Medical Terminology Simplified

Vascular Tunic

11–3 The vascular tunic,or uvea,is the middle layer of the eyeball. It is com-

posed of the choroid, ciliary body, and iris. The (3) choroidlayer lies below the sclera

and contains blood vessels. It also contains a dark, pigmented tissue that prevents

glare within the eyeball because of its ability to absorb light. The anterior portion of

the choroid is modified and forms the (4) ciliary body(or muscle) and the (5) iris,

the colored portion of the eye. Observe the location of the middle layer of the eyeball

(vascular tunic) as you label the choroid, ciliary body, and iris in Figure 11–1.

Sensory Tunic

11–4 The innermost layer, the sensory tunic, is the delicate, double layered

(6) retina. This structure lines the posterior two-thirds of the eyeball and is the be-

ginning of the visual pathway. It contains rods and cones, the sensory receptors for

vision and image formation. Rods perceive the presence of light only, whereas cones

perceive different wavelengths of light as colors. Cones are concentrated in the

depression near the center of the retina called the (7) fovea, which is the area of

sharpest vision. Surrounding the fovea is the yellowish macula, which also has an

abundance of cones. In addition, the retina is the only place in the body where blood

vessels can be seen directly. Label Figure 11–1 as you observe the location of the

structures responsible for image formation.

11–5 The CF scler/orefers to hardening; sclera (white of the eye); choroid/o

refers to the choroid; and retin/orefers to the retina.

Use these CFs to build medical terms that mean inflammation of the

sclera:____________________ / __________

choroid:____________________ / __________

retina:____________________ / __________

11–6 Practice building medical words that mean disease of the

choroid:____________________ / _____ / ____________________

retina:____________________ / _____ / ____________________

11–7 The CF kerat/orefers to horny tissue; hard; cornea. The CF irid/orefers

to the iris.

Use these CFs to build medical terms that mean

rupture of the cornea:____________________ / _____ / ____________________

herniation of the iris:__________ / _____ / __________

Boldfaceindicates a word root or combining form. Blueindicates a suffix. Pinkindicates a prefix.

512 CHAPTER 11• Special Senses: Eyes and Ears

scler/itis

sklĕ-RĪ-tĭs

choroid/itis

kō-royd-Ī-tĭs

retin/itis

rĕt-ĭ-NĪ-tĭs

choroid/o/pathy

kō-roy-DŎP-ă-thē

retin/o/pathy

rĕt-ĭn-ŎP-ă-thē

kerat/o/rrhexis

kĕr-ă-tō-RĔK-sĭs

irid/o/cele

ĭ-RĬD-ō-sēl