Muscular System Part 2 Muscle and Movement

AIM All- understand the terms contract, relax, prime mover and antagonist MOST- explain how muscles work in pairs SOME- apply origin and insertion to practical example

STARTER Recap location of muscles If your target grade is A/B you also have to identify what movement the muscle causes

Upper arm muscles The biceps and triceps work together as an antagonistic pair to move the elbow joint. To flex the elbow, the biceps (the prime mover) contracts and the triceps (the antagonist) relaxes. To extend the elbow, the actions are reversed so that the triceps contracts and the biceps relaxes.

Why are muscles arranged in pairs? Muscles always work in ……… E.g the biceps works in a pair with the ………… E.g the quadriceps work in a pair with the ……………… Muscles working in pairs allows m…………………. It is also because muscles p…………. but can not p…………… When two muscles work together doing opposite things they are called a………… p……..

Contraction and Relaxation of Muscles Flexion extension

Antagonistic Pairs In the pair the muscle that contracts (bulges) or is working is called the P…………………. In the pair the muscle that relaxes (extends) is called the A……………………….

Understanding muscle action The tendon at the non-moving (or fixed) end is known as the origin. The tendon at the moving end is known as the insertion. Muscles pull by contracting – they cannot push to produce the opposite movement. Muscles are arranged in antagonistic pairs. As one muscle contracts (shortens) its partner relaxes (lengthens). They swap actions to reverse the movement.

Origin and Insertion The role of the tendons is to attach ……………….. to …………….. O…………… is the end of the muscle which is fixed by tendons to the ……………….. bone I……………. is the part of the muscle which is fixed by tendons to the ……………… bone

TASK 1-Label diagram

TASK 2 The quadriceps and hamstrings in the legs are another antagonistic pair. Can you answer the following questions? Which joint do they move? quadriceps What types of movement are produced? hamstrings Which is the prime mover and which is the antagonist? Identify the origin and insertion of each muscle.

Muscular Contractions When muscles contract they do so in one of two ways Isotonic Contractions- change in muscle length (lucozade) Isometric- no change in muscle length (metre ruler)

Muscle Contraction Isotonic can be broken down further Concentric- when the muscle shortens under tension Eccentric- when the muscle lengthens under tension

TASK 3 Are the following isotonic or isometric: Biceps and triceps in a handstand Bicep in a bicep curl upwards Bicep in a bicep curl downwards Gymnastics- crucifix

Muscular Endurance Discuss with your partner What do you think this term means In the gym how exactly could you improve it What sports may require muscular endurance

Muscle System and Flexibility How are muscle bulk and flexibility inter linked? The more muscle bulk you have the poorer your range of movement and hence your flexibility

Exam-style questions 1. This picture shows part of the muscular system. Name muscles a–e. a b Janine exercises her deltoids by lifting heavy weights. She raises her arms out to the sides until her hands are level with her shoulders. c d e What type of movement is occurring at the shoulder? What type of muscle contraction is involved? Janine changes her exercise to holding the weights out to the sides at shoulder level for 10 seconds at a time. a) a = trapezius; b = deltoid; c = latissimus dorsi; d = tricep; e = gluteal. b) abduction. c) isotonic d) static strength d) What type of strength will this improve?

Exam-style questions 2. Explain what is meant by an antagonistic pair and give one example. Muscular endurance can be improved by training. Andrew is trying to improve his muscular endurance. He performs five biceps curls a day with a very heavy weight. Andrew’s muscular endurance is not increasing much. What is meant by muscular endurance? How is muscular endurance important in everyday life? An antagonistic pair are a pair of muscles that work together to move a joint. As one contracts and shortens, the other relaxes and lengthens, causing movement. The muscles swap roles to achieve the opposite movement. The biceps and triceps are the antagonistic pair that operate the elbow joint. a) Muscular endurance is the ability of muscles to contract repeatedly without getting tired. b) Muscular endurance is important in the performance of many everyday tasks like gardening and DIY. People with poor muscular endurance can find these tasks very tiring. C) Andrew’s exercises will improve his strength rather than his muscular endurance. He should use a lighter weight and increase the number of repetitions he performs. c) Suggest how he could change his exercise so that he achieves better results.

Can you remember all these keywords? Isotonic contraction Isometric contraction Muscular endurance Antagonistic pair Origin Insertion