PRELIMINARY TOPIC 2: THE BODY IN MOTION Key Idea 1: How do the musculoskeletal and cardiorespiratory systems of the body influence and respond to movement? Skeletal System SUMMARY

● 206 bones ● Framework for muscle, tissue and organs ● Protects organs ● Movement from skeletal + muscular systems ● Bones connected at joints

MAJOR BONES IN MOVEMENT

● Long Bones - In legs + arms - Long - Act as levers

● Short Bones - Found in hands, feet + wrists

● Flat Bones - Larger surface area - Protect vital organs

● Irregular Bones - Very strong - E.g. pelvis, teeth, jaw

KEY WORDS

● Anterior - To the front ● Medial - Toward midline

● Posterior - To the back ● Lateral - Away from midline

● Superior - Towards top ● Proximal - Nearer body mass

● Inferior - Toward bottom ● Distal - Away from body mass

STRUCTURE AND FUNCTION OF SYNOVIAL JOINTS Joint: Point where two or more bones meet

- Allow bones to move in relation to each other without wear and tear Synovial: Freely moveable (most common type)

● Tendons, ligaments, cartilage + synovial fluid - Tendon: muscle connection to bone - Ligament: bone connection to bone - Cartilage: firm, flexible tissue - Synovial Fluid: fluid in cavities of synovial joints (lubricates joint)

TYPES OF JOINTS

● Ball and Socket - Move forward, back + sideways - E.g. Shoulders, hips

● Hinge - Open and close - E.g. Elbow

● Saddle - Move side to side - E.g. Carpals

● Gliding - Small gliding movements - E.g. Joints between vertebrae

● Pivot - Pivot - E.g. Spine, neck

● Ellipsoid - Large range of motion - E.g. Wrists

JOINT ACTIONS

● Flexion: angle at joint decreases

● Abduction: movement away from midline

● Extension: angle at joint increases

● Adduction: movement toward midline

● Rotation: movement around a central axis

● Plantarflexion: point toes down

● Circumduction: circular movement ● Dorsiflexion: raise foot up

Muscular System

SUMMARY ● Over 600 functioning muscles ● 3 groups: cardiac, skeletal, smooth ● Half of body weight

MUSCLE TYPES AND FUNCTIONS ● Cardiac

- Muscles of heart (propel blood) ● Skeletal

- 40% of body weight - Support movement of skeleton - Voluntary

● Smooth - Majority of internal organs - Controlled by nervous system (brain,

spinal cord, nerves) + hormones - Involuntary

● Muscle Fibres - Speed of muscle contractions - 2 types: slow + fast twitch

MUSCLE RELATIONSHIPS ● Agonist

- Produces most force - Contracts/shortens during action

● Antagonist - Opposition to agonist - Determines speed and range of agonist - Extends/lengthens

● Stabiliser - Fixator/synergist (provide fixed base) - Partially contracted - Support main movement

MUSCLE CONTRACTION TYPES Contraction: Shortening or tensing of a part or organ.

- When muscle is stimulated (arouse organism to action).

● Isotonic - Concentric contraction: muscle shortens, causes movement at joint - Eccentric contraction: muscle lengthens, causes movement at joint

● Isometric

- Isometric contraction: muscle contracts, no movement produced

Respiratory System SUMMARY

● Transfers oxygen from air to blood ● Disposal of carbon dioxide (CO2) (waste product) ● Work with cardiovascular system to transport oxygen ● Availability of oxygen & delivery to working muscles to enable repeated movements

LUNG FUNCTIONS Deoxygenated blood → right side of heart → lung (disposal of CO2) → blood becomes oxygenated → back to heart → to working muscles, tissues + organs Diaphragm: muscles sheet across chest, contract → draw oxygen, relax → pump CO2 out of lungs Pulmonary Ventilation: mechanical process relying on pressure changes in thoracic activity.

- Inspiration = Inhaling - Expiration = Exhaling

EXCHANGE OF GASES *occurs in the capillaries

1. Blood in capillaries arriving at alveoli: low in oxygen, high in CO2

2. Oxygen moves across alveolar-capillary wall into blood 3. Oxygen attaches to haemoglobin in red blood cells. 4. CO2 unloaded from blood into alveoli across wall to be breathed out 5. Alveoli supplied with fresh air: high in oxygen, low in CO2

Haemoglobin: red protein that transports oxygen in the blood. Pressure Difference: Different concentrations of O2 and CO2 between blood and air.

