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45 terms

chapter 8 Muscles

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A skeletal muscle is covered by and separated from nearby muscles by connective
Fascia
The layer of connective tissue most closely surrounding a skeletal muscle is called the:
Epimysium
The layer of connective tissue covering each muscle fiber (within the bundles of fascicles):
Endomysium
Connective tissue that extends inward from the Epimysium dividing the muscle tissue into compartments is called:
Perimysium
Myofibrils are composed primarily of:
Actin and myosin
Neurotransmitters are stored in vesicles within
Motor neuron endings (synaptic knobs)
The enzyme acetylcholinesterase causes the acetylcholine to
Decompose
Creatine phosphate serves to
Supply energy for the synthesis of ATP
The amount of oxygen needed by the liver to support the conversion of lactic acid to glucose is called the
Oxygen debt
A muscle cramp is most likely due to a lack of
ATP
Athletes usually experience muscular fatigue less quickly than non-athletes because they
Produce less lactic acid
The all-or-nothing response means that
When a muscle fiber contracts, it contracts completely
The striated appearance of skeletal muscle results from the
Myofilament arrangement in a sarcomere
At the neuromuscular junction the muscle fiber membrane is folded to form a
Motor end plate
What is the function of the transverse tubules?
o To transmit a muscle action potential into the cell interior
A neuromuscular junction can be described as
o All of the above
An Aponeuroses is characterized as
A broad, fibrous sheet of connective tissue that connects muscles to muscles
A motor unit is defined as
A motor neuron and the muscle fiber it inneruates
The role of the ATP in the muscle contraction is to supply energy for
Movement of myofilaments actin and myosin
The maintenance of body temperature is related to the action of skeletal muscles because
The more active they are the more heat is released
Threshold stimulus is defined as the?
Minimal amount of stimulus required to cause a muscular contraction
The strength of a muscle contraction in response to different levels of stimulation is determined by?
The number of motor units stimulated
The union between a neuron and a muscle fiber is called the?
Neuromuscular junction
24. The smallest, functional, contractile unit of muscle is called the?
Sarcomere
25. The protein muscle that has heads jutting out for cross binding is?
Myosin
Which protein molecule comprises the thick myofilaments?
Myosin
Thick myofilaments extend across the length of this section of a sarcomere?
A band
One sarcomere extends from?
Z line to Z line
Attempting to pick up object too heavy to lift result in which type of muscle contraction?
Isometric
The ion needed for cross-bridging to occur is?
Calcium
In the sarcoplasm of the muscle fiber are ___ that are parallel to one another; they contain the protein myofilaments myosin and actins
Myofibrils
The cell membrane surrounding each skeletal muscle fiber is called
o Sarcolemma
Muscle that provides for most of the movement
o Prime mover
The end of the muscle that connects to a movable part
Insertion
Thin actin filaments
I Band
Thick myosin with overlapping actin
A Band
Line where actin and myosin attach
Z Line
A thickening of myosin
M Line
Central region of only myosin filaments
H Zone
A recording of a muscle contraction is called
Myogram
The energy used in muscle contraction is primarily supplied by the decomposition of
ATP
The characteristics striated appearance of skeletal muscle is due to the arrangement of the alternating patter of the protein myofilaments
Actin and myosin
A bundle of muscle fibers is called a
Fascicle
Muscle fatigue is most likely due to an accumulation of
Lactic acid
A forceful sustained muscle contraction is called
Summation