The Cardiovascular System Heart-------Blood Vessels------Blood Cells

1. The Cardiovascular SystemHeart-------Blood Vessels------Blood Cells Medical Terminology

2. Anatomy of the Heart • 4 chambers • 2 upper = right & left atria separated by interatrial septum • 2 lower = right & left ventricles separated by interventricular septum • lining = 3 layers • Pericardium --- 2 layers: a. parietal pericardium = pericardium b. visceral pericardium = epicardium peri = surrounding; epi = upon; endo = inner 2. Myocardium 3. Endocardium • Heart Valves • Tricuspid = between right atrium & ventricle • Bicuspid (Mitral) = between left atrium & ventricle • Pulmonary semilunar = between R. ventricle & Pulmonary artery • Aortic semilunar = between L. ventricle & aorta

4. Blood Flow Through the Heart • combines 2 circulatory systems • Pulmonary circulation • primarily right side of heart • key = getting blood to lungs • Systemic circulation • primarily left side of heart • key = getting blood to all other parts of body

5. Coronary Circulation • 2 coronary arteries ----right coronary & left coronary • first two branches off ascending aorta • supplies oxygen & nutrients for heart, especially myocardium

6. Conduction System of the Heart • Impulse route through the heart • SA node (sinoatrial) = “pacemaker” • located in upper right corner of R. atrium near opening of superior vena cava • stimulates depolarization of both atria • AV node (atrioventricular) • located in inferior wall of R. atrium near a-v septum • stimulates the initiation of depolarization of both ventricles • slowing of impulses through this node allows time for the ventricles to fill with blood from the contracting atria • Bundle of His • located at top of interventricular septum • Right Bundle Branch & Left Bundle Branch • Purkinje’s Fibers

8. Electrocardiogram • The electrical impulses traveling through the heart are picked up at the patient’s skin surface by a machine (electrocardiograph) • 5 basic parts 1. P wave = atrial depolarization & contraction 2. P-R interval = time it takes from beginning of atrialcontraction to beginning of ventricular contraction 3. QRS wave = ventricular depolarization & contraction 4. S-T segment = time it takes from end of ventricular contraction to the beginning of ventricular recovery 5. T wave = repolarization of the ventricles

10. Blood Vesselsvascular system --- vas = vessel (Latin) • Structure • Both arteries & veins have 3 layers of tissue • Phleb/o- = combining form means vein • outer layer = tunica externa (adventitia) • composed of connective tissue • middle layer = tunica media • composed of muscle & elastic tissue • inner layer = tunica intima • composed of endothelium • Veins have one-way flow valves from the endothelium • Capillaries: only one (1) layer of endothelial cells • Arterioles = small arteries • Venules = small veins

11. Vessels • Arteries carry blood away from heart • Capillaries join arteries and vein • Microscopic • Nutrients and oxygen exchanged at cellular level • Veins carry blood to the heart

12. Functions of Blood Vessels • Arteries • distribution of nutrients • maintenance of blood pressure • Veins • takes waste products back to heart for circulation & disposal • valves keep flow going in one direction • Capillaries • where internal respiration occurs • i.e. the exchange of O2 & CO2 between vessel & cell • where exchanges occur for nutrients, wastes, and fluids

13. Blood Composition • Blood = Plasma (55%) + Formed Elements (45%) • Plasma = the liquid faction of blood; blood minus its formed element • Serum = plasma minus clotting factors

14. Formed Elements ---------- “The Cells” • Red Blood Cells------------erythrocytes------------- 5 million/mm3 • White Blood Cells ------------leukocytes---------------5000/mm3 • Platelets --------------------thrombocytes------------250,000/mm3

15. Types of WBC’s • granular: • neutrophils (60%) ---------- phagocytes; first line of defense • eosinophils (3%) ------------seen in allergies & parasitic diseases • basophils (1%) -------------- release heparin & histamine • nongranular: • lymphocytes (30%) • * B lymphocytes • * T lymphocytes • monocytes (5%) ---------------------- become macrophages

16. Blood Diseases • Essentially one gets Too Much or Too Little • RBC ---------------- polycythemia ---------------- anemia • Platelets ---------- thrombocytosis ------------ thrombocytopenia • WBC---------------- leukocytosis ------------------leukopenia (-penia = poverty) • Cancer of WBC’s = Too Much = leukemia

17. Coronary artery disease Ischemia (partial O2 block) Angina pectoris Infarct (complete O2 block) Myocardial infarction Congestive heart failure Carditis Pericarditis Myocarditis Endocarditis Heart murmur Cardiac arrhythmia Tachycardia (2X) Flutter (3X) Fibrillation (4X) Cardiovascular Pathology

18. Aneurysm Raynaud’s phenomenon Thrombosis Phlebitis Varicose veins Thrombophlebitis Embolus Hypertension Essential hypertension Essential = idiopathic Secondary hypertension Malignant hypertension

19. Cardiac catheterization Stress test Thallium stress test Echocardiography Angioplasty Endarterecomy (endo-; arter/o; -ectomy) CABG Valvuloplasty Pacemaker Defibrillation Cardiovascular Procedures & Treatments

21. Arteriolar disease Arteriosclerosis Atherosclerosis Thrombosis Embolus CVA = stroke = cerebrovascular accident