Three basic components 1 Heart 2 Blood vessels
Three basic components 1. Heart 2. Blood vessels 3. Blood Cardiovascular system function: 1. 2. 3. 4. Transport oxygen Nutrients Cell wastes Hormones via the blood
ØCone shape ØMuscular pump Ø 250 – 300 g ØSize of a person’s fist
Location – Mediastinum – Superior surface of diaphragm – Anterior to the vertebral column – Posterior to the sternum – Apex is directed toward the left, rests on the diaphragm, at about the fifth intercostals space
Pericardiu m
Pericardium : • • A superficial fibrous pericardium A deep two-layer serous pericardium 1. The parietal layer 2. The visceral layer 3. They are separated by the fluid-filled pericardial cavity The pericardium: Protects Prevents overfilling Allows for the heart to work in a relatively friction-free environment
Heart Wall • Epicardium – visceral layer of the serous pericardium • Myocardium • Endocardium
Anatomical position • surface 1. Sternocostal 2. Diapgragmatic 3. Pulmonary R &L • Borders 1. 2. 3. 4. Left Right Inferior superior • Base • Apex
Four hollow chambers: • 2 atria – receiving chambers – divided by the interatrial septum • 2 ventricles – discharging chambers – divided by the interventricular septum
Atria Septum Ventricles
Sternocostal surface Left Atrium Right Atrium Sinus coronary sulcus Anterior Inter ventricular sulcus Right Ventricle Left Ventricle
Diaphragmatic surface Left Ventricle posterior Inter ventricular sulcus Coronary Sulcus
Right atrium – Ineratrial septum – Fossa ovalis – Right auricle – Superior Vena Cava – inferior Vena Cava – Coronary sinus – Right atrioventricular foramen
Pectinate Muscle Fovea Ovalis
Blood Enters The Right Atrium Via Three Veins Superior vena cava 1. Superior vena cava 2. Inferior vena cava 3. Coronary sinus Inferior vena cava
Right ventricle – Papillary muscles – Chorda tendineae Right ventricle: • Papillary muscles Chorda tendineae Tricuspid valves Pulmonary artery – – – Tricuspid valves – Pulmonary artery Trabeculae carneae
Chordae tendoneae Papillary muscles
Left atrium – Left auricle – Left atrioventricular foramen – Aorta foramen
Blood enters the left atrium via four veins Right and left pulmonary veins Left pulmonary veins Right Pulmonary veins
Left ventricle • – Papillary muscles – Chorda tendineae – Bicuspid valves – Aorta Papillary muscles – Chorda tendineae – bicuspid valves – Aorta –
Radiographic Landmarks
Major Vessels of the Heart Vessels returning blood to the heart include: • • • Superior venae cavae inferior venae cavae Right and left pulmonary veins Vessels conveying blood away from the heart include: • Pulmonary trunk • Ascending aorta
Valves of the Heart Atrioventricular valves Semilunar valves • Right AV (Tricuspid) • Pulmonary valve • Left AV (Bicuspid) • Aortic valve
Right AV (tricuspid) valve Chordai tendineae Papillary muscle Pulmonary semilunar valve Aortic semilunar valve Left AV (bicuspid) valve
Circulatory System • Pulmonary circulation • Systemic circulation
Pathway of Blood Through the Heart and Lungs • RA tricuspid valve RV • RV pulmonary semilunar valve pulmonary arteries lungs • Lungs pulmonary veins LA • LA bicuspid valve LV • LV aortic semilunar valve aorta • Aorta systemic circulation
Pulmonary Circulation
Systemic Circulation
Two systems act to regulate heart activity: 1. Extrinsic conduction system 2. Intrinsic conduction system = or nodal system Setting the basic rhythm 1. Sinoatrial (SA) node : • • 2. located in right atrium pacemaker of the heart Atrioventricular (AV) node : • at junction of atria and ventricles 3. Atrioventricular (AV) Bundle (Bundle of his) 4. Bundle branches 5. Purkinje fibers
SA Node Bundle of His Internodal Pathways Bundle Branches AV Node Purkinje Fibers
Regulation of Heart Rate Increased heart rate · · · Sympathetic nervous system thoracic N – 1 - 4 Low blood pressure Hormones 1. Epinephrine 2. Thyroxine Exercise Decreased blood volume Decreased heart rate · Parasympathetic vagus N · High blood pressure or blood volume
Heart sounds – Lub dup – Lub – closing of AV valves ( systole ) – Dup – closing of semilunar valves (diastole ) • Murmurs = abnormal heart sounds
Cardiac Cycle Systole : lup • Rising ventricular pressure results in closing of AV valves • Atria relax Diastole : dup • relaxation of heart muscle
Capillary Beds Figure 19. 4 a
Blood Pressure (BP) • Force wall of a blood vessel by its contained blood – Expressed in millimeters of mercury (mm Hg) – in large arteries near the heart Systemic pressure: – Is highest in the aorta – Declines throughout the length of the pathway – Is 0 mm Hg in the right atrium
Measuring Blood Pressure first sound heard = systolic pressure Second sound heard = diastolic pressure Systole = contraction Diastole = relaxation
Blood Pressure: Effects of Factors · Normal 140– 110 mm Hg systolic 80– 75 mm Hg diastolic · Hypotension Low systolic (below 110 mm HG) · Hypertension High systolic (above 140 mm HG) · Neural factors (sympathetic division) · Renal factors ( Renin ) · Temperature Ø Heat has a vasodilation effect Ø Cold has a vasoconstricting effect · Chemicals Ø Various substances can cause increases or decreases · Diet
Types Of Cardiovascular Disease • Atherosclerosis ----(Plaque ) • Coronary heart disease (CHD) ---Myocardial infarction (MI) or heart attack • Chest pain (angina pectoris) – Ischemia Irregular heartbeat (arrhythmia) » Tachycardia = more than 100 beats/min » Bradycardia = less than 60 beats/min • • Congestive heart failure (CHF) – heart muscle is unable to keep blood circulating normally • Congenital heart disease • Stroke--- Myocardial infarction (MI) • Embolism: blockage of blood vessels
Common Blood Vessel Disorders
Angioplasty Versus Bypass Surgery Coronary bypass surgery
Pericarditis Inflammation of pericardial sac • Clinical Manifestations of Pericarditis 1. 2. 3. 4. Chest pain Dyspnea Chills Fever
Clinical Manifestations of Mitral Stenosis • • Cough Frequent respiratory infections Weakness, fatigue Diastolic murmur
Varicose Veins
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