Which muscle contraction is involuntary?Group of answer choicesskeletal onlycardiac onlycardiac and smooth musclesmooth onlycardiac, smooth and skeletal muscle

Break Down the Problem

1. Identify the types of muscle contractions: skeletal, cardiac, and smooth muscles.
2. Determine which of these muscle types are voluntary and which are involuntary.

Relevant Concepts

• Skeletal Muscle: Generally under voluntary control, meaning we can consciously contract these muscles.
• Cardiac Muscle: Found in the heart, operates involuntarily, controlled by the autonomic nervous system.
• Smooth Muscle: Found in organs and vessels, also operates involuntarily, controlled by the autonomic nervous system.

Analysis and Detail

1. Skeletal Muscle:

   • Controlled voluntarily; people can decide when to use these muscles (e.g., moving arms or legs).

2. Cardiac Muscle:

   • Involuntary muscle required for pumping blood.

3. Smooth Muscle:

   • Involuntary muscle located in walls of organs (e.g., intestines, blood vessels) that work without conscious control.

Verify and Summarize

Only cardiac and smooth muscles are involuntary. Skeletal muscles are voluntary. Therefore, the situation demands identifying the muscles that do not operate under conscious control, leading to the conclusion that both cardiac and smooth muscles are considered involuntary.

Final Answer

The correct choice is cardiac and smooth muscle.