Answer the following statements true (T) or false (F)
1. The iris is actually an involuntary muscle in the choroid layer.
2. In very dim light the circular fibers of the iris contract, causing the pupil to dilate.
3. Presbyopia is a term for the nearsightedness of old age.
4. Cataracts may be caused by exposure to the ultraviolet radiation of the sun.
5. A cataract is a condition in which the cornea becomes less transparent and “milky” in appearance.
1. TRUE
2. FALSE
3. FALSE
4. TRUE
5. FALSE
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Match each product with the cell or region that secretes or contains it.
1. parietal cells 2. goblet cells 3. brush border 4. pancreatic cells A. enzymes B. HCl C. HCO 3- D. mucus E. more than one of these
Photoreceptors contain the enzyme to re-isomerize the all-trans retinal back to the 11-cis form.
Answer the following statement true (T) or false (F)
The lipoprotein known as _____________ reduces surface tension within the alveoli so they do not collapse during exhalation.
A) surfactant B) phospholipid C) beryllium D) alveolar membrane lipoprotein
When Harry stepped on a nail, inflammation and infection were severe, but localized. Which of the following functions serves to wall off or isolate the injured area to the greatest degree?
A. increased temperature B. coagulation of plasma proteins C. loss of function D. swelling E. vasodilation