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