Circulatory System SUMMARY

● Includes cardiovascular system ● 3 main parts:

- Heart - Vessels - Blood

● Transport materials (i.e. nutrients, blood, hormones, waste) to muscles and organs via bloodstream

● Convert lactic acid to pyruvic acid COMPONENTS OF BLOOD

● White Blood Cells (leukocytes) - Protect body against disease - Fight infections (no. of white

blood cells increase to fight) - Destroy germs as they enter

body

● Red Blood Cells (erythrocytes) - Transport oxygen and CO2

around body

● Platelets - Blood clotting agencies - Stop bleeding - Stick to damaged blood

vessels to block blood flow

● Plasma - Liquid part of blood transports materials (blood cells, nutrients, hormones, gases) - Mostly water - Contains mainly oxygen

Artery:

- Leaves the heart - High blood flow pressure (blood pumped out)

Vein:

- Returns to the heart - Low blood flow pressure (blood returning)

STRUCTURE AND FUNCTION Structure

- Two ventricles carry deoxygenated blood (right) and oxygenated blood (left) - Left and right atriums pump blood out into arteries - Pulmonary veins carry fresh oxygenated blood to left side - Aorta pumps oxygenated blood out to rest of body

Function

- Distribute blood around body to working muscles and organs - Pumped to lungs (to be oxygenated) - Heart relaxes when filled with blood, contracts when releasing

PULMONARY AND SYSTEMIC CIRCULATION

● Transport system pump - delivers oxygen around body

Pulmonary Circuit: heart → lungs → heart (right) pulmonary = to the lungs Systemic Circuit: heart → every part of body → heart (left) BLOOD PRESSURE

● Varies in response to posture e.g. lying, sleeping, breathing, emotion, exercise

● Temporary rises - excitement, stress, physical exertion

● Information on how well circulatory system is operating

Diastolic - lowest/minimum pressure recorded - when heart relaxes + fills - (diastole)

Systolic

- highest/peak pressure recorded when heart contracts - blood forced into arteries (left ventricle) - Systole

Sphygmomanometer: Measures blood pressure.

Key Idea 2: What is the relationship between physical fitness, training and movement efficiency? Health & Skill Related Components of Fitness SUMMARY - HEALTH RELATED

● Ability to perform vigorous daily activities ● Prevent chronic disease ● High level fitness = less fatigue doing tasks

SUMMARY - SKILL RELATED

● Aspects of fitness forming basis for successful sport/activity output ● Important in and improves activity performance

HEALTH COMPONENTS SKILL COMPONENTS

Cardiorespiratory Endurance - Circulatory & respiratory system (aerobic fitness) - Supply oxygen, remove waste during exercise - Perform long strenuous activity without fatigue - E.g. beep test

Power - Ability to combine strength and in speed in an

explosive action - Speed Dominated: power through emphasised speed- Strength Dominated: power through emphasised

strength - E.g. Standing long jump test, vertical jump test

Muscular Strength - Ability to produce force against resistance - E.g. handgrip strength test

Speed - Ability to perform movement quickly - Amount of time it takes to perform movement - E.g. Stopwatch sprint

Muscular Endurance - Ability to regenerate force over a period of time - E.g. prone hold

Agility - Ability to change direction of body efficiently - E.g. Agility course

Flexibility - Move a muscle through complete range of motion - Static vs. Dynamic - E.g. stretch muscles, measuring cm of movement

Coordination - Integration of hand/foot movement with sense input

producing controlled movement - E.g. Ball toss

Body Composition - Percentage of bone, muscles (organs) and fat - E.g. BMI (Body Mass Index), Skinfolds

Balance - Ability to maintain equilibrium while stationary or

moving - Static (Stationary) vs Dynamic (Moving) - E.g. One foot (static) test

Reaction Time - Time taken to respond to stimulus - E.g. Catch ruler

Aerobic and Anaerobic Training SUMMARY

● Training programs to develop range of fitness components ● Skill development + strategies ● Identify correct energy pathway/body system to convert nutrients → energy ● Anaerobic Pathway: Short sharp movements (oxygen is absent) ● Aerobic Pathway: sustained/moderate intensity (with oxygen)

F.I.T.T. PRINCIPLE

F requency - How often? - No. of sessions

I ntensity - How hard? - % of MHR (max. heart rate) reached - MHR = 220 - age

T ime - How long? - Duration of session

T ype - What are you doing? - Type of activity to be completed

F.I.T.T. PRINCIPLE - AEROBIC TRAINING

● Low to moderate intensity ● Longer than 90 seconds ● Oxygen becomes available to cells of muscles for energy generation ● Continuous activities for long duration ● Must be at least 3 times a week

