Heart Laboratory Circulatory System Organs and Cells Organization and Functions

Circulatory System Heart 4 chambers: 2 atria + 2 ventriclesHeart 4 chambers: 2 atria + 2 ventricles –Blood flow regulated by valves: 2 atrioventricular + 2 semilunar Blood VesselsBlood Vessels –arteries and veins –arterioles and venules –capillaries

(c)Mammals, Birds (b) “Herptiles” The Evolution of the Vertebrate Heart Ventricle Atriu m (a) Fish Gill Capillaries Body Capillaries Ventricle Lung Capillaries Atria Body Capillaries Ventricles Lung Capillaries Body Capillaries

Left Ventricle Human Heart Semilunar Valves Aorta Descending Aorta (to lower body) Inferior Vena Cava (from lower body) Right Atrium Superior Vena Cava (from upper body) Pulmonary Artery (to right lung) Pulmonary Artery (to left lung) Atrioventricular Valve Right Ventricle Pulmonary Veins (from right lung) Pulmonary Veins (from left lung) Left Atrium Atrioventricular Valve

The Cardiac Cycle Atria Contract Deoxygenated blood from body Oxygenated blood from lungs Ventricles Contract Deoxygenated blood to lungs Oxygenated blood to body Heart Relaxes; atria fill passively

Fibrouspericardium Visceralpericardium Layers of Heart Tissue Structure of the Heart Three Layers of tissue Endocardium- lining Myocardium- muscle Pericardium- outside

The Structure of Cardiac Muscle

Two views of coronary arteries and veins Blood Flow to the Heart Coronary Arteries and Veins Coronary Arteries and Veins

The Heart’s Pacemaker and Its Connections Sinoatrial (SA) Node Atrioventricular (AV) Node Excitable Fibers SA Node = pacemaker AV Node receives signals from SA node, sends signal through excitable fibers for ventricles to beat simultaneously

Heart Function Heartbeat visualized with ECG Heartbeat visualized with ECG Atria Contract Ventricles Relax Atria Relax Ventricles Contract Atrioventricular Valves Close “lubb” sound Semilunar Valves Close “dup” sound

Blood Pressure Blood pressure = Systolic pressure Diastolic pressure Systolic: pressure during ventricular contraction Diastolic: pressure during ventricular relaxation

Artery Vein Arteriole Precapillary Sphincters Capillaries Venule Endothelium ConnectiveTissue Muscle Connective Tissue Structures and Interconnections of Blood Vessels Arteries carry blood away from the heart Veins carry blood back to the heart

Blood Return Through Veins SkeletalSkeletal muscles help return blood to the heart ValvesValves prevent back-flow

Blood Components Red blood cells carry oxygen White blood cells defend against invaders Platelets initiate blood clotting Plasma is the fluid portion of blood. Lipid Carriers distribute triglycerides and cholesterol. LDL = low density lipoprotein delivers cholesterol HDL= high density lipoprotein returns cholesterol to liver for destruction

Functions of Blood Supplies nutrientsSupplies nutrients Removes wastesRemoves wastes Equalizes temperatureEqualizes temperature Transports hormones and antibodiesTransports hormones and antibodies Diseases HypertensionHypertension AtherosclerosisAtherosclerosis StrokeStroke Heart AttackHeart Attack

Worksheet Complete pages from lab manualComplete pages from lab manual Be sure your instructor checks your completed worksheet before you leave the labBe sure your instructor checks your completed worksheet before you leave the lab