PSA762 Fundamentals of Sports Science L3 PDF

PSA762 Fundementals of Sports Science L3 - Khan academy as free learning site - Functions of cardiovascular system - Delivery (oxygen, nutrients to muscles) - Removal (CO2 from tissue to lungs, other waste products) - Transport (also transports hormones) - Maintenan...

PSA762 Fundementals of Sports Science L3 - Khan academy as free learning site - Functions of cardiovascular system - Delivery (oxygen, nutrients to muscles) - Removal (CO2 from tissue to lungs, other waste products) - Transport (also transports hormones) - Maintenance (of homeostasis, of pH) - Protection (1. Maintain hydration blood plasma mainly made of water 2. White blood cells -\> fight infection) - Components - A closed loop system -\> everything joins up - Fluid medium (blood) - A system of channels (blood vessels) - A pump (heart) - Structure of heart - Two sections "two pumps", "blue side and red side" - Right hand side deals with deoxygenated blood, pulmoary - comes into right atrium through vena cava, goes through AV valve, gets pumped to lungs (blood gets oxygenated) through pulmonary artery (away from the heart and only artery that contains deoxygenated blood) - Left hand side deals with oxygenated blood, systemic - comes back to the heart to get pumped through the body through left pulmonary vein (only vein in the body that contains oxygenated blood) into left atrium, goes through AV valve, into ventricle, out through Aorta and around the body - Other features - -\> 4 valves in the heart stop blood from going in the wrong direction - septum in the middle -\> divides heart into sections, is thicker (more muscle) on left side because more pressure is needed to pump blood through the entire body than to pump if from the heart to the lungs - Electrical activity of the heart - SA node -\> pacemaker of heart, heart works as electrical system, sends electrical signals - SA node controls how quickly the heart beats, send outs electrical signal -\> to AV node then through the middle of the septum and the branches out - Composition of total blood volume - Made mostly out of water, depends on hydration of individual (55% plasma) - 45% formed elements -\> mostly red blood cells(\>99% of formed elements) + white blood cells and platelets (\ plasma volume increases (55% to 59%) and red blood cells increase, but plasma increases more in comparison therefore the red blood cells percentage in the blood decreases (44% to 41%) - More plasma volume is good because it means more blood volume overall -\> easier to get blood through the body -\> advantage, more plasma than solids in the blood helps blood flow better through the body, blood less thick/less discus - Vascular system - Blood is generally stored: - A lot is stored in the venous system (64%) and less in the artery system (10%)  - Aorta big vessel (2.5cm), thicker than other vessels because more muscle because it is under more pressure - Going down diameter and thickness decreases because eg. capillary needs to be small and thin to aid with diffusion, also surface area increases diffusion - Arterioles - Determines/ controls blood flow to individual organs, important for redistribution of blood flow during exercise - extrinsic control (brain decides size) or intrinsic control (can control size of vessels at the vessel level, control size of diameter) - At rest they are vasoconstricted when blood flow is needed, they vasodilate - Vasodilation -\> when high CO2 and low O2 - Known as resistance vessels because they can control the resistance to flow - Redistribution of blood flow with exercise - When exercising the amount of blood increases dramatically - Redistribution from intestines to working muscles - The amount of blood going to the blood stays the same, percentage goes down only because the amount of blood increases - Results in getting nutrients, oxygen to the muscles and removal of any waste products and removal of CO2 - Venous system - Arteries have blood under loads of pressure, but venous system low pressure -\> trying to get blood back to the heart, easily distended (stretched) and hold blood there - Risking: No movement standing upright, blood goes to feet -\> none to brain -\> collapsing because of venous pooling (eg. soldiers displaying) - Muscle pump (prevent venous pooling) - Transporting blood against pull of gravity - Muscles press on veins and pumps blood upwards, valves prevent blood from flowing back down, (use skeletal muscles to squeeze veins) - Cardiac Output - Q (cardiac output)-- total volume pumped out by each ventricle per minute - Q -- heart rate x stroke volume - SV -- the blood volume ejected by each ventricle with each beat - SV -- end diastolic volume (heart relaxed) -- end systolic volume (contraction and ventricles empty)