Download EMI Huang: First third of NED CIRC NOTES 2009 Systole: Heart

EMI Huang: First third of NED CIRC NOTES 2009
Systole: Heart ventricles contract/chamber pump
Diastole: Heart ventricles relax/chamber fills
AIM: What are the parts of the heart and blood?
William Harvey established direction of blood flow and elucidated difference between pulmo
and systemic circulation.
TYPES OF CIRCULATION:
Pulmonary: travel of blood between heart and lungs
Coronary: supplies blood to heart
Renal: supplies blood to kidneys
Hepatic portal: supplies liver with nutrients; receive oxygenated blood from the aorta
HEART: CHAMBERS AND VALVES
Atria: blood into upper chambers
Ventricles: blood out of lower chambers. Valves/regulated one-way flow.
A/V: Atria Ventricular S/L: Semilunar
(Valves separate chambers, preventing blood from mixing)
2 A/V valves separate atria from ventricles
1. Right A/V: tricuspid (3 teeth)
2. Left A/V: bicuspid or mitral
2 S/L valves regulate flow from ventricle to vessel
1. Right S/L: pulmonary
2. Left S/L: aortic
FLOW IN VESSELS AND CHAMBERS
Aorta: major artery carrying blood from heart
Vena cava(e): empty deoxygenated blood into right atrium
Pulmonary artery: leaves right ventricle and carries blood to lungs
Pulmonary veins: returns oxygenated blood from lungs to left atrium
Left side [of chamber]: delivers blood to systems (systemic)
Right side [of chamber]: delivers blood to lungs (pulmonary)
NODES: STIMULUS TIMING
Cardiac muscle contracts in syncitium. Nodes stimulate atria and ventricles to act together.
SA (Sinoatrial) node: located in right atrium—is considered ‘pacemaker.’ Atria contract together.
AV (Atrioventricular) node: located in septum (wall) between atria—delays ventricle contraction
until ventricles fill with blood.
-Harvey (17th century)- discovered veins-toward and arteries-away.
-Previously, Galen’s predominate idea that blood ebbed and flowed without direction had
taken hold.
-Harvey challenged authority—did a dissection experiment—artery cut—blood spurts from and
near heart (artery flow from heart). Vein cut—blood flows from end farther from heart, inward
or forward.
-Capillaries were harder to study—Malpighi discovered them in 1661; wanted for instruments.