The Musculo -skeletal system (muscular)

The Musculo-skeletal system(muscular) 1.1: The structure and functions of the musculo-skeletal systems • Classification of muscles types • Locations and role of voluntary muscle types • Antagonstic muscle pairs • Characteristics of muscle types • How the skeletal and muscular systems work to allow participation N. Walker GCSE PE Edexcel

Muscles Types Voluntary muscles (skeletal): • Attached to the skeleton by tendons • Muscle fibres that are long and thin contract and pull the sleleton to cause movement. N. Walker GCSE PE Edexcel

Muscles Types Involuntary muscles: • Not under your control, contract and relax automatically, spindle shaped • Found in the organs of the digestive, circulatory and urinary systems • Found in blood vessels – vascular smooth muscles contract and relax to change the volume and pressure of the vessel to distribute blood where it is needed in the body N. Walker GCSE PE Edexcel

Muscles Types Cardiac muscle: • Found in the walls of the heart • Specialised type of involuntary muscle • Interlaced fibres that spread signals from the brain to the heart to regulate heart rate. N. Walker GCSE PE Edexcel

Muscle Types N. Walker GCSE PE Edexcel

Biceps Pectoralis major External obliques Hip flexor Quadriceps Tibialis anterior N. Walker GCSE PE Edexcel

Deltoids Triceps Latissimus Dorsi Gluteus maximus Hamstrings Gastrocnemius N. Walker GCSE PE Edexcel

N. Walker GCSE PE Edexcel

How do muscles work? • Muscles work in pairs- when one contracts the other relaxes. • Agonist- muscle that contracts to cause movement. • Antagonist- muscle that relaxes. N. Walker GCSE PE Edexcel

Antagonistic Muscle Pairs • Gastrocnemius and tibialis anterior acting at the ankle • Quadriceps and hamstrings acting at the knee • Biceps and triceps acting at the elbow • Hip flexors and gluteus maximus acting at the hip (all flexion to extension) N. Walker GCSE PE Edexcel

Flexion (Bending the Arm) Biceps (Agonist) Triceps (Antagonist) N. Walker GCSE PE Edexcel

Extension (Straightening the Arm) Biceps (Antagonist) Triceps (Agonist) N. Walker GCSE PE Edexcel

Task • Explain the role of the quadriceps and hamstrings during flexion and extension at the knee joint. • Use the words below to help you. • Contract • Relax • Agonist • Antagonist N. Walker GCSE PE Edexcel

Exam Questions • Give an example of an antagonistic pair of muscles. (1) • For the pair that you have chosen, explain how they function together to perform a specific action. (3) N. Walker GCSE PE Edexcel

Muscle Fibres There are two main types: • Slow twitch (type I) • Fast twitch (type II) N. Walker GCSE PE Edexcel

Muscle Fibres • We all have both types of fibres but in different quantities, probably determined by our genes • Althletes with more slow twitch tend to do better at endurance events • Athletes with more fast twitch tend to do better in speed events N. Walker GCSE PE Edexcel

Slow Twitch Fibres • Darker in colour because they contain a lot of myoglobin • They have a good supply of oxygen • Contract slowly therefore can work for longer periods of time. N. Walker GCSE PE Edexcel

Fast Twitch Fibres (II) • Fast twitch can be further broken down into: Type IIa Type IIx • Lighter in colour because they don’t use much oxygen • Contract quickly and tire easily N. Walker GCSE PE Edexcel

Fast Twitch Fibres (II) N. Walker GCSE PE Edexcel

Can we change our fibres? • Fibres are genetical- we are born with more of one than the other! • However, they can be trained to be more efficient at certain activities. N. Walker GCSE PE Edexcel

What training methods are suited to each fibre? • Slow twitch fibres- continuous training to improve the aerobic system. • Fast twitch fibres- interval training to improve the anaerobic system. • Games players require both fibres- fartlek training- ‘speed play.’ N. Walker GCSE PE Edexcel

Exam Question • How do the muscular and skeletal systems wprk together to allow participation in physical activity and sport? N. Walker GCSE PE Edexcel

The Musculo -skeletal system (muscular)