186 Introduction to Anatomy and Physiology
Muscular Dystrophy
Muscular dystrophy (MD) is a group of
similar, inherited disorders characterized by
progressively worsening muscle weakness and
loss of muscle tissue. Depending on the specific fi
type, the onset of MD may occur during either
childhood or adulthood, and the symptoms vary.
Some forms of MD affect only certain muscle
groups, whereas other forms affect all of the
muscles. The more severe types of MD begin in
childhood; symptoms may include intellectual
disability, delayed development of motor skills,
frequent falling, drooling, and drooping of the
eyelids. Some forms of MD also affect the heart
muscle, resulting in an irregular heartbeat.
There are no known cures for the various
muscular dystrophies; the goal of treatment is to
control symptoms (Figure 5.26). Some types of
muscular dystrophy lead to a shortened life; others
cause little disability, allowing for a normal lifespan.
Hernia
A hernia is a balloon-like section of the
abdominal cavity lining that protrudes through
a hole or weakened section of the muscles in
the abdomen. A hernia can be caused by heavy
lifting or by any activity or medical problem that
increases pressure inside the abdominal cavity. In
1. What is the role of the neuromuscular
system in whiplash injuries?
2. What causes swimmer’s shoulder?
3. What is the difference between tennis
elbow and Little Leaguer’s elbow?
4. What are the characteristics of MD?
5. What are the different forms that MD
may take?
Check Your Understanding
Figure 5.26 Two young girls, both with rare forms of muscular dystrophy, have fun playing together at an event
to benefit the Muscular Dystrophy Association (MDA). We currently have no cures for the various forms of
muscular dystrophy but hopefully research conducted in genetics labs such as the one shown here will lead to
methods and treatments that reduce the effects of or eliminate the disease. Have you donated to a campaign to
raise money for muscular dystrophy research?