5 Written questions
5 Matching questions
- Excitation- contraction coupling is a series of events that occur after the events of the neuromuscular junction have transpired. The term excitation refers to which step in the process.
A) Excitation refers to the shape change that occurs in voltage-sensitive proteins in the sarcolemma.
B) Excitation refers to the propagation of action potentials along the axon of a motor neuron.
C) Excitation refers to the release of calcium ions from the sarcoplasmic reticulum.
D) Excitation refers to propagation of action potentials along the sarcolemma.
- A triad is composed of a T-tubule and two adjacent terminal cisternae of the sarcoplasmic reticulum. How are these components connected?
A) potassium leak channels
B) myosin cross-bridge binding sites
C) a series of proteins that control calcium release
D) voltage-gated sodium channels
- What is the role of tropomyosin in skeletal muscles?
A) Tropomyosin serves as a contraction inhibitor by blocking the actin binding sites on the myosin molecules.
B) Tropomyosin is the chemical that activates the myosin heads.
C) Tropomyosin serves as a contraction inhibitor by blocking the myosin binding sites on the actin molecules.
D)Tropomyosin is the receptor for the motor neuron neurotransmitter.
- What is the functional unit of a skeletal muscle called?
- Hypothetically, if a muscle were stretched to the point where thick and thin filaments no longer overlapped, ________.
cross bridge attachment would be optimum because of all the free binding sites on actin
ATP consumption would increase because the sarcomere is "trying" to contract
maximum force production would result because the muscle has a maximum range of travel
no muscle tension could be generated
- a D
- b sarcomere
- c no muscle tension could be generated
- d C
- e C) a series of proteins that control calcium release
5 Multiple choice questions
- D) arrival of an action potential
- A) skeletal
5 True/False questions
A motor neuron and all the muscle cells that it stimulates are referred to as a motor end plate. → sarcoplasmic reticulum
A muscle that is lengthening while it produces tension is performing a(an) ________ contraction.
D) maximal → A) eccentric
Skeletal muscle cells have glycosomes → a state of sustained partial contraction
What is the role of calcium ions in muscle contraction?
A) reestablish glycogen stores
B) increase levels of myoglobin
C) form hydroxyapatite crystals
D) bind to regulatory sites on troponin to remove contraction inhibition → C
Which of the following is CORRECTLY paired?
A) smooth muscle: striated
B) cardiac muscle: nonstriated
C) cardiac muscle: voluntary control
D) skeletal muscle: voluntary control → D) skeletal muscle: voluntary control