Review of Muscular System Lecture (OpenStax A&P 2e – Chapter 11)

A comprehensive set of flashcards covering key concepts, terminology, and individual muscles from the OpenStax Anatomy & Physiology chapter on the muscular system. Use these Q&A cards to test knowledge of muscle names, locations, actions, and functional groupings.

What is the main role of the muscular system illustrated by the yoga example in Figure 11.1?

To produce voluntary body movements such as flexing, extending, and contorting the body.

In muscle actions, what is the difference between a prime mover (agonist) and a synergist?

A prime mover is the main muscle responsible for a specific movement, whereas a synergist assists the prime mover by adding force or reducing undesirable movements.

Which muscle is the prime mover for elbow flexion in Figure 11.2, and which two muscles act as its synergists?

Prime mover: biceps brachii. Synergists: brachialis and brachioradialis.

Skeletal muscles are generally classified into how many basic shapes (Figure 11.3)?

Seven.

What is the thick, central part of a skeletal muscle called (Figure 11.4)?

The belly.

What structures connect a muscle belly to bone and enable movement of the skeleton?

Tendons.

On anatomical charts, what is the difference between superficial and deep muscles (Figure 11.5)?

Superficial muscles lie closest to the skin surface, while deep muscles are situated underneath the superficial layer.

Using the Latin roots ab (away from) and duct (to move), what does the muscle name abductor digiti minimi literally mean (Figure 11.6)?

A muscle that moves the little finger or toe away from the midline.

What unique feature allows muscles of facial expression to produce expressions such as smiling or frowning (Figure 11.7)?

Many insert into the skin around the eyelids, nose, and mouth instead of inserting on bone.

Which muscle raises the eyebrows as in showing surprise (Figure 11.8)?

The frontal belly of the occipitofrontalis.

Which small muscle lowers the eyebrows to create a frown or scowl (Figure 11.8)?

Corrugator supercilii.

Name the circular muscle that shapes the lips during speech and puckering.

Orbicularis oris.

Where do the extrinsic eye muscles originate and insert (Figure 11.9)?

They originate on the bones of the skull and insert onto the exterior surface of the eyeball.

Why are the jaw-closing muscles located in the cheek region (Figure 11.10)?

Their position provides a mechanical leverage advantage needed for powerful chewing.

Which tongue muscle protrudes the tongue by contracting and pulling it forward (Figure 11.12–11.13)?

Genioglossus.

Which group of neck muscles originates above the hyoid bone and assists in swallowing (Figure 11.13)?

The suprahyoid muscles.

What midline connective-tissue seam separates the left and right rectus abdominis muscles (Figure 11.16)?

Linea alba.

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

External oblique, internal oblique, transversus abdominis.

What dome-shaped muscle forms the floor of the thoracic cavity and is the primary muscle of breathing (Figure 11.17)?

The diaphragm.

Which intercostal muscles elevate the ribs during quiet inspiration (Figure 11.18)?

External intercostals.

Give two major functions of the pelvic floor muscles (Figure 11.19).

Support pelvic organs and serve as sphincters for the urethra, vagina, and rectum.

Which paired muscle forms the largest part of the pelvic diaphragm and helps resist increases in intra-abdominal pressure (Figure 11.21)?

Levator ani (includes pubococcygeus and iliococcygeus).

What is the primary purpose of the muscles that stabilize the pectoral girdle (Figure 11.22)?

To provide a steady base from which other muscles can move the arm.

Which large anterior thoracic muscle flexes, adducts, and medially rotates the humerus, bringing the elbows together during an upper-cut motion (Figure 11.24)?

Pectoralis major.

Which broad back muscle extends, adducts, and medially rotates the humerus, as when pulling something toward the body (Figure 11.24)?

Latissimus dorsi.

What multipennate shoulder muscle is the prime mover of arm abduction to 90 degrees (Figure 11.24)?

Deltoid.

Name the four rotator cuff muscles.

Supraspinatus, infraspinatus, teres minor, and subscapularis.

Which muscle is chiefly responsible for forearm flexion during a biceps curl (Figure 11.26)?

Biceps brachii.

What muscle acts as the main forearm extensor when throwing a punch (Figure 11.26)?

Triceps brachii.

Turning the palm downward involves which prime mover located in the anterior forearm (Figure 11.26)?

Pronator teres (assisted by pronator quadratus).

Which small deep forearm muscle supinates the forearm, turning the palm upward (Figure 11.26)?

Supinator.

Flexor carpi radialis and flexor carpi ulnaris both flex the wrist; what additional movement does each perform (Figure 11.27)?

Flexor carpi radialis abducts the wrist, while flexor carpi ulnaris adducts the wrist.

What is the collective name for the four muscles that extend the knee and form the anterior thigh (Figure 11.32)?

Quadriceps femoris group (rectus femoris, vastus lateralis, vastus medialis, vastus intermedius).

Which muscle group on the posterior thigh flexes the knee and extends the hip (Figure 11.32)?

The hamstrings (biceps femoris, semitendinosus, semimembranosus).

What two muscles combine to form the iliopsoas, the chief hip flexor (Figure 11.31)?

Psoas major and iliacus.

Which large gluteal muscle is the prime mover of hip extension, especially when climbing stairs (Figure 11.31)?

Gluteus maximus.

Name the thick tract of fascia running down the lateral thigh that is tightened by tensor fasciae latae (Figure 11.31).

Iliotibial tract (IT band).

What action do the six lateral rotators (piriformis, obturator internus and externus, superior and inferior gemellus, quadratus femoris) have on the femur?

They laterally rotate (externally rotate) the thigh and stabilize the hip joint.

Which muscle is the prime mover for dorsiflexion and inversion of the foot (Figure 11.33)?

Tibialis anterior.

What two superficial posterior-leg muscles share the calcaneal (Achilles) tendon and plantar-flex the foot (Figure 11.33)?

Gastrocnemius and soleus.

Which lateral-leg muscle everts the foot and helps maintain the lateral longitudinal arch (Figure 11.33)?

Fibularis (peroneus) longus.

Flexor hallucis longus performs what two primary actions (Figure 11.33)?

Flexes the big toe and assists plantar flexion of the foot.

Which small muscle behind the knee unlocks the extended knee by medially rotating the tibia (Figure 11.33)?

Popliteus.

Intrinsic hand muscles both originate and insert within the hand. What is their primary functional advantage (Figure 11.28)?

They allow fine motor control of individual finger and thumb movements.

Which intrinsic foot muscle of layer 1 abducts and flexes the great toe (Figure 11.35-36)?

Abductor hallucis.

Name the dome-shaped muscle that contracts and flattens to enlarge the thoracic cavity during inspiration.

Diaphragm.

What Latin root means toward, and when paired with duct results in the term adductor (Figure 11.6)?

ad (meaning toward).

Which abdominal muscle is deepest of the three lateral layers and compresses the abdomen like a corset?

Transversus abdominis.

While performing a sit-up, which muscle primarily flexes the vertebral column?

Rectus abdominis.

What facial muscle compresses the cheeks, aiding in sucking and blowing?

Buccinator.

Which neck muscle, when contracting unilaterally, turns the head to the opposite side, and when contracting bilaterally, flexes the neck?

Sternocleidomastoid.