Special Senses: Vision
Anatomy of the Eye
1. Name five accessory eye structures that contribute to the formation of tears and/or aid in lubrication of the eyeball, and then name the major secretory product of each. Indicate which has antibacterial properties by circling the correct secretory product.
Accessory structures lacrimal glands conjunctiva tarsal or meibomian glands caruncle ciliary glands
Product saline solution; Clysozym0 mucus oily secretion whitish, oily secretion sweat
2. The eyeball is wrapped in adipose tissue within the orbit. What is the function of the adipose tissue? To package, protect, and cushion the eyeball in the bony orbit.
3. Why does one often have to blow one's nose after crying? Because tears drain into the nasal cavities via the nasolacrimal ducts.
4. Identify the extrinsic eye muscle predominantly responsible for each action described below. lateral rectus medial rectus inferior oblique inferior rectus superior rectus superior oblique
turns the eye laterally turns the eye medially turns the eye up and laterally turns the eye inferiorly and medially turns the eye superiorly and medially turns the eye down and laterally
S. What is a sty? Inflammation of a small oil or sweat gland associated with the eye exterior.
of the conjunctiva.
6. Correctly identify each lettered structure in the diagram by writing the letter next to its name in the numbered list. a
1. anterior chamber 2. anterior segment 3. bipolar neurons
4. choroid 5. ciliary body and processes 6. ciliary muscle 7. cornea 8. dura mater 9. fovea centralis 10. ganglion cells 11. iris 12. lens 13. optic disc 14. optic nerve 15. photoreceptors 16. posterior chamber 17. retina
q u o b r k s n
h d m
18. sclera 19. scleral venous sinus 20. suspensory ligaments (ciliary zonule) 21. posterior segment
Notice the arrows drawn close to the left side of the iris in the diagram above. What do they indicate? The flow of aqueous humor from the ciliary processes of the ciliary body to the scleral venous sinus (canal of Schlemm).
7. The iris is composed primarily of two smooth muscle layers, one arranged radially and the other circularly. Which of these dilates the pupil? _Th_e_ra_d_ia_l_l-'ay:....e_r 8. You would expect the pupil to be dilated in which of the following circumstances? Circle the correct response(s). a. in bright light _
in dim light)
focusing for near vision
observing distant objects)
9. The intrinsic eye muscles are controlled by (circle the correct response): ( autonomic nervous system) somatic nervous system
Review Sheet 24
10. Match the key responses with the descriptive statements that follow. Key: a. b. c. d. aqueous humor choroid ciliary body ciliary processes of the ciliary body e. f. g. h. i. cornea fovea centralis iris lens optic disc j. k. l. retina sclera scleral venous sinus m. vitreous humor
a; aqueous humor
k: sclera i: optic disc c· ciliary body
1. fluid filling the anterior segment of the eye 2. the "white" of the eye 3. part of the retina that lacks photoreceptors 4. modification of the choroid that controls the shape of the crystalline lens and contains the ciliary muscle 5. drains the aqueous humor from the eye 6. layer containing the rods and cones 7. substance occupying the posterior segment of the eyeball 8. forms the bulk of the heavily pigmented vascular layer g; iris 9. smooth muscle structures (2) 10. area of critical focusing and discriminatory vision 11. form (by filtration) the aqueous humor 12. light-bending media of the eye (4)
I; scleral venous sinus
m; vitreous humor b; choroid
f; fovea centralis d; ciliary processes of the ciliary body a; aqueous humor m; vitreous humor e; cornea k; sclera e; cornea h; lens...