Winter Break Book

Prep for dissection Senior event Frog Dissection Design Lab Due Frog Dissection Clean-Up Heart Notes Activity Test Corrections Heart Quiz Plan Design Lab Design Lab Read Stiff: The Curious Life of Human Cadavers

*Watch Discovery Education exploration Cardiovascular System to introduce topic* Note: If you are taking the IB Bio HL Test, you need to include 19.5 in your preparations!

 It is designed as a pair of side by side pumps that work simultaneously  Each side contains: › An ATRIUM; a thin-walled collection chamber for blood moving in slowly from the veins › AVENTRICLE; thick-walled muscular pump that sends blood out of the heart

 The blood usually follows this general path when being pumped out of the heart: › Aorta to › A large artery to › Smaller artery branches to › An arteriole to › A capillary bed (this is where O 2 /CO 2 exchange) › A venule to › Larger veins to › A large vein that takes blood back to heart to › Vena cava

Let’s Review our Heart Diagram Let’s Sing!

 Right atrioventricular valve between right atrium and ventricle  Left atrioventricular valve between left atrium and ventricle  Right semilunar valve going from right ventricle into pulmonary artery  Left semilunar valve going from left ventