Heart - Slide 65

Cardiac Striated Muscle Tissue

Observation: The cells of Cardiac Striated Muscle Tissue have center core, plus anastomosed fibers.

Cardiac Striated Muscle Fibers in Cross Section - Greater increase

Cardiac Striated Muscle Tissue with anastomosed fibers.

Rectangle - intercalated discs (the cardiac cells are connected to each other by them.

Cardiac Striated Muscle Fibers in Cross Section - Greater increase

Cardiac Striated Muscle Tissue.

Cardiac Striated Muscle Fibers in Longitudinal Section - Greater increase

Cardiac Striated Muscle Tissue with anastomosed fibers.

Rectangle - intercalated discs (the cardiac cells are connected to each other by them.

Notice:
Purkinje fibres lie in the deepest layer of the endocardium and supply the papillary muscles. Hence the apex of the heart contracts first, followed by the papillary muscles, and then the wave of depolarisation spreads up the walls of the ventricles from the base upwards. They are specialised conducting fibres, which extend from the interventricular septum, to the papillary muscles, and up the lateral walls of the ventricles.