Sample Chapter 10 from the Textbook (35559.0K) - McGraw-Hill

328 PART 2 Support and Movement
Optic nerve
Levator palpebrae
superioris (cut)
View
Lateral rectus
Superior rectus
Inferior oblique
Medial rectus
Superior oblique
Trochlea
(a) Superior view
Trochlea
Levator palpebrae
superioris (cut)
Optic nerve
Inferior rectus
Superior oblique
Superior rectus
Lateral rectus
View
Inferior oblique
(b) Lateral view
FiGuRe 10.13 Muscles That Move the Right eyeball
(Names of muscles of eye movement are in bold.)
Muscles Moving the Vertebral column
The muscles that extend, laterally flex, and rotate the vertebral
column are divided into superficial and deep groups (table 10.9).
In general, the muscles of the deep group extend from vertebra to
vertebra, whereas the muscles of the superficial group extend from
the vertebrae to the ribs. These back muscles are very strong to
maintain erect posture. The erector spinae (spī′nē) group of
muscles on each side of the back consists of three subgroups: the
iliocostalis (il′ē-ō-kos-tā′lis), the longissimus (lon-gis′i-mŭs),
and the spinalis (spī-nā′lis). The longissimus group accounts for
most of the muscle mass in the lower back (figure 10.14). The
deepest muscles of the back attach between the spinous and transverse
processes of individual vertebrae (figure 10.15).
Back Pain
Clinical
IMPaCT
Low back pain can result from injury, poor posture, being overweight,
or lack of fitness; it is the primary cause of missed
work and the second most common neurological affliction in
the United States. In addition to chronic pain, a low back injury is
often accompanied by muscle spasms, which are spontaneous,
painful, uncontrolled muscle contractions. A few changes may help
prevent more spasms and reduce pain. Patients should sit and stand
up straight; use a low back support when sitting; lose weight; exercise,
especially the back and abdominal muscles; and try to sleep on
their side on a firm mattress. If lifestyle changes are not sufficient,
treatment with muscle relaxants, anti-inflammatory drugs, or pain
medication may be necessary.