1. blood, veins, arteries, and the heart

2. The central organ responsible for pumping blood throughout the transport system is your heart Four chambers (two atria & two ventricles) and four valves (two semilunar & two atrioventricular) Five major blood vessels (aorta, superior & inferior vena cava, and pulmonary artery & vein) Make sure you know this basic anatomy of the heart

3. The blood flows through the heart in the same path over and over again Note the difference in thickness of the chamber walls…why such a difference?

4. After leaving the left ventricle, blood enters the largest artery in the body, the aorta Many branches exist along the aorta, one of the first leads to the coronary arteries Coronary arteries supply oxygen and nutrients Blocked coronary arteries can lead to heart attacks

5. The beating contractions of the heart are controlled by electrical impulses Contractions are not controlled by the nervous system (Myogenic muscle contraction) In the right atrium you’ll find the sinoatrial (SA) node Natural pacemaker of the heart—sends out electrical signal

6. The SA node impulse causes both atria to contract Simultaneously a signal is sent to the atrioventricular (AV) node AV node delays ~.1 seconds then sends out its own signal This second impulse cause both ventricles to contract Exercise (increase need for O 2 ) and adrenaline will cause the heart to beat faster Exercise causes increase in CO 2, which signals the medulla in the brain relays a signal to the SA node via the cranial nerve

7. Heart splits the blood flow up into two distinct paths Pulmonary circulation — capillary bed/terminal location LUNGS Originates from right side of heart Systemic circulation — capillary bed/terminal location BODY Originates from left side of heart ARTERIES= away Nothing to do with O 2

8. Blood is the actual medium transport relies on Blood is made up of four components Plasma, RBC (erythrocytes), WBC (leukocytes), platelets Main substrates transported by blood are nutrients oxygen, carbon dioxide hormones antibodies urea heat

9. Arteries, capillaries and veins are the actual structures that allow blood to flow throughout the body Arteries have a smooth muscle layer which allows for contraction to regulate blood pressure Arteries  aterioles  capillary bed  single capillary Capillaries have very thin walls to allow for chemical exchange Capillary beds all empty into venules  veins  heart Veins have thin walls, larger diameter, and valves to help move blood