Excitation - contraction coupling in the heart

describe Cardiac muscle

Rectangular shaped, striated muscle cells (myocytes) connected via gap junctions allowing ions to pass between cells, organized in branched networks.

Intercalated discs

Structures holding cardiac muscle cells together via desmosomes, containing gap junctions and known as the site of nexus.

what are T-tubules

Invaginations of the plasma membrane in cardiac muscle cells, bringing it close to organelles and facilitating excitation-contraction coupling.

What sarcoplasmic reticulum

Network wrapping around myofibrils and t-tubules in cardiac muscle cells, serving as the main intracellular store of Ca2+ for muscle contraction.

Excitation-contraction coupling

Mechanism in cardiac muscle cells where Ca ions are released from the sarcoplasmic reticulum to trigger muscle contraction.

what is sliding filament theory of contraction

Concept where actin and myosin interact to form crossbridges, generating force in muscle contraction through ATP hydrolysis and power strokes.