The Body in Motion PDF

Core 2: the body in motion Skeletal system: Major bones involved in movement: About bones Humans are born with 300 bones but at maturity the human skeleton has 206 bones as the bones fuse together by cartilage after being born e.g. the skull Anatomical terms Superior - towards the...

Core 2: the body in motion Skeletal system: Major bones involved in movement: About bones Humans are born with 300 bones but at maturity the human skeleton has 206 bones as the bones fuse together by cartilage after being born e.g. the skull Anatomical terms Superior - towards the head, e.g. the chest is superior to the hips Inferior - towards the feet, e.g. the foot is inferior to the leg Anterior - towards the front, e.g. the breast is on the anterior chest wall Posterior - towards the back, e.g. the backbone is posterior to the heart Medial - towards the midline of the body, e.g. the big toe is on the medial side of the foot Lateral - towards the side of the body, e.g. the little toe is on the lateral side of the foot Proximal - towards the bodies mass, e.g. the shoulder is proximal to the elbow Distal - away from the bodies mass, e.g. the elbow is distal to the shoulder Supine - lying face down Prone - lying face up Major skeletal bones Structure of bones The outer part of the bone consists of dense, strong compact bone tissue and forms the actual shaft of long bones, spongy bone (cancellous bone) is strong and light able to withstand stress and meets with adjacent bones forming joints. The centre cavity and the spaces between spongy bone is filled with bone marrow containing blood vessels, fat and blood forming tissue. The articular surface is soft and resilient, preventing jarring and allowing bones to move freely on each other. Types of bones Long bones - long in length consisting of two ends and a shart, made up of hard shell casing (compact bone) and spongy bone on the inside e.g. femur, humerus, radius, ulna Short bones - cube-like and made up of spongy bone with a thin layer of compact bone providing the shape e.g. carpals, tarsals, metacarpals, metatarsals Flat bones - flat thing bones that usually protect organs e.g. skull, sternum Irregular bones - do not fall into above categories and usually complicated in shape e.g. vertebrae, pelvis Sesamoid bones - usually small, round and flat, found where tendons pass over a joint e.g. patella. They aim to protect the tendon and increase movement Five main functions of bones 1. Support - bones provide the framework of the body; they support it and give the body shape, e.g. the vertebrae supports the ribs to enable us to stand 2. Protection - bones protect vital organs within the body, e.g. the pelvis surrounds the reproduction organ 3. Movement - in conjunction with muscles, bones act as levers to allow the body to move, e.g. the flexion of the knee joint allows us to kick a ball 4. Storage of minerals - bones store minerals needed for the functioning of the body e.g. calcium 5. Blood cell production - the formation of blood cells occurs in the cavities of certain bones The skeleton Axial skeleton Includes the skull, ribs and vertebral column Is the central main structure of the overall skeleton with the stability allowing bones of the appendicular system to move more efficiently Many of these bones do not move or have minimal movements Appendicular skeleton Includes the pelvic girdle, the limbs and shoulder (clavicle and scapular) Key long bones directly involved in effecting moving Structure and function of synovial joints Types of synovial joints Plane (intertarsal joints) – allows limited gliding movements Hinge (elbow and knee) – allows movements along one axis for flexion or extension Pivot (C1 to C2 vertebral joint - top of the neck) – allows rotational movements and some bending Ellipsoid/Condyloid (radius to carpal joint – wrist) – allows movement in two planes, allowing flexion, extension, adduction, abduction, and circumduction Saddle (base of the thumb) – allows the same movements as the condyloid but with no axial rotation Ball-and-socket (pelvis and shoulder) – allows movement through three planes (flexion, extension; abduction, adduction; rotation) and is the most mobile of the synovial joints Cartilaginous joints - a joint joined by cartilage (strong and flexible connective tissue) that is slightly moveable e.g. joints between the vertebrae Fibrous joints - A joint where no movement is possible and the bones are joined by fibre (connective tissue, collagen fibres connect periosteum to bone) Ligaments - well defined fibrous bands that connect articulating bones. They are designed to assist the joint capsule to maintain stability in the joint by restraining excessive movement, controlling the degree and direction of movement that occurs Tendons - tough inelastic cords of tissue that attach muscle to bone Synovial fluid - acts as a lubricant keeping the joint oiled and the moving surfaces apart. It forms a fluid cushioning between joints providing nutrition for the cartilage and carrying  away waste. When the articular cartilage is under pressure (during movement), fluid is ‘pumped’ into the joint space with the viscosity (stickiness) varying. The fluid becomes more viscous in cooler temperature potentially causing joint stiffness in cold weather Synovial membrane - The