Muscle System

slow, red muscle fibers.

Activities such as swimming and running are most likely to stimulate development of

when a muscle fiber contracts, it contracts completely

The all-or-none response means that

stimulation occurs when acetylcholine is released from the end of the motor neuron.

The first event in muscle fiber contraction is that

fast, fatigable white fibers. muscle fibers developing new filaments of actin and myosin. hypertrophy, or enlargement, of muscle.

Weightlifting, in which a muscle exerts more than 75% of its maximum tension, involves

to transmit a muscle impulses into the cell interior

What is the function of the transverse tubules?

there is a reduction in capillary networks. the number of mitochondria decreases. the size of actin and myosin filaments decreases.

When a muscle undergoes atrophy in response to disuse,

Red muscles have fewer mitochondria than white.

Which of the following is not true when comparing red and white muscle types?

Actin filaments slide inward along myosin filaments.

Which of the following major events in muscle contraction are stated properly?

a motor neuron and the muscle fibers connected to it.

A motor unit is defined as

being composed of a junction between a motor neuron and a muscle fiber a site where there is actually a gap, or cleft, between the neuron and muscle a site where neurotransmitters are released into the synaptic cleft from the motor neuron

A neuromuscular junction can be described as

cordlike and connects muscles to bones; a broad, fibrous sheet of connective tissue that connects muscles to muscles

A tendon is characterized by being ______, whereas an aponeurosis is characterized by being ______.

myosin

ADP molecules on the surface of actin serve as active sites for the formation of cross-bridges with molecules of

creatine phosphate supplying energy to regenerate ATP from ADP and phosphate

ATP is related to creatine phosphate by

motor end plate

At the neuromuscular junction, the muscle fiber membrane is folded to form a

reduction in capillary networks within the muscle fibers. decrease in the number of mitochondria within the muscle fibers. decrease in the size of actin and myosin filaments.

Atrophy, or decrease in size and strength of a muscle, involves a

smooth muscle contraction.

Both acetylcholine and norepinephrine can affect

contracts more slowly and relaxes more slowly.

Compared to skeletal muscle, smooth muscle

supply energy for the synthesis of ATP.

Creatine phosphate serves to

latent period.

In a recording of a muscle twitch, the delay between the time a stimulus is applied and the time the muscle responds is called the

actin and myosin

Myofibrils are composed primarily of

motor neuron endings

Neurotransmitters are stored in vesicles within

a decrease of ATP and increased permeability to calcium.

Rigor mortis that occurs in skeletal muscles a few hours after death is due to

cardiac muscle contraction.

Self-exciting fibers result in

smooth muscle fibers.

Short muscle cells with centrally located nuclei are

the more active they are, the more heat is released.

The maintenance of body temperature is related to the action of skeletal muscles because

epimysium

The outermost layer of connective tissue surrounding a skeletal muscle is called the

myofilament movement.

The role of ATP in muscle contraction is to supply energy for

sarcomere arrangement.

The striated appearance of skeletal muscle results from the

refractory period.

The very brief moment following stimulation when a muscle remains unresponsive to additional stimulation is called the

minimal amount of energy required to cause a muscle to contract.

Threshold stimulus is defined as the

skeletal muscle fibers.

Transverse tubules and sarcoplasmic reticulum are well developed in