180 likes | 262 Views
Introduction To The Cardiovascular System. Chapter 12:305-315 Anatomy and Histology. The Coast of Maine? Pretty Much!. General Anatomy. Complex muscle: The muscle is folded and wrapped about a fibrous structure Forms four chambers that can transport (pump) blood.
E N D
Introduction To The Cardiovascular System Chapter 12:305-315 Anatomy and Histology
General Anatomy • Complex muscle: • The muscle is folded and wrapped about a fibrous structure • Forms four chambers that can transport (pump) blood. • Right (venous) and Left (arterial) Sides • Two Atria and Two Ventricles
Fibrous “scaffolding” makes up • Valves and muscular support. II. The fibrous network forms chambers of the ventricles
I. Muscle then forms attachments along the fibrous structure II. You end up with a very strong muscle in the shape of a multi-chambered pump
Blood pumped by the heart Superior Vena cava • Blood circulating in the veins (de-oxygenated) returns to the heart into the right atrium • The right atrium serves as a collection point Rt. atrium Inferior Vena Cava
Blood flows into the right ventricle... • The tricuspid valve opens. • Blood first flows passively into the right ventricle (70% at rest) • Remaining 30% is pumped • Called: (Ventricular) End-Diastolic Volume (EDV)
Right Ventricle pumps blood to the lungs • Right Ventricle contracts • Increased pressure causes tricuspid valve closure • Blood leaves heart via Pulmonary Artery • Only artery with O2
Return of oxygenated blood Pulmonary Vein returns blood to Left Atrium Left atrium fills, opening Mitral Valve Blood flows passively into Left Ventricle Left Atrial contraction completes Cardiac Filling (Diastole)
Diastole: • The filling of the left and right ventricles with blood • Both left and right atria contract at the same time • The Second Heart Sound (“Dub”) occurs when the aortic valve shuts, and diastole begins
Left Ventricle Pumps Blood to the Body Aorta • The Left Ventricle contracts • Mitral Valve: Closes • Aortic Valve: Opens • Blood is pumped out via the Aorta
Systole: • The ejection of blood from the ventricles • Both the right and left ventricles contract at the same time • The First Heart Sound (“Lub”) occurs when the A-V Valves close (tricuspid and mitral)
Systemic Arterial Blood Pressure • Systolic: Systole cause increased pressure in the arterial vessels: • Systolic pressures indicate the strength of cardiac contraction • Diastolic: During diastole, arterial pressure is at it’s lowest • Diastolic Pressures indicatethe total resistance to blood flow
Question: • What happens to systolic and diastolic pressures during: • Exercise • Atherosclerosis • Hypovolemia • Heart Failure
Shall we try it? • Run up and down the stairs: 5 times • Quickly take your pulse • I will take Blood Pressures • Summarize what happened:
Layers of Heart Tissue: • Pericardium: Double Layered • Outer, Fibrous: Tough connective fibrous tissue • Inner, Serous:Epithelial and thin connective tissue layer • Facing the Outer: Parietal • Facing the Inner: Visceral, epicardium
So what’s the Problem with Joe? • Injury to the pericardium has allowed bleeding into the pericardial space. • The heart cannot fill with blood • Cardiac Tamponade: Acute heart failure
Assignment: • Read: 12:315-320 • The Electrical Activity of the Heart • The Cardiac Cycle and Heart Sounds