PDF Podcast: Cardiovascular and Respiratory Systems

CV system: Hormonal, Neural, and Chemical Regulation During Physical Activity: Anticipatory Rise: Increase in heart rate before exercise due to adrenaline release. Respiratory System Gas Exchange Systems at Alveoli and Muscles; Principles of Di usion and Partial Pressures: ◦ Partial Pressu...

CV system: Hormonal, Neural, and Chemical Regulation During Physical Activity: Anticipatory Rise: Increase in heart rate before exercise due to adrenaline release. Respiratory System Gas Exchange Systems at Alveoli and Muscles; Principles of Di usion and Partial Pressures: ◦ Partial Pressure (pO2, pCO2): Re ects the concentration of gases; gases move from high to low partial pressure. ◦ Di usion Gradient: Gases move across di usion gradients; the greater the di erence, the faster the exchange. Partial Pressure and Di usion Gradients: ◦ Alveolar-Capillary Exchange: ‣ Oxygen moves from alveoli to blood due to lower pO2 in capillaries. ‣ Carbon dioxide moves from blood to alveoli due to higher pCO2 in capillaries. ◦ Muscle-Capillary Exchange: ‣ Oxygen moves from capillaries to muscle tissue; CO2 moves in the opposite direction. Adaptations of Alveoli for E cient Di usion: Large surface area. Extensive blood supply with numerous capillaries. Thin, semi-permeable membrane (one cell thick). Arterio-Venous Oxygen Di erence (a-vO2 Di erence): De nition: Di erence in oxygen content between arterial and venous blood, indicating the amount of oxygen extracted by tissues. Short-Term Changes in a-vO2 Di erence: During exercise, more oxygen is used by muscles, increasing the di usion gradient. (a-v)O2 di erence increases due to greater oxygen extraction. Long-Term Adaptations from Training: Increased capillarization enhances oxygen extraction. Improved (a-v)O2 di erence contributes to better performance. Transport of Oxygen: Oxygen Transport: 3% dissolved in plasma. 97% bound to haemoglobin as oxyhaemoglobin. Haemoglobin is fully saturated when it binds four oxygen molecules. Haemoglobin vs. Myoglobin: Haemoglobin: Found in red blood cells; carries oxygen to tissues. Myoglobin: Found in muscle; higher a nity for oxygen than haemoglobin, stores oxygen for rapid use by muscles. Oxyhaemoglobin Dissociation Curve: Curve Shift During Exercise (Bohr Shift): ◦ Curve shifts right during exercise, enhancing oxygen release to muscles due to increased CO2, decreased pH, and increased temperature. Bohr Shift Explained: Occurs due to higher CO2, increased blood acidity, and elevated temperatures during exercise. Results in haemoglobin releasing oxygen more readily to active muscles. Redistribution of Blood During Exercise: Blood Flow Changes: ◦ Blood is redirected away from organs like the gut to working muscles, heart, and skin. ◦ Maintains cognitive function with constant blood ow to the brain. Mechanism of Redistribution: ◦ Increased CO2 and acidity detected by chemoreceptors. ◦ Signals sent via the sympathetic nervous system cause: ‣ Vasodilation: Increased blood ow to muscles. ‣ Vasoconstriction: Reduced blood ow to non-essential organs (e.g., kidneys, liver). Mechanics of Breathing: Expiration: ◦ Intercostal muscles relax, diaphragm relaxes, and abdominals contract. ◦ Air is forced out due to increased pressure and decreased volume in the thoracic cavity. Inspiration: ◦ External intercostals and diaphragm contract, increasing thoracic volume and decreasing pressure. ◦ Air is drawn in, assisted by accessory muscles like the sternocleidomastoid during deep breaths. Injuries How do Injuries occur; 2 main sources; Intrinsic Factors; Age Gender Body Weight and Composition Muscle Weakness Joint Hyperlaxity- hypermobility Poor exibility Malalignment of body parts (e.g. legs di erent lengths) Extrinsic Factors; Training methods Training volume (overtraining) Inappropriate or unfamiliar playing surface Inappropriate equipment Inappropriate clothing/ footwear Environmental conditions Sprain: overstretching or tear of a ligament Strain: is an overstretch or tear of a muscle (more detail of both later) Acute injuries Acute injuries occur suddenly after exercise e.g. sprained ankle or torn ligament Pain is felt straight away and is often severe Can display the following; Sudden, severe pain Swelling/ bruising around the injured site Not being able to bear weight Restricted movement Extreme leg or arm weakness A protruding bone or joint that is visibly out of place Chronic injuries Occurs after playing sport or exercise for a long time Often called overuse injuries They develop slowly and can last a long time They are often ignored by performers which makes the injury worse causing more problems Characteristics: Pain when you compete or exercise A dull ache when you rest Swelling e.g. tendonitis Fractures A break or crack in a bone Symptoms Swelling or bruising Deformity Pain in the injured area Loss of function In compound fractures, bone protruding from the skin Types: Comminuted- here the bone breaks or splinters into 3+ pieces Buckle - A partial fracture Greenstick - Occurs in children where the bone partly fractures on one side but does not break