Muscle test

The cell membrane of a muscle fiber is called ________. myofibril sarcolemma sarcoplasm myofilament

sarcolemma

Thin and thick filaments are organized into functional units called ________. myofibrils myofilaments T-tubules sarcomeres

sarcomeres

Which cell type helps to repair injured muscle fibers? ganglion cells myotube cells myoblast cells satellite cells

satellite cells

If cardiac muscle cells were prevented from undergoing aerobic metabolism, they ultimately would ________. undergo glycolysis synthesize ATP stop contracting start contracting

stop contracting

Depolarization of the sarcolemma means ________. the inside of the membrane has become less negative as sodium ions accumulate the outside of the membrane has become less negative as sodium ions accumulate the inside of the membrane has become more negative as sodium ions accumulate the sarcolemma has completely lost any electrical charge

the inside of the membrane has become less negative as sodium ions accumulate

The muscles of a professional marathon runner are most likely to have ________. 80 percent fast-twitch muscle fibers and 20 percent slow-twitch muscle fibers 20 percent fast-twitch muscle fibers and 80 percent slow-twitch muscle fibers 50 percent fast-twitch muscle fibers and 50 percent slow-twitch muscle fibers 40 percent fast-twitch muscle fibers and 60 percent slow-twitch muscle fibers Correct!

20 percent fast-twitch muscle fibers and 80 percent slow-twitch muscle fibers

The muscles of a professional sprinter are most likely to have ________. 80 percent fast-twitch muscle fibers and 20 percent slow-twitch muscle fibers 20 percent fast-twitch muscle fibers and 80 percent slow-twitch muscle fibers 50 percent fast-twitch muscle fibers and 50 percent slow-twitch muscle fibers 40 percent fast-twitch muscle fibers and 60 percent slow-twitch muscle fibers

80 percent fast-twitch muscle fibers and 20 percent slow-twitch muscle fibers

Which element is important in directly triggering contraction? sodium (Na+) calcium (Ca++) potassium (K+) chloride (Cl-)

Calcium

Which of the following statements is true? Fast fibers have a small diameter. Fast fibers contain loosely packed myofibrils. Fast fibers have large glycogen reserves. Fast fibers have many mitochondria.

Fast fibers have large glycogen reserves.

Which of the following statements is false? Slow fibers have a small network of capillaries. Slow fibers contain the pigment myoglobin. Slow fibers contain a large number of mitochondria. Slow fibers contract for extended periods. Correct!

Slow fibers have a small network of capillaries.

The muscle that has a striped appearance is described as being ________. -elastic -non-striated -excitable -striated

Striated

Which of the following statements describes smooth muscle cells? They are resistant to fatigue. They have a rapid onset of contractions. They cannot exhibit tetanus. They primarily use anaerobic metabolism.

They are resistant to fatigue.

In relaxed muscle, the myosin-binding site on actin is blocked by ________. titin troponin myoglobin tropomyosin

Tropomyosin

A sprinter would experience muscle fatigue sooner than a marathon runner due to ________. anaerobic metabolism in the muscles of the sprinter anaerobic metabolism in the muscles of the marathon runner aerobic metabolism in the muscles of the sprinter glycolysis in the muscles of the marathon runner

anaerobic metabolism in the muscles of the sprinter

Which of the following properties is not common to all three muscle tissues? excitability the need for ATP at rest, uses shielding proteins to cover actin-binding sites elasticity

at rest, uses shielding proteins to cover actin-binding sites

According to the sliding filament model, binding sites on actin open when ________. creatine phosphate levels rise ATP levels rise acetylcholine levels rise calcium ion levels rise

calcium ion levels rise

Muscle relaxation occurs when ________. calcium ions are actively transported out of the sarcoplasmic reticulum calcium ions diffuse out of the sarcoplasmic reticulum calcium ions are actively transported into the sarcoplasmic reticulum calcium ions diffuse into the sarcoplasmic reticulum

calcium ions are actively transported into the sarcoplasmic reticulum

During muscle contraction, the cross-bridge detaches when ________. the myosin head binds to an ADP molecule the myosin head binds to an ATP molecule calcium ions bind to troponin calcium ions bind to actin

calcium ions bind to troponin

Cardiac muscles differ from skeletal muscles in that they ________. are striated utilize aerobic metabolism contain myofibrils contain intercalated discs

contain intercalated discs

During which phase of a twitch in a muscle fiber is tension the greatest? resting phase repolarization phase contraction phase relaxation phase

contraction phase

Muscle fatigue is caused by ________. buildup of ATP and lactic acid levels exhaustion of energy reserves and buildup of lactic acid levels buildup of ATP and pyruvic acid levels exhaustion of energy reserves and buildup of pyruvic acid levels

exhaustion of energy reserves and buildup of lactic acid levels

The correct order for the smallest to the largest unit of organization in muscle tissue is ________. fascicle, filament, muscle fiber, myofibril filament, myofibril, muscle fiber, fascicle muscle fiber, fascicle, filament, myofibril myofibril, muscle fiber, filament, fascicle

filament, myofibril, muscle fiber, fascicle

Smooth muscles differ from skeletal and cardiac muscles in that they ________. lack myofibrils are under voluntary control lack myosin lack actin

lack myofibrils

From which embryonic cell type does muscle tissue develop? ganglion cells myotube cells myoblast cells satellite cells

myoblast cells

What aspect of creatine phosphate allows it to supply energy to muscles? ATPase activity phosphate bonds carbon bonds hydrogen bonds

phosphate bonds