Chamberlain bios 252 exam 1 Latest Update 2024-2025 Actual Exam 250 Questions and 100% Verified Correct Answers Guaranteed A+
1st step at neuromuscular junction - CORRECT ANSWER: AP (action potential) travels down the axon to the axon terminal
1st step of contraction cycle - CORRECT ANSWER: myosin head hydrolyzes ATP & become energized & oriented
1st step of muscle relaxation - CORRECT ANSWER: Once the nerve impulses stops
the leftover Ach is broken down by ACHase (steps)
- muscle fiber membrane is no longer stimulated
1st step of nerve conduction - CORRECT ANSWER: polarization
- sodium outside, potassium inside
1st step of sliding filament theory - CORRECT ANSWER: myosin pulls on actin, causing thin filament to slide inward
- ratchet along filaments
2nd step at neuromuscular junction - CORRECT ANSWER: electrical gated Ca2+
channels open & Ca2+ enters axon terminal
2nd step of contraction cycle - CORRECT ANSWER: myosin head binds to actin,
forming a cross-bridge
2nd step of nerve conduction - CORRECT ANSWER: resting potential
- nothing happens
- waiting for impulse
2nd step of relaxation - CORRECT ANSWER: potassium ions leave the muscle cell
causing repolarization
2nd step of sliding filament theory - CORRECT ANSWER: z discs move towards each
other, & sarcomere shortens
3rd step at neuromuscular junction - CORRECT ANSWER: Ca2+ causes vesicles to
release ACh into synaptic cleft
3rd step of contraction cycle - CORRECT ANSWER: myosin head pivots, pulling the
thin filament past the thick filament toward center of sarcomere (power stroke)
3rd step of nerve conduction - CORRECT ANSWER: action potential 1 / 2
- sodium ion begins to move
- impulse copies into axon
3rd step of relaxation - CORRECT ANSWER: calcium ions are actively transported back into sarcoplasmic reticulum
3rd step of sliding filament theory - CORRECT ANSWER: thanks to structural proteins, there is a transmission of force throughout the entire muscle
- resulting in whole muscle contraction
4th step of contraction cycle - CORRECT ANSWER: as myosin head binds ATP, cross- bridge detaches from actin
4th step of nerve conduction - CORRECT ANSWER: repolarization
- potassium moves out
- impulse done thru axon & myelin sheath
4th step of neuromuscular junction - CORRECT ANSWER: ACh diffuses across
synaptic cleft & bind to its receptors on the muscle
4th step of relaxation - CORRECT ANSWER: linkage b/w actin & myosin filaments break
4th step of sliding filament theory - CORRECT ANSWER: changes in I band & H zone as muscle contracts
5th step at neuromuscular junction - CORRECT ANSWER: ACh binding opens ion
channels & sodium rushes into muscle
5th step of nerve conduction - CORRECT ANSWER: hyperpolarization
- potassium & sodium have switch places
- nothing is moving
- impulse is moving to next neuron
5th step of relaxation - CORRECT ANSWER: actin & myosin filaments slide apart
6th step at neuromuscular junction - CORRECT ANSWER: if muscle reaches threshold (-55mv)at motor end plate, an AP occurs on muscle
6th step of nerve conduction - CORRECT ANSWER: refractory period
- everything is moving back to RMP
6th step of relaxation - CORRECT ANSWER: muscle fiber (sarcomere) relaxes
7th step at neuromuscular junction - CORRECT ANSWER: ACh is broken down by
acetylcholine esterase
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