Muscle Anatomy and Function Quiz

Facial Muscles

• Contraction of the zygomaticus muscle draws the angle of the mouth upward, resulting in a smile.
• Contraction of the orbicularis oris muscle compresses the lips together.

Muscles of Mastication

• The digastric muscles are essential for chewing, as they lower the mandible and open the mouth when contracted.

Muscles of the Back

• Flexion of the vertebral column occurs when the liliocostalis muscles are contracted.

Muscles of the Upper Limb

• The triceps brachii muscle originates from processes on the humerus and scapula.
• The pectoralis minor muscle rotates and adducts the humerus when contracted.

Muscles of the Lower Limb

• The semimembranosus muscle flexes the leg at the knee joint and may also extend the thigh at the hip joint when contracted.
• The gracilis muscle is involved in a pulled groin muscle.
• The sartorius muscle acts only on the hip joint.
• The quadriceps femoris muscles are antagonistic to the hamstring muscles.
• The three gluteal muscles insert on the greater trochanter of the femur.

Muscles of the Foot

• The gastrocnemius, soleus, and plantaris muscles function synergistically in plantar flexion of the foot.

Muscles of the Abdominal Wall

• The anterior abdominal wall consists of the external abdominal oblique, internal abdominal oblique, and transverse abdominis muscles, in order from superficial to deep.