CARDIOVASCULAR SYSTEM

 Often referred to as the transportation system  Consists of the: Heart, Blood Vessels and the Blood  It carries oxygen and nutrients to the cells and metabolic material and carbon dioxide away from the cells

THE HEART

 Muscular hollow organ that pumps blood throughout the body  Weighs less than a pound and about the size of your fist  It contracts about 100,000 times a day and pumps the equivalent of 2000 gallons of blood through the body  Located in the mediastinal cavity which is located between the lungs, behind the sternum and above the diaphragm

TISSUE OF THE HEART  Endocardium-smooth layer of tissue that lines the inside of the heart and is continuous in the vessels. It allows for smooth flow of blood.  Myocardium-muscular middle layer of the heart that allows for contraction and movement of blood flow.  Pericardium-Double layered membrane or sac that covers that outside of the heart. Filled with pericardial fluid that diminishes friction and damage to the membranes as the heart beats

PARTS OF THE HEART  Septum-muscular wall that separates the heart into right and left sides  Prevents blood flow between right and left sides  Two parts:  Interatrial Septum  Interventricular Septum

PARTS OF THE HEART  The Right Atrium  Receives blood as it returns from the body cells  Blood enters from the Superior and Inferior Vena Cava  Blood is deoxygenated

PARTS OF THE HEART  The Right Ventricle  Receives blood from right atrium  Pumps blood to the lungs for oxygen via the Pulmonary Artery

PARTS OF THE HEART  Left Atrium  Receives oxygenated blood from the lungs via Pulmonary Veins

PARTS OF THE HEART  Left Ventricle  Receives blood from the left atrium  Pumps oxygenated blood to the body  Uses the Aorta to transport blood

PARTS OF THE HEART  Valves  Tricuspid Valve-Located between the right ventricle and right atrium, it closes when the right ventricle contracts, allowing blood to flow to the lungs and preventing blood from following back into the right atrium.

PARTS OF THE HEART  Pulmonary Valve  Located between the right ventricle and pulmonary artery  Closes when the right ventricle finishes contraction  Prevents blood flow back into the right ventricle

PARTS OF THE HEART  Mitral Valve  Located between left atrium and left ventricle  Closes when left ventricle contracts  Prevents blood flow back into left atrium

PARTS OF THE HEART  Aortic Valve  Located between the left ventricle and aorta  Closes when the left ventricle finishes contracting  Prevents blood flow back into the left ventricle from the aorta

CARDIAC CYCLE (HEART BEAT)  Though the heart is separated into two halves it does work in unison when the heart beats.  The cycle consist of a brief rest period called Diastole  The contraction that follows Diastole comes from the ventricles and is known as systole  Two contractions in one beat, first the atriums contract then relax then the ventricles contract then relax. That gives us the “lub-dub” sound we here

CONDUCTIVE PATHWAY  Electrical impulses originating in the heart cause cyclic contraction of the muscle fibers of the heart.  Group of nerves located in the right atrium called the Sinoatrial Node  Sends out electrical signal over both atria, which forces contraction.  Once impulse passes through atria it reaches the Atrioventricular node which then send impulse to the Bundle of His  Bundle of His branches into a right bundle branch and a left bundle branch.  These carry the impulse throughout the ventricles into the Purkinje Fibers  These fibers are another bundle of nerve fibers that insure the impulse reaches all fibers of the heart causing ventricular contraction

CONDUCTIVE PATHWAY

CONDUCTIVE PATHWAY OF THE HEART  Electrical Pathway occurs approximately every.8 seconds  We can record this via (ECG) or electro-cardiogram to detect abnormal rhythm or disease  Abnormal rhythms are called Arrhythmias  May be mild or life threating depending on location and severity  Treatment is dependent on type and severity  Defibrillators, pacemakers and medicines are common treatments

CONDUCTIVE PATHWAYS  Pace Makers  Small battery powered device with electrodes  Electrodes are threaded through a vein into the right atrium and the apex of the right ventricle  Device monitors heart rhythm and delivers shocks based on the rhythm  Either deliver predetermined shocks (fixed) or shocks when it senses heart is out of rhythm (demand)

BLOOD VESSELS  Arteries- carry blood away from the heart  Aorta is the largest artery  Aorta branches into all other arteries of the body that supply blood  1 st branch of the aorta is the coronary artery which divides into right and left branches which supply blood to the myocardium of the heart  Smallest branches of arteries are called arterioles and they join with the capillaries  Arteries are more muscular and elastic than other blood vessels because they receive blood pumped from the heart

BLOOD VESSELS

 Capillaries connect arterioles with venules (smallest veins)  Capillaries are located within close proximity to almost every cell in the body  Have very thin walls and only have one layer of cells  These walls allow from transmission of oxygen and nutrients and receiving of metabolic waste and carbon dioxide