F.I.T.T. PRINCIPLE - ANAEROBIC TRAINING

● High intensity ● Two minutes or less (+ high intensity) ● Muscles work without oxygen ● E.g. sprinting: instant muscle response, exhaust fuel reserves quick ● Can require aerobic foundation

PHYSICAL FITNESS & MOVEMENT EFFICIENCY RELATIONSHIP

● Improved physiological responses to exercise, higher skill levels

● Sustain and recover from physical effort quicker

● Execute skills consistently with less effort

Immediate Physiological Responses to Training SUMMARY

● Heart Rate, Ventilation Rate, Stroke Volume, Cardiac Output, Lactate Levels Increase ● All observable/measurable ● Exercise causes physiological changes in body ● E.g. need more oxygen, increased body temperature

HEART RATE

● Number of beats heart makes in set time ● Increase exercise = Increase heart rate ● Average: 70 bpm ● After exercise - drops to resting rate

- Speed depends on fitness ● Pulmonary + systemic circulation

increase to meet increased oxygen needs STROKE VOLUME

● Amount of blood ejected per beat ● Increase exercise = Increase stroke volume ● Average: 70-80 ml per contraction

- During exercise: 150 ml ● Speeds up blood oxygenation process

CARDIAC OUTPUT ● Volume of blood pumped out of heart per minute ● Increase exercise = Increase cardiac output ● Heart Rate x Stroke Volume ● Average: 5-6 L

- During exercise: 25L

VENTILATION RATE ● Amount of air inhaled at set time ● Increase exercise = Increase ventilation rate ● Rate + depth rapid increase proportional to effort ● + O2 consumption & CO2 production ● Average: 20 L per min

- During exercise: 170 L per min

LACTATE LEVELS ● Amount of lactic acid in bloodstream ● Lactic Acid System: sugar broken down to chemicals → produce energy for muscles ● Enough oxygen = products carbon dioxide + water ● Average: 1 millimole per litre ● Lactate: chemical (ions + hydrogen ions in water) formed in breakdown of carbs (in

absence of O2)

Key Idea 3: How do biomechanical principles influence movement? SUMMARY

● Combine biology and mechanics (physics) study ● Explain body functions ● Concepts of biomechanics + application to movement ● Forces + effects of forces on human body

Motion

APPLICATION OF MOTION

Linear Motion Movement in straight line E.g. 50m swim

Angular Motion Circular movement around central point E.g. Gymnast (bars)

Projectile Motion Move along curved path under action of gravity E.g. Javelin

Distance Path travelled from one displacement to another

Displacement Location measured with respect to other known point

APPLICATION OF VELOCITY

● Rate of change of displacement ● Does not move in straight line (when used) ● Displacement of object over time ● Magnitude + direction of body

APPLICATION OF SPEED

● Distance/Time ● No direction ● Rate body moves from one place to another ● Magnitude of body

APPLICATION OF ACCELERATION

● Displacement/Time (change in velocity/time) ● Rate velocity changes over time ● Increase = Positive Acceleration ● Decrease = Negative Acceleration

APPLICATION OF MOMENTUM

● Velocity x Mass ● Quantity of motion body possesses ● Once in motion, stays in motion ● More speed = More distance to stop

Balance and Stability

SUMMARY ● Balance

- Static: object not moving - Dynamic: object moving, stay upright

● Stability: resistance of body to changes in equilibrium (linear/angular acceleration)

CENTRE OF GRAVITY ● Point all weight in object is equally distributed ● Not always within physical limits ● When moving/rotating, is also axis of rotation ● Lower centre of gravity = Greater stability

BASE OF SUPPORT ● Region of body in contact with surface applying

reactive force ● More stable when centre of gravity is in centre of base ● Increase base of support = Increase stability

LINE OF GRAVITY ● Imaginary vertical line through centre of gravity ● Represent direction gravity acts on body ● Altered by movement

Fluid Mechanics SUMMARY

● Range of mechanics concerned with properties of liquids & gases FLOTATION (CENTRE OF BUOYANCY)

● Ability to maintain stationary position on surface of water ● Centre of Gravity ● Body Density: mass unit volume of body or object

- mass/volume FLUID RESISTANCE

● Body or object moves through water or air, exerts force when encountering resisting force ● Lift is force operates at right angles to the drag

Force SUMMARY

● Push or pull acting on/by a body ● External - forces acting on individual from outside body ● Internal - forces acting within individual

BODY ABSORBS FORCE

● Through joints + muscles that bend + flex (injury if not absorbed bending) APPLYING FORCE TO AN OBJECT Newton’s Laws

1. All objects, if in motion, will remain in motion unless as external force acts on it 2. Force = Mass x Acceleration 3. For every action, there is an equal and opposite reaction