how do muscles move?

Answer 1

Muscles move by responding to the brain and relaxing and contracting and when you get cramp ur muscles are contracting really fast making lactic acid causing the pain

Emma
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Answer 2

Skeletal muscle has to main components in a muscle fiber: actin and myosin. In the illustration, the blue is actin, and the red, myosin.
(http://en.wikipedia.org/wiki/Image:SlidingMyofibril.svg)

The myosin is composed of a head (the rounded part in the diagram) and a tail. Normally, they all lay flat, as shown in the diagram, but they are capable of bending at the tail, like a lever. Actin, on the other hand, is comparatively simple. It possesses sites that the myosin heads can bind to, but they are normally covered by a molecule called Tropomyosin.

When a nerve tells a muscle to contract, structures in the muscle cell release calcium, which causes the tropomyosin to move, and expose the myosin binding sites. The myosin then binds to the actin, and bends at the tail, pulling the actin forward. In the process, it converts ATP to ADP (uses up the energy stored in ATP). Once the myosin has bent as far as it can, it binds fresh ATP (containing more energy), which causes it to 'reset' and lay flat again. The myosin is then free to bind a new site on the actin and pull it forward a little more. The bundles of myosin face away from each other, so when they pull on the actin, they pull towards each other (kind of like tug-of-war if the rope pulled the people instead of the other way around). This causes the actin filaments to move in towards each other and shortens (contracts) the muscle.

Think of an unpowered treadmill as an analogy, where you must provide the motion (instead of just walking on a moving treadmill). The treadmill represents the actin filaments. When the signal from a nerve causes calcium release, it moves the tropomyosin, which would be like taking a cover off of the treadmill. Your legs would then be like the myosin. When you use energy, you push the surface of the treadmill a little bit. You then need to pick up your foot and bring your leg forward again, so you can push with it again. Imagine thousands of people on treadmills at the same time, facing in opposite directions.

On a side note, rigor mortis is when, after a person dies, the muscles lock in place and the body becomes very stiff. This happens because, once a person dies, their metabolism stops, which means they no longer convert the energy in food into ATP. Without ATP, the myosin in the muscles can no longer release the actin and reset. The myosin remains locked to the actin and the muscle stays immobile. The condition only ends a day or two later, when the actin and myosin in the muscles starts to naturally break down.

Answer 3

You've got 3 types inside you. Firstly your SKELETAL MUSCLES are those that move under voluntary control of your brain. An "extenser" opens out a joint, a "flexor" closes it, an "adductor" draws a part of your body inwards, an "abductor" outwards.

Secondly your "SMOOTH" muscles are those that involuntarily move your internal organs like peristalsis in your intestine or contractions of your uterus when you have a baby as well as such parts of you as your bronci of your lungs and the muscles you use when you perform at the loo or hold it back when youi need to.

Finally your vital muscle is called a CARDIAC MUSCLE found only in your heart. It has unique properties enabling it to contract rhythmically all by itself about 100,000 times a day to send blood around you.from birth to death.

Answer 4

Contraction is caused by a process called sliding filament theory. And in most cases allows movement through a range via the origin and Insertion of the muscle across a joint.

Answer 5

when the brain sends messages to it. the brain tells them to move

Answer 6

very slowly