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ch 9
muscles
Question | Answer |
---|---|
Functions of muscles are for | A.the heartbeat.B.muscle tone.C.distribution of heat.D.moving bones. |
The outermost layer of connective tissue surrounding a skeletal muscle is the | Epimysium. |
Myofibrils are composed primarily of | actin and myosin. |
The striated appearance of skeletal muscle results from the | sarcomere organization. |
Transverse tubules | transmit muscle impulses into the cell interior. |
The discoloration and swelling of a muscle strain is due to | ruptured blood vessels. |
A tendon is ______, whereas an aponeurosis is ______. | cordlike and connects muscles to bones; a broad, fibrous sheet of connective tissue that connects muscles to muscles |
Muscle fibers are basically a collection of | sarcomeres |
Transverse tubules and sarcoplasmic reticulum are well developed in fibers | skeletal muscle fibers |
The functional unit of muscle contraction is | the sacomere |
Neurotransmitters are stored in vesicles in | motor neuron endings |
The enzyme acetylecholinesterase causes acetylcholine to | decompose |
creatine phosphate | supplies energy for the synthesis of ATP. |
The amount of oxygen liver cells require to react lactic acid to produce glucose or the glycogen glycogen is the | oxygen dept |
Tawanda finishes a sprint and suffers great pain in her calf muscles. Her muscle cramps are most likely dueto a temporary deficit of | ATP |
Athletes usually experience muscle fatigue less quickly than nonathletes because they | .produce less lactic acid. |
At a neuromuscular junction the muscle fiber membrane folds forming a | motor end plate |
The toxin that causes botulism | prevents release of acetylcholine. |
Rigor mortis affects skeletal muscles a few hours after death due to | decreased ATP and increased permeability to calcium. |
At a neuromuscular junction | .neurotransmitters are released. |
The first event in muscle fiber contraction is that. | acetylcholine is released from the end of the motor neuron. |
Which of the following statements is correct? | Actin filaments slide along myosin filaments. |
The functional connection between a neuron and a skeletal muscle fiber is | synapse |
__________ degrades acetylcholine keeping it from accumulating in the synapse. | Acetylcholinesterase |
A shift in metabolism that breaks down pyruvic acid to lactic acid is called | anaerobic threshold. |
Oxygen debt in muscles may develop because of | the inability of respiratory and circulatory systems to supply enough oxygen to skeletal muscles when used strenuously for a minute or two. |
The relationship between ATP and creatine phosphate is that | creatine phosphate supplies energy to regenerate ATP from ADP and phosphate. |
A motor unit is | a motor neuron and the muscle fibers connected to it. |
during muscle contraction ATP supplies energy for | myofilament movement. |
Skeletal muscles help maintain body temperature in that | .the more active they are the more heat is released. |
Threshold stimulus is the | minimal amount of energy required to contract a muscle fiber |
A myogram is | a recording of the events of a twitch. |
An example of a partial but sustained contraction is | muscle tone |
Which of the following is not true | Red fibers have fewer mitochondria than white. |
in a recording of a muscle twitch the delay between the time a stimulus is applied and the time the muscleresponds is called the | latent period |
The very brief moment following stimulation when a muscle remains unresponsive to additional stimulationis called the | refractory period |
Smooth muscle lacks | transverse tubules and striations. |
Smooth muscle has ___________ and not troponin. | calmodulin |
Compared to skeletal muscle smooth muscle | contracts more slowly and relaxes more slowly. |
The type of muscle cell that lacks transverse tubules has a single nucleus and is under involuntary control is | smooth muscle |
Short muscle cells with centrally located nuclei are | smooth muscle fibers |
Both acetylcholine and norepinephrine can affect | smooth muscle contraction |
The structures that connect cardiac muscle cells are. | intercalated disc |
Cardiac muscle | A.contracts as a syncytium.B.excites itself. C.responds in an all-or-none manner D.is only in the heart. |
Bones and muscles function as mechanical devices called | levers |
The movable end of a muscle is its | insertion |
The muscle primarily responsible for an action is the | prime mover |
A muscle that assists a prime mover is a(n) | synergist |
The buccinator muscle is in the | cheek |
The muscle that adducts and flexes the arm is the | coracobrachialis. |
The linea alba is | a band of tough connective tissue to which abdominal wall muscles attach. |
The soleus is a muscle that forms part of the | calf |
Which of the following is not a muscle of mastication? | mandibular |
Which of the following is unique in that its insertion is to fascia and not bone? | palmaris longus. |
The triangle of auscultation commonly used to hear sounds of respiratory organs is located near the border of the | trapezius and latissimus dorsi. |
A gluteal gait in which a person walks with a waddling limp is usually caused by a disorder of the | gluteus medius and gluteus minimus. |
A sign of aging of the muscular system is | decreased supplies of myoglobin to muscles. |
Muscle atrophy that progresses with aging is caused by reduction in | A.ATP.B.myoglobin.C.the sizes of muscle fibers.D.creatine phosphate. |
People with myasthenia gravis lack | about two-thirds of the normal number of acetylcholine receptors |
Myasthenia gravis is | an autoimmune disorder |
Weightlifting in which a muscle exerts more than 75% of its maximum tension stimulates | muscle fibers developing new filaments of actin and myosin |
Fibers of muscles whose motor neurons are severed. | may be replaced by fat or fibrous connective tissue. |
Temporomandibular joint (TMJ) syndrome cause | A.insomnia.B.ringing in the ears.C. backache.D.clicking sound from the jaw. |
Binding sites on the surface of actin allow the formation of cross-bridges with molecules of | myosin |
the characteristic reddish brown color of skeletal muscle comes from this substance | myoglobin |
Activities such as distance swimming and distance running are most likely to stimulate development of | slow, fatigued, resistant muscle fibers |
the increase in the number of motor units activated are a result of more intense stimulation | recruitment |