Muscles Anatomy study guide
The arrangement of fascicles in orbiculares oris is
circular
muscles tissue has the ability to shorten when adequately stimulated, a characteristic known as
contracility
The heads of the myosin myofilaments are called ________ when they link the thick and thin filaments together during skeletal muscles contraction
cross bridges
contractions which muscles shorten and produces movement are known as
isotonic contractions
Epiymysium is represented by
label A
The A band witching a myofibril is indicated by
label A
The I band within a skeletal muscle fiber is indicated by
label B
Then endomysim that wraps individual muscle fibers is indicated by
label B
perimysium wraps a fascicle of muscle cells and is represented by
label C
which of the following is a type of isometric exercise in which muscles increase in size and strength
lifting weights
One neuron and all the skeletal muscles it stimulates is known as
motor unit
a motor neuron and all of the skeletal muscle fibers it stimulates are termed a
motor unit
according to the sliding filament theory, how does muscle contraction occur
myosin heads form cross bridges and pull thin filaments, causing them to slide
the points of muscle attachment to an immovable or less movable bone is know as the
origin
the plasma membrane of a skeletal muscle is called the
sarcolemma
What organelle wraps and surrounds the myofibril and stores calcium
sarcoplasmic reticulum
Which type of muscle tissue contracts most quickly apon stimulation
skeletal
which term does not describe smooth muscles
skeletal
Creative phosphate (CP) functions within the muscle cells by
storing energy that will be transferred to adp to resynthesize ATP as needed
Which of the following muscles acts as a generalist to masseter and closes the jaw
temporalis
a sarcomere is
the contractile unit between two Z discs
The condition of skeletal muscle fatigue can be explained best by
the inability of the muscle to contract even if its being stimulated
Why are calcium ions necessary for skeletal muscle contraction?
Calcium ions trigger the binding of myosin heads to actin filaments
What type of muscle is shown
Smooth muscle
The gap between the axon terminal of a motor neuron and the sarcolemma of a skeletal muscles cell is called the
Synaptic cleft
Jason injured his hamstring muscle group during football practice. He will be unable to perform ________.
Thigh extension and knee flex
what is released by axon terminals into the synaptic cleft to stimulate a muscle to contract
acetylcholine
Which of these events most occur first to trigger the keel tail muscle to generate an action potential and contract
acetylcholine (ACh) binds to receptors on the sarcolemma and allows passage of sodium ions into the cell
what enzyme breaks down acetylcholine into acetic acid and choline to prevent continued contraction of the muscle fiber?
acetylcholinesterase
During skeletal muscle contraction , to what do myosin heads bind
actin filaments
what is the unstoppable electrical current that travels down the length of the entire surface of sarcolemma
action potential
which movement is opposite to abduction
adduction
what is covered by the endomysium
an individual muscle cell
Which method of regenerating ATP during muscle contraction can produce lactic acid
anaerobic glycolysis
what creates the alternating light and dark bands that provides the striating pattern on skeletal muscle tissue
A bands and I bands
Striated involuntary muscle tissue found in the heart is ________.
Cardiac muscles
skeletal muscle as a whole can generate different amounts of force and different degrees of shortening in response to stimuli, what is this concept called
Graded response
muscles that perform opposite actions to one another are termed
antagonists
neurotransmitters are released upon stiumulation from a nerve impulse from the
axon terminals of the motor neuron
Striated involuntary muscle tissue is classified as ________ muscle.
cardiac
The prime mover of arm abduction is the Muscle
Deltoid
the myofiliment composed of actin is indicated by
Label C
Muscle fiber (cell) is indicated by
Label D
The H zone, located within the A band, lacks thin filaments and is represented by
Label D
An inherited disease that causes muscles to degenerate and atrophy is known as
Muscular dystrophy
What must rush into a muscle cell to promote its depolarization?
Potassium ions
Which of the following is an example of an isometric contraction
Pushing against an immovable wall
which fascial muscles is considered the smiling muscle since it raises the corners of the mouth
Zygomaticus
What is acetylcholine
a neurotransmitter that stimulates skeletal muscle to contract
The mechanical force of contraction is generated by
a sliding of thin filaments past thick filaments
Which of the following is not a function of the muscular system
blood cell formation
A smooth, sustained contraction, with no evidence of relaxation, is called ________.
fused, or complete, tetanus
anaerobic glycolysis requires ______ to make ATP
glucose only
a skeletal muscle twitch differs from a titanic contraction in that
the muscle twitch is a brief and jerky movement while the tetanic contraction is prolonged and continuous
Which of the following is composed mostly of the protein myosin
thick filaments