#1
Which muscle is responsible for closing the jaw?
Masseter
ExplanationPrimary jaw-closing muscle
#2
What is the primary function of the rectus abdominis muscle?
Flexion of the spine
ExplanationMainly responsible for spine flexion
#3
Which muscle is responsible for wrinkling the forehead?
Frontalis
ExplanationForehead muscle, causes forehead wrinkling
#4
What is the antagonist muscle to the biceps brachii?
Triceps brachii
ExplanationOpposes biceps action, extends the elbow
#5
What is the function of the orbicularis oris muscle?
Closing the mouth
ExplanationCloses and shapes the mouth
#6
Which muscle is responsible for rotating the shoulder externally?
Infraspinatus
ExplanationPrimary external shoulder rotator
#7
Which muscle is responsible for flexing the knee joint?
Hamstring muscles
ExplanationGroup of muscles behind the thigh, knee flexors
#8
Which abdominal muscle is responsible for lateral flexion of the spine?
External oblique
ExplanationMajor muscle for lateral spine flexion
#9
What is the primary function of the transversus abdominis muscle?
Stabilization of the spine and pelvis
ExplanationMainly for spine and pelvis stabilization
#10
Which facial muscle is responsible for smiling?
Zygomaticus major
ExplanationKey muscle for smiling expression
#11
What is the primary action of the serratus anterior muscle?
Protraction of the scapula
ExplanationPulls scapula forward and around the chest
#12
Which abdominal muscle is deep to the external oblique?
Internal oblique
ExplanationInnermost abdominal muscle layer