Moodle Muscle Physiology

a state of sustained partial muscular contraction that is vital for the health of muscles

Muscle Tone

Both actin and myosin are found in this band

A Band

The only energy source that can be used to directly power muscle activity is ____

ATP

A neurotransmitter that stimulates skeletal muscle

Acetylcholine

When muscles are unable to be used due to injury or illness, this will begin to set in

Atrophy

Which one of the following connective tissue sheaths surrounds an individual skeletal muscle cell:

Endomysium

True or False: Muscle fatigue and soreness are caused by a buildup of pyruvic acid.

False

True or False: A nerve cell and all the muscle cells that it stimulates are referred to as motor end plate.

False

True or False: Action potential (myofibril contraction) will occur before sodium ions enter the muscle cell.

False

Contains only the actin filaments:

I band

Muscle fatigue and soreness are caused by a buildup of

Lactic Acid

The contractile unit between two Z lines

Sacromere

A myofibril is composed of many linked-segments of myofilaments called:

Sarcomeres

True or False: A contraction in which a skeletal muscle does not shorten but its tension increases is called isometric. Answer:

True

True or False: A sustained partial contraction of skeletal muscle is called muscle tone.

True

True or False: One of the important functions of skeletal muscle is to generate heat

True

True or False: Positively charged sodium ions are what cause the action potential to spread throughout a muscle fiber.

True

True or False: Skeletal muscles need nerve stimulation for contraction to occur.

True

True or False: The neurotransmitter used by the nervous system to activate skeletal muscle cells is acetylcholine.

True

Which of the following muscle movements would primarily allow you to do jumping jacks?

abduction, adduction

Which one of the following groups of skeletal muscle terms is placed in order from largest to smallest:

fascicle, fiber, myofibril, myofilament

Which of the following is NOT a function of the muscular system:

growth of the individual

What is the initial event that must occur before a muscle can contract?

impulse travels to neuron

The condition of skeletal muscle fatigue can be best explained by

insufficient amounts of oxygen and ATP to the muscle cells

Otherwise known as thick filaments:

myosin filaments

Muscle fiber contraction ultimately happens when:

myosin pulls actin inward toward H zone

Neurotransmitters are stored within:

neuron endings

Which of the following muscle actions would NOT be classified as an Isotonic contraction:

pushing against a stationary wall

The distance between two Z lines

sarcomere

During impulse transmission Calcium ions:

stimulate the release of acetylcholine

The gap between the motor neuron and the muscle fiber it supplies at the neuromuscular junction is called the ____.

synaptic cleft

The space between an axon terminal and sarcolemma is called a

synaptic cleft

The striations that give skeletal muscle its characteristic striped appearance are produced, for the most part, by:

the arrangement of myofilaments

Which one of the following is composed of myosin protein:

thick filaments