Transcript II. Naming Skeletal Muscles

II. Naming Skeletal Muscles
A. Names of the 700+ muscles
are based on a few characteristics
1. Direction of muscle fibers in relation
to the midline of the body
a. Rectus- run parallel to the
midline
b. Transverse run perpendicular to
midline
c. Oblique run diagonally to the
midline
2. Location- named for the structure
that it is near
3. Size- relative size of the muscle
a. Maximus/minimus- largest and
smallest
b. Longus/brevis- longest and
shortest
4. Number of origins- number of
tendons for the origin
a. Biceps, triceps, quadriceps
5. Relative shape of the muscle
a. Deltoid- triangular
b. Trapezius- trapezoid
c. Serratus- saw toothed
d. Rhomboidus- rhomboid or
diamond shape
6. Sites where the muscle originates and
inserts
7. Action- principle action of the
muscle
a. Flexor- decreases an angle at
the joint
b. Extensor- increases angle at the
joint
c. Abductor- moves bone away
from the midline
d. Adductor- moves bone toward
midline
e. Levator- upward movement
f. Depressor- downward
movement
g. Pronator- turn palm down ro
posterior
h. Supinator- turn palm up or
anteriorly
i. Sphincter- closes an opening
j. Tensor- makes a body part
more rigid
k. Rotator- moves a bone around
an axis