cardiac physiology Q3.

the process by which an electrical action potential leads to the contraction of cardiac muscle cells. as (contractile proteins) convert a chemical sign into mechanical energy.

a crucial mediator that couples electrical excitation to physical contraction by cycling in and out of myocyte's cytosol.

at -60mv, funny channels in SAN open,Na+ enters the cell, the inside of the cell is now less negative compare to the outside, this triggers a type of Ca++ voltage gated channel to open, Ca++ flow in, start depolarisation gradually, threshold is reached which triggers more Ca++ inside through another Ca++ channel>>rapid depolarisation-action potential.

<p>T-type Ca++ channels.</p> Signup and view all the answers

<p>Na+ flow in through na+ voltage gated channel, rapid depolarisation, K+ flow out through some K+ voltage gated channel and Ca++ flow in through L-type channel (plateau), Ca++ closed and K+ continues to flow out (repolarisation).</p> Signup and view all the answers

<p>sarcolemma.</p> Signup and view all the answers

<p>L-type Ca++ channel during phase 2 of action potential .</p> Signup and view all the answers

<p>they r specialised Ca2+ release receptors in the (SR), when ca++ flow through L-type, raynodine receptors induce a larger release of Ca++ from SR stores.</p> Signup and view all the answers

<p>T-tubules in sarcolemma.</p> Signup and view all the answers

<p>electrical trace resulting from action potential in all the heart muscle fibres.</p> Signup and view all the answers