Chapter 6 The Muscular System

fusiform

A modification of the parallel arrangement, called _____________, results in a spindle-shaped muscle with an expanded belly (midsection); an example is the biceps brachii muscle of the arm.

anterior

A muscle that crosses on the __________ side of a joint produces flexion.

lateral

A muscle that crosses on the ___________ side of a joint produces abduction.

medial

A muscle that crosses on the ___________ side of a joint produces adduction.

posterior

A muscle that crosses on the ___________ side of a joint produces extension.

Pectoralis Minor

A synergist muscle to the pectoralis major.

C. They are under involuntary control

All of the following are characteristics of skeletal muscles, except: a. They are under voluntary control b. They are striated C. They are under involuntary control d. Their ability to contract depends on the structure of their fibers and the surrounding nerves

C. The chordae tendineae

All of the following are part of the cardiac conduction system, except: a. The Purkinje fibers b. The sinoatrial node C. The chordae tendineae d. The atrioventricular node

c. It is not striated

All of the following statements about cardiac muscle are true, except: a. It is found only in the myocardium b. It responds to involuntary impulses from the conduction system c. It is not striated d. It contracts in a constant rhythm to make the heart beat

closes the jaw

As it runs from the zygomatic process of the temporal bone to the mandible, the masseter (mă-se'ter) covers the angle of the lower jaw. This muscle _____________ by elevating the mandible.

orbicularis

Circular muscles surrounding the eyes and mouth.

a. Flexion of the vertebral column

Contraction of the abdominal muscles results in: a. Flexion of the vertebral column b. Extension of the vertebral column c. Rotation of the hip d. Forced inspiration

c. Ureter

Contractions of smooth muscle in the ___________ wall propel urine into the bladder. a. Urethra b. Kidneys c. Ureter d. Renal pelvis

multipennate

If the fascicles insert from several different sides, the muscle is ______________.

bipennate

If the fascicles insert into opposite sides of the tendon, the muscie is ___________.

pennate

In a ____________ "feather" pattern, short fascicles attach obliquely to a central tendon.

convergent

In a ______________ muscle, the fascicles converge toward a single insertion tendon. This muscle is triangular or fan-shaped, such as the pectoralis major muscle of the anterior thorax.

b. Agonist, antagonist

In elbow flexion, the biceps brachii is the __________ and the triceps brachii is the _________ a Antagonist, agonist b. Agonist, antagonist c. Origin, insertion d. Agonist, prime mover

torticollis

In some difficult births, one of the sternocleidomastoid muscles may be injured and develop spasms. A baby injured in this way has _____________ or wryneck.

unipennate

In the extensor digitorum muscle of the leg, the fascicles insert into only one side of the tendon, and the muscle is _________.

Deltoid

Meaning "triangular" muscle.

c. Extend, flex

Muscles in the anterior compartment of the thigh ____________ the knee, and muscles in the posterior compartment of the thigh _________. a. Flex, extend b. Rotate medially, rotate laterally c. Extend, flex d.Pronate, supinate

antagonists

Muscles that oppose or reverse a movement are ______________.

Gastrocnemius

Origin: Distal femur Insertion: Calcaneus (heel via calcaneal primary action: Plantar flexes foot and flexes knee

Brachialis

Origin: Distal humerus Insertion: Proximal ulna Primary actions: Flexes elbow

Orbicularis oculi

Origin: Frontal bone and maxilla Insertion: Tissue around eyes Primary action: Blinks and closes eye

Sartorius

Origin: Ilium Insertion: Proximal tibia Primary action: Flexes thigh on hip

Latissimus dorsi

Origin: Lower spine and iliac crest Insertion: Proximal humerus Primary actions: Extends and adducts humerus

Trapezius

Origin: Occipital bone and all cervical and thoracic vertebrae Insertion: Scapular spine and clavicle Primary action: Raises, retracts, and rotates scapula

Rectus abdominis

Origin: Pubis Insertion: Sternum and fifth to seventh ribs Primary action: Flexes vertebral column (Six-Pack muscles)

Gluteus maximus

Origin: Sacrum and ilium Insertion: Proximal femur Primary action: Extends hip (when forceful extension is required)

Biceps brachi

Origin: Scapula of shoulder girdle Insertion: Proximal radius Primary action: Flexes elbow and supinates forearm

