Muscle

Click all that apply. Which of these make up a motor unit?

• Motor neuron

• Motor fiber

• Muscle

• Nerve

What is the contractile unit of the muscle?

• Z disk

• Sarcomere

• Muscle fiber

• Muscle cell

What is the name of the neurotransmitter that is released from the neuron to the sarcolemma?

• Acetylcholine

• Acetone

• ATP

• Calcium

Which of these occurs first during a muscle contraction?

• The nerve signal reaches the neuromuscular junction

• Ach is released and opens Na ion channels

• The sarcomere shortens

• The myosin binds to the actin

Which of these occurs last during a muscle contraction?

• The nerve signal reaches the neuromuscular junction

• Ach is released and opens Na ion channels

• The sarcomere shortens

• The myosin binds to the actin

The all-or-none response means

• all of the muscles in a region contract together

• all of the muscle fibers within a muscle contract together

• when a muscle fiber contracts, it contracts completely

• when a muscle fiber contracts, all of its ATP is changed to ADP

Muscle fatigue is most likely due to an accumulation of

• citric acid

• lactic acid

• creatine

• myosin

Tags

NGSS.HS-LS2-3

What two chemicals are necessary for muscle contraction to occur?

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

A person who exhibits very large muscles has the condition of 

• atrophy
• hypertrophy
• muscular dysterophy
• muscle 

• Flexion
• extension
• abduction
• adduction