Ch. 11 Muscular System Flashcards
Which of the following helps an agonist work?
A) A synergist.
B) A fixator.
C) An insertion.
D) An antagonist.
A) a synergist.
Explanation: A synergist is a muscle that assists the prime mover (agonist) in performing a movement.
Incorrect Answers:
B) A fixator stabilizes the origin of the agonist but doesn’t assist movement directly.
C) Insertion refers to the attachment site of a muscle, not a helper.
D) An antagonist opposes the agonist’s action.
Which of the following statements is correct about what happens during flexion?
A) The angle between bones is increased.
B) The angle between bones is decreased.
C) The bone moves away from the body.
D) The bone moves toward the center of the body.
B) The angle between bones is decreased.
Explanation: Flexion refers to the movement that reduces the angle between two bones, such as bending the elbow.
Incorrect Answers:
A) Increasing the angle is known as extension.
C) Movement away from the body is abduction, not flexion.
D) Vague and not always accurate—flexion can occur in multiple directions depending on the joint.
Which is moved the least during muscle contraction?
A) The origin.
B) The insertion.
C) The ligaments.
D) The joints.
A) The origin.
Explanation: The origin is typically the fixed point of attachment that does not move during muscle contraction.
Incorrect Answers:
B) The insertion is the part that moves toward the origin during contraction.
C) Ligaments are not actively involved in muscle contraction.
D) Joints are affected by muscle movement and do change position.
Which muscle has a convergent pattern of fascicles?
A) Biceps brachii.
B) Gluteus maximus.
C) Pectoralis major.
D) Rectus femoris.
C) Pectoralis major.
Explanation: The pectoralis major has a broad origin and converges to a single insertion point, making it a classic example of a convergent muscle.
Incorrect Answers:
A) Biceps brachii is a fusiform muscle.
B) Gluteus maximus has a broad origin but is not typically classified as convergent.
D) Rectus femoris is a bipennate muscle.
A muscle that has a pattern of fascicles running along the long axis of the muscle has which of the following fascicle arrangements?
A) Circular.
B) Pennate.
C) Parallel.
D) Rectus.
C) Parallel.
Explanation: In parallel muscles, fascicles run along the long axis, allowing for greater range of motion but less force.
Incorrect Answers:
A) Circular muscles have fascicles arranged in concentric rings, such as sphincters.
B) Pennate muscles have short fascicles that attach obliquely to a tendon.
D) “Rectus” describes direction (straight) but is not a fascicle arrangement.
Which arrangement best describes a bipennate muscle?
A) The muscle fibers feed in on an angle to a long tendon from both sides.
B) The muscle fibers feed in on an angle to a long tendon from all directions.
C) The muscle fibers feed in on an angle to a long tendon from one side.
D) The muscle fibers on one side of a tendon feed into it at a certain angle and muscle fibers on the other side of the tendon feed into it at the opposite angle.
A) The muscle fibers feed in on an angle to a long tendon from both sides.
Explanation: Bipennate muscles, such as the rectus femoris, have fascicles arranged on both sides of a central tendon.
Incorrect Answers:
B) Describes multipennate muscles, such as the deltoid.
C) Describes unipennate muscles.
D) Overly complex version of A; A is the more accurate and direct description.
The location of a muscle’s insertion and origin can determine (BLANK).
A) Muscle name.
B) Action.
C) Type of movement.
D) All of these.
D) All of these.
Explanation: The location of a muscle’s origin and insertion can indeed determine: A) Muscle name – Many muscles are named based on their attachment points (e.g., sternocleidomastoid originates on the sternum and clavicle, inserts on the mastoid process). B) Action – The direction of pull between origin and insertion determines the muscle’s function (e.g., flexion, extension). C) Type of movement – Depending on where the muscle spans and inserts relative to a joint, it can produce flexion, rotation, abduction, etc. While not always the case, each of these can be influenced or determined by origin and insertion—making D) all of these the best choice when considering the possibility rather than the rule.