Deltoid

Origin: Scapular spine and clavicle Insertion: Humerus Primary action: Abducts humerus

Triceps brachii

Origin: Shoulder girdle and proximal humerus Insertion: Olecranon process of ulna Primary action: Extends elbow

Pectoralis major

Origin: Sternum, clavicle, and first to sixth ribs Insertion: Proximal humerus Primary action: Adducts and flexes humerus

Temporalis

Origin: Temporal bone Insertion: Mandible Primary action: Closes jaw

a. Actin and myosin filaments

Sarcomeres contain: a. Actin and myosin filaments b. Actin filaments and epimysium c. Fascicles and motor neurons d. Myofibrils and capillaries

d. All of the above

Smooth muscle can be found in which of the following systems? a. Circulatory b. Respiratory c. Digestive d. All of the above

c. Contract voluntarily to move blood through the vasculature

Smooth muscle does all of the following except: a. Move food along the digestive tract b. Generate peristalsis c. Contract voluntarily to move blood through the vasculature d. Form part of the walls of the airways of the respiratory system

d. Gastrocnemius and soleus

The Achilles or calcaneal tendon is the common tendon of insertion for which muscles? a. Soleus and tibialis posterior b. Fibularis longus and fibularis brevis c. Tibialis anterior and tibialis posterior d. Gastrocnemius and soleus

platysma

The _________ is a single sheetlike muscle that covers the anterolateral neck. It originates from the connective tissue covering of the chest muscles and inserts into the area around the mouth. Its action is to pull the corners of the mouth inferiorly, producing a downward sag of the mouth like a "sad clown."

frontalis

The __________ which covers the frontal bone, runs from the cranial aponeurosis to the skin of the eyebrows, where it inserts. This muscle allows you to raise your eyebrows, as in surprise, and to wrinkle your forehead.

Zygomaticus

The ____________ extends from the corner of the mouth to the cheekbone. It is often referred to as the "smiling" muscle because it raises the corners of the mouth.

b. Conus arteriosus

The _____________ is a conical pouch formed by the upper and left portion of the right ventricle that leads to the pulmonary trunk. a. Interventricular septum b. Conus arteriosus c. Chordae tendineae d. Moderator band

d. Extensor

The _____________ muscles are located on the posterior side of the forearm. a. Flexor b. Pronator C. Adductor d. Extensor

Hamstring muscles

The biceps femoris, semitendinosus, and semimembranosus are all a part of the ___________ _________. Together they work to flex the knee and extend the hip.

c. Acetylcholine, sodium

The binding of ____________ to the receptor on an ion channel causes the channel to open, allowing an influx of __________ ions into the muscle fiber. a. Calcium, sodium b. Acetylcholine, calcium c. Acetylcholine, sodium d. Sodium, acetylcholine

prime mover.

The muscle that has the major responsibility for causing a particular movement is called the __________ ________.

Quadriceps group

The muscles; vastus medialis, intermedius, and lateralis, and the rectus femoris are all part of the ______________ _________.

a. Acetylcholine

The neurotransmitter released by motor neurons that stimulates skeletal muscle is called: a. Acetylcholine b. Norepinephrine C. Acetylcholinesterase d. Epinephrine

a. Longitudinal layer

The outermost smooth muscle layer of the stomach is the: a. Longitudinal layer b, Oblique layer c. Circular layer d. Spiral layer

Sternocleidomastoid

The paired _______________ muscles are two- headed muscles, one found on each side of the neck. Of the two heads of each muscle, one arises from the sternum, and the other arises from the clavicle.

d. Neuromuscular junction

The place where an impulse is transmitted from a motor neuron to a skeletal muscle is called the: a. Intercalated disc b. Myofibril c. Origin point d. Neuromuscular junction

c. Origin and insertion

The points at which the tendons of a skeletal muscle attach to two articulating bones are called the ________________. a. Agonist and antagonist b. Aponeuroses c. Origin and insertion d. Bursae

d. Myofibrils

The proteins within a muscle cell are organized into large cells called: a. Sarcomeres b. Filaments c. Fascicles d. Myofibrils

mandible

The temporalis is a fan-shaped muscle overlying the temporal bone. It inserts into the ______________ and acts as a synergist of the masseter in closing the jaw.

b. Smooth, cardiac, skeletal

The three types of muscle tissue are: a. Skeletal, digestive, vascular b. Smooth, cardiac, skeletal c. Skeletal, smooth, striated d. Cardiac, skeletal, tendinous

Buccinator

This fleshy muscle runs horizontally across the cheek and inserts into the orbicularis Oris. It flattens the cheek.It is also listed as a chewing muscle because it compresses the cheek to hold food between the teeth during chewing.

