Y8 lesson on human body structure including antagonistic muscles, function of the skeleton and types of joints. Includes resources from Education Using Powerpoint and Framework.

4. Joints An “immovable” joint A “slightly” movable joint” “ Hinge” joints A “ball and socket” joint

5. 9B Knees up!

6. 9B Bend it! Muscles can only contract (get shorter) or relax (when they can be pulled longer again).

7. 9B Antagonistic muscles What are your muscles doing when you bend your arm? Are they contracting or relaxing? The biceps and triceps are an antagonistic pair of muscles. What does this mean? Muscles can only pull, not push. So one muscle pulls the bone one way, and the paired muscle pulls it back again. Which muscle contracts when you straighten your leg? contracting relaxing relaxing contracting triceps biceps straightening the arm bending the arm muscle group

8. sit-ups 9B Hot and sweaty Contracting is hard work for muscles. They get hot. Respiration releases energy so that they can work. Look at these thermal images. The hot areas of the body are red. Which exercise belongs with which image? arm wrestling arm wrestling swimming cycling swimming cycling press-ups press-ups sit-ups

9. A joint is a place where two or more bones meet. Joints allow us to move. 9B Know your pelvis from your elbow Name these joints. Which are ball-and-socket joints? Which are hinge joints? a b c d e f g shoulder elbow hip wrist finger knee ankle shoulder hip elbow finger knee

10. What is meant by antagonistic muscles? Muscles are said to work in “antagonistic pairs”. This is because they oppose each other’s movement: