CARDIOVASCULAR SYSTEM Chapter 15

OVERVIEW BASIC FUNCTION: Bulk Transport BASIC FUNCTION: Bulk Transport –Move nutrients and gases to tissue areas  Nutrients for energy, building materials  Oxygen for cellular respiration –Remove wastes from tissue areas  Urea and other metabolic wastes  Carbon dioxide BASIC STRUCTURE: Heart + Vessels BASIC STRUCTURE: Heart + Vessels –Heart – force pump –Pulmonary Circuit – blood to lungs and back to heart  Pulmonary Artery  alveoli + pulmonary capillaries  pulmonary veins –Systemic Circuit – circulation to all parts of body  Arteries – take blood away from heart  Capillaries – material exchange  Veins – take blood towards heart DIAGRAM

HEART STRUCTURE Coverings Coverings –Pericardium  Double layered  Separated by pericardial cavity –Epicardium – visceral pericardium  Outer layer  Serous membrane –Mycardium – cardiac muscle tissue  Thickest –Endocardium – lines chambers  Purkinje fibers Chambers Chambers –Atria – upper (L & R)  Auricles – outside flaps –Ventricles – lower (L & R) –Ineratrial and interventricle septums Valves  one way flow Valves  one way flow –Chordae Tendinae and Papillary muscles –Tricuspid – b/w R. Atria & R. Ventricle –Bicuspid (mitral) – b/w L. Atria & L. Ventricle –Pulmonary Semilunar – b/w R. Ventricle & Pulmonary Arteries –Aortic Semilunar – b/w L. Ventricle & Aorta DIAGRAM INTERACTIVE DIAGRAM VALVE DIAGRAM

HEART STRUCTURE Order of Blood Flow (Deoxygenated Blood) Order of Blood Flow (Deoxygenated Blood) –Veins from Systemic (Body) Circuit –Superior/ Inferior Vena Cava –Right Atria –Tricuspid Valve –Right Ventricle –Pulmonary Semilunar Valve –Pulmonary Arteries –Lungs (capillaries) Order of Blood Flow (Oxygenated Blood) Order of Blood Flow (Oxygenated Blood) –Lungs (capillaries) –Pulmonary Arteries –Left Atria –Bicuspid Valve –Left Ventricle –Aortic Semilunar Valve –Aorta –Arteries of Systemic Circuit Heart circulation Heart circulation –Coronary arteries  capillaries  cardiac veins  coronary sinus HEART DIAGRAM

CARDIAC CONDUCTION SYSTEM Specialized tissue to transmit muscle impulse for proper heart contractions Specialized tissue to transmit muscle impulse for proper heart contractions –Functional synctium –Self-excitatory Cardiac cycle – 1 complete heartbeat Cardiac cycle – 1 complete heartbeat –Systole – contraction –Diastole – relaxation “lub” – “dup” “lub” – “dup” –1 st sound – A-V valves –2 nd sound – semilunar valves Atria systole; Ventricle diastole Atria systole; Ventricle diastole –Blood through A-V valves –SA (sinoatrial) node  Pacemaker  Transmit impulse to atria Atria diastole; Ventricle systole Atria diastole; Ventricle systole –AV (atrialventricular) node  AV bundle (Bundle of His)  purkinje fibers –Blood forced through semilunar valves –“Lub” – AV valves slam shut  Murmur - defect Atria diastole; Ventricle diastole Atria diastole; Ventricle diastole –Heart resets DIAGRAM

EKG AND HEART ACTIONS Electrocardiogram – graph of electrical activity of heart during cardiac cycle Electrocardiogram – graph of electrical activity of heart during cardiac cycle –P wave – depolarization of atria  Impulse causes atria systole –P-Q interval – flat line  Impulse travels from atria to ventricular fibers  No contraction –QRS Complex – depolarization of ventricles; repolarization of atria  Ventricular systole  Atria returning to relaxed state –T wave – repolarization of ventricles DIAGRAM

FACTORS AFFECTING CARDIAC CYCLE Parasympathetic pathways – inhibit Parasympathetic pathways – inhibit –Ach –Vegas Nerve Sympathetic pathway – excitatory Sympathetic pathway – excitatory –Norepinephrine Controlled by cardiac center (medulla oblongata) Controlled by cardiac center (medulla oblongata) –Baroreceptors in carotid arteries and aorta –Cerebrum and hypothalamus  Fainting – slow down  Anxiety – speed up –Temperature –Ions Arrythmias – irregular heartrate (ECG) Arrythmias – irregular heartrate (ECG) –Clinical Application 15.3 – P –Tachycardia, bradycardia, ventricular fibrillation –ECG interactive tool ECG interactive toolECG interactive tool

LAYERS OF THE HEART

OPERATION OF VALVES

ECG – Depolarization and Repolarization of cardiac tissue

CORONARY ARTERIES & CARDIAC VEINS