An action potential from a motor neuron.

What is the initial stimulus for muscle contraction?

stabilize

When a muscle crosses two or more joints, its con- traction will cause movement in all the joints crossed unless synergists are there to ____________ them.

Flex your neck

When both sternocleidomastoid muscles contract together, they _________ _____ _______. (It is this action of bowing the head that has led some people to call these muscles the "prayer" muscles.)

c. Diaphragm

When breathing normally (not forced), which of the following muscles are you using? a. Internalintercostals b. Abdominals c. Diaphragm d. a and c

C. Radius

When the biceps brachii contract, which bone is pulled upward? a, Humerus b. Scapula C. Radius d. Clavicle

d. Upper back muscles

When you lift your chin when nodding, which muscles are contracting? a. Prevertebral muscles b. Platysma c. Mastication muscles d. Upper back muscles

a. Fascicle, fiber, myofibril, thick and thin filaments

Which best describes the structural components of skeletal muscle from largest to smallest? a. Fascicle, fiber, myofibril, thick and thin filaments b. Fiber, fascicle, thick and thin filaments, myofibrils C. Thick filaments, thin filaments, myofibrils, fascicle, fiber d. Myofibril, thick filament, fascicle, thin filament

b. Pectoralis major

Which is a prime mover of the humerus? a. Teres major b. Pectoralis major c. Infraspinatus d. Biceps brachii

d. The endocardium

Which layer of the heart wall lines the heart's internal structures and is continuous with the lining of blood vessels that attach to the heart? a The epicardium b. The visceral pericardium C The myocardium d. The endocardium

d. Latissimus dorsi muscles

Which muscles are not prime movers of back extension? a. Spinalis muscles b.Longissimus muscles c. Iliocostalis muscles d. Latissimus dorsi muscles

b. Gastrocnemius

Which muscles contract to produce the main effort required to stand on your toes? a. Quadricep b. Gastrocnemius c. Biceps femoris d. Tibialis anterior

a. Lifting the chin

Which of the following actions is an example of a first-class lever? a. Lifting the chin b. Standing on tip-toe c. Flexing the elbow d. All of the above

b. Supination, pronation

Which of the following are paired and opposing muscle actions? a. Extension, rotation b. Supination, pronation c Rotation, supination d.Flexion, bending

b. Zygomaticus major

Which of the following is not a muscle of mastication? a Temporalis b. Zygomaticus major c. Deep masseter d. Lateral pterygoid

a. The tunica media

Which of the following is the layer of the blood vessel wall that consists of smooth muscle and elastic fibers? a. The tunica media b. The tunica adventitia c. The tunica intima d. The internal elastic membrane

b. The cross bridges are established

Which of the following occurs when the myosin heads bind to actin? a. The myosin heads are cocked for the next stroke b. The cross bridges are established c. The sarcoplasmic reticulum within a muscle fiber releases calcium lons d. Calcium ions bind to a protein complex

c. ii, iii, and iv

Which of the following statements about muscle tissue are true? i. Skeletal muscle tissue is the only striated type of muscle tissue ii. Cardiac and smooth muscle respond to involuntary nervous signals iii. Cardiac muscle is found only in the heart iv. Smooth muscle of the esophagus contracts in peristaltic waves a. i, ii, ii, and iv b. ili and iv c. ii, iii, and iv d. i only

d. Myosin heads move the actin filaments inward, shortening the sarcomere

Which step of muscle contraction is called the "power stroke"? a. Troponin slides to reveal actin-binding sites b. Myosin filaments pull together and slide across one another c. The sarcoplasmic reticulum within a muscle fiber releases calcium ions d. Myosin heads move the actin filaments inward, shortening the sarcomere

Fixators

_______________ are specialized synergists. They hold a bone still or stabilize the origin of a prime mover so all the tension can be used to move the insertion bone.

Synergists

_______________ whelp prime movers by producing the same movement or by reducing undesirable movements.