Muscular System – Key Concepts & Muscles

55 question-and-answer flashcards covering major muscles, their actions, anatomical terminology, and key concepts from the lecture on the muscular system.

What is the primary function of the muscular system illustrated by yoga practice?

Voluntary movement, flexion, and contortion of the body.

In muscle action, what term describes muscles that provide the main force for a movement?

Prime movers (agonists).

Which two muscles act as synergists to the biceps brachii during forearm flexion?

Brachioradialis and brachialis.

Skeletal muscles typically come in how many general shapes?

Seven.

What is the large, central thick portion of a muscle called?

The belly.

What structures connect a muscle’s belly to its associated bones?

Tendons.

How do superficial and deep muscles differ?

Superficial muscles lie at the surface; deep muscles lie underneath them.

In Latin-based muscle names, what does the prefix “ab-” mean?

Away from.

In Latin-based muscle names, what does the prefix “ad-” mean?

Toward.

Which muscle primarily raises the eyebrows?

Occipitofrontalis (frontal belly).

Which facial muscle flares the nostrils by compressing nasal cartilage?

Nasalis.

Which facial muscle is the prime mover for smiling?

Zygomaticus major.

What ring-shaped muscle encircles the mouth and shapes the lips during speech?

Orbicularis oris.

Where do the extrinsic eye muscles originate?

On the skull outside the eyeball.

Name the two main elevators of the mandible for chewing.

Masseter and temporalis.

What group of muscles moves the tongue by originating outside of it?

Extrinsic tongue muscles.

Which extrinsic tongue muscle protrudes the tongue out of the mouth?

Genioglossus.

What is the collective name for the muscles above the hyoid bone that assist in swallowing?

Suprahyoid muscles.

Which paired neck muscle rotates and flexes the head and is visible on the lateral neck?

Sternocleidomastoid.

Name the sheet of connective tissue that covers the rectus abdominis.

Linea alba.

List the three layers of the lateral abdominal wall from superficial to deep.

External oblique, internal oblique, transversus abdominis.

Which major muscle separates the thoracic and abdominal cavities?

The diaphragm.

Through which opening does the inferior vena cava pass in the diaphragm?

The caval opening.

Which intercostal muscles are located laterally and assist with inspiration?

External intercostals.

State the primary function of the pelvic floor muscles.

Support pelvic organs, resist intra-abdominal pressure, and act as sphincters for urethra, rectum, and vagina.

Which muscle group stabilizes the pectoral girdle to serve as a base for arm movement?

The muscles that position the pectoral girdle (e.g., trapezius, serratus anterior).

Which large anterior chest muscle flexes, adducts, and medially rotates the humerus?

Pectoralis major.

Which broad back muscle extends, adducts, and medially rotates the humerus?

Latissimus dorsi.

Name the shoulder muscle responsible for arm abduction.

Deltoid.

Which rotator-cuff muscle assists with medial rotation of the humerus and stabilizes the shoulder?

Subscapularis.

What is the primary action of the supraspinatus muscle?

Abduction of the humerus (initial 15°) and stabilization of the shoulder joint.

What three-headed posterior arm muscle extends the forearm?

Triceps brachii.

Which anterior arm muscle is the prime mover for forearm flexion and supination during a biceps curl?

Biceps brachii.

Name the muscle that pronates the forearm located near the elbow.

Pronator teres.

Which muscle turns the palm upward (supination) and originates from the lateral epicondyle of the humerus and proximal ulna?

Supinator.

Which forearm muscle flexes the wrist and abducts it toward the radial side?

Flexor carpi radialis.

What four muscles compose the quadriceps femoris group?

Rectus femoris, vastus lateralis, vastus medialis, vastus intermedius.

Which hamstring muscle has two heads and laterally rotates the leg?

Biceps femoris.

What two muscles form the iliopsoas group?

Psoas major and iliacus.

Which gluteal muscle is the primary extensor of the thigh?

Gluteus maximus.

Name the ligament-like tract stabilized by tensor fasciae latae.

Iliotibial tract.

What anterior leg muscle dorsiflexes and inverts the foot?

Tibialis anterior.

Which calf muscle has two heads and, with the soleus, forms the Achilles tendon?

Gastrocnemius.

Which deep posterior leg muscle flexes the big toe?

Flexor hallucis longus.

What is the main action of fibularis (peroneus) longus?

Plantar flexion and eversion of the foot.

Which intrinsic foot muscle abducts and flexes the big toe?

Abductor hallucis.

How many distinct layers are described for the plantar intrinsic muscles of the foot?

Four.

Which muscle group forms the anatomical perineal sphincter controlling voluntary urination?

External urethral sphincter.

What structure passes through the esophageal hiatus of the diaphragm?

The esophagus.

What term describes muscles that assist a prime mover by adding extra force or reducing undesirable movements?

Synergists.

What tendinous sheet connects the frontal and occipital bellies of occipitofrontalis?

Epicranial aponeurosis.

Which small muscle located deep to the biceps brachii is a strong forearm flexor?

Brachialis.

Which pelvic-floor muscles make up the levator ani?

Pubococcygeus and iliococcygeus.

What small posterior arm muscle helps the triceps extend the forearm and abducts the ulna during pronation?

Anconeus.

Which lateral rotator of the hip originates on the anterior sacrum and inserts on the greater trochanter?

Piriformis.