tissue that lines the non-contact parts of the joint capsule. It secretes synovial fluid Hyaline cartilage - a smooth shiny cartilage that allows the bones to move freely over each other. It receives nourishment through the synovial fluid and is thicker where greater weight bearing Joint actions Muscular system: Major muscles involved in movement: About muscles There are more than 600 muscles, all attached to bones Muscles can only pull Types of muscle tissue Cardiac - involuntary, striated in appearance, occurs in the wall of the heart Smooth - involuntary, non striated in appearance, occurs in walls of internal organs and blood vessels Skeletal - voluntary, striated in appearance, attached to the skeleton to provide movement Muscle fibres Slow twitch - contracts slowly especially during sustained physical activity requiring endurance Fast twitch - contracts quickly especially during brief high-intensity and explosive movements Origins and insertions When a muscle contracts, one bone moves while another stays stationary Origin - stable stationary bone Insertion - attachment at moveable end Muscle relationships (agonist + antagonist): Agonist - the working/contracting muscle (primary mover) that shortens Antagonist - relaxing muscle that lengthens Stabiliser - gives the muscle a fixed base, acting as a joint, so agonist can work more efficiently Isotonic - Contractions which cause the muscle to change length as it contracts and causes movement of a body joint Concentric - the muscle shortens Eccentric - the muscle lengthens Isometric - contraction occurs when the muscle fibres are activated and develop force, but the muscle length does not change; that is, movement does not occur Respiratory system: Structure and function: Structure Function Nose Nostrils bring air into the nose where it is filtered, warmed and moistened Nasal Cavity Tiny hairs called cilia protect the nasal passageways, filtering out dust and other particles that enter through the breathed air Pharynx The pharynx carries food and air, used for digestion and respiration. The oesophagus is for food leading to the stomach. The trachea is for air, with a small flap called the epiglottis, stopping food and liquid from going into the lungs Larynx The larynx (voicebox) is at the top of the trachea, this is where our vocal cords are Trachea The trachea (windpipe) is a 2-3 cm tube that extends downwards from the bottom of the larynx for about 12 cm. The walls of the trachea are made strong by stiff rings of cartilage that keep it open. It is also lined with tiny hairs that sweep foreign particles and fluids out of the airway. It divides into two branches Lungs The lungs and respiratory system allow us to breathe Bronchi The trachea divides into two branches, the left and right bronchi, with each entering one lung. The branches resemble the limbs of a tree, dividing into smaller and finer branches called bronchioles which end in alveoli.  Alveoli The bronchioles end in tiny air sacs called alveoli. The alveoli structure enables fresh air to get to the air sacs which are surrounded by tiny blood vessels, capillaries. It has a permeable membrane and this is where gaseous exchange occurs. Function - delivers oxygen to the cardiovascular system for distribution to the body and removes carbon dioxide Lung function (inspiration, expiration): Inspiration - breathing in; diaphragm contracts, and thoracic cavity expands whilst the pressure within it decreases, as a result the lungs expand and air is taken in Expiration - the diaphragm relaxes, the volume of the thoracic cavity decreases and the pressure within it increases, the lungs contract and air is forced out Lung ventilation - movement of air in and out of the lungs Around 6L of air is ventilated each minute, and during moderate exercise, that increases to approx 90L/min Tidal volume - amount of air inhaled and exhaled during one breath Respiratory frequency - amount of breaths taken in a minute VO2 max - maximal oxygen uptake that can be used by the body in one minute during max exercise ranging from 20-40 ml/kg/min (unit and ordinary) up to 8-90 ml/kg/min (elite endurance athletes) Formulas Increase in ventilation - measured by determining tidal volume and respiratory frequency Minute ventilation (amount of air inhaled and exhaled each minute) = tidal volume x resp frequency Exchange of gases (internal, external): Internal gas exchange Refers to exchange of gases between the cells of the body and the blood Oxygenated blood is brought to the cell, oxygen is taken out of the blood and transferred to the cell whilst carbon dioxide travels from the cell to the blood through capillaries Carbon dioxide then taken to the lungs through the heart to remove carbon and receive oxygen (external respiration) Blood flows from the left side to the right side of the heart (systemic circulation) External gas exchange Exchange of gases across the respiratory membrane in the lungs Deoxygenated blood travels to the capillaries that cover alveoli, carbon dioxide diffuses out of blood and into the alveoli where it is expired  At the same time oxygen that has been breathed in diffuses across the alveoli, membrane and into capillaries where it is taken away from the lungs, back to the heart to be pumped around the body and used by cells Blood flows from the right