Skeletal Muscle and Sarcomeres

The contractile unit of a muscle:

• sarcomere

• motor unit

• fascicle

• myofibril

Thick filaments within a myofibril are:

• ATPase

• Sarcoplasmic reticulum

• Actin

• Myosin

Thin filaments in a myofibril are

• Sarcomeres

• Sarcoplasm

• Actin

• Myosin

Do the lengths of the thick and thin filaments change during contraction?

• Yes

• No

What state is the sarcomere in #1

• Relaxed
• Contracting
• Fully Contracted
• None of the above

The contraction of a muscle exerts a pull on a bone because

• muscles are attached to bones by ligaments

• muscles are directly attached to bone

• muscles that are attached to bones by tendons

• All of the above are correct

Which filament slides inward during muscle contraction

• Actin

• Myosin

Which part separate one sarcomere to the next?

• M line

• I band

• H zone

• Z line

The Z Line provides attachment for the ...

• Troponin

• Myosin

• Actin

• ATP

Higher Questioning: Do the lengths of the thick and thin filaments change during contraction?

• Yes

• No