Everything Life Sciences Grade 10

FACT

WATCH:The
mechanics of the
antagonism within
the biceps and
triceps.
See video:
SHORTCODEat
http://www.everythingscience.co.za

FACT
Learn more about
antagonistic
muscles:http://
http://www.botany.uwc.
ac.za/Sci_Ed/
grade10/manphys/
skel_mus.htm

The triceps has three points of origin, two on the humerus and one on the scapula, and a

single point of insertion on the ulna.

7.5 Human locomotion

Locomotion refers to the ability to move. Specifically, it refers to the way in which organisms

travel from one place to another. Examples of types of locomotion include running, swim-

ming, jumping or flying. Human locomotion is achieved by the use of our limbs. Below we

discuss the major organs and structures that bring about movement in humans.

Figure 7.20: A marathon event in progress: this locomotion is facilitated by the skeletal framework

described in this section.

The structures used during locomotion include:

1.Bonesprovide the body’s supporting structure. They provide the framework that help

maintain the body’s shape and provide a surface for the attachment of muscles.

2.Jointsare points of contact between individual bones. They allow bones to move

against and past each other to enable movement.

3.Ligamentsconnect bones the ends of bones together in order to form a joint. Most

ligaments limit dislocation, or prevent certain movements that could form breaks. They

hold bones in place so that they work in a coordinated manner.

4.Tendonsconnect muscle to bone. They transfer the force generated by muscle con-

traction into movement of the skeleton.

5.Muscleswork in antagonist pairs to cause bones to move. Muscles are attached to

bone via the tendon. Therefore as the muscle contracts, the bone moves.

7.6 Muscle structure and function

You learnt about three types of muscle tissue (skeletal, smooth and cardiac) in Chapter 4. In

this chapter, we will look atstriatedorskeletal muscle. Skeletal muscle is voluntary muscle

which means it can be controlled by will.They are the muscles that you use to enable you to

run, skip, walk etc.

The basic units of a muscle are called myofibrils. Myofibrils make up the muscle fibre

(muscle cell). Numerous muscle fibres are found in bundles. These bundles are surrounded

212 7.5. Human locomotion