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45 Cards in this Set
- Front
- Back
A sarcomere is best described as |
a unit within a myofibril |
|
Myofibrils are composed primarily of |
actin and myosin |
|
A motor unit typically includes |
one motor neuron and several muscle fibers |
|
Endomysium separates individual muscle fibers from each other
True or False |
True |
|
A motor neuron and the muscle fibers that it controls constitute a motor unit
True or false |
True |
|
A broad sheet of dense connective tissue that connects muscle to muscle is called |
aponeurosis |
|
The electrical impulse that triggers a contraction travels deep into a skeletal muscle fiber by means of |
transverse tubules |
|
Neurotransmitter molecules are stored in vesicles within |
motor neuron endings |
|
The enzyme acetylcholinesterase causes acetylcholine to |
decompose |
|
Creatine phosphate |
supplies energy for the synthesis of ATP |
|
Binding sites on the surface of actin allow the formation of cross bridges with molecules of |
myosin |
|
The amount of oxygen needed to support the conversion of lactic acid to glucose by the liver is called the |
oxygen debt |
|
A muscle cramp is most likely due to a temporary lack of |
ATP |
|
In the initiation of muscle contraction, calcium ions bind to tropomyosin, exposing active sites on actin for cross bridge formation
True or false |
False
|
|
The enzyme ATPase occurs in the globular portion of myosin molecules.
True or false |
True |
|
A C H released by a motor neuron crosses the synaptic cleft and reaches the motor end plate by diffusion
True or false |
True |
|
An example of a partial but sustained contraction of a whole muscle is |
eye blinking |
|
The characteristic reddish brown color of skeletal muscle comes from |
myoglobin |
|
The threshold stimulus is the |
minimum strength of stimulus required to cause muscle fiber contraction to occur |
|
The botulinum toxin that causes botulism acts by blocking acetylcholine receptors on the motor end plate What is an example of this? |
muscle weakness or paralysis |
|
Rigor mortis that occurs in skeletal muscles a few hours after death is due to |
a lack of ATP increased membrane permeability to calcium ions |
|
ATP is necessary for muscle relaxation
True or false |
True |
|
During anaerobic respiration, pyretic acid molecules are converted into molecules of |
lactic acid |
|
Anaerobic muscle fatigue is most likely due to an accumulation of |
lactic acid |
|
The increase in the number of motor units activated as a result of more intense stimulation is called |
recruitment |
|
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 |
latent period |
|
Activities such as distance swimming and distance running are most likely to stimulate development of |
slow fatigue resistant muscle fibers |
|
When a muscle undergoes atrophy in response to disuse |
the muscle gets smaller |
|
The minimal strength of stimulation needed to elicit a muscle contraction is called the threshold stimulus
true or false |
True
|
|
The time lag between she n a muscle is stimulated and when it begins to contract is called the |
latent period |
|
The rhythmic, wavelike motion produced by visceral smooth muscle is called |
peristalsis |
|
The enlargement of muscle fibers such as a result of exercise is called |
hypertrophy |
|
Multiunit smooth muscle cells |
respond to stimulation b neurons and certain hormones |
|
The term Muscle can refer to |
a cell a tissue an organ |
|
Compared to skeletal muscle, smooth muscle |
contracts more slowly and relaxes more slowly |
|
The two neurotransmitters that affect smooth muscle cells are acetylcholine and |
norepinephhrine |
|
Cardiac muscle is located in the walls of the blood vessels
True or false |
false, heart |
|
Muscles that assist a prime mover are called |
synergists |
|
Functions of muscle include |
the heartbeat muscle tone production of heat moving body parts |
|
The movable end of a muscle is attached at its |
insertion |
|
The muscle primarily responsible for opposing a particular action is called the |
antagonist |
|
Identify the three basic types of muscles |
skeletal, smooth, cardiac |
|
Describe the roles of actin and myosin |
Myosin is thick filaments of myofibrils, actin is thin filaments - type of muscle protein |
|
Describe a motor unit |
a motor neuron and the muscle fibers it controls makes up a motor unit. when simulated to do so, the muscle fibers of the motor unit contract all at once |
|
Muscles are named according to |
size, shape, location, action, number of attachments or direction of its fiber |