Skeletal Muscle Structure and Function Quiz

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Questions and Answers

What is the term used for the smallest functional units of muscle?

Sarcolemma
Myofibrils
Sarcomeres (correct)
Myofilaments

What are tendons primarily responsible for?

Connecting muscle fibres
Supporting the skeleton
Attaching muscles to bones (correct)
Facilitating muscle contraction

What is the composition of thin filaments in a sarcomere?

Actin and troponin
Tropomyosin and myosin
Actin and myosin
Actin and other proteins (correct)

What is the primary function of myosin in muscle contraction?

Generating the force for muscle contraction (B) Signup and view all the answers

What is the role of the sarcolemma in muscle fibres?

Surrounding individual muscle fibres (D) Signup and view all the answers

Describe the structure and composition of skeletal muscle fibres.

Skeletal muscle fibres are formed by the fusion of undifferentiated myoblast cells, resulting in a single cylindrical, multinucleated cell. They range in diameter from 10-80 μm and may be more than 35cm long. Each muscle fibre is surrounded by a plasma membrane called the sarcolemma. Signup and view all the answers

Explain the organization of myofibrils within skeletal muscle fibres.

Each skeletal muscle fibre contains several hundred to several thousand myofibrils, which are rod-like structures running the length of the muscle fibres. Myofibrils appear as long strands of smaller subunits called sarcomeres, which are the smallest functional units of muscle. Signup and view all the answers

What are sarcomeres and how are they organized within myofibrils?

Sarcomeres are the smallest functional units of muscle, composed of filaments of actin and myosin. They are joined end to end at the Z line within myofibrils. Signup and view all the answers

Discuss the role of myofilaments in muscle contraction and the composition of thin and thick filaments.

Myofilaments, including actin and myosin, are responsible for muscle contraction. Actin forms thin filaments, while myosin forms thick filaments folded into a globular head at one end, consisting of twisted strands of heavy and light portions. Signup and view all the answers

How are myofilaments arranged within a sarcomere and in parallel within a myofibril?

Myofilaments are arranged in series from one sarcomere to another and in parallel within a myofibril, with approximately 6000 sarcomeres end to end in a myofibril with a length of 15mm. Signup and view all the answers