Which muscle name does not make sense?
A) Extensor digitorum.
B) Gluteus minimus.
C) Biceps femoris.
D) Extensor minimus longus.
D) extensor minimus longus.
Explanation: This name incorrectly combines “minimus” (smallest) and “longus” (long), which are contradictory size descriptors not used together in anatomical naming.
Incorrect Answers:
A) Valid name for a finger-extending muscle.
B) Correctly refers to the smallest of the gluteal muscles.
C) Describes a muscle with two heads in the femur region.
Which of the following terms would be used in the name of a muscle that moves the leg away from the body?
A) Flexor.
B) Adductor.
C) Extensor.
D) Abductor.
D) Abductor.
Explanation: An abductor moves a limb away from the body’s midline.
Incorrect Answers:
A) Flexor bends a joint.
B) Adductor moves a limb toward the midline.
C) Extensor straightens a joint.
Which of the following is unique to the muscles of facial expression?
A) They all originate from the scalp musculature.
B) They insert onto the cartilage found around the face.
C) They only insert onto the facial bones.
D) They insert into the skin.
D) They insert into the skin.
Explanation: Facial muscles are unique because they insert into the skin, allowing them to create facial expressions.
Incorrect Answers:
A) Only some facial muscles, like occipitofrontalis, originate near the scalp.
B) Cartilage is not a common insertion site for these muscles.
C) Facial muscles typically insert into skin, not bone.
Where is the temporalis muscle located?
A) On the forehead.
B) In the neck.
C) On the side of the head.
D) On the chin.
C) On the side of the head.
Explanation: The temporalis muscle is found on the side of the head, above the ear, and is involved in elevating the mandible during chewing.
Incorrect Answers:
A) The frontalis muscle is located on the forehead.
B) Neck muscles include sternocleidomastoid, not temporalis.
D) The chin contains muscles like the mentalis.
Which of the following is a prime mover in head flexion?
A) Occipitofrontalis.
B) Corrugator supercilia.
C) Sternocleidomastoid.
D) Masseter.
C) Sternocleidomastoid.
Explanation: The sternocleidomastoid flexes the neck and rotates the head.
Incorrect Answers:
A) Occipitofrontalis moves the scalp and eyebrows.
B) Corrugator supercilii moves the eyebrows.
D) Masseter elevates the mandible for chewing.
Where is the inferior oblique muscle located?
A) In the abdomen.
B) In the eye socket.
C) In the anterior neck.
D) In the face.
B) In the eye socket.
Explanation: The inferior oblique is one of the extrinsic eye muscles, responsible for moving the eye upward and outward.
Incorrect Answers:
A) Abdominal muscles include obliques, but not the inferior oblique.
C) Neck muscles include sternocleidomastoid and scalene.
D) Facial muscles are for expression, not eye movement.
What is the action of the masseter?
A) Swallowing.
B) Chewing.
C) Moving the lips.
D) Closing the eye.
B) Chewing.
Explanation: The masseter elevates the mandible and is the primary muscle for chewing.
Incorrect Answers: A) Swallowing involves muscles in the neck and throat. C) Lip movement is controlled by muscles like orbicularis oris. D) Orbicularis oculi is responsible for closing the eye.
The names of the extrinsic tongue muscles commonly end in (BLANK).
A) -glottis.
B) -glossus.
C) -gluteus.
D) -hyoid.
B) -glossus.
Explanation: Extrinsic tongue muscles like genioglossus, styloglossus, and hyoglossus all end in “-glossus.”
Incorrect Answers:
A) -glottis refers to part of the larynx.
C) -gluteus refers to buttock muscles.
D) -hyoid relates to the hyoid bone, not tongue muscles.
What is the function of the erector spinae?
A) Movement of the arms.
B) Stabilization of the pelvic girdle.
C) Postural support.
D) Rotating of the vertebral column.
