Muscle Contraction

where the terminal branches of a motor neuron and the sarcolemma of a skeletal muscle fiber "join"

• plasmodesmata

• neuromuscular junction

• gap junction

• intercalated disc

specialized smooth endoplasmic reticulum surrounding each myofibril that stores the calcium

• sarcolemma

• transverse tubules

• terminal vesicle

• sarcoplasmic reticulum

the source of energy used to directly power muscle activity

• ATP

• acetylcholine

• creatine phosphate

• lactic acid

Tags

NGSS.HS-LS1-7

Which of the following puts these structures in order from largest to smallest?

• sarcomere, muscle fiber, fascicle, myofibril, myofilament

• muscle fiber, fascicle, sarcomere, myofibril, myofilament

• fascicle, muscle fiber, myofibril, sarcomere, myofilament

• fascicle, muscle fiber, myofilament, myofibril, sarcomere

Tags

NGSS.HS-LS1-2

a neurotransmitter that stimulates skeletal muscle fibers

• dopamine

• serotonin

• acetylcholine

• epinephrine

During a muscle contraction...

• actin pulls on the myosin

• myosin pulls on the actin

• tropomyosin pulls on the myosin

• troponin pulls on the actin

Which of the following ions, when present, changes the conformation of tropomyosin?

• sodium ions

• potassium ions

• hydrogen ions

• calcium ions

In order to expose the myosin binding sites on the thin filament, Ca²⁺ ions must bind to...

• troponin

• actin

• titin

• acetylcholine

During full muscle contraction the A Band will...

• disappear

• increase in width

• stay the same

• decrease in width

During a muscle contraction the 'Z' Lines of the sarcomere will...

• disappear

• remain in place

• move farther apart

• move closer together