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Unformatted text preview: Biol 2404 Lecture Notes: Aging and Disorders of Muscular System; Ziser, 2005 1 Effects of Aging on M uscular System strength and m uscle m ass peak in 20’s by age 80 m ost have only half as m uch strength and endurance eg. a large percentage of 70 yr olds cannot lift 10 lb w e ig h ts ‡ m ajor factor in falls, fractures, etc as w e age lean body m ass is replaced w ith fat eg. young w ell conditioned m ale, m uscle accounts for 90% of cs area of m id thigh; in 90 yr old w om an only 30% especially loose fast tw itch fibers m uscle fiber have few er m yofibrils; sarcom eres less organized, less ATP, glycogen, m yoglobin, etc ‡ fatigue m ore quickly reduced circulation m eans m uscles heal m ore slow ly m otor units have few er m uscle fibers per neuron less ACh is produced Disorders of the M uscular System the m uscular system suffers few er disorders than m ost other organ system s but it is particularly vulnerable to stress injuries often exacerbated by overzealous exertion or im proper w arm up exercises ‡ m ost athletic injuries can be prevented by proper conditioning “no pain, no gain” is a dangerous creed typ ica l in ju rie s a re tre a te d w ith RICE : R e s t – p re ve n ts fu rth e r in ju ry...
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This note was uploaded on 09/13/2011 for the course RNSG 1443 taught by Professor Lynneandrus during the Spring '11 term at Austin Community College.
- Spring '11