Muscles are attached to bones by _____.

• Ligaments
• Tendons
• Cartilage
• Axons

Contractile unit of a muscle.

• sarcomere
• motor unit
• fascicle
• myofibril

A bundle of muscle cells.

• sarcomere
• fiber
• fascicle
• Tendon

Ribbon like organelle found in muscle cells that have a banded appearance

• sarcomere
• myofibril
• fascicle
• actin

Thick filaments are in a myofibril are

• ATPase
• Sarcoplasmic reticulum
• Actin
• Myosin

Thin filaments in a myofibril are

• Sarcomeres
• Sarcoplasm
• Actin
• Myosin

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

• sarcomere
• myofilament
• sarcolemma
• sarcoplasm

The functional unit of the muscle cell is the: 

• Sarcomere
• Osteon
• Myofilament
• Muscle fiber

What two chemicals are necessary for muscle contraction to occur?

• Niacin and Potassium
• Calcium and ATP
• Sodium and Potassium
• Ach and Potassium

Calcium:

• causes ATP binding to actin
• increases the action potential along the sarcolemma
• binds to proteins on myosin
• triggers the binding of myosin to actin