Cardiovascular system FUNCTION Transport nutrients, dissolved gasses, hormones, and metabolic waste COMPOSED OF Heart pumps blood through blood vessels Blood vessels arteries, capillaries, veins “highway’ for blood Blood dissolved nutrients, gasses, electrolytes, metabolic waste, hormones, proteins, etc. in plasma and RBCs to carry oxygen and carbon dioxide in hemoglobin and WBCs to protect body from pathogens

Heart In pericardial cavity covered by pericardium Contracts to pump blood through Pulmonary circuit = to lungs for gas exchange Systemic circuit = rest of the body Heart has 4 chambers 2 atria 2 ventricles - pump blood to ventricles - pump blood to lungs/body

Heart blood enters heart from : vena cava INTO Right atrium Blood leaves right atrium and goes INTO Right ventricle Passes through right atrioventricular (AV) valve (tricuspid valve) Chordae tendineae attached to papillary muscle prevent Valve from allowing 2 way blood flow

Heart Blood moves from right ventricle INTO right and left pulmonary arteries Pulmonary semilunar valve prevents backflow L and R pulmonary arteries bring blood to L and R lung for gas exchange Blood returns to left atrium via two left and two right pulmonary veins Blood leaves left atrium into left ventricle Blood passes through left atrioventricular valve (AV) (bicuspid valve OR mitral valve) Blood leaves left ventricle via aortic semilunar valve into aorta cardiac blood flow

Conducting System Pacemaker cells in sinoatrial node (SA node) In right atrium Initiate contraction of atria Stimulus passed to atrioventricular node (AV node) Floor of right atrium Takes approx. 100 msec for impulse to move from AV node to ventricular contraction Result = atria contract and ventricles contract approx 0.1 seconds after atria contract ECG/EKG = measurement of conducting impulse SA to AV node heart animations

Heart Cardiac cycle Systole = contraction phase = 1 st contraction is the atria (top higher number in blood pressure reading) Diastole = relaxation phase (bottom lower number in blood pressure reading) Blood Pressure = ventricular systole/ventricular diastole measure of the amount of force against the artery walls Heartbeat 1 st sound = AV valves closing as ventricles contract 2 nd sound = semilunar valves closing as ventricles filling (atria contract)

Blood vessels Function Insure continuous flow of blood and constituents throughout body Includes plasma and interstitial fluid in extracellular fluid Composed of arteriesMove blood away from heart capillariesSite of fluid exchange veinsMove blood towards heart blood vessels

Blood flow control Vasoconstriction Vasodialation Vessels smaller = decreased flow = increased blood pressure Vessels larger = increased blood flow = decreased blood pressure

Blood Function  Transport dissolved gases, nutrients,hormomes,metabolic waste  Regulate pH and electrolytes of interstitial fluid  Restrict fluid loss at damage/injury site  Stabilize body temperature Components PlasmaFormed elements Fluid portion of blood Proteins and serum ~55% of blood volume RBCs = erythrocytes WBCs = leukocytes Platelets ~ 45% of blood volume