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Unit 3 Chapter 11
Muscular Tissue
Question | Answer |
---|---|
What is the characteristic that allows muscles to pull on bones and organs to create movement called? | Contractility |
Where is skeletal muscle usually found? | Attached to bones |
Which are long protein cords found in sarcoplasm of skeletal muscle cells? Myofibrils Glycogen Myoglobin | Myofibrils |
Which protein makes up the thick filaments of a myofibril? | Myosin |
Within skeletal muscle cells, what extends from one Z disc to the next and constitutes one contractile unit? | Sarcomere |
What is the ability of muscle cells to shorten called? | Contractility |
What is a motor unit? | All of the muscle fibers innervated by a single motor nerve fiber |
Skeletal muscle exhibits alternating light and dark bands called ______________ | Striations |
A synapse is the point where a nerve fiber meets a target cell. When the target cell is a muscle fiber, this type of synapse is called a __________ junction | : neuromuscular |
Muscle cells contain __________, a starch-like carbohydrate that provides energy during intense exercise. | Glycogen |
Resting membrane potential is which of the following? A distance An amount of liquid A voltage | A voltage |
In a myofibril, a thick filament is composed of pairs of _____________ molecules intertwined together. | Myosin |
Excitation involves the generation of action potentials, and occurs in both neurons and muscle fibers. True False | True |
The portion of a myofibril from one Z disc to the next is called a(n) _______________. | Sarcomere |
Action potentials spread across the sarcolemma and continue down which structures into the sarcoplasm? | T tubules |
One nerve fiber and all the muscle fibers it innervates is called what? A ganglion A motor unit A somatic cell A fascicle | A motor unit |
The prevailing theory regarding muscle contraction is called the ___________ filament theory. | Sliding |
What is a neuromuscular junction? | A site where a nerve fiber communicates with a muscle fiber |
Acetylcholinesterase is which of the following? A form of energy An enzyme A neurotransmitter | An enzyme |
The voltage measured across the muscle cell at rest is about -90mV and is called the resting membrane ______________________. | potential |
A continuous state of partial contraction of a muscle is called muscle ______________ | Tone |
A record of the timing and strength of a muscle's contraction is called a(n) | myogram |
Action potentials cause the opening of voltage-gated sodium ion channels in the_________________ tubules. This leads to the opening of calcium ion channels in the terminal cisternae of the sarcoplasmic reticulum. | t |
The minimum voltage necessary to generate a muscle twitch is called the __________ | threshold |
What does the sliding filament theory describe? | Muscle contraction |
What type of contraction involves the development of tension but no change in length? | Isometric |
What is the role of acetylcholinesterase? | It breaks down ACh, ending muscle stimulation. |
The partial contraction of a resting muscle is known as which of the following? | Muscle tone |
A myogram is a graph of what? | A muscle twitch |
Aerobic respiration utilizes what two molecules as fuel to generate ATP? | Fatty acids Glucose |
The progressive weakness and loss of contractility that results from prolonged use of the muscles is known as muscle __________ | Fatigue |
Which type of contraction maintains joint stability and posture? | Isometric |
Isotonic contraction | This type of contraction is used for body movements and for moving objects. |
Why does increased oxygen consumption continue after exercise? | To replace the oxygen bound to myoglobin and hemoglobin |
Aerobic respiration produces Blank______ ATP than glycolysis. | more |
In high-intensity short-duration exercise, what does muscle fatigue result from? | Increased potassium |
When lifting something heavy, which type of contraction occurs first? | Isometric |
Fibers that are well adapted to aerobic respiration are called Blank______ -twitch fibers. | slow |
Excess postexercise oxygen consumption is also known as which of the following? | Oxygen debt |
When a muscle is at rest, most of its ATP is generated by Blank______ of fatty acids | aerobic respiration |
Which of the following is true of endurance exercise? | It increases oxygen transport in the blood. |
Which describes slow-twitch fibers? | They have a rich blood supply. |
Which types of muscle tissue are considered involuntary? | Cardiac and smooth |
What function does increased oxygen consumption after exercise serve? | To allow the conversion of lactic acid to pyruvate and glucose by the liver |
Where is cardiac muscle found? | In the heart wall only |
Which occurs during high intensity, short-duration exercises that causes fatigue? | ADP and phosphate accumulation |
Smooth muscle is named for the fact that it has no Blank______. | striations |
Resistance exercise causes muscle growth by stimulating which of the following? | An increase in myofibril size |
Walls of the heart consist of _______ muscle tissue. | cardiac |
Which describes smooth muscle tissue? | Uninucleate, non-striated |