Heart Anatomy

Which valves are most commonly affected by infective endocarditis?

What is the name of the muscle found in the atrium

There are [blank_start]two[blank_end] specialised types of cardiac muscle cell. The contractile cells, composing [blank_start]99%[blank_end] of cardiac muscle cells and the auto-rhythmic cells, which initiate and conduct [blank_start]action potentials[blank_end] for contraction of working cells.

The SA node, is always in transient state towards hyperpolarisation. This causes activation of the funny Na+ channels allowing an influx of Na+. K+ channels close slowly allowing threshold to be reached. The next step is?

The auto-rhythmic cells of the SA node set the pace of the heart at [blank_start]70-80[blank_end] BPM, in the presence of parasympathetic tone. These cells have the fastest rhythm at controlling heart rate. The cells of the AV node are [blank_start]slower[blank_end] and set a rhythm of 40-[blank_start]60BPM[blank_end].