completely. This is because the bone is softer and more elastic so it can bend Hairline- A partial fracture of the bone that is di cult to detect Dislocations Occurs at joints They are very painful When the bone is forced out of position Cause Fall or a blow, sometimes from playing a contact sport Symptoms Swollen, painful and visibly out of place/ unable to move joint/ limb Treatment Manipulation to reposition bones, a splint/ sling, and rehabilitation Strains Often called pulled or torn muscle A strain occurs when muscle bres are stretched too far and tear Strains often occurs regularly in team games from contact with other players when a performer continues to accelerate and decelerates quickly Elite athletes are also prone to strains where the intensity of their training is high and overuse of muscles occur Sprains Occur to ligaments (join bone to bone) Playing sport involves lots of twisting and turning and excessive force in applied to a join, a strain can occur When the ligament is stretched too far or tears Sprained ankle is the most common Chronic Injuries- Achilles Tendonitis Tendons (muscles to bones) Overuse injury- Runners who tend to suddenly increase intensity or distance Causes pain and in ammation Chronic Injury- Tennis Elbow Over use injury In the muscles that are used to straighten the wrist Muscles become in amed and tiny tears occurs in muscles and tendons Lateral epicondylitis Any activity that places repeated stress on the elbow can cause tennis elbow -itis = in ammation or swelling Chronic Injuries- Stress fracture Over use injury Area becomes tender and swollen Most common in weight baring bones of the legs Often occurs when there is an increased amount of exercise or the intensity is increased too quickly It happens when the muscles become fatigued so are no longer able to absorb the added shock Fatigued muscles eventually transfers the stress to the bone Injury Prevention Intrinsic Considerations Warm up Necessary tness levels Athlete not fatigued (allow recovery) Strengthening exercises Good nutritional programme Extrinsic Considerations Avoid abrupt changes to trining Correct/ appropriate equipment  Appropriate footwear/ clothing Pay attention to environmental factors/ conditions Rules of activity are followed Taping Failure to prepare can lead to injuries Injury management Managing an injury requires an assessment of why the injury occurred Then need to maintain and minimize losses in tness Establish a structured rehabilitation programme (P) RICE P - Protection of the injured part (sling/ crutches) R - Rest the injured part not the whole body I - Ice C - Compression to reduce swelling E - Elevation to restrict blood ow to injury Sports Rehabilitation Physios, athletes and coaches have one aim; ◦ To get the athlete back to training as quickly as possible and minimise tness lost There are a number of approaches to reduce recovery time For each you need to state whats involved, the physiological reasons for its use, those performers likely to bene t and comment on whether it achieves desired e ect. HyperBaric chambers Originally creates to treat decompression sickness developed by scuba divers Delivers O2 at a very high pressure (2.5 x greater than atmospheric pressure) 100% pure oxygen delivered (atmospheric is 20% oxygen, 80% nitrogen) How it aids repair; Saturates the blood plasma and haemoglobin with oxygen Red blood cells become more malleable, (able to penetrate restricted blood vessels) oxygen is able to reach the injury site Cells heal quicker (protein synthesis) and athletes get back faster Faster rate of cell turnover (enhancing growth and repair) Linear Motion Momentum: Mass x velocity (kgm/s) Impulse: Change in momentum; force applied over time. Impulse = Ft (Ns) Relationship with Momentum: Increased impulse increases momentum, crucial for sprint acceleration. Angular Motion LOMIAR Law of Motion; Inertia, Acceleration, Reaction Newton’s First Law: Constant angular motion unless acted upon by external torque. Newton’s Second Law: Torque causes angular acceleration proportional to moment of inertia. Newton’s Third Law: Equal and opposite reaction a ects rotational movements. Angular Displacement: Angle of rotation (rad)  Angular Velocity: Rate of change of angular displacement. ◦ Equation: AV = Angular Displacement/ time (rad/s) Angular Acceleration: Rate of change of angular velocity. ◦ Angular acceleration = (Final Angular Velocity − Initial Angular Velocity) / time ◦ Units: radians per second squared (rad/s²). Conservation of Angular Momentum During Flight Angular Momentum: Product of moment of inertia and angular velocity; remains constant without external torque. Equation: Angular Momentum = Moment of Inertia × Angular Velocity Angular Momentum = Moment of Inertia × Angular Velocity. Moment of Inertia: Resistance to rotational motion; decreasing it (e.g., tucking in) increases angular velocity. Analysis of Movement in Sporting Contexts Joint Actions: Flexion, extension, abduction, adduction, and rotation. Muscle Roles: Agonist (Prime Mover): Main muscle responsible for movement. Antagonist: Muscle that opposes the agonist..