Question 1

Q: A Strength-Duration curve is plotted for a skeletal muscle. Identify the parameters labeled in the correct order to successfully determine the tissue excitability.

A: Chronaxie; B: Rheobase; D: Utilization Time. ***A: Chronaxie; B: Rheobase; D: Utilization Time*** - The **Strength-Duration curve** shows the inverse relationship between the **stimulus strength** and the **stimulus duration** required to elicit a response. - **Chronaxie** (A) is defined as the minimum duration of stimulus required to excite a tissue at twice the **rheobase** strength, while **rheobase** (B) is the minimal stimulus strength required to excite the tissue with a long duration, and **utilization time** (D) is the minimum duration required to excite with a stimulus of precisely rheobase strength. *A: Utilization Time; B: Rheobase; D: Chronaxie* - **Utilization time** is significantly longer than **chronaxie**; mislabeling these confuses the fundamental principles of **excitability threshold**. - Placing **chronaxie** at the end of the duration axis is anatomically incorrect as it is a specific, shorter duration compared to the total **utilization time**. *A: Rheobase; B: Chronaxie; D: Utilization Time* - **Rheobase** represents a measure of **stimulus voltage** (y-axis), not a point on the duration axis. - Assigning rheobase to the duration parameters ignores the distinction between **intensity** and **time constants**. *A: Chronaxie; B: Utilization Time; D: Rheobase* - **Utilization time** is the minimum stimulus duration at **rheobase** intensity, making it distinct from **chronaxie**. - Swapping these values disrupts the physiological definition of **tissue excitability** markers.

Question

A Strength-Duration curve is plotted for a skeletal muscle. Identify the parameters labeled in the correct order to successfully determine the tissue excitability.

Accepted Answer

A: Chronaxie; B: Rheobase; D: Utilization Time

Answer

A: Utilization Time; B: Rheobase; D: Chronaxie

Answer

A: Rheobase; B: Chronaxie; D: Utilization Time

Answer

A: Chronaxie; B: Utilization Time; D: Rheobase

Nerve and Muscle Physiology — MCQs

Nerve and Muscle Physiology — MCQs

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