Question

homeostatic imbalance 8.6
if drainage of aqueous humor is blocked, fluid backs up like a clogged sink. pressure within the eye may increase to dangerous levels and compress the delicate (1) and optic nerve. the resulting condition, glaucoma (glaw-komah; \vision going gray\), can lead to blindness unless detected early. glaucoma is a common cause of blindness in the elderly. unfortunately, many forms of (2) progress slowly and have almost no symptoms at first. thus, sight deteriorates slowly and painlessly until the damage is done. signs of advanced glaucoma include seeing halos around lights, headaches, and blurred vision. a simple instrument called a tonometer (to-nome-ter) is used to measure the (3) pressure, which should be tested yearly in people over 40. glaucoma is commonly treated with eyedrops that increase the rate of aqueous humor drainage. laser or surgical enlargement of the drainage channel is another option.
the ophthalmoscope (of-thalmo-skop) is an instrument that (4) the interior of the eyeball, allowing the retina, optic disc, and internal blood vessels at the fundus, or posterior wall of the eye, to be viewed and examined (figure 8.7). such an examination can detect certain pathological conditions, such as diabetes, arteriosclerosis, and (5) of the optic nerve and retina.

1. degeneration 2. retina 3. glaucoma 4. intraocular 5. illuminates
2. retina 2. glaucoma 3. intraocular 4. illuminates 5. degeneration
3. glaucoma 2. intraocular 3. illuminates 4. degeneration 5. retina
4. intraocular 2. illuminates 3. degeneration 4 retina 5. glaucoma
5. illuminates 2. degeneration 3. retina 4. glaucoma 5. intraocular

Explanation:

• For (1): The retina is a delicate part of the eye. When fluid backs up (due to blocked aqueous humor drainage), it can compress the retina and optic nerve.
• For (2): Glaucoma is the condition being discussed. Many forms of glaucoma progress slowly.
• For (3): Intraocular pressure is measured with a tonometer.
• For (4): The ophthalmoscope illuminates the interior of the eyeball.
• For (5): Degeneration of the optic nerve and retina can be detected with an ophthalmoscope examination.

Answer:

1. retina 2. glaucoma 3. intraocular 4. illuminates 5. degeneration