side to the left side of the heart (pulmonary circulation) Diffusion - movement of substance from a high to low concentration of that substance e.g. exchange of gas across the membranes of the capillary and cell Circulatory system: Components of blood: Blood accounts for about 7-8% of our total body weight Healthy adults have 5-6L of blood A person can donate blood every 90 days Blood recovery Plasma recovers within 24 - 48 hours Red blood cells recover in about 3 weeks Platelets and white blood cells recover within minutes Functions of blood To transport: nutrients, oxygen, carbon dioxide, waste products and hormones to cells and organs around the body To protect us from diseases (white blood cells) To regulate the bodies temperature Components of blood Red blood cells or RBC (erythrocytes) - Make up more than 99% of formed elements in blood - Contain oxygen carrying pigment called haemoglobin, giving blood cells its red colour - Live for around 120 days, replaced at a rate of 2 million per second - Formed in red bone marrow - About 44% White blood cells (leucocytes) - Combat infection and inflammation in a process called phagocytosis - Live from a few hours to a few days - Formed in thymus, spleen and bone marrow Platelets (thrombocytes) - Involved in clotting and help to repair slightly damaged vessels - Lifespan of 5-9 days - Formed in bone marrow White blood cells and platelets are about 1% Plasma - fluid/liquid component of blood - Largest component of human blood (about 55%) - Contains water, salts, enzymes, antibodies and other proteins Structure and function of the heart: 1. Deoxygenated blood enters right atrium from superior and inferior vena cava, right atrium contracts 2. Blood in right atrium flows through right AV valve (tricuspid) into right ventricle 3. Contraction of right ventricle forces pulmonary valve open 4. Blood flows through pulmonary valve into pulmonary trunk 5. Blood is distributed by right and left pulmonary arteries to the lungs where it unloads CO2 and loads O2 6. Oxygenated blood returns from lungs via pulmonary veins to left atrium that contracts 7. Blood in left atrium flows through left AV valve (mitral) into left ventricle 8. Contraction of left ventricle (simultaneous with step 3) forces aortic valve open 9. Blood flows through aortic valve into ascending aorta 10. Blood in aorta is distributed to every organ in the body where it unloads O2 and loads CO2 In muscles and body organs, the blood releases oxygen and nutrients, absorbs food and water from intestines. The liver processes nutrients and, together with kidneys, purifies the blood. 11. Deoxygenated blood returns to heart via vena cava Arteries + veins + capillaries: Arteries - carry away from the heart to the tissue, thick elastic walls Veins - carry from tissues back to the heart, thinner and less elastic walls, have valves to prevent blood flowing back the wrong way Capillaries - very small networks of vessels where nutrients and gases are exchanged between blood and cells, lie between arterioles and venules connecting both systems Oxygenated blood - appears bright red Deoxygenated blood - appears dark red Valves - prevent backflow of blood Pulmonary and systemic circulation: Pulmonary circulation - circulates deoxygenated blood from the right side of the heart to the lungs, then back to the heart (step 1-6) Systemic circulation - pumps oxygenated blood from left side of the heart out to all body tissues, then back to the right side of the heart (step 7-11) Blood pressure: The force that blood exerts on the walls of blood vessels, expressed in millimetres of mercury (mmHg) Sphygmomanometer - instrument for measuring blood pressure Systolic blood pressure - amount of pressure in your arteries during the contraction of your heart (top number) Diastolic blood pressure - blood pressure when your heart is between beats (in relaxation) (bottom number) Therefore, blood pressure peaks when the heart muscle contracts and pumps blood (a cycle called systole), and falls when the heart relaxes and refills with blood (a cycle called diastole) E.g. 120/80 mmHg is a normal reading, 140/90 is a high reading Health components of fitness: Related closely to improvements in health outcomes and make up the base work of fitness. They provide general conditioning for most sports performances. Cardiorespiratory endurance: The ability of the working muscles to take up and use the oxygen that has been breathed in during exercise and transferred to muscle Commonly referred to as aerobic power (with oxygen) Cycling, triathlons, marathons Tests - beep test Muscular strength: The ability to exert force against a resistance in a single maximal effort Muscle hypertrophy - w\increase in the size of the muscle from an increase in the cross sectional area of the individual muscle fibres Weightlifting, wrestling, rugby league, gymnastics Tests - grip strength dynamometer or 1RM Muscular endurance: Ability of the muscles to endure for physical work for extended periods of time without undue fatigue Cycling, cross country, rowing Tests - push up or sit up test Flexibility: Ability to move joints and use muscles through their full range of motion Heavy influence on avoiding injury Increases mobility Improves posture Improves blood circulation Gymnastics, dancing Tests - sit and reach