MUSCLE PHYSIOLOGY

Detailed explanation-1: -Skeletal and cardiac muscles are known as striated muscles, because the filaments of actin and myosin that power their contraction are organized into repeating arrays, called sarcomeres, that have a striated microscopic appearance.

Detailed explanation-2: -Cardiac and skeletal muscle cells both contain ordered myofibrils and are striated.

Detailed explanation-3: -The cardiac muscle cell has one central nucleus, like smooth muscle, but it also is striated, like skeletal muscle. The cardiac muscle cell is rectangular in shape. The contraction of cardiac muscle is involuntary, strong, and rhythmical.

Detailed explanation-4: -Both skeletal and cardiac muscles appear striated, or striped, because their cells are arranged in bundles. Smooth muscles are not striated because their cells are arranged in sheets instead of bundles.

Detailed explanation-5: -Correct answer: Cardiac muscle and skeletal muscle are both composed of sarcomeres. This layout gives both muscle types a striated appearance, alternating dark bands of myosin with lighter bands of actin.