210 Chapter 9
Frontalis
Masseter
Sternocleidomastoid
Deltoid
Pectoralis major
Serratus anterior
External oblique
Flexors of hand
and fingers
Sartorius^
Vastus
lateralis^
Quadriceps tendon
Patella
Patellar ligament
Tibialis anterior
Peroneus longus
Temporalis
Orbicularis oculi
Orbicularis oris
Trapezius
Biceps brachii
Rectus abdominis
Linea alba
Extensors of hand
Tensor fasciae latae
Adductors^
of thigh
Rectus femoris
Vastus medialis
Gastrocnemius
Soleus
Tibia
(^) ®
Learning
Cengage ©
Figure 9-7A The superficial muscles of the body (anterior
view).
In performing any given movement, such as bend-ing
the leg at the knee joint, the muscles performing the actual
movement are called the prime movers or agonists-.
Those muscles that will straighten the knee are the
antagonists-. The agonist or prime mover must relax for
the antagonists to perform their function and vice versa.
Synergists (SIN-er-jistz) are the muscles that -assist the
prime movers.
The Function and Location of
Selected Skeletal Muscles
The superficial muscles of the body are those that can be
found directly under the skin (Figure 9-7). Some parts of
the body, like the arms and legs, will have up to three dif-
ferent layers of muscles (superficial, middle, and deep
layers). Other areas will have only superficial muscles,