1. Sliding Filament Theory
Learning Outcomes:
All demonstrate understanding of the muscle structure and the three types of muscle fibres.
Most gain understanding of the sliding filament theory through practical activity
Few can apply the muscle concept and are able to lead the rest of the class in practical activity.

2. Muscle Structure Starter activity
Describe the structure of skeletal muscle
(4 marks)
Extension: draw a diagram to further illustrate your understanding.

3. Home Work
Complete exam question on Sliding filament theory: Handout p42 Q1 & 2.
Watch Muscle fibre types A2 PE video (link on weebly website), making notes.
Complete table on characteristics of the three muscle fibre types
Complete Muscle fibre and me hand out.

4. The Sliding Filament Theory
Myofibril is –
These can be divided into units called
Each sarcomere contains 2 types of protein filaments –
During contraction these slide across one another and connect or make
This overlapping creates a striped appearance.

5. Draw and clearly label a Sarcomere
Include the following:
- Myosin, Actin, Sarcomere and Z line.
Extension – add to the diagram the following:
- A band, I band and H zone
- explain what each of these are.

6. Task
1. In groups go through the roles of the labels 2. In your own words describe the process that occurs for the sarcomere to close together. (The muscles to contract) You can use your homework to help complete this.

7. Muscle Fibres
Within skeletal muscle there are 3 types of muscle fibres. All contain a mixture of all three but not in equal proportions.
This mix is mainly genetically determined.
These fibres are grouped into motor units, only one type of fibre can be found in one unit.
(Motor unit – the motor nerve and the group of muscle fibres that it controls)

8. Muscle Fibres
In groups complete the I am type….. sheet to demonstrate your knowledge of the three types of fibres.
Extension: Look at Fig 2.07 – what does it suggest?
Although fast twitch fibres generate much greater forces they have a higher fatigue index meaning shorter contraction time.

9. Plenary Activity
Rearrange the sliding filament theory,