Muscles

Open Ended

Why is the musculoskeletal system important for human health and movement?

Multiple Choice

Which of the following statements about skeletal muscles is correct?

• Skeletal muscles contain about 70% water.

• Skeletal muscles are not richly supplied with blood vessels.

• Only 1% of capillaries are active at rest in skeletal muscles.

• Skeletal muscles do not contain proteins like myoglobin.

Multiple Choice

What is the main difference between smooth muscle and cardiac muscle in terms of structure and function?

• Smooth muscle is striated and voluntary, cardiac muscle is non-striated and involuntary.

• Smooth muscle is non-striated and involuntary, cardiac muscle is striated and involuntary.

• Smooth muscle is striated and involuntary, cardiac muscle is non-striated and voluntary.

• Smooth muscle is voluntary, cardiac muscle is involuntary.

Fill in the Blanks

Fill in the blank: The basic unit of a skeletal muscle is the

, which can be up to 30 cm long.

Open Ended

What role does the neuromuscular junction play in muscle contraction?

Multiple Choice

Which of the following statements about skeletal muscle movement is correct?

• Skeletal muscles contract involuntarily.

• Skeletal muscles are controlled by the autonomic nervous system.

• Skeletal muscles are composed of multinucleated fibers and are voluntarily controlled.

• Skeletal muscles do not contain myofibrils.

Multiple Select

Which of the following are components found within a skeletal muscle fiber?

• Sarkolema

• Sarkoplazma

• Myofibrily

• Mitochondria

Open Ended

Describe how the structure of skeletal muscle fibers supports their function.

Multiple Choice

Which filament shortens during muscle contraction, actin or myosin?

• Actin

• Myosin

• Both actin and myosin

• Neither actin nor myosin

Open Ended

Explain the role of ATP and Ca2+ ions in the contraction of skeletal muscle.

Multiple Choice

Which of the following statements about the neuromuscular junction is correct?

• It is the site where a nerve fiber meets a muscle fiber.

• It is responsible for muscle relaxation only.

• It is not affected by toxins or medications.

• It does not involve synapses.

Fill in the Blanks

The main source of energy for muscle work is

.

Multiple Choice

Match the muscle function to its type: flexores, extensores, adductores, sphincteres.

• Flexores - bending; Extensores - straightening; Adductores - pulling toward; Sphincteres - closing

• Flexores - straightening; Extensores - bending; Adductores - closing; Sphincteres - pulling toward

• Flexores - closing; Extensores - pulling toward; Adductores - bending; Sphincteres - straightening

• Flexores - pulling toward; Extensores - closing; Adductores - straightening; Sphincteres - bending

Fill in the Blanks

Fill in the blank: Skeletal muscles contain about

percent water.

Open Ended

Summarize what you learned today about the muscular system and its functions. How do muscles contribute to movement and overall health?