The heart sparks

Many of us know that calcium is important for bones and teeth but calcium is also crucial for a healthy heart. It is calcium signalling within the heart muscle cells that determines normal heart contraction.

“Calcium signalling - getting to the heart of the matter” is a stand that uses the role of calcium within the heart to explain the anatomy, function and electrical properties of the heart. The experimental research feeds into knowledge about heart disease.

Visitors explored the relative sizes of hearts from different animals and learnt that the number of beats per minute is dependent on the size of the animal. The exhibit included real hearts that could be picked up and observed.

The muscle cells within the heart are called myocytes and their contraction is caused by the influx of calcium when specialised channels open. This rapidly increases the calcium concentration resulting in waves of contraction.

Beautiful images of a ‘calcium spark’ dramatically demonstrate the need for calcium in a healthy myocyte. These sparks can be visualised with flashes of light and are caused by clusters of receptor channels opening to let calcium enter the cell.

Comparing the images of healthy and diseased heart muscle cells clearly shows the problem arises when calcium signals occur at the wrong place or time. The sparks can be seen to cause continuous rounds of calcium signalling rather than a normal wave.

Does this mean we need to eat more calcium in our diets to ensure our heart is healthy? Not necessarily – the levels of calcium in the heart are closely regulated so if necessary calcium can be removed from the bones for use in the heart.

So whilst it is crucial to eat a healthy diet with enough calcium for our bodies needs we do not need to consume excessive amounts. If we consume more than is required for cellular function calcium will simply be excreted from the body.
 

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