A&P Chpt 09: Muscles & Muscle Fibers

What is the name of the place where a nerve meets a muscle fiber?

• Nerve junction

• Muscle junction

• Neuromuscular junction

• Cross bridge

How does the sarcomere shorten (contract) ?

• The myosin filaments contract

• The myosin is pulled by the actin

• The actin filaments contract

• The actin is pulled by the myosin

What two chemicals are necessary for muscle contraction to occur?

• Niacin and Potassium

• Sodium and Potassium

• Calcium and ATP

• Acetylcholine and Potassium

___ and ___ are regulatory proteins bound to actin.

• Myosin and actin

• Calcium and oxygen

• Glycogen and hemoglobin

• Troponin and tropomyosin

Skeletal Muscle contraction is initiated when the ________ sends a message to the muscle cell.

• Muscle cell

• Neuron

• Gland

• Sarcomere

What is the structure that stores calcium in the muscle cell?

• Sarcoplasmic reticulum

• Neuron

• Myoglobin

• Neuromuscular junction

The neurotransmitter that signals muscle contraction is...

• Calcium

• Myosin

• Actin

• Ach (acetylcholine)

The contractile unit of the muscle cell is the:

• Sarcomere

• Osteon

• Myofilament

• Muscle fiber

Which of the following refers to the muscle cell?

• Myofibril

• Fascicle

• Myofilament

• Muscle fiber

The __ zone of a sarcomere contains no actin filaments while the skeletal muscle is at rest

• H

• Z

• I

• A