c09 Practice Quiz
On this quiz, score 80% or higher, and receive a +5 bonus on the test.
Your LAST Name:
1. Oxygen starved tissues can release chemical signals into the blood that can change the diameter of nearby blood vessels delivering oxygen and nutrients to the tissues. In doing so the blood vessels will respond through vasodilation (widening of the vessel). Which muscle type is responsible for this vasodilation?
2. Rigor mortis occurs because ________.
sodium ions leak into the muscle causing continued contractions
no ATP is available to release attached actin and myosin molecules
the cells are dead
proteins are beginning to break down, thus preventing a flow of calcium ions
3. If a muscle fiber were to suddenly and permanently stop producing ATP the fiber would no longer be able to actively transport calcium out of the cytoplasm (sarcoplasm) and the intracellular calcium concentration would rise. Which of the following would you expect to happen?
No change would occur in a muscle that was relaxed to begin with.
Calcium would be transported to the sarcoplasmic reticulum therefore contractions would cease.
Myosin would be able to bind to the exposed binding sites on thin filaments but it would not be able to detach.
The fiber would twitch uncontrollably due to excessive calcium bound to troponin.
4. Of the following muscle types, which has only one nucleus, no sarcomeres, and few gap junctions?
multiunit smooth muscle
visceral smooth muscle
5. Curare is a poisonous plant extract. Curare molecules have a chemical structure like the neurotransmitter ACh. Curare can bind to the ACh receptor site on the chemically gated ion channels in the motor end plate. Even though curare will bind to the receptor site it will not open the ion channel and no ions will pass through. What do you think the symptoms of curare poisoning would look like?
Curare will only affect muscles with ACh receptors, paralyzing them.
Muscles will respond too quickly and cause a severe tremor.
Curare will only affect cardiac muscle, causing fibrillations of the heart.
Smooth muscles will become stimulated causing quick movement of nutrients through the digestive system.
6. A myosin molecule in the thick filaments can be considered a protein having a quaternary structural level. Which of the following best describes this structural level?
Myosin molecules consist of two heavy and two light polypeptide chains.
Myosin is a primary component within a myofibril.
Myosin has an ATP binding site, actin binding site and flexible hinge region.
Myosin is involved in the power stroke of muscle contraction.
7. What is the role of tropomyosin in skeletal muscles?
Tropomyosin serves as a contraction inhibitor by blocking the actin binding sites on the myosin molecules.
Tropomyosin is the chemical that activates the myosin heads.
Tropomyosin is the receptor for the motor neuron neurotransmitter.
Tropomyosin serves as a contraction inhibitor by blocking the myosin binding sites on the actin molecules.
8. Although all the anatomical parts of muscle work together to give it it's characteristics, which of the following proteins listed below would be most associated with the characteristics of excitability?
the Na+-K+ pump
actin of thin filaments
acetylcholine receptors in the motor end plate
elastic (titin) filaments
9. What is the functional role of the T tubules?
synthesize ATP to provide energy for muscle contraction
stabilize the G and F actin
enhance cellular communication during muscle contraction
hold cross bridges in place in a resting muscle
10. Which of the following statements best illustrates the fact that skeletal muscle is voluntary muscle?
Skeletal muscle is wrapped in several layers of connective tissue. The deepest layer being the endomysium.
The shivering reflex aids in maintaining body temperature.
Skeletal muscle appears striated due to the structure of the sarcomeres.
Skeletal muscle fibers are innervated by somatic motor neurons.
Never submit passwords through Google Forms.
This content is neither created nor endorsed by Google.
Terms of Service