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The Purkinje fibers are further specialized to rapidly conduct impulses (having numerous fast voltage-gated sodium channels and mitochondria, and fewer myofibrils, than the surrounding muscle tissue). Purkinje fibers take up stain differently from the surrounding muscle cells because of having relatively fewer myofibrils than other cardiac cells.
P-type calcium channels were named after Purkinje cells, where they were initially encountered (Llinas et al. 1989), which are crucial in cerebellar function. Activation of the Purkinje cell by climbing fibers can shift its activity from a quiet state to a spontaneously active state and vice versa, serving as a kind of toggle switch. [25]
The bundle of His (BH) [1]: 58 or His bundle (HB) [1]: 232 (/ h ɪ s / "hiss" [2]) is a collection of heart muscle cells specialized for electrical conduction.As part of the electrical conduction system of the heart, it transmits the electrical impulses from the atrioventricular node (located between the atria and the ventricles) to the point of the apex of the fascicular branches via the ...
After a short delay that gives the ventricles time to fill with blood, the electrical signal diverges and is conducted through the left and right bundle branches of His to the respective Purkinje fibers for each side of the heart, as well as to the endocardium at the apex of the heart, then finally to the ventricular epicardium; causing the ...
The bundle branches were separately described by Retzer and Braeunig as early as 1904, but their physiological function remained unclear and their role in the electrical conduction system of the heart remained unknown until Sunao Tawara published his monograph on Das Reizleitungssystem des Säugetierherzens (English: The Conduction System of the Mammalian Heart) in 1906. [4]
Cardiac physiology or heart function is the study of healthy, unimpaired function of the heart: ... The Purkinje fibers have a fast inherent conduction rate, and the ...
The funny current is highly expressed in spontaneously active cardiac regions, such as the sinoatrial node (SAN, the natural pacemaker region), the atrioventricular node (AVN) and the Purkinje fibres of conduction tissue. The funny current is a mixed sodium–potassium current that activates upon hyperpolarization at voltages in the diastolic ...
Early in development, Purkinje cells are innervated by multiple climbing fibers, but as the cerebellum matures, these inputs gradually become eliminated resulting in a single climbing fiber input per Purkinje cell. These fibers provide very powerful, excitatory input to the cerebellum which results in the generation of complex spike excitatory ...