A dark band formed by parallel thick filaments that partly overlap the thin filaments is known as an H band
Clinically, dystrophin is the most important noncontractile protein to occur in muscle fibers
The sliding filament theory of muscle contraction has emerged from research only in the last 10 to 15 years.
to neutralize carbon dioxide buildup
Which of the following is not a purpose of the excess postexercise oxygen consumption in muscle?
Which muscle type depends solely on the sarcoplasmic reticulum as its calcium source?
Michael Jordan was arguably the best player in professional basketball history. Scientifically one would expect him to have highly developed
intercalated discs of cardiac muscle
Where would you expect to find numerous gap junctions in muscular tissue?
it does not have Z discs
The contraction strength of smooth muscle is relatively independent of its resting length partly because
Which of the following is very important for muscle to continue contraction during anaerobic respiration?
If one nerve stimulus arrives at a muscle fiber so soon that the fiber has only partially relaxed from the previous twitch, the most likely result will be
The muscle lengthens but tension remains constant.
Which of the following is true concerning isotonic eccentric contraction?
To stimulate muscle contraction, acetylcholine is released from the ___________ into the
to inhibit the function of cholinesterase
Which statement best describes the goal of medications used to treat myasthenia gravis?
Aerobic respiration produces approximately _____ more ATPs per glucose molecule than glycolysis does
longer aerobic respiration
Athletes who train at high altitudes increase their red blood cell count and thus increase their oxygen supply during exercise. Increased oxygen supply results in
recruit more muscle fibers.
As you are lifting a box someone places extra weight on top of it. For your muscle to continue contracting and lifting the box, the muscle must
prevent calcium from entering smooth muscle, thus allowing the muscle to relax
Drugs called calcium channel blockers may be used to lower blood pressure by causing arteries to vasodilate. These drugs
Exposure to Clostridium tetani causes continuous release of ACh. What effect does this have on smooth muscle?
between the thin myofilaments and the sarcolemma of a muscle fiber.
Dystrophin, the protein that is defective in muscular dystrophy, is normally found
Ca2+ accumulates in the sarcoplasm faster than the sarcoplasmic reticulum can reabsorb it.
A reason that muscle twitches become progressively stronger in treppe is
The intracellular environment is negatively charged.
Which of the following best describes the resting membrane potential (RMP)?
. The triad allows for Ca2+ release when a muscle fiber is excited.
What is the purpose of the triad?
a 22-year-old football player
Which of the following individuals would have more mitochondria in his skeletal muscle?
the phosphagen system
Which of the following systems would provide energy for a racquetball player?
an elastic filament.
A myofilament that flanks a thick filament and anchors it to a Z disc is called
The bladder's ability to greatly distend and return to normal tension is due to the ___ of smooth muscles
partially stretched before being stimulated
A skeletal muscle generates the greatest tension when it is
make more use of aerobic respiration.
A volleyball player depends on the gastrocnemius muscles for plantar flexion, whereas a marathon runner depends more on the soleus muscles for the same action. This is because the soleus muscles