https://infinitespider.com/spider-legs-work/

Dec 16, 2014 ... But how does this relate to their creepy-cool movement? Spiders don't have internal bones, which means they don't have the same muscles ...

https://www.realclearscience.com/blog/2013/02/spiders-their-amazing-hydraulic-legs-and-genitals.html

Feb 4, 2013 ... So why do spiders move in this unnatural, mechanical fashion? Well ... While spiders have muscles to flex their spindly limbs inward, they use ...

https://asknature.org/strategy/leg-uses-hydraulics-and-muscle-flex/

Feb 16, 2019 ... Spiders have four pairs of legs, and each pair has a specialized task for ... jumps, large spiders apparently do not use it primarily for propulsion.

https://animals.howstuffworks.com/arachnids/spider1.htm

Spiders have the same basic bodily systems as people, but they don't work in the same ... The spider's simple heart -- a tube surrounded by a muscle, with a one- way valve on ... They do not spin webs, and they aren't venomous to humans.

https://www.quora.com/Do-bugs-and-spiders-have-muscles

I'm unsure on any other parts of the body, but I know that spiders use a system of biological "hydraulics" to move and bend their legs by adding ...

http://jeb.biologists.org/content/215/4/578

Unlike most other arthropods, spiders have no extensor muscles in major leg .... spiders (in contrast to small species) do not show distinct jumps with specific ...

https://en.wikipedia.org/wiki/Spider

Spiders (order Araneae) are air-breathing arthropods that have eight legs and chelicerae with ... Unlike most arthropods, spiders have no extensor muscles in their limbs and instead extend ... They also grind food with the bases of their pedipalps, as arachnids do not have the mandibles that crustaceans and insects have.

https://askentomologists.com/2015/04/13/when-a-spider-loses-a-leg-does-its-whole-hydraulic-system-lose-pressure/

Apr 13, 2015 ... These points have special muscles which clamp shut, to ensure the spider doesn' t lose too much blood. This process is called 'autotomy', and ...

http://www.findaspider.org.au/info/Mobility.htm

Dec 24, 2018 ... What physiological mechanisms do spiders use to make their ... Flexor muscles allow the limb to bend and extensors straighten it, the two kinds ...

https://www.straightdope.com/columns/read/2180/do-spiders-have-hydraulic-legs/

Sep 28, 2004 ... It's the combination of hydraulics and internal muscles that make arthropods work . Arthropods ... Some arthropods, like spiders, can't do that.