HAP 8

The pull of gravity assists the muscles in maintaining body posture.

False

The thickmyofilament in a muscle fiber is made of actin.

False

Which of the following muscles is nota muscle of the trunk? the following are located in the trunk:

rectus abdominis, internal oblique and the external oblique

Striations are found in:

skeletal and cardiac muscle

Another name for skeletal muscle is:

striated or voluntary

To produce smooth movement at a joint:

the prime movers and synergists must contract

The minimal level of stimulation required to cause a fiber to contract is called:

threshold stimulus

A single motor neuron with all the muscle cells it innervates is called a:

motor unit

The basic contractile unit of a muscle is called a sarcomere.

True

Moving a part of the body away from the midline of the body is called:

abduction

The thinmyofilament of the skeletal muscles is made of:

actin

Moving a part of the body toward the midline of the body is called:

adduction

When a muscle fiber is subjected to a stimulus, it contracts completely. This is called:

all-or-none law

Strength training leads to:

an increased number of myofilaments

The hand position when the body is in anatomical position is:

supination

A bursae is a saclike structure which is filled with:

synovial fluid

If a prime mover flexes a joint:

the antagonist will extend the joint

If an injury caused damage to the insertion of the biceps brachii muscle (the anterior muscle of the upper arm), the injury would be nearest:

the elbow

A motor neuron and all the muscle cells it stimulates are called a neuromuscular junction.

False

All motor units in a given muscle have the same threshold stimulus.

False

Another name for aerobic training is strength training.

False

Both tonic and isotonic contractions cause movement of a joint.

False

Dorsiflexion allows you to stand on your toes.

False

Endurance training causes muscle hypertrophy.

False

Hypothermia refers to a dangerous elevation in body temperature.

False

In order for movement to take place, when the prime mover contracts, the synergist must relax.

False

In order for the necessary cross bridges to form, potassium must be released from the endoplasmic reticulum.

False

Like skeletal muscles, cardiac muscles have intercalated disks.

False

Prolonged inactivity in a muscle can result in disuse hypertrophy.

False

Raising your arm laterally away from your body is an example of adduction.

False

Research has shown that anabolic steroids do not increase muscle size and strength.

False

Smooth muscle is also called voluntary muscle.

False

Strength training results in an increase in the number of muscle fibers.

False

The insertion of a muscle is on the more stationary bone.

False

The lifting of a 10 lb weight requires the activation of fewer motor units than the lifting of a 5 lb weight.

False

The origin of a muscle is on the more movable bone.

False

The point of contact between the nerve and muscle is called a motor unit.

False

Tonic contractions provide rapid movement for skeletal muscles.

False

Trying to lift a car (and failing) is an example of an isotonic muscle contraction.

False

Twitch contractions play an important role in normal muscle activity.

False

When muscles must use energy release that does not require oxygen, the waste product ascorbic acid is produced, which can cause soreness in the muscle.

False

A motor neuron and all the muscle cells it stimulates are called a motor unit.

True

All muscles specialize in contraction or shortening.

True

Bursae and tendon sheaths have the same function.

True

Bursae are small fluid-filled sacs that lie between some tendons and bones.

True

Cardiac muscle is found in the heart.

True

During strenuous exercise, the muscles' use of oxygen and nutrients can outstrip the blood's ability to supply them.

True

Endurance training increases the blood flow to a muscle.

True

Energy for muscle contraction is provided when ATP is broken down.

True

Good posture can be defined as holding the body parts in the position that favors best function.

True

In an isometric contraction, no movement occurs but the muscle tension increases.

True

In order for movement to take place, the antagonists must do the opposite of the prime mover.

True

In the anatomical position, the hands are supinated.

True

In the sliding filament model of muscle contraction, cross bridges are formed between the myosin and actin.

True

Involuntary muscles are also called visceral muscles.

True

Lifting your textbook off the desk is an example of an isotonic muscle contraction.

True

Like skeletal muscles, cardiac muscles have striations.

True

Most anabolic steroids are made of synthetic testosterone.

True

Movement of your hand from a supinated to pronated position requires rotation of the forearm.

True

Research has shown that prolonged use of anabolic steroids can have severe, even life-threatening, consequences.

True

Skeletal muscle cells contain more than one nucleus.

True

Skeletal muscle is also called striated muscle.

True

Strength training results in an increase in the number of myofilaments in each muscle fiber.

True

Tenosynovitis in the wrist can cause carpal tunnel syndrome.

True

The breakdown of ATP is the energy source that helps supply heat to the body.

True

The contraction of the biceps brachii muscle causes flexion of the elbow joint.

True

The minimum level of stimulation required to cause a muscle fiber to contract is called the threshold stimulus.

True

The origin of a muscle is on the more stationary bone.

True

The overuse of vitamins can cause a serious health problem called hypervitaminosis.

True

The production of heat is a primary function of the muscular system.

True

The respiratory and nervous systems also play important roles in body movement.

True

The term oxygen debt describes the continued increased metabolism that must occur in a cell to remove the excess acid that accumulates during prolonged exercise.

True

The thinmyofilament in a muscle fiber is made of actin.

True

When a muscle fiber is exposed to a greater than threshold stimulus, it contracts completely. This is called an all-or-none response.

True

When stimulated, the entire muscle follows the all or none law.

True

Z-lines mark the ends of individual sarcomeres.

True

Endurance training leads to:

an increased number of blood vessels to the muscle

Which of the following muscles is nota muscle that moves the upper extremities? The following are located in the upper extremities:

biceps brachii, triceps brachii and the latissimus dorsi

According to the sliding filament model, in order for a sarcomere to contract:

bridges must form between the actin and myosin, ATP must be broken down for energy and calcium must be released from the endoplasmic reticulum

A fluid-filled sac that acts as a lubricating structure for muscle movement is a(n):

bursae

Intercalated disks are found in:

cardiac muscle

The muscle contracts but does not shorten, even though an increase in muscle tension does occur. This sentence describes:

isometric contractions

The muscle contracts and shortens and the insertion end moves toward the point of origin. This sentence describes:

isotonic contractions

Which of the following muscles is nota muscle of the head and neck?

latissmus dorsi

Movement around a longitudinal axis is:

rotation

The basic contractile unit of a skeletal muscle is the:

sarcomere

Which of the following muscles is nota muscle that moves the lower extremities? The following are located in the lower extremities

sartorius, iliopsoas and the gracilis

The connective tissue that attaches muscle to bone is called:

tendons

When a muscle contraction occurs:

the Z lines are pulled closer together

Tendons anchor muscles to bones.

True

The muscle attachment to the more movable bone is called the:

insertion

Tonic contractions:

do not shorten the muscle and are important in maintaining posture

The term that refers to ankle and foot movement is:

dorsiflexion

The opposite movement of rotation is:

immobility, inaction, or fixed

The thickmyofilament of the skeletal muscles is made of: myosin

myosin

The point of contact between the nerve and the muscle fibers it stimulates is called a: neuromuscular junction

neuromuscular junction

What allows you to lift different weights with the same muscle is:

number of motor units used by the muscle

The muscle attachment to the more stationary bone is called the:

origin

The movement that is opposite dorsiflexion is:a:

plantar flexion

Another name for smooth muscle is:

visceral