Talk:Skeletal muscle

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[edit] Skeletal (Striated) Muscle

Do all mammals have the same form of striated muscle fibre? I expect the metabolism is the same but what about other groups? Derek H

All mammals have the basic "fast" and "slow" muscle fiber types, denoted by different isoforms of Myosin: Type I (slow), Type II (Fast). Fast muscle can be subdived into sub-types: IIA, IIB, II C, etc. Different mammals may have different proportions of Fast and Slow muscle fibers in distinc muscles, in comparison to human, for example. Gacggt 14:23, 29 May 2006 (UTC)

Does anyone know if skeletal muscle fibres (i.e. single cells) stretch the whole length between tendons? Thanks. -postglock 09:18, 25 May 2006 (UTC)

This is probably the case, since a single muscle fibre may be thirty centimetres long. --Smajie

Cheers, thanks. -postglock 01:59, 24 October 2006 (UTC)

[edit] Fascicle

Skeletal Muscle = Fascicle + Blood vessel

Type I (Slow) Muscle: Outside of Fascicle

Type II (Fast) Muscle: Center of Fascicle

--Smajie 06:40, 2 July 2006 (UTC) _____________ Sorry that is not true... a fascicle is just the muscle bundle surrounded by connective tissue; there is no preference of fiber types to the outside vs the center.

Gacggt 21:08, 23 June 2006 (UTC)

In pig muscle there is a distribution with slow in the centre, IIa around and IIx on outside of a fascicle.

[edit] Type 2x

"Human type IIx (aka IIB) are our fastest fibers." Is there a source that says humans have Type 2x muscle fibers? Studies I've read only talk about rats and mice having them. If you respond, please do so to my discussion page as well because I can never keep up with articles. Jamesters 23:39, 16 November 2006 (UTC)

[edit] Pre load forces

Two questions- 1. Does anyone know what happens to muscles at its highest pre load forces? 2. What is the physiological mechanism that causes muscle to contract more forcefully when stretched? —The preceding unsigned comment was added by 124.186.110.222 (talk) 12:43, 25 April 2007 (UTC).

I don't understand question one. If you give a muscle a large pre-load it will stretch (if I understand pre-load). If you keep increasing its pre-load it'll stretch until it tears. At a long enough length you can actually (in skeletal muscle) decrease thin and thick filament overlap to the point of not being able to have any actin-myosin interaciton and only extracellular stuff (collagen, elastin) is holding the muscle together. Second question, nobody knows. There is increased calcium sensitivity (more force for a given calcium), increased maximal force, some think greater cooperativity. Its called length dependent activation, and in the heart the Frank-Starling law of the heart. There are many theories, but nothing has panned out yet.Rjkd12 18:10, 18 May 2007 (UTC)

[edit] Size?

In the article for smooth muscles, sizes are mentioned. I mis that here. I found information about the size of skeletal muscle cells here: http://compepid.tuskegee.edu/syllabi/biomedical/Anatomy/microanat309/chapter10.htm If the source meets the demands of the wiki, someone could add the info to the article.

[edit] Picture

The individual in the picture has never competed in any sanctioned bodybuilding contest, and therefore cannot be called a bodybuilder. He may be a muscular individual, but is not deserving of the title "bodybuilder".—The preceding unsigned comment was added by 170.140.6.250 (talk • contribs).

Wrong. Bodybuilder-noun- someone who does special exercises to develop a brawny musculature. [[1]] Wikidudeman (talk) 11:47, 11 July 2007 (UTC)
The definition of a bodybuilder is somone who exercises to increase the size and symmetry of their muscles. Someone can bodybuild and not compete. If he self-identifies, and has developed, symetrical muscles, he's a bodybuilder. There's no reason to remove the picture. WLU 20:00, 13 July 2007 (UTC)

[edit] unlcear phrase

types of fibers (AKA "fibers") This is either a typo or needs to be clarified/reworded. I know nothing of the subject, so unfortunately am unable to DIY it.Lisa4edit (talk) 18:43, 16 May 2008 (UTC)