Unit 1: The Body in Unit 1: The Body in SportSport

2. Understanding the muscular 2. Understanding the muscular system and how it is affected system and how it is affected

by exerciseby exerciseIn this section you will learn how the skeletal and muscular systems are linked in the creation of movement during sports activities. You will also learn about the structure of joints and levers in the production of movement.

Classification of musclesClassification of muscles• All sports performers need to be able to

move. Movement is possible through the use of muscles, but not all muscles bring about movement.

• There are three different types of muscle tissue that make up the muscular system.

• Can you name them?

The three different types of The three different types of muscle tissue are:muscle tissue are:

1. Cardiac muscle, which is only found in the heart.

2. Smooth muscle, also known as involuntary muscle.

3. Skeletal muscle, also known as voluntary muscle

• The structure and function of each of these muscle tissues are very different, and they are controlled by different methods

Cardiac MuscleCardiac Muscle• This type of muscle is only found in

the heart, and is a special form of involuntary muscle in that we have no direct conscious control over it. It also differs from voluntary muscle in that it does not tire, but continues to contract and relax throughout our lives.

Involuntary or Smooth Involuntary or Smooth MuscleMuscle

• Examples of this type of muscle can be found in parts of the digestive tract propelling food through the digestive system and the blood vessels that aid blood flow away from the heart to all parts of the body.

Skeletal or Voluntary MuscleSkeletal or Voluntary Muscle• This type of muscle is attached to the

skeleton of the human body and is responsible for bringing about movement and maintaining body posture. These muscles are controlled by the central nervous system and we move these muscles with conscious thought.

Your body has over 600 muscles to Your body has over 600 muscles to enable it to move.enable it to move.

• Hamstrings• Quadriceps• Triceps• Deltoid• Latissimus dorsi• Gastrocnemius

• Bicep• Pectoral• Gluteus maximus /

Gluteals• Trapezius• Abdominals

You are going to concentrate on just 11. Can you name any muscles?

Anterior View of the Anterior View of the muscular systemmuscular system

Posterior view of the Posterior view of the muscular systemmuscular system

Muscle and Sporting actionMuscle and Sporting action

Triceps - Extends lower arm at the elbowVolleyball player has arms outstretched to block theballBiceps - Flexes arm at the elbowTennis serve – racket preparation, when racket isbehind headDeltoids - Abducts upper arm at the shoulderPreparation for a cartwheel in gymnasticsPectorals - Adduction of upper arm at the shoulderArm action in front crawl (pull)Trapezius - Adducts and rotate scapula, rotation ofhead at atlas and axisLifting of the head to watch the flight of the shuttlein badminton

Muscle and Sporting actionMuscle and Sporting actionGluteals - Extends the leg at the hipRunning action, one leg is left stretched backbehind the otherQuadriceps - Extends the leg at the kneeFollow through after kicking a ball in footballHamstrings - Flexes the leg at the kneeTaking the leg back in preparation to strike the ballin rugbyGastrocnemius - Plantar flexion of the foot Going up onto toes prior to take off in a divingcompetitionLatissimus dorsi - Adducts and rotates thehumerus at the shoulderPulling the arm back in archeryAbdominals - Flexes and rotates the trunkForward action in sit ups

Structure and function of skeletal Structure and function of skeletal musclemuscle

Skeletal muscles aremade up of manythousands of fibres.These in turn aremade of even smaller fibres called myofibrils. It iswithin these smallestfibres that thecontraction of themuscle takes place.

Muscle movementMuscle movement

• Skeletal muscle has a vast supply of nerve and blood vessels. Skeletal muscle is also termed voluntary muscle because movement is created via conscious thought process. Muscles pull to produce movement. In other words, the cells of the muscle tissue contract and then relax to their original size.

How Muscles Work:How Muscles Work:When you move a

part of your bodyyour muscles will

either:• CONTRACT –

Bulge (get fatter) and shorten

Or:• RELAX – Return to

their original length

Muscle ContractionMuscle Contraction• Muscles work (contract and shorten) when

stimulated (told to do so) by the central nervous system (CNS). The brain sends messages via the spinal cord to the muscles it wishes to move. The spinal cord acts like a telephone wire.

• Muscular tissue has the ability to contract (shorten and bulge) and then return to its original length because it has ELASTICITY.

• Voluntary / Skeletal muscles usually works across a joint. They are attached to both bones by strong cords called Tendons.

• Tendons are white, flexible, very strong and are different shapes depending upon the muscle.

• In other words Tendons are the cords that connect Muscles to Bone so a muscle has tendons at both ends.

Antagonistic PairsAntagonistic Pairs

Muscles work in pairs to provide movement for physical activity, for example the biceps and triceps work together to create movement.

Antagonistic pairsAntagonistic pairsPrime movers – thesemuscles determine themovement of an action viacontraction. For exampleduring the bicep curl, theprime mover during theflexion phase is the bicep.

Antagonistic – this muscleworks together with theprime mover but creates anopposition action. Using theexample of the bicep curlagain, during the flexionphase the triceps enable thearm to bend at the elbowjoint for the bar to movetowards the shoulder girdle.

Antagonistic pairsAntagonistic pairs

During the downward phaseof the bicep curl the oppositeoccurs. For example theprime mover (Agonist) is thetriceps and the antagonisticmuscle is the bicep.

Origins and InsertionOrigins and Insertion

Muscles PULL on Bones – muscles areattached to two different bones withtendons.To make a joint move – one of thesebones will move but not the other• ORIGIN –attached to the STATIONARY

bone• INSERTION – attached to the MOVING

bone

Origins and insertionOrigins and insertion

Muscle ContractionMuscle ContractionMuscles contract to produce movement. There arethree main types of muscle contraction: two whereobvious movement occurs and one where noobvious movement is visible.

• Isometric contraction is where the muscle stays the same length during contraction, or when the activity is being carried out. Tension occurs in the muscle but the distance between the ends stay the same

Muscle ContractionMuscle Contraction

• Isotonic concentric contraction is when the muscle shortens when performing an action. There is obvious movement when the ends of the muscle move closer together.

• Isotonic eccentric contraction occurs when the muscles lengthen under tension. The ends of the muscle move further away during an action.