Muscle Tissue
50 questions available
Questions
Which property of muscle tissue is defined as its ability to be stretched or extended?
View answer and explanationWhat is a key structural difference between skeletal muscle fibers and cardiac muscle fibers?
View answer and explanationWhich layer of connective tissue wraps around an entire skeletal muscle?
View answer and explanationWhat is the term for a bundle of muscle fibers organized by a middle layer of connective tissue called the perimysium?
View answer and explanationWhat is the specialized smooth endoplasmic reticulum in a muscle fiber that stores, releases, and retrieves calcium ions?
View answer and explanationWhich structure is considered the functional unit of a skeletal muscle fiber, defined as the region from one Z-disc to the next?
View answer and explanationWhat is the function of the T-tubules in a skeletal muscle fiber?
View answer and explanationWhat neurotransmitter is released at the neuromuscular junction (NMJ) to initiate skeletal muscle contraction?
View answer and explanationAccording to the sliding filament model, what is the first step that initiates muscle contraction after an action potential reaches the muscle fiber?
View answer and explanationWhat happens to the sarcomere during muscle contraction according to the sliding filament model?
View answer and explanationWhat is the function of the protein tropomyosin in a resting skeletal muscle?
View answer and explanationIn the cross-bridge cycle of muscle contraction, what is the direct role of ATP binding to the myosin head?
View answer and explanationWhat is the direct physiological cause of rigor mortis, the rigidity observed in skeletal muscles soon after death?
View answer and explanationFor approximately how long can creatine phosphate-derived ATP power muscle contraction?
View answer and explanationIn the absence of oxygen, what is pyruvic acid converted to, which may contribute to muscle fatigue?
View answer and explanationApproximately how many ATPs are produced per molecule of glucose via aerobic respiration compared to anaerobic glycolysis?
View answer and explanationWhat is meant by the term 'oxygen debt' following intense muscle activity?
View answer and explanationWhich of the following events initiates the relaxation of a skeletal muscle fiber?
View answer and explanationWhat is the term for the increase in muscle mass and bulk resulting from the increased production of sarcomeres and myofibrils within muscle fibers?
View answer and explanationDuchenne muscular dystrophy (DMD) is a progressive weakening of skeletal muscles caused by a lack of which protein?
View answer and explanationWhich type of skeletal muscle contraction involves the muscle producing tension without changing the angle of a skeletal joint, such as when attempting to lift a weight that is too heavy?
View answer and explanationLowering a hand weight in a slow and controlled manner, where muscle tension diminishes and the muscle lengthens, is an example of what type of contraction?
View answer and explanationWhere in the human body would you expect to find small motor units, where a single motor neuron supplies a small number of muscle fibers?
View answer and explanationWhat is the term for the increase in muscle contraction strength that occurs as more motor units are enlisted to activate larger muscle fibers?
View answer and explanationAt what percentage of its resting length does a sarcomere produce the maximal tension?
View answer and explanationWhat is the first phase of a muscle twitch, during which the action potential is being propagated along the sarcolemma but contraction has not yet occurred?
View answer and explanationWhen a muscle fiber is stimulated while a previous twitch is still occurring, the second twitch will be stronger. What is this response called?
View answer and explanationWhat is the state of muscle contraction called when the stimulus frequency is so high that the relaxation phase disappears completely, leading to continuous contraction?
View answer and explanationWhat is the term for the small amount of contraction that allows muscles to stabilize joints and maintain posture, even when not producing movement?
View answer and explanationWhich type of skeletal muscle fiber contracts relatively slowly and uses aerobic respiration to produce ATP, making it highly resistant to fatigue?
View answer and explanationWhich characteristic is typical of fast glycolytic (FG) fibers?
View answer and explanationWhy do slow oxidative (SO) muscle fibers have a red color?
View answer and explanationFast oxidative (FO) fibers, which produce more tension than SO fibers but are more fatigue-resistant than FG fibers, are primarily used for which type of movement?
View answer and explanationWhat is the primary effect of endurance exercise on slow oxidative (SO) muscle fibers?
View answer and explanationWhat is the term for irreversible, age-related muscle atrophy where muscle fibers die and are replaced by connective and adipose tissue?
View answer and explanationResistance exercise, which requires large amounts of FG fibers, primarily affects muscles by increasing the formation of what structures, thereby increasing muscle thickness?
View answer and explanationWhat is the main function of erythropoietin (EPO) when used as a performance-enhancing substance by endurance athletes?
View answer and explanationWhich of the following is a characteristic feature of cardiac muscle tissue?
View answer and explanationWhat two structures, important for cardiac muscle contraction, are contained within intercalated discs?
View answer and explanationWhat is the term for the ability of specialized cardiac muscle cells, called pacemaker cells, to self-excite and fire action potentials on their own at set intervals?
View answer and explanationHow are smooth muscle fibers typically described in terms of shape and number of nuclei?
View answer and explanationIn a smooth muscle fiber, which regulatory protein does Ca++ bind to in order to initiate contraction, as it does not contain troponin?
View answer and explanationWhat is the key difference between single-unit smooth muscle and multiunit smooth muscle?
View answer and explanationWhat is the name for the subset of cross-bridges in some smooth muscles that can remain linked together for a prolonged period without the need for ATP, allowing for the maintenance of muscle tone?
View answer and explanationUnlike skeletal and cardiac muscle, smooth muscle can divide to produce more cells. What is this process called?
View answer and explanationMost muscle tissue of the body, excluding those of the head and limbs, develops from which embryonic structures that arise from paraxial mesodermal cells?
View answer and explanationDuring early development, embryonic myoblasts fuse to form a syncytium, or a continuous cytoplasm with many nuclei. What is this structure called?
View answer and explanationWhat is the function of satellite cells in skeletal muscle tissue?
View answer and explanationWhen a muscle is damaged to a greater extent than can be repaired by satellite cells, the muscle fibers are replaced by scar tissue. What is this process called?
View answer and explanationWhich type of muscle tissue has the greatest ability to regenerate and repair itself, utilizing stem cells called pericytes found in some small blood vessels?
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