The Following Are the Main Steps in the Generation of an Action

question 157

Multiple Choice

The following are the main steps in the generation of an action potential. 1. Sodium channels are inactivated.
2) Voltage- gated potassium channels open and potassium moves out of the cell, initiating repolarization.
3) Sodium channels regain their normal properties.
4) A graded depolarization brings an area of an excitable membrane to threshold.
5) A temporary hyperpolarization occurs.
6) Sodium channel activation occurs.
7) Sodium ions enter the cell and depolarization occurs.
The proper sequence of these events is

• A) 4, 6, 7, 1, 2, 3, 5.
• B) 6, 7, 4, 1, 2, 3, 5.
• C) 4, 2, 5, 6, 7, 3, 1.
• D) 2, 4, 6, 7, 1, 3, 5.
• E) 4, 6, 7, 3, 2, 5, 1.

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Definitions:

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The fused head and thorax found in certain arthropods, such as spiders and crustaceans.

Pyothorax

Accumulation of pus in the pleural cavity caused by infection, which can lead to compromised lung function and requires medical intervention.

Metathorax

The third and last of the three segments in the thorax of an insect, carrying the second pair of wings and the second pair of legs.

Water Vascular System

A hydraulic system used by echinoderms, like starfish, for locomotion, food and water transportation, and waste removal.