Week 3 Worksheet - Muscle Tissue PDF

**Worksheet 3** **Muscle Tissue / Sliding Filament Model of Muscle Contraction** **Reading:** Chapter 9 of Marieb, E.N., Hoehn, K.N. (2012). Human Anatomy and Physiology **Or** the appropriate chapter of another anatomy and physiology text. 1. State the 3 types of muscle tissue & the character...

**Worksheet 3** **Muscle Tissue / Sliding Filament Model of Muscle Contraction** **Reading:** Chapter 9 of Marieb, E.N., Hoehn, K.N. (2012). Human Anatomy and Physiology **Or** the appropriate chapter of another anatomy and physiology text. 1. State the 3 types of muscle tissue & the characteristics of muscle tissue Smooth (not striated), cardiac (striated) and skeletal (striated) 2. Describe the microscopic anatomy of a skeletal muscle cell E:\\Image\_Library\\JPEG\_IL\\09\_IL\_jpeg\\09-04cd\_thickthnfil\_2.jpg 3. Working from top left, name the structures indicated in the diagram above & give a brief description of each component identified 1. 2. 3. 4. Actin 5. Myosin 6. Working from top down, name the structures indicated in the diagram below. Do you know what each of these structures do? Ok, here's the challenge, explain them to your peers in class? 1. 2. 3. 4. 5. 6. 7.  E:\\Image\_Library\\JPEG\_IL\\09\_IL\_jpeg\\09-07ac\_neuromusjunc\_2.jpg 7. Summarise the events depicted in figures (a), (b), (c) below  E:\\Image\_Library\\JPEG\_IL\\09\_IL\_jpeg\\09-11\_filamentscont\_2.jpg 8. Cross bridge cycle. Describe the events that are depicted in figures (1), (2), (3), (4) above 1 Myosin cross bridge attaches to myosin receptor on actin filament 2 the working stroke -- the myosin head pivots and bends, sliding the actin filament towards the m line 3 ATP binds to the myosin head, detaching the cross bridge from the actin filament 4 the ATP is split into ADP and P2+, which cocks the myosin head back 9. What factors would limit this? How would this differ in an eccentric contraction? 10. Describe briefly how muscle contractions are graded Because muscle contractions are not 'all or nothing', a muscle may contract very slightly to perform a light movement and that same muscle may recruit more muscle fibres and there will be more neural stimulation to the muscle fibres to perform a much more strenuous movement 11. What factors determine the force of muscle contraction? How many muscle fibres are recruited and the frequency of neural stimulation to the muscle fibres 12. You want to train to become an endurance athlete whilst your colleague is looking to increase speed and power. Discuss in your groups how you would do this? What would happen to the size of your muscles in each case and what would happen microscopically? What factors would help you to achieve your goals? Why may you become injured ?