Cardiovascular System Organs and CellsOrgans and Cells Organization and FunctionsOrganization and Functions Cardiovascular Health as a Multifactorial TraitCardiovascular Health as a Multifactorial Trait

Heart Chambers and Valves Left Ventricle Right Atrium Right Ventricle Semilunar Valves Left Atrium Atrioventricular Valve

Tissues of the Heart  Endocardium- lining  Myocardium- muscle  Pericardium- outside Layers of Heart Tissue Fibrouspericardium Visceralpericardium

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

Flow of Blood to Lungs and Body Ventricles Lung Capillaries Body CapillariesAtria

Control of Heartbeat 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

Connecting Vessels Aorta Descending Aorta (to lower body) Inferior Vena Cava (from lower body) Superior Vena Cava (from upper body) Pulmonary Artery (to right lung) Pulmonary Artery (to left lung) Pulmonary Veins (from right lung) Pulmonary Veins (from left lung)

Blood Vessels of the Heart Coronary arteries (red) and cardiac veins (blue) serve heart muscle Imaging methods can detect blockages in coronary arteries

Applying Your Knowledge A.Which structure receives blood returning from the lungs? B.Which structure prevents blood from flowing back into the ventricles? C.Which structure pumps blood to the body capillaries? 1. Left Ventricle 2. Semilunar Valve 3. Right Atrium 4. Left Atrium 5. Atrioventricular valve

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 Irregular heart rhythm Irregular heart rhythm

Artery Vein Arteriole 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 --Capillaries allow blood to reach tissues

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

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

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

Applying Your Knowledge A.Which one transports nutrients? B.Which one fights foreign invaders? C.Which one carries oxygen? 1. Plasma 2. Red blood cells 3. White blood cells

Multifactorial and Polygenic Traits Multifactorial Trait: Phenotype is influenced by the environmentMultifactorial Trait: Phenotype is influenced by the environment –Heritability: measure of genetic contribution to the phenotype Polygenic Trait: Phenotype is determined by the activities of more than one genePolygenic Trait: Phenotype is determined by the activities of more than one gene –Show a range of phenotypes –Likely to also be Multifactorial Traits

Multifactorial Polygenic Trait: Heart Health Heart health depends on 1.Blood pressure 2.Lipid metabolism 3.Blood clotting 4.Tendency for white blood cells to adhere to blood vessel walls

Genes Involved in Cardiovascular Health Rare alleles related to risk for cardiovascular diseases