Excitation, Contraction & Coupling

two structures found in close proximity to each other within the skeletal muscle cells called?

• Transverse Tubules

• Sarcoplasmic Reticulum

Transverse Tubules are formed by?

• Sarcolemma (Plasma Membrane)

• Penetrate all the way through the Muscle.

• The Tubules are continous with the Sarcolemma.

These transverse tubules also contain voltage-gated?

• Ca+ Channels

What is the Sarcoplasmic Reticulum?

• A Modified Endoplasmic Reticulum

• Found close proximity to Transverse Tubules

The SR forms large terminal cisternae that surrounds each transverse tubule ensuring?

• Colocalization of the SR and Transverse Tubules

The SR also spreads throughout the myocyte via interconnected…?

• Sacs around the Myofibrils

The SR contains a huge?

• Ca+ Store

• Upon Excitation releases Ca+ into the Cytosol

Most of the Ca+ That enters the Cytosol comes from?

• Intracellular Stores.

somatic motor neuron it stimulates the skeletal muscle cell to contract this process is known as?

• Excitation, Contraction & Coupling

This action potential propagates like a wave across the?

• Sarcolemma of the Skeletal Myocyte

• Also moves down the Transverse Tubules.

The voltage-gated Ca2+ channels of the transverse tubule are directly and mechanically coupled with?

• Ryanodine Receptors of the SR.

What are Ryanodine Receptors?

• Specialized Ca+ channels found embedded in the SR.

Review Structure Diagram