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Eric Lindross http://www.youtube.com/watch?v=WVeqzYgTELk Daniel Alfredsson http://www.youtube.com/watch?v=jE5Nz2efcW8 Marion Hossa http://www.youtube.com/watch?v=fY9CmK86fhs Sidney Crosby http://www.youtube.com/watch?v=yQQ7lmeWqBI. http://www.youtube.com/watch?v=fFkWTGKNLT8 Colt McCoy
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Eric Lindross • http://www.youtube.com/watch?v=WVeqzYgTELk • Daniel Alfredsson • http://www.youtube.com/watch?v=jE5Nz2efcW8 • Marion Hossa • http://www.youtube.com/watch?v=fY9CmK86fhs • Sidney Crosby • http://www.youtube.com/watch?v=yQQ7lmeWqBI
http://www.youtube.com/watch?v=fFkWTGKNLT8 Colt McCoy • http://www.youtube.com/watch?v=VASrGGsC234 • Junior Seau • http://www.youtube.com/watch?v=mxK5MafuNWs
Role of Cardiovascular System Transport O2 and nutrients to tissues Remove CO2 and waste products from tissues Maintenance of constant body temperature Prevention of infection
Anatomy of the Heart Cardiac muscle About size of fist Located in thoracic cavity between lungs directly behind sternum Titled Apex (pointed end) is oriented to left
Walls of heart: • Pericardium – protective sac (reduces friction) • Epicardium – outer layer • Myocardium – layer made of cardiac muscle • Endocardium – innermost layer
The “Double Pump” • Right and left heart • Separated by interventricular septum • Right heart = right pump • Pump deoxygenated blood (just returned from body) to the lungs • Pulmonary circulation • Left heart = left pump • Pump oxygenated blood (just returned from lungs) to the rest of the body • Systemic circulation
4 chambers • Upper chambers = Atria (right & left) • Lower chambers = Ventricles (right & left) • Left ventricle (thickest) – pump blood through entire body • Right ventricle – pump blood short distance to lungs
Heart Valves • Atria & ventricles separated by valve = Atrioventricular (AV) valves • Allows only one flow of blood (atria ventricles) • Right side of heart tricuspid valve • Prevent backflow from right ventricle to right atrium • Left side of heart bicuspid (or mitral) valve • Prevent backflow from left ventricle to left atrium • Valves where blood leaves ventricles • Right side of heart Pulmonary semilunar valve • Prevent backflow from pulmonary arteries to right ventricle • Left side of heart Aortic semilunar valve • Separates aorta from left ventricle
Pathway of Blood Flow • Right atrium receives deoxygenated blood from superior & inferior vena cava • Superior vena cava = returns blood from upper body • Inferior vena cava = returns blood from lower body • Blood moves from right atrium (through tricuspid vavle) to the right ventricle (passes tricuspid valve) • Pumped out of pulmonary arteries (through pulmonary semilunar valve) to lungs pumps it to the lungs (pulmonary circulation)
This is known as SYSTEMIC CIRCULATION Oxygenated blood returns from lungs now O2-rich Through pulmonary veins into left atrium (only time a vein carries O2-rich blood!) Blood travels from left atrium (through bicuspid valve) to left ventricle Blood enters aorta (through aortic semilunar valve) & pumps to the whole body
Cardiac Cycle • Series of Events that lead to one heart beat • Relaxation = diastole • Contraction = systole • When blood pressure is measured it’s systolic pressure (120 mm Hg)/diastolic pressure (80 mm Hg)
Arteries, Veins & Capillaries Arteries = vessels that carry blood away from heart Veins = vessels that carry blood toward heart Capillaries = microscopic vessels, 40, 000 km in length, exchange gasses and nutrients by diffusion between blood and tissues
In systemic circulation, arteries carry oxygenated blood from heart to body tissues, while veins carry deoxygenated blood back to heart In pulmonary circulation, pulmonary arteries carry deoxygenated blood from heart to lungs, while pulmonary veins carry oxygenated blood from lungs back to heart
SA node = Pacemaker AV node passes signal from atrium to ventricle Purkinje fibres contract ventricles to push blood through pulmonary veins/arteries Excitation of the Heart
P wave-atrial depolarization and immediate repolarization QRS complex-depolarization of ventrical T wave-ventricular repolarization EKG
Cardiac Output • Q = L/min • At rest Q = 5-6 L/m, during exercise Q = 30 L/min
Stroke Volume • Is the amount of blood that is ejected from the left ventricle in a single beat • SV (mL) = LVEDV (mL) – LVESV (mL) • SV is regulated by 3 main factors: • LVEDV • Aortic blood pressure • Strength of ventricular contraction
Heart Rate (HR) • Number of times the heart contracts per minute • Cardiac output is the product of stroke volume and heart rate: • Q (L/min) = SV (mL) x HR (beats/min) • Avg HR at rest = 72 b/min, average SV = 71 mL, therefore Q = 5040 mL/min or 5L/min
Cardiovascular Drift • Initially during exercise, both SV and HR will increase, but after prolonged exercise SV may drop while HR continues to rise to maintain Q. This phenomena is called cardiovascular drift.
Blood distribution changes during exercise: • moving blood from less important systems and organs like the digestive tract, to more important areas, like muscles and the heart. • The brain always receives a constant supply (by volume) of blood, while the heart receives a constant % of blood. • Training will increase the efficiency of all of these factors at rest: • (BP (down), Q (up), HR (down), SV (up)) • may increase the diameter of the coronary arteries and even blood volume.