test, goniometer Body composition: The percentage of fat opposed to lean body mass in a human being Heavy influence on what sport individual suited to All people need essential fat (15-20% for men, 20-25% for women) that surrounds vital organs including the kidneys, heart and liver for protection, insulation and shock absorption Absence of fat would lead to chronic health problems Tests - BMI, body composition scan, skinfold test Skill components of fitness: Related specifically to skills that are used in sport. Not essential for health but help athletes perform at a high level in their sport. Power: The ability to combine strength and speed in an explosive action calculated by strength x speed Speed dominated power - greater emphasis on speed e.g. track events, throwing Strength dominated power - greater emphasis on strength e.g. weightlifting, field events Includes accelerating, jumping and throwing implements Tests - standing broad jump, vertical jump Speed: Ability to perform body movements quickly Body weight and air resistance reduce speed Largely determined by fibre type Footy, track, touch, cricket Tests - 10-50m sprint Agility: Ability to change direction with speed and precision Multi directional sport requires athlete to dodge and weave, quickly changing direction and ac/decelerating Agile player responds quickly to stimuli (opponent) Skiing, soccer, basketball, netball Tests - illinois agility test Coordination: The ability to harmonise messages from senses with body parts to produce smooth, skillful, controlled movements Interaction between brain and muscle Less prone to injuries or accidents Throwing and catching e.g. netball, gymnastics, table tennis Tests - hand wall toss Balance: Ability to maintain equilibrium while either stationary or moving Static - when stationary Dynamic - when moving Improved by practise Reduces chance of injury Walking on bar in gymnastics, landing on one foot in netball Tests - stork stand (static), Y balance test (dynamic) Reaction time: Time taken to respond to a stimuli Time between realising presence of stimulus and appropriate response Sprinting, running, shooting Tests - ruler test Aerobic and anaerobic training: Aerobic - Exercise dependent on oxygen utilisation by the body at a low to moderate intensity, for 90s or more, and can continue for an extended period of time, e.g. marathon, 1500m swim. 60-85% max HR Anaerobic - Exercise in absence of oxygen relying on stored energy (glucose and fat) in the body that can be metabolised, at a higher intensity but for a shorter period of time, 90s or less, e.g. sprinting, high jump, long jump, weightlifting. Above 85% max HR FITT principle: Frequency How often and should be at least 3-5 times per week Training session frequency should sufficiently stress body so an adaptation can occur Rest days essential for muscle fibres to regenerate and to reduce risk of injury Intensity Amount of effort required by an individual to achieve a fitness benefit Measured by heart rate Moderate (60-70% of max heart rate), vigorous (70-85% of max heart rate) Time 20-30 min for people in good health, increasing to 50 if possible Longer than 60 min will lead to exhaustion with risk of overtraining and developing injuries Expectation for elite athletes who should be able to train for longer 6 weeks in minimum for realisation of training effects Type Best type - continuous and using large muscle groups (running, swimming, cycling) Practise should incorporate movements at competition speed or skill level Many different sessions and exercises to maximise variety and reduce boredom Immediate psychological responses to training: Heart rate: Rises at start of training to meet increased oxygen demand  Heart rate plateaus as intensity remains constant as the body can supply sufficient oxygen to working muscles Only returns to normal after waste products (CO2 and lactic acid are removed) Ventilation rate: Total volume of oxygen breathed into the lungs per minute Will plateau after a period of time if exercise intensity remains constant Remains elevated after exercise until waste products removed Stroke volume: The amount of blood pumped out of left ventricle during a single contraction Increases gradually as heart rate increases Increases as the body required more oxygen High stroke volume and low heart rate indicated better general health (same result, less effort) Cardiac output: Total amount of blood pumped out of the heart each minute Increases as heart rate increases Untrained people can increase to approx 21 L per min, elite endurance athletes can increase to approx 35 L per min Lactate levels: Amount of lactate acid found in muscles and blood stream during intense aerobic activity When anaerobic energy (energy without oxygen above 85% intensity) is when lactic acid is produced Oxygen is required to remove lactic acid from body, and will lead to fatigue, muscle soreness and cramps when insufficient oxygen to remove it Motion: Types of motion: Linear motion - movement in a straight line, all body parts moving in the same direction at the same speed e.g. a swimmer gliding off the wall after tumble turn, a downhill skier holding a body position as they move down in a straight line Angular motion - occurs around an axis that can be internal (a joint in the body around which a body