BLOOD VESSELS

 Veins carry blood back to the heart  Venules are the smallest veins and connect to capillaries  Two largest veins are the Superior Vena Cava and Inferior Vena Cava  Veins are thinner and less musclur  Contain valves that prohibit blood flow backwards

BLOOD VESSELS

BLOOD COMPOSITION  Approximately 4-6 quarts of blood within the average adult  Transports oxygen and nutrients to the body systems and removes waste and carbon dioxide from the systems  Also transports hormones, heat and metabolic wastes  Composed of two parts: Plasma and Blood Cells

BLOOD PLASMA  90% water  Contains blood proteins as well: Fibrinogen and Prothromin, both needed for clotting  Also contains: nutrients, carbon dioxide and oxygen, metabolic and waste products, hormones and enzymes

BLOOD CELLS  Erythrocytres  Red Blood Cells  Produced in red bone marrow at a rate of one million per minute  Live about 120 days  About 4.5 to 5.5 million per millimeter of blood (one drop)  Contain Hemoglobin which is part protein (globin) part iron (heme)  Carries both oxygen and carbon dioxide

BLOOD CELLS  Leukocytes  White Blood cells  Formed in yellow bone marrow  Not as numerous  Live 3-9 days  per millimeter of blood  Can pass through capillary walls and enter tissue  Main function is to fight infection  Most do this through phagocytosis

BLOOD CELLS  Leukocytes  5 types  Neutrophils-phagocytize bacteria by secreting an enzyme called lysozyme  Eosinophils-remove toxins and defend the body from allergic reaction by producing antihistamines  Basophils-participate in the bodies inflammatory response; produce histamine (vasodilator) and heparin (anticoagulant)  Monocytes-phagocytize bacteria and foreign materials  Lymphocytes-provide immunity for the body by developing antibodies

BLOOD CELLS  Thrombocytes  AKA Platelets  Form in red bone marrow  Live 5-9 days  250, ,000 per millimeter of blood  Important for clotting purposes

STEPS TO BLOOD CLOTTING

PROBLEMS IN THE SYSTEM  Anemia  Lack of red blood cells or hemoglobin or both  Symptoms include: pallor (paleness), fatigue, dyspnea (difficulty breathing), and rapid heart rate  Types:  Acute-Blood-Loss-hemorrhage that results in rapid blood loss  Iron Deficiency-Inadequate amount of iron in the system  Aplastic-Injury to the bone marrow leads to lack of formation of blood cells  Pernicious-abnormally large blood cells but not as many  Sickle Cell-inherited anemia that results in abnormally shaped red blood celss

PROBLEMS OF THE SYSTEM  Aneurysm  Ballooning out of the artery wall  Disease, congenital defect or injury leads to weakened wall  Can cause pain or pressure or could result in no symptoms at all  Potential for ruptures can lead to hemorrhage and possible death  Surgical removal is best treatment with replacement of wall with plastic or another vessel

PROBLEMS OF THE SYSTEM  Arteriosclerosis  Hardening or thickening of the artery walls, resulting in loss of elasticity and contractility  Results from ageing  Can cause hypertension-aneurysm- cerebral hemorrhage  Treatment is lower blood pressure through diet, medications or both

PROBLEMS OF THE SYSTEM  Atherosclerosis  Occurs when fatty plaques are deposited on the walls of the arteries  This narrows the opening which can reduce or eliminate blood flow  Have the potential to break loose causing embolisms  Treatment includes: diet, exercise, reduction of stress, avoidance of tobacco products, angioplasty, bypass surgery

PROBLEMS OF THE SYSTEM  Embolus  A foreign substance circulating in the bloodstream. It can be air, a blood clot, bacterial clots, or a fat globule  Enters a passage too small can result in blockage of the vessel

PROBLEMS OF THE SYSTEM  Hemophilia  Inherited disease that occurs almost exclusively in males  Lack of a blood protein leads to inability to clot  Hypertension  High blood pressure  Systolic over 140  Diastolic over 90  Risk factors include: family history, race, obesity, smoking, stress and age  Treatment is diet, exercise and medication

PROBLEMS OF THE SYSTEM  Myocardial Infarction  Heart Attack  Blockage of coronary artery cuts off the supply of blood to the heart  The affected heart tissue dies this is known as an infarct  Death can occur immediately  Symptoms include: crushing chest pain, radiates to the neck and down left side of the body, cold sweats, dyspnea, and blood pressure change  Treatment if caught: medications, diet, exercise and surgery if needed

PROBLEMS OF THE SYSTEM  Phlebitis  Inflammation of a vein  Usually occurs in the leg  Symptoms include: pain, edema, redness, and discoloration

PROBLEMS OF THE SYSTEM  Varicose Veins  Dilated swollen veins that have lost elasticity and causes stasis  Occur in the leg  Result from: pregnancy, prolonged sitting or standing, and heredity factors  Treatment: exercise, support garments, avoidance of prolonged sitting or standing and tight fitting clothing, possible surgery