Question 9
1.
A severe mutation of troponin C has occurred. A likely result of this
Answer
prevents troponin from binding to actin.
increases the power stroke.
myosin binds more strongly to actin.
reduction of the affinity of troponin to bind to actin.
causes separation of the F-actin filaments from the tropomyosin.
exposes more myosin binding active sites to myosin.
causes the tropomyosin to more tightly bind the actin.
is troponin-tropomyosin inhibition of actin does not occur.
1 points
Question 10
1.
Motor units vary in size. The smaller motor units are innervated by smaller, more excitable alpha motor neurons, and are therefore simulated first. Increased need for more contraction results in incorporation of larger and larger motor unit incorporation innervated by larger, but less excitable alpha motor neurons. This gradation of muscle force is referred to as:
Answer
frequency summation
tetanization
Treppe
muscle tone
gamma motor neuron inhibition
multiple fiber summation
hypertrophy
muscle fatigue
1 points
Question 11
1.
The cellular biological basis for rigor mortis is:
Answer
tropomysosin and actin degrades, thereby preventing myosin binding
no calcium is able to binding to troponin
the muscles undergo tetanization
unavailable ATP prevents mysosin from detaching from actin
calcium remains in the sarcoplasmic reticulum
calcium remains in the sarcomere
calmodulin inhibits the ryanodine receptor in sarcoplasmic reticulum
muscular atrophy from disuse results in paralysis
1 points
Question 12
1.
Which of the following does not shorten during a muscular contraction?
Answer
myofibril
H band
I band
sarcomere
muscle fasciculus
A band
Z-Z
muscle
1 points
Question 13
1.
An action potential has a plateau before repolarization commences. Which of the following is a reasonable explanation for the plateau?
Answer
slower opening of voltage-gated Na+ channels
faster opening of voltage-gated K+ channels
closing of voltage-gated Na+ channels
slow opening of voltage-gated Ca2+ channels
slow closing of voltage-gated K+ channels
fast opening of Cl- channels
increases permeability of leaky K+ channels
1.
A severe mutation of troponin C has occurred. A likely result of this
Answer
prevents troponin from binding to actin.
increases the power stroke.
myosin binds more strongly to actin.
reduction of the affinity of troponin to bind to actin.
causes separation of the F-actin filaments from the tropomyosin.
exposes more myosin binding active sites to myosin.
causes the tropomyosin to more tightly bind the actin.
is troponin-tropomyosin inhibition of actin does not occur.
1 points
Question 10
1.
Motor units vary in size. The smaller motor units are innervated by smaller, more excitable alpha motor neurons, and are therefore simulated first. Increased need for more contraction results in incorporation of larger and larger motor unit incorporation innervated by larger, but less excitable alpha motor neurons. This gradation of muscle force is referred to as:
Answer
frequency summation
tetanization
Treppe
muscle tone
gamma motor neuron inhibition
multiple fiber summation
hypertrophy
muscle fatigue
1 points
Question 11
1.
The cellular biological basis for rigor mortis is:
Answer
tropomysosin and actin degrades, thereby preventing myosin binding
no calcium is able to binding to troponin
the muscles undergo tetanization
unavailable ATP prevents mysosin from detaching from actin
calcium remains in the sarcoplasmic reticulum
calcium remains in the sarcomere
calmodulin inhibits the ryanodine receptor in sarcoplasmic reticulum
muscular atrophy from disuse results in paralysis
1 points
Question 12
1.
Which of the following does not shorten during a muscular contraction?
Answer
myofibril
H band
I band
sarcomere
muscle fasciculus
A band
Z-Z
muscle
1 points
Question 13
1.
An action potential has a plateau before repolarization commences. Which of the following is a reasonable explanation for the plateau?
Answer
slower opening of voltage-gated Na+ channels
faster opening of voltage-gated K+ channels
closing of voltage-gated Na+ channels
slow opening of voltage-gated Ca2+ channels
slow closing of voltage-gated K+ channels
fast opening of Cl- channels
increases permeability of leaky K+ channels