rotates), or external e.g. swing of baseball bat, gymnast around high bar, figure skater doing axle jump General motion - combination of linear and angular motion e.g. running in a 100m sprint caused by angular motion of the arms and legs, freestyle swimmer uses angular motion of their arms to propel the body forward in a linear motion Velocity + speed: Velocity: Describes both magnitude and direction (displacement/time) Displacement - the change in position of an object from point A to point B Speed Describes only the magnitude (how quickly the body is moving) (distance/time) Distance - full length travelled to get from point A to point B Speed and velocity only equal if movement occurs in straight line, thus speed and velocity of a cricket batter running the same but speed and velocity of 400m sprinter around oval shaped track is different Acceleration: The rate at which an object increases its velocity (velocity/change in time) Can be uniform (constant change in velocity) or varied (because of fatigue or opponents e.g. in rugby player comes to tackle so direction change) Length and frequency of an individual's stride affects acceleration Faster acceleration helps to reach top speed faster Relates directly to agility - faster acceleration allows for better agility A baseballer runner needs to increase velocity quickly to get to the next base fast and decrease quickly to ensure they stay on the base Momentum: The measure of an object’s motion with magnitude and direction (mass x velocity) A players mass stays the same so to increase momentum they need to increase velocity and the greater the momentum, the greater the effect upon collision E.g. triple long jump, long distance running, hitting or throwing sports Linear momentum - describes translating motion Angular momentum - describes rotating motion Balance and stability: Static balance - person remains stable over relatively fixed base e.g. handstand on a beam Dynamic balance - when performer is in motion e.g. during flips on floor routine Stability - degree to which a body resists being upset or moved Centre + line of gravity: Centre of gravity - point at which all weight is evenly distributed and about which the object is balanced e.g. when standing for a human is about 55-60% of height depending on leg length, upper body development etc. Line of gravity - imaginary line drawn vertically downward from centre of gravity, where it touches the ground affects stability Base of support: The area enclosed by the outline of the support on the ground, whether hands or feet, and as the base of support increases (e.g. feet move further apart), stability increases - For a person to maintain a stable position, the line of gravity must pass through the base of support e.g. through lowering body - Increased mass increases stability as tends to remain steadier as requires more force to be accelerated (in image unstable as line of gravity falls outside base of support) Fluid mechanics: Flotation + centre of buoyancy: Flotation - any change in the density of the surrounding water affects the level at which an object floats, fresh water is denser and thinner then salt so a boat floats lower Buoyancy - loss in weight an object seems to undergo when places in liquid as compared to its weight in the air - Centre of buoyancy is the centre of gravity of the volume of water which the person or object displaces - Stable when centre of gravity and centre of buoyancy on same vertical line Archimedes principle: “An object fully or partially immersed in a liquid is buoyed upward by a force equal to the weight of the liquid displaced by that object” - Means a floating object displaces an amount of water equal to its own weight Drag, lift, stabilising: Fluid resistance force applied by a gas or liquid resisting the motion of a body through it Shaving, proper form, tight swimwear reduces resistance Drag Pressure drag - comes from frontal area exposed to water, a swimmer must streamline their body to reduce it Skin drag - resistance due to new water rubbing against swimmers body, fastskin tight swimsuits mimic the skin of a shark to reduce skin drag Wave drag - waves created by swimmer moving in water, less splashes and smoother strokes reduce waves, lane roped stop wave drag affecting swimmers in other lanes Lift Arm stroke produces most drive in lifting the body Optimum efficiency - pushing a large amount of water a small distance Stabilising Kick stabilises with propulsive force Force: How the body applies force: The body generates force by manipulating the gravitational force and using its muscles and arm momentum e.g. in vertical jump “For every action there is an equal and opposite reaction” How the body absorbs force: Bones, body tissue and muscles absorb force by transferring the force to our muscles where contractions in the opposite direction absorb the force The body increases time of absorption, movement length or area to more safely absorb force E.g. gymnastics position after doing flips finishing off bar routine Applying force to an object: Movement of the limb or body that makes contact with the external object is where the force is transferred to an object Body uses largest muscle groups to generate maximum force E.g. twisting their body in shot put before final push with arms, or run before power shot in NFL