Chapter 9 Quiz Show Flashcards
What is the functional unit of a skeletal muscle termed?
a. The sarcomere
b. The A band
c. The myofibril
d. The sarcolemma
a. the sarcomere
A sheet-like extension of the epimysium is called a(n) ________.
a. aponeurosis
b. fascicle
c. sarcoplasmic reticulum
d. tendon
a. aponeurosis
Thick filaments are found in the ________ of the sarcomere.
a. Z disc
b. I band
c. A band
d. All of the above contain thick
filaments.
c. a band
In a resting muscle cell, the myosin-binding sites are blocked by ________.
a. actin
b. troponin
c. titin
d. tropomyosin
d. tropomyosin
T tubules are an extension of the ___________.
a. sarcomere
b. sarcoplasmic reticulum
c. sarcolemma
d. endomysium
c. sarcolemma
When a muscle cell is at rest, most of the intracellular calcium is found stored in the ___________.
a. sarcoplasm
b. T tubule
c. sarcoplasmic reticulum
d. myosin heads
c. sarcoplasmic reticulum
Calcium ions will bind to ________ when present in the sarcoplasm.
a. myosin heads
b. ATP
c. myosin-binding sites
d. troponin
d. troponin
What substance must bind to myosin heads in order for the heads to detach from the thin filaments?
a. Calcium
b. ATP
c. Troponin
d. Sodium
b. ATP
Calcium is released from the terminal cisterns in response to ______.
a. ATP
b. calcium pumps
c. an action potential
d. troponin
c. an action potential
How does calcium reenter the terminal cisterns after muscle contraction is finished?
a. Diffusion
b. Active transport
c. Filtration
d. Endocytosis
b. active transport
A single contraction in response to a single threshold stimulus is defined as _________.
a. summation
b. tetany
c. treppe
d. a twitch
d. a twitch
The force exerted by a contracting muscle is __________.
a. muscle summation
b. muscle twitch
c. muscle tension
d. muscle load
c. muscle tension
The time that elapses between the stimulation of a muscle and the contraction of that muscle is defined as the _______.
a. depolarization period
b. latent period
c. recruitment period
d. refractory period
b. latent period
Which is NOT a factor that affects the force of muscle contraction?
a. Relative size of muscle fibers
b. Number of muscle fibers stimulated
c. Degree of muscle stretch
d. Method of muscle stimulation
d. method of muscle stimulation
Skeletal muscle contractions increase in strength because of ___________.
a. incomplete tetany
b. recruitment of motor units
c. an increase in threshold stimulus
d. increasing the number of twitches
b. recruitment of motor units
The energy source that is used directly for muscle contraction is ______.
a. ATP
b. glucose
c. creatine phosphate
d. fatty acids
a. ATP
Muscle soreness may be due in part to which pathway of ATP production?
a. Phosphorylation
b. Aerobic respiration
c. Anaerobic glycolysis
d. Oxidation
c. anaerobic glycolysis
After about 30 minutes of exercise, which substance becomes the major source of fuel?
a. Glucose
b. Pyruvic acid
c. Fatty acid
d. Lactic acid
c. fatty acid
Which activity would be most dependent upon creatine?
a. Tennis
b. Soccer
c. Jogging
d. Diving
d. diving
Which term refers to the length of time a muscle can continue to contract using aerobic pathways?
a. Aerobic threshold
b. Anaerobic threshold
c. Aerobic endurance
d. Anaerobic endurance
c. aerobic endurance
Contraction of which sheet of smooth muscle results in shortening of the organ?
a. Circular layer
b. Transverse layer
c. Longitudinal layer
d. Square layer
c. longitudinal layer
Smooth muscle cells can contract as a unit because of the presence of __________.
a. dense bodies
b. gap junctions
c. diffuse junctions
d. motor end plates
b. gap junctions
Calcium binds to this substance in smooth muscle contraction.
a. Troponin
b. Calmodulin
c. ATP
d. Myosin kinase
b. calmodulin
Smooth muscle contains ________ that correspond to the Z discs of skeletal muscle.
a. dense bodies
b. varicosities
c. diffuse junctions
d. gap junctions
a. dense bodies