C) Postural support.
Explanation: The erector spinae group keeps the spine erect and provides postural support.
Incorrect Answers:
A) Arm movement involves muscles like deltoid and biceps.
B) Pelvic girdle stabilization involves gluteal and deep hip muscles.
D) Rotating the spine is the function of transversospinales like the multifidus.
Which of the following abdominal muscles is not a part of the anterior abdominal wall?
A) Quadratus lumborum.
B) Rectus abdominis.
C) Interior oblique.
D) Exterior oblique.
A) Quadratus lumborum.
Explanation: The quadratus lumborum is part of the posterior abdominal wall.
Incorrect Answers:
B) Rectus abdominis is a key anterior abdominal muscle.
C) Internal oblique is a layer of the anterior wall.
D) External oblique is the outermost layer of the anterior wall.
Which muscle pair plays a role in respiration?
A) Intertransversarii, interspinales.
B) Semispinalis cervicis, semispinalis thoracis.
C) Trapezius, rhomboids.
D) Diaphragm, scalene.
D) Diaphragm, scalene.
Explanation: The diaphragm is the primary muscle of breathing, and the scalene muscles assist in inhalation by elevating the ribs.
Incorrect Answers:
A) These are stabilizing muscles of the vertebrae.
B) Semispinalis muscles rotate and extend the spine.
C) Trapezius and rhomboids move and stabilize the scapula.
What is the linea alba?
A) A small muscle that helps with compression of the abdominal organs.
B) A long tendon that runs down the middle of the rectus abdominis.
C) A long band of collagen fibers that connects the hip to the knee.
D) Another name for the tendinous inscription.
B) A long tendon that runs down the middle of the rectus abdominis.
Explanation: The linea alba is a fibrous structure that runs vertically between the left and right sides of the rectus abdominis.
Incorrect Answers:
A) It is not a muscle.
C) This describes the iliotibial (IT) band.
D) Tendinous inscriptions are horizontal lines across the rectus abdominis.
The (BLANK) muscle that makes up the levator ani along with the iliococcygeus.
A) Posterior scalene.
B) Rectus abdominis.
C) Pubococcygeus.
D) Quadratus lumborum.
C) Pubococcygeus.
Explanation: The levator ani is a key component of the pelvic floor and is composed of two main muscles: the pubococcygeus and the iliococcygeus. These muscles support pelvic organs and assist in functions like urination, defecation, and childbirth.
Incorrect Answers:
A) Posterior scalene is a neck muscle involved in respiration and head movement.
B) Rectus abdominis is a major abdominal wall muscle, not part of the pelvic floor.
D) Quadratus lumborum is located in the posterior abdominal wall and helps with lateral trunk flexion, not pelvic floor support.
The rhomboid major and minor muscles are deep to the (BLANK).
A) Rectus abdominis.
B) Scalene muscles.
C) Trapezius.
D) Ligamentum nuchae.
C) Trapezius.
Explanation: The rhomboids lie deep to the trapezius and help retract and stabilize the scapula.
Incorrect Answers:
A) Rectus abdominis is in the abdomen, not the upper back.
B) Scalenes are in the neck, not directly over the rhomboids.
D) Ligamentum nuchae is a midline neck ligament, not superficial to rhomboids.
Which muscle extends the forearm?
A) Biceps brachii.
B) Triceps brachii.
C) Brachialis.
D) Deltoid.
Correct Answer: B) Triceps brachii.
Explanation: The triceps brachii is the primary extensor of the forearm at the elbow joint.
Incorrect Answers:
A) Biceps brachii flexes the forearm.
C) Brachialis also flexes the elbow.
D) Deltoid abducts the arm at the shoulder, not the elbow.
What is the origin of the wrist flexors?
A) The lateral epicondyle of the humerus.
B) The medial epicondyle of the humerus.
C) The carpal bones of the wrist.
D) The deltoid tuberosity of the humerus.
