Question

because of its rich blood supply, skeletal muscle is amazingly resistant to infection throughout life, and given good nutrition, relatively few problems afflict skeletal muscles. we repeat, however, that muscles, like bones, will ( 1. ), even with normal tone, if they are not used continually. a lifelong program of regular exercise keeps the whole body operating at its best possible level.
homeostatic imbalance 6.5
one rare autoimmune disease that can affect muscles during adulthood is myasthenia gravis (mi\as - thene - ah grāvis; asthen = weakness; gravi = heavy), a disease characterized by drooping upper eyelids, difficulty in swallowing and talking, and generalized muscle ( 2. ) and fatigability. the disease involves a shortage of acetylcholine receptors at neuromuscular junctions caused by antibodies specific for acetylcholine receptors. antibodies are immune molecules that will mark the receptors for destruction. because the muscle fibers are not ( 3. ) properly, they get progressively weaker. death usually occurs when the respiratory muscles can no longer function, which leads to respiratory failure.
a female patient with myasthenia gravis. notice the effect on the patients eyelid muscles.
as we age, the amount of connective tissue in muscles increases, and the amount of muscle tissue decreases; thus the ( 4. ) become stringier, or more sinewy. because skeletal muscles represent so much of our body mass, body weight begins to decline in older adults as this natural loss in muscle mass occurs. muscle strength also decreases by about 50 percent by age 80. regular exercise can help offset the effects of ( 5. ) on the muscular system, and frail older people who begin to \pump iron\ (use leg and hand weights) can rebuild muscle mass and dramatically increase their strength.

o 1. stimulated 2. muscles 3. aging 4. atrophy 5. weakness
o 1. muscles 2. aging 3. atrophy 4. weakness 5. stimulated
o 1. aging 2. atrophy 3. weakness 4. stimulated 5. muscles
o 1. weakness 2. stimulated 3. muscles 4. aging 5. atrophy
o 1 atrophy 2. weakness 3. stimulated 4. muscles 5. aging

Explanation:

1. Muscles, like bones, will atrophy if not used continuously. So the first blank is 'atrophy'.
2. Myasthenia gravis is characterized by generalized muscle weakness. So the second blank is 'weakness'.
3. Muscle fibers need to be stimulated properly. So the third blank is'stimulated'.
4. As we age, muscles become stringier. So the fourth blank is'muscles'.
5. Regular exercise can offset the effects of aging on the muscular - system. So the fifth blank is 'aging'.

Answer:

1. atrophy 2. weakness 3. stimulated 4. muscles 5. aging