The Blank______ is the basic structural and functional unit of skeletal muscle.Multiple choice question.sarcolemmasarcomeremyofibrilmyosin filament

Breaking Down the Problem

1. We need to identify the basic structural and functional unit of skeletal muscle from the listed options.
2. The options given are: sarcolemma, sarcomere, myofibril, and myosin filament.

Relevant Concepts

1. Sarcolemma: This is the cell membrane surrounding a muscle fiber but it is not the basic unit itself.
2. Sarcomere: This is the fundamental unit of a muscle's striated tissue and is responsible for muscle contraction.
3. Myofibril: These are the long, filamentous structures within a muscle fiber that contain the sarcomeres.
4. Myosin filament: These are one of the two types of filaments that make up the sarcomere, along with actin.

Analysis and Detail

• The sarcomere is the smallest contractile unit of muscle tissue. It is defined as the segment between two neighboring Z-lines, and it contains the necessary elements for muscle contraction. It includes both actin and myosin filaments, which interact during the contraction process.
• Therefore, while myofibrils are the structures containing the sarcomeres, and myosin filaments are part of the sarcomeres, the sarcomere itself is what is specifically referred to as the basic functional unit.

Verify and Summarize

• The question asks for the basic structural and functional unit of skeletal muscle, which is clearly identified as the sarcomere.

Final Answer

The correct answer is sarcomere.