus (accommodation)
d. provide structural support

10. Based on the normal anatomy the structure least susceptible to injury from a fist blow to the orbit and eye is the:
a. iris root
b. sclera over the rectus muscle insertions
c. nerves of the inferior orbital fissure
d. intracanalicular portion of the optic nerve

Friday, February 17, 2006

Histology of the Eye for Dental Students

Study Guide for Eye Histology for Dental Students-
Welcome UCLA Dental Students. It is from the material below that questions will be drawn for examination. As you see it is far more complete than is possible in a 50 minute lecture.
The list below is in a question answer format so you can test yourself. Please simply click on the link to go to the answers. Frequently the link forces you to identify the structures. In this way you can further learn histology of the eye. At the end of this list is a sample of examination questions. The choices are linked to information that will enable you to answer the questions.

  1. Name the bones of each orbital wall.

  2. Which orbital bones are prone to blow out fractures and infection?
  3. Name the paraorbital sinuses and their respective locations (and bones).
  4. Which sinus is most relevant to symptoms encountered by a dentist?
  5. What type of epithelium lines the sinuses?
  6. Describe the location and histology of the lacrimal glands.
  7. Name the 3 major proteins that are produced in the lacrimal gland and their role.
  8. What anatomic structures do the tears traverse as they pass from the lacrimal gland cover the eye and exit the orbital area?
  9. Describe the histology of the tear outflow apparatus.
  10. Name the layers of the eyelid and their functions.
  11. Go to the virtual microscope and click on eyelid and study the histology identify the layers of the eyelid including skin, orbicularis muscle, tarsus, meibomian glands, levator, Muller’s muscle and conjunctiva. Your computer becomes a microscope so move the image and change the magnification!
  12. Go to the virtual microscope and click on eye and study the histology.
  13. In a gross photograph of a sectioned eye identify the following structures:
  14. a. conjunctiva, b. cornea, c. anterior chamber, d. lens, e. trabecular meshwork, f. Schlemm’s canal, g. iris, h. ciliary body, i. Pars plana, j. ora serrata, k. retina, l. macula, m. fovea.
  15. Name and describe the layers of the cornea.
  16. Name and describe the layers of the conjunctiva.
  17. What vital component of the tear film is produced by conjunctiva?
  18. Name and describe the layers of the iris.
  19. With contraction which muscle in the iris diminishes and which one enlarges the size of the pupil?
  20. Describe the anatomic structures that make up the anterior chamber.
  21. Follow the flow of aqueous from the cells of production to its exit from the eye.
  22. Name and describe the layers of the lens.
  23. What is structure and composition of the lens zonule?
  24. Describe the gross structure of the ciliary body, pars plana and pars plicata.
  25. Name and describe the layers of the ciliary body.
  26. What is the function of the ciliary muscle in the ciliary body?
  27. What is the structure of vitreous? Where is it most firmly attached?
  28. Name and describe the layers of the retina.
  29. Compare and contrast the histology of the macula, fovea and peripheral retina.
  30. What is the function of the rods? Of the cones?
  31. Describe the process of phototransduction from a histologic point of view (the tissues responsible for each point in the process.
  32. Name and describe the layers of the optic nerve.
  33. What is the artery whose branches supplies all portions of the optic nerve?
  34. Follow a photon of light as it enters the tear film to the final generation of a nerve impulse that synapses in the lateral geniculate body naming all of the structures in between. Sorry no link; it requires integration of all topics.

Sample Questions for the Final Examination!