Muscular System

What is flexion?

A decrease in the angle between two bones.

What is extension?

An increase in the angle between two bones.

What is abduction?

Movement away from the midline, such as moving your legs outward.

What is adduction?

Movement toward the midline, such as bringing your legs inward.

What is pronation?

Turning the hand so the palm points posteriorly.

What is supination?

Turning the hand so the palm points anteriorly.

What is dorsiflexion?

Moving the top of the foot toward the ankle, such as standing on your heels.

What is plantarflexion?

Pointing the foot downward, such as standing on your toes.

What is eversion?

Turning the sole of the foot laterally, or outward.

What is inversion?

Turning the sole of the foot medially, or inward.

What is the origin of the temporalis?

Temporal bone.

What is the insertion of the temporalis?

Mandible.

What is the primary action of the temporalis?

Closes the jaw.

What is the origin of the masseter?

temporal bone

What is the insertion of the masseter?

Mandible.

What is the primary action of the masseter?

Closes the jaw.

What is the origin of the sternocleidomastoid?

Sternum and clavicle.

What is the insertion of the sternocleidomastoid?

Temporal bone, at the mastoid process.

What is the primary action of the sternocleidomastoid when contracted bilaterally?

Flexes the neck.

What is the primary action of the sternocleidomastoid when contracted unilaterally?

Rotates the head to the opposite side.

What is the primary action of the pectoralis major?

Adducts and flexes the humerus.

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What is the primary action of the latissimus dorsi?

Extends and adducts the humerus.

What is the primary action of the deltoid?

Abducts the humerus.

What is the primary action of the biceps brachii?

Flexes the elbow and supinates the forearm.

What is the primary action of the triceps brachii?

Extends the elbow.

What is the primary action of the iliopsoas?

Flexes the hip.

Where is the quadriceps group located?

Anterior thigh.

What is the primary action of the quadriceps group?

All extend the knee.

What is the primary action of the tibialis anterior?

Dorsiflexes and inverts the foot.

What is the primary action of the gluteus maximus?

Extends the hip.

What is the primary action of the gluteus medius?

Abducts the thigh and steadies the pelvis while walking.

What is the primary action of the hamstring muscles?

Flex the knee.

What is the primary action of the gastrocnemius?

Plantarflexes the foot.

Where does the piriformis originate?

Anterior surface of the sacrum.

Where does the piriformis insert?

Proximal femur

What is the primary action of the piriformis?

Externally rotates the hip.

What is external rotation of the hip?

Rotating the thigh outward, away from the midline.