Medical Research Council - London Institute of Medical Sciences

Now in our 12th year of bringing you beautiful imagery from biomedical science every day

Muscling In

Simulations from high resolution muscle scans reveal mesh-like connections between fibres

27 August 2020

Muscling In

Cut through a bungee cord and you’ll see many elastic strands bundled together, flexing to give strength to the overall rope. Muscle is often described in a similar way – a bundle of parallel tube-like myofibrils stretching independently but at the same time, to contract or relax the muscle. Yet these simulations tell a slightly different story, based on scans of mouse muscles with an advanced scanning electron microscope. Instead of being entirely separate, stretchy regions called sarcomeres (measured between the vertical black bands) often form branches between neighbouring myofibrils – connected regions are highlighted in different colours. While this occurs to different degrees in cardiac muscle (top) compared to skeletal muscle (bottom), it suggests that mice muscles, and ours, may behave more like muscular meshes than bungee cords, raising new questions for how these structures are affected by age and disease.

Written by John Ankers

Search The Archive

Submit An Image

What is BPoD?

BPoD stands for Biomedical Picture of the Day. Managed by the MRC London Institute of Medical Sciences the website aims to engage everyone, young and old, in the wonders of biomedicine. Images are kindly provided for inclusion on this website through the generosity of scientists across the globe.

Read More

BPoD is also available in Catalan at with translations by the University of Valencia.