Chapter 09: Muscular System

"Make like a scarecrow" by contracting which muscle?

Deltoid

Joey has had his leg in a non-weight-bearing cast for 8 weeks. When the cast is removed, the diameter of the leg appears smaller than the uninjured leg. Which term best describes this observation?

Disuse atrophy

Which of the following best describes a sphincter muscle?

Encircle

Which of the following is true of the hamstrings?

Extension of the thigh, Forms posterior fossa, and Biceps femoris

Which of the following is least related to the rectus femoris?

Forms the popliteal foss

Which flat muscle covers the forehead and raises the eyebrows (for a "surprised" look)?

Frontails

The Achilles tendon attaches the soleus and which muscle to the calcaneus?

Gastrocnemius

On which large muscle do you sit?

Gluteus maximus

The biceps femoris, semitendinosus, and semimembranosus:

Hamstrings

Which group of muscles is located on the posterior thigh?

Hamstrings

Which of the following muscles is (are) located on the posterior body?

Latissimus dorsi

Which group is incorrect?

Muscles involved in breathing: diaphragm, intercostals, hamstrings

Which of the following is true of the chewing muscles?

Must be attached to the mandible.

Which of the following words means "muscle weakness"?

Myasthenia

Which of the following is composed of a series of sarcomeres?

Myofibrils

Which of the following does not refer to the thin filament?

Myosin

What is the stimulus for the release of ACh from the prejunctional membrane?

Nerve action potential

Acetylcholine is released from the neuron's membrane in response to the:

Nerve impulse

Which of the following "muscle words" refers to the chest?

Pectoralis

This large anterior chest muscle inserts on the anterior humerus and has its origins on the clavicle, upper ribs, and sternum. It allows a person to point toward an object directly in front of him.

Pectoralis major

Which of the following normally terminates muscle contraction?

Pumping of calcium back into the sarcoplasmic reticulum

Which of the following increases the force of contraction of a whole muscle?

Recruitment

With regard to skeletal muscle contraction, which event comes first?

Release of neurotransmitter (ACh) from the somatic motor neuron

This long muscle lies obliquely across the anterior thigh. It allows you to sit in a crossed-leg (lotus) position. It flexes the leg at the knee and abducts and laterally rotates the thigh at the hip.

Sartorius

Which type of muscle requires stimulation by a somatic motor neuron?

Skeletal

Which of the following is least related to the platysma?

Squinting

Which structure is an extension of the sarcolemma or cell membrane, which penetrates the interior of the muscle and carries the electrical signal to the deepest part of the muscle?

T-tubule

Which of the following functions do the muscles NOT perform?

They lower blood pressure.

Where is the vastus lateralis located?

Thigh

Which muscle is located in the upper back and posterior neck region (contraction of this muscle causes you to look up at the sky)?

Trapezius

Which muscle lies along the posterior surface of the arm and extends the forearm and is used to bear weight in crutch walking?

Triceps brachii

To which contractile protein does calcium bind?

Troponin

Which group is incorrect?

Types of striated muscle: skeletal, cardiac, smooth

Where are the pronators and supinators located?

Upper extremities

The rectus, transversus, internal oblique, and external oblique refer to:

abdominal muscles.

Which muscle lies along the anterior surface of the humerus and acts synergistically with the brachialis and brachioradialis to flex the forearm at the elbow?

biceps brachi

The somatic motor nerve that supplies the muscles of the thigh have been severed; therefore, the person:

cannot walk.

Which of the following muscles is described as striated and involuntary?

cardiac

Curare-induced muscle blockade at the NM receptors within the neuromuscular junction:

causes paralysis.

The somatic motor neuron:

causes release of ACh into the NMJ.

The supinator and pronator muscles:

change the position of the hand.

Acetylcholinesterase

degrades ACh

Which muscle covers the shoulder like a shoulder pad?

deltoid

Which muscle separates the thoracic and abdominal cavities and is also the chief breathing muscle?

diaphragm

If you are pointing directly behind you, your ___________________ is (are) contracting.

latissimus dorsi

Which muscle is located on the posterior area of the body?

latissimus dorsi

The quadriceps femoris group and the hamstrings:

lie along the thigh

Long-term use of steroids is dangerous because it may result in:

liver cancer, stunted growth, and severe psychotic mood swings.

