Skeletal Muscle Contraction and Relaxation Events

These flashcards cover key vocabulary and concepts related to skeletal muscle contraction and relaxation events.

Troponin

A protein that binds calcium ions and helps regulate muscle contraction.

ACh (Acetylcholine)

A neurotransmitter released at the synaptic cleft that initiates muscle contraction.

Crossbridge

The attachment of myosin heads to actin filaments during muscle contraction.

End-plate potential

A depolarization of the motor end plate in response to ACh binding.

Calcium ions (Ca2+)

Ions that play a crucial role in muscle contraction by binding to troponin.

Sarcoplasmic reticulum

An organelle that stores calcium ions and releases them during muscle contraction.

Myosin ATPase

An enzyme that splits ATP to provide the energy needed for muscle contraction.

Acetylcholinesterase

An enzyme that hydrolyzes ACh in the synaptic cleft, terminating the muscle contraction stimulus.

T-tubules

Extensions of the sarcolemma that transmit action potentials into muscle cells.

Cocked position

The position of the myosin head after ATP hydrolysis, ready to bind to actin.

Calcium pumps

Proteins that help return calcium ions to the sarcoplasmic reticulum after contraction.

Myosin-binding sites

Sites on actin filaments that are exposed during muscle contraction, allowing for crossbridge formation.