6.2 Quiz: Microscopic Anatomy of Skeletal Muscles

What is shown in the image?

• neuron

• myelin sheath

• segment of a muscle fiber

• blood vessel

What is the arrow pointing at?

• bare zone

• thin filament

• thick filament

• myofibril

The plasma membrane of a skeletal muscle cell is called the:

• sarcomere

• centromere

• sarcolemma

• dilemma

What feature(s) gives skeletal muscle cells their striped appearance?

• Dark (A) band

• thin (actin) filament

• thick (myosin) filament

• Light (I) band

What is shown in the image?

• myofibril

• microfilaments

• sarcoplasmic reticulum

• cross bridges

Tiny contractile units that make up myofibrils are called:

• sarcolemma

• cross bridges

• myosin

• sarcomeres

There are two types of threadlike protein ______________________ within each of our "boxcar" sarcomeres.

• cross bridges

• myofilaments

• microfilaments

• sarcoplasmic reticulum

What feature of skeletal muscles "link the thick and thin filaments together during contraction"?

• myosin

• actin

• cross bridges

• sarcomeres

What feature of myofilaments is shown at the green arrow?

• thick filaments, myosin

• cross bridges

• bare zone

• thin filaments, actin

What feature of myofilaments is shown at the red arrow?

• cross bridges

• thick filaments, myosin

• thin filaments, actin

• bare zone