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
