Biology:Muscle fascicle
{{Infobox anatomy | Name = Muscle fascicle | Latin = fasiculus muscularis | Image = Illu muscle structure.jpg | Caption = Structure of a skeletal muscle. (Fascicle labeled at bottom right.) | Image2 = | Caption2 = | System = | part_of = Skeletal muscle A muscle fascicle is a bundle of skeletal muscle fibers surrounded by perimysium, a type of connective tissue.[1]
Structure
Muscle cells are grouped into muscle fascicles by enveloping perimysium connective tissue.[1] Fascicles are bundled together by epimysium connective tissue.[1] Muscle fascicles typically only contain one type of muscle cell (either type I fibres or type II fibres), but can contain a mixture of both types.[2]
Function
In the heart specialized cardiac muscle cells transmit electrical impulses from the atrioventricular node (AV node) to the Purkinje fibers – fascicles, also referred to as bundle branches.[citation needed] These start as a single fascicle of fibers at the AV node called the bundle of His that then splits into three bundle branches: the right fascicular branch, left anterior fascicular branch, and left posterior fascicular branch.
Clinical significance
Myositis may cause thickening of the muscle fascicles.[3] This may be detected with ultrasound scans.[3]
Muscle fascicle structure is a useful diagnostic tool for dermatomyositis. Myocytes towards the edges of the muscle fascicle are typically narrower, while those at the centre of the muscle fascicle are a normal thickness.[4]
Muscle fascicles may be involved in myokymia, although commonly only individual myocytes are involved.[5]
See also
- Connective tissue in skeletal muscle
- Endomysium
- Epimysium
References
- ↑ 1.0 1.1 1.2 Damjanov, Ivan (2009-01-01), Damjanov, Ivan, ed., "Chapter 21 - Skeletal Muscles" (in en), Pathology Secrets (Third Edition) (Philadelphia: Mosby): pp. 434–447, doi:10.1016/b978-0-323-05594-9.00021-0, ISBN 978-0-323-05594-9, http://www.sciencedirect.com/science/article/pii/B9780323055949000210, retrieved 2020-11-04
- ↑ Gandevia, SIMON C.; Burke, DAVID (2004-01-01), Paxinos, GEORGE; Mai, JÜRGEN K., eds., "CHAPTER 5 - Peripheral Motor System" (in en), The Human Nervous System (Second Edition) (San Diego: Academic Press): pp. 113–133, doi:10.1016/b978-012547626-3/50006-5, ISBN 978-0-12-547626-3, http://www.sciencedirect.com/science/article/pii/B9780125476263500065, retrieved 2020-11-04
- ↑ 3.0 3.1 Möller, Ingrid; Bong, David; Mendieta, Eugenio de Miguel (2010-01-01), Wakefield, Richard J.; D'Agostino, Maria Antonietta, eds., "Chapter 19 - Soft Tissue Rheumatism" (in en), Essential Applications of Musculoskeletal Ultrasound in Rheumatology (Philadelphia: W.B. Saunders): pp. 219–235, doi:10.1016/b978-1-4377-0127-2.10019-x, ISBN 978-1-4377-0127-2, http://www.sciencedirect.com/science/article/pii/B978143770127210019X, retrieved 2020-11-04
- ↑ Harati, Yadollah; Biliciler, Suur (2010-01-01), Rolak, Loren A., ed., "CHAPTER 4 - Myopathies" (in en), Neurology Secrets (Fifth Edition) (Philadelphia: Mosby): pp. 63–82, doi:10.1016/b978-0-323-05712-7.00004-0, ISBN 978-0-323-05712-7, http://www.sciencedirect.com/science/article/pii/B9780323057127000040, retrieved 2020-11-13
- ↑ Ha, Ainhi D.; Jankovic, Joseph (2011-01-01), Brotchie, Jonathan; Bezard, Erwan; Jenner, Peter, eds., "An Introduction to Dyskinesia—The Clinical Spectrum" (in en), International Review of Neurobiology, Pathophysiology, Pharmacology, and Biochemistry of Dyskinesia (Academic Press) 98: 1–29, doi:10.1016/b978-0-12-381328-2.00001-8, ISBN 9780123813282, PMID 21907081, http://www.sciencedirect.com/science/article/pii/B9780123813282000018, retrieved 2020-11-13
External links
- Histology image: 77_04 at the University of Oklahoma Health Sciences Center – "Slide 77 skeletal muscle"
- Anatomy Atlases - Microscopic Anatomy, plate 05.83 – "Smooth Muscle"
- Diagram at kctcs.edu
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