Electrophysiological Measurements — Flashcards

Flashcard 1: Slow twitch muscle fibers are _____ due to increased myoglobin concentration

Answer: red

Flashcard 2: For Na+ ion the equilibrium potential calculated by Nernst equation is _____.

Answer: +60mV

Flashcard 3: Resting membrane potential of a nerve fiber is equal to the equilibrium potential of _____ and is _____ mV.

Answer: Cl-; -70

Flashcard 4: Absolute refractory period is due to closure of _____ gates of sodium channel.

Answer: inactivation

Flashcard 5: Resting membrane potential of a _____ muscle is -90 mV

Answer: skeletal and myocardial

Flashcard 6: Which nerve fibres are the most susceptible to pressure?_____

Answer: A

Flashcard 7: When the membrane potential is _____, the inactivation gate of the Na+ channel is closed.

Answer: between +35 mV and the resting potential

Flashcard 8: Chemical Events during Muscle Contraction: The **power stroke** is initiated by the release of _____ from the myosin head.

Answer: inorganic phosphate (Pi)

Extra: Sequence of chemical events in the cross-bridge cycle: 1. ATP binding: Myosin head detaches from actin. 2. ATP hydrolysis: Myosin head "cocks" into a high-energy state. 3. Cross-bridge formation: Myosin head binds to actin. 4. Power stroke: Release of inorganic phosphate (Pi) triggers the force-generating pivot. 5. ADP release: Occurs after the power stroke.

Flashcard 9: Fast twitch muscle fibers are _____ due to decreased myoglobin concentration

Answer: white

Flashcard 10: _____ is absent in smooth muscle but present in skeletal muscle

Answer: Troponin