B) the medial epicondyle of the humerus.
Explanation: Most wrist flexor muscles originate from the medial epicondyle of the humerus.
Incorrect Answers:
A) The lateral epicondyle is the origin of wrist extensors.
C) The carpal bones are points of insertion, not origin.
D) The deltoid tuberosity is where the deltoid inserts, unrelated to wrist flexors.
Which muscles stabilize the pectoral girdle?
A) Axial and scapular.
B) Axial.
C) Appendicular.
D) Axial and appendicular.
D) axial and appendicular.
Explanation: Stabilization of the pectoral girdle involves both axial muscles (like trapezius and sternocleidomastoid) and appendicular muscles (like serratus anterior and subclavius).
Incorrect Answers:
A) “Scapular” isn’t a defined category in this context.
B) Axial muscles help, but are not solely responsible.
C) Appendicular alone is not enough to stabilize the girdle.
The small muscle on the lateral posterior elbow that extends the forearm is the (BLANK).
A) Anconeus.
B) Brevis.
C) Brachioradialis.
D) Piriformis.
A) Anconeus.
Explanation: The anconeus is a small triangular muscle located on the posterior lateral side of the elbow. It assists the triceps brachii in extending the forearm at the elbow joint.
Incorrect Answers:
B) Brevis is a term meaning “short” and is part of names like “extensor carpi radialis brevis,” but it’s not a muscle by itself.
C) Brachioradialis flexes the forearm, not extends it.
D) Piriformis is a lateral rotator of the thigh, located in the gluteal region—not related to the elbow.
The large muscle group that attaches the leg to the pelvic girdle and produces extension of the hip joint is the (BLANK) group.
A) Gluteal.
B) Obturator.
C) Adductor.
D) Abductor.
A) Gluteal.
Explanation: The gluteal group—especially gluteus maximus—extends the thigh at the hip and connects the leg to the pelvic girdle.
Incorrect Answers:
B) Obturator muscles are lateral rotators.
C) Adductors bring the leg toward the midline.
D) Abductors move the leg away from the midline but do not primarily extend the hip.
Which muscle produces movement that allows you to cross your legs?
A) The gluteus maximus.
B) The piriformis.
C) The gracilis.
D) The sartorius.
D) The sartorius.
Explanation: The sartorius is the longest muscle in the body and is responsible for flexion, abduction, and lateral rotation of the thigh—movements that allow leg-crossing.
Incorrect Answers:
A) Gluteus maximus extends the hip.
B) Piriformis is a lateral rotator.
C) Gracilis adducts the thigh but doesn’t assist in crossing the legs.
What is the largest muscle in the lower leg?
A) Soleus.
B) Gastrocnemius.
C) Tibialis anterior.
D) Tibialis posterior.
B) Gastrocnemius.
Explanation: The gastrocnemius is the largest and most prominent calf muscle, responsible for plantar flexion at the ankle.
Incorrect Answers:
A) Soleus is large but lies beneath the gastrocnemius.
C) Tibialis anterior is in the front and smaller.
D) Tibialis posterior is a deep posterior muscle, not the largest.
The vastus intermedius muscle is deep to which of the following muscles?
A) Biceps femoris.
B) Rectus femoris.
C) Vastus medialis.
D) Vastus lateralis.
B) Rectus femoris.
Explanation: The vastus intermedius lies deep to the rectus femoris in the anterior thigh, as part of the quadriceps group.
Incorrect Answers:
A) Biceps femoris is a hamstring muscle located posteriorly.
C & D) Vastus medialis and lateralis are lateral to the intermedius, not superficial.
The pelvic girdle attaches the (BLANK) to the axial skeleton.
A) Arms.
B) Vertebrae.
C) Pelvis.
D) Legs.
D) Legs.
Explanation: The pelvic girdle connects the lower limbs (legs) to the axial skeleton through the hip bones (ilium, ischium, and pubis), forming a strong, stable support structure for
