Movements we control
Skeletal muscles and voluntary movement.
Running, writing, lifting
Running to catch a bus, writing in your notebook and lifting a bag are movements that you choose to make.
Which muscles do you think carry out these movements?
What this lesson covers
The idea
Voluntary movements, under conscious control, are produced by skeletal muscles attached to the skeleton, made of long, cylindrical, unbranched, multinucleate and striated muscle fibres.
Running, writing, lifting
Running to catch a bus, writing in your notebook and lifting a bag are movements that you choose to make.
Which muscles do you think carry out these movements?
- Muscles attached to the skeleton
- Muscles in the wall of the heart
- Muscles that move food in the intestine
Zoom into a muscle
Press the three buttons one after another.
Controlled by us
Movements like running, writing and lifting are under our conscious control. They are carried out by skeletal muscles, which are attached to the skeleton. A skeletal muscle is made of bundles of long fibres, and each fibre looks the same along its length, with many nuclei and light and dark bands.
Voluntary movements, under conscious control, are produced by skeletal muscles attached to the skeleton, made of long, cylindrical, unbranched, multinucleate and striated muscle fibres.
Notes
Voluntary movements are under conscious control and made by skeletal muscles: long, cylindrical, unbranched, multinucleate and striated fibres.
Check yourself
Voluntary movements are movements that…
Which of these is a voluntary movement?
Which fibres belong to skeletal muscle?
What does striated mean?
- happen automatically. Movements that happen automatically are called involuntary movements.
- are carried out by the heart. The beating of the heart is an involuntary movement.
- are under our conscious control — correct. Yes!
- Writing — correct. Yes!
- The beating of the heart. The heart beats automatically, so its movement is involuntary.
- The movement of food in the intestine. Food moves in the intestine without our conscious control, so this is involuntary.
- Spindle-shaped cells, each with a single nucleus and no bands. These are the cells of smooth muscle.
- Long and cylindrical, unbranched, with many nuclei and bands — correct. Yes!
- Cylindrical and branched, with a single nucleus and faint bands. These are the fibres of cardiac muscle.
- Having many nuclei. Having many nuclei is called multinucleate.
- Having branches. Skeletal muscle fibres are unbranched. Striated means showing light and dark bands.
- Showing light and dark bands — correct. Yes!