Muscle Contraction and Neuromuscular Junction

These flashcards cover key concepts related to muscle contraction and the neuromuscular junction.

ACh is released from synaptic vesicles at the terminal.

axon

After ACh binds to receptors on the sarcolemma, channels open allowing sodium ions to enter the cell.

Na+

The release of calcium from the SR into the sarcoplasm begins the cycle.

contraction

Acetylcholine is destroyed in the synaptic cleft by the enzyme _.

acetylcholinesterase

Botulinum toxin interferes with neural transmission by blocking the release of _.

acetylcholine

The site where motor neurons meet muscle fibers is known as the _.

neuromuscular junction (NMJ)

The is a modified smooth endoplasmic reticulum that regulates intracellular calcium levels.

sarcoplasmic reticulum (SR)

Muscle contraction begins when calcium binds to _, causing a shift in tropomyosin.

troponin

One of the main roles of is to store and release calcium ions in muscle cells.

sarcoplasmic reticulum (SR)

During muscle contraction, filaments slide past filaments without changing their length.

thin; thick