In Cardiac Muscle, the Fast Depolarization Phase of the Action

question 84

Multiple Choice

In cardiac muscle, the fast depolarization phase of the action potential is the result of

• A) increased membrane permeability to sodium ions.
• B) increased membrane permeability to potassium ions.
• C) decreased membrane permeability to calcium ions.
• D) decreased membrane permeability to sodium ions.
• E) increased membrane permeability to chloride ions.

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Definitions:

Ascending Fibres

Nerve paths that carry sensory information from the body up to the brain.

Reticular Activating System

A network of neurons located in the brainstem that plays a crucial role in controlling arousal and alertness levels.

REM Sleep

A stage of sleep characterized by rapid eye movements, vivid dreaming, and increased brain activity.

Pons

A part of the brainstem that links the medulla oblongata and the thalamus, playing a crucial role in controlling breathing, communication between different parts of the brain, and sensations such as hearing and taste.