Muscles 2

How many steps are involved in muscle contraction?

• 10 steps
• 4 steps

• 5 steps
• 12 steps

What is the first step of muscle contraction?

• activating myosin heads by splitting ATP into ADP and P

• myosin binds to actin

• myosin pulls actin

• myosin binds to a new ATP, this causes the myosin head to release from actin

What is the second step of muscle contraction?

• activating myosin heads by splitting ATP into ADP and P

• myosin binds to actin

• myosin pulls actin

• myosin binds to a new ATP, this causes the myosin head to release from actin

What is the third step of muscle contraction?

• activating myosin heads by splitting ATP into ADP and P

• myosin binds to actin

• myosin pulls actin

• myosin binds to a new ATP, this causes the myosin head to release from actin

What is the fourth step of muscle contraction?

• activating myosin heads by splitting ATP into ADP and P

• myosin binds to actin

• myosin pulls actin

• myosin binds to a new ATP, this causes the myosin head to release from actin

Immediately after binding to actin, the myosin head pivot. The energy that was stored in the _____ head powers the pull. ADP and P are finally released.

• tropomyosin
• titin
• cocked

• actin

Neural stimulation is the first in the sequence of muscle contraction

• True

• False

1. 1. The _____ or _____ ____ activates a motor neuron which is a nerve cell that controls muscle

• cerebellum, basal ganglia

• sensory cortex, visual area

• frontal lobe, temporal lobe

• brain, spinal cord

2. 2. Nerve impulse(aka. action potential) reaches the end of the motor neuron and causes the release of __________ (ACh; a neurotransmitter)

• acetylcholine
• norepinephrine
• serotonin
• dopamine

3. 3. ACh diffuses across the tiny space that separates the end of the motor neuron from the sarcolemma. This tiny gap is called the ____________ _______.

• motor end plate
• neuromuscular junction
• axon terminal
• synaptic cleft