The muscles of mastication must insert on the:

mandible

Clinically, an elevated blood level of creatine phosphate is indicative of:

muscle damage.

Fascicles are:

muscle fibers bound together by connective tissue.

The rectus femoris, vastus lateralis, vastus medialis, and vastus intermedius:

muscles of quadriceps femoris

Each muscle fiber is composed of long cylindrical structures called:

myofibrils

Which of the following forms cross-bridges with actin?

myosin

The force of muscle contraction is most related to the:

numbers of cross-bridges formed between actin and myosin.

Muscle relaxation:

occurs when calcium is pumped back into the sarcoplasmic reticulum.

Which muscle is located in the lower extremities?

peroneus longus

levator palpebrae superioris

raises upper eyelid

A stronger force of muscle contraction develops when additional motor units are stimulated. This is called:

recruitment

The ___________________ inserts on the quadriceps ligament, causing extension of the leg at the knee.

rectus femoris

As the electrical signal travels through the T tubules, it causes the:

release of calcium from the sarcoplasmic reticulum.

Contraction of the right sternocleidomastoid muscle:

rotates the head down and to the left.

Which group of muscles moves the arm at the shoulder?

rotator cuff muscles

Which of the following is a series of contractile units that make up each myofibril (each unit extends from Z line to Z line)?

sarcomeres

What is the site of calcium storage in a relaxed skeletal muscle?

sarcoplasmic reticulum

Which muscle are you using as you turn your head down and to the left and then to the right?

sternocleidomastoid

Which of the following is not a facial muscle?

sternocleidomastoid

The purpose of myoglobin is to:

store oxygen

The orbicularis oris muscle:

surrounds the mouth

What is the name of the cord of connective tissue that connects muscle to bone?

tendon

Which of the following describes a muscle that remains in a contracted state?

tetany

The gastrocnemius and the soleus are commonly called the:

toe dancer's muscles

Recruitment increases the:

two of the options are correct

The smiling muscle is the

zygomaticus major

Which of the following is classified as disuse, denervation, and senile?

Atrophy

How does curare paralyze a muscle?

Blocks the postjunctional NM receptors.

This muscle flattens the cheek and positions the food between the teeth.

Buccinator

Which of the following is responsible for muscle relaxation?

Calcium is pumped back into the sarcoplasmic reticulum

What is the function of the masseter muscle?

Chews food.

Which of the following describes actin and myosin?

Considered contractile proteins, Form force-generating cross-bridges, and Sliding filaments

Actin is:

A contractile protein that is part of the thin filament.

Which of the following activates the NM receptors within the neuromuscular junction?

ACh

This muscle group attaches to the linea alba.

Abdominal

This muscle group has four muscles: two oblique, one rectus, and one transverse.

Abdominal

The calf muscle (gastrocnemius) attaches to the calcaneus by the:

Achilles tendon.

Which of the following "slide" in the sliding filament hypothesis?

Actin and myosin

Which muscles are located on the inner (medial) surface of the thigh and move the thigh toward the midline of the body

Adductors

A tendon

attaches muscle to bone.

The orbicularis oculi:

encircles the eye.

Creatine phosphate provides the skeletal muscle with:

energy used to synthesize ATP.

sarcoplasmic reticulum

envelops the sarcomere-containing myofibrils.

brachialis and brachioradialis

flex forearm at elbow

The biceps brachii, brachioradialis, and brachialis muscles:

flex the forearm at the elbow.

Which muscle attaches to the cranial aponeurosis and wrinkles the forehead?

frontalis

An injury to the adductor muscles that are located on the medial surface of the thigh is known as a

groin injury

Which large muscle or muscle group extends the thigh at the hip?

hamstring

Shivering occurs when skeletal muscle contracts in an attempt to restore normal body temperature. Intense shivering can lead to

hyperkalemia, kidney failure, and destruction of muscle cells

"Pumping iron" is most likely to cause:

hypertrophy

Which muscles are located between the ribs and help move the rib cage during breathing?

intercostal muscles

An aponeurosis

is flat, sheetlike fascia, is composed of connective tissue, and forms a site of attachment for skeletal muscle