Uploaded February 2025 | Updated September 2026, 2 hours ago

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In this video, we take a close look at the structure of skeletal muscle. We explore the structure of muscle fibres. This includes the structure of the myofibrils and the arrangement of myosin and actin. We then look at how the banding pattern in the muscle fibre changes when muscles contract and explain this in terms of the arrangement of the thick and thin filaments.

Image credits:

Types of Muscle
commons.wikimedia.org/wiki/File:Types_Of_Muscle.jpg
www.scientificanimations.com, CC BY-SA 4.0 creativecommons.org/licenses/by-sa/4.0, via Wikimedia Commons

Myofibril
commons.wikimedia.org/wiki/File:Figure_38_04_03.jpg
CNX OpenStax, CC BY 4.0 creativecommons.org/licenses/by/4.0, via Wikimedia Commons

Skeletal muscle fibres
commons.wikimedia.org/wiki/File:Muskel_(_1).jpg
Rollroboter, CC BY-SA 3.0 creativecommons.org/licenses/by-sa/3.0, via Wikimedia Commons

TEM of muscle tissue
commons.wikimedia.org/wiki/File:Human_skeletal_muscle_tissue_1_-_TEM.jpg
Louisa Howard, Public domain, via Wikimedia Commons

Muscle fibres (adapted by S. Donnelly with thanks to the creators OpenStax)
commons.wikimedia.org/wiki/File:1022_Muscle_Fibers_(small).jpg
OpenStax, CC BY 4.0 creativecommons.org/licenses/by/4.0, via Wikimedia Commons

Myosin
commons.wikimedia.org/wiki/File:Rheumatology_-_Myosin_4_--_Smart-Servier.png
Laboratoires Servier, CC BY-SA 3.0 creativecommons.org/licenses/by-sa/3.0, via Wikimedia Commons

Actin
commons.wikimedia.org/wiki/File:Actin_strand.png
Boumphreyfr, CC BY-SA 3.0 creativecommons.org/licenses/by-sa/3.0, via Wikimedia Commons