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Cardio Vascular System Audience: Health/Physical educators and health aspiring students. By Vince Colucci. Size of Heart. Average Size of Heart 14 cm long 9 cm wide. Location of Heart. posterior to sternum medial to lungs base lies beneath 2 nd rib lies upon diaphragm.
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Cardio Vascular System Audience: Health/Physical educators and health aspiring students By Vince Colucci
Size of Heart • Average Size of Heart • 14 cm long • 9 cm wide
Location of Heart • posterior to sternum • medial to lungs • base lies beneath 2nd rib • lies upon diaphragm
Heart Chambers • Right Atrium • receives blood from • Left Atrium • receives blood from pulmonary veins • Right Ventricle • receives blood from right atrium • Left Ventricle • receives blood from left atrium
Skeleton of Heart • fibrous rings to which the heart valves are attached
Electrocardiogram • recording of electrical changes that occur in the myocardium • used to assess heart’s ability to conduct impulses P wave – atrial depolarization QRS wave – ventricular depolarization T wave – ventricular repolarization
Electrocardiogram A prolonged QRS complex may result from damage to the A-V bundle fibers
Regulation of Cardiac Cycle Additional Factors that Influence HR • physical exercise • body temperature • concentration of various ions • potassium • calcium • parasympathetic impulses decrease heart action • sympathetic impulses increase heart action • cardiac center regulates autonomic impulses to the heart
Blood Vessels • arteries • carry blood away from ventricles of heart • arterioles • receive blood from arteries • carry blood to capillaries • capillaries • sites of exchange of substances between blood and body cells • venules • receive blood from capillaries • veins • carry blood toward ventricle of heart
Arteries and Arterioles • Arterioles • thinner wall than artery • endotheliallining • some smooth muscle tissue • small amount of connective tissue • helps control blood flow into a capillary • Artery • thick strong wall • endothelial lining • middle layer of smooth muscle and elastic tissue • outer layer of connective tissue • carries blood under relatively high pressure
Metarteriole connects arteriole directly to venule
Capillaries • smallest diameter blood vessels • extensions of inner lining of arterioles • walls are endothelium only • semipermeable • sinusoids – leaky capillaries
Venules and Veins • Venule • thinner wall than arteriole • less smooth muscle and elastic tissue than arteriole • Vein • thinner wall than artery • three layers to wall but middle layer is poorly developed • some have flaplike valves • carries blood under relatively low pressure • serves as blood reservoir
Arterial Blood Pressure Blood Pressure – force the blood exerts against the inner walls of the blood vessels • Arterial Blood Pressure • rises when ventricles contract • falls when ventricles relax • systolic pressure– maximum pressure • diastolic pressure – minimum pressure
Pulse • alternate expanding and recoiling of the arterial wall that can be felt
Informational Link http://www.ambulancetechnicianstudy.co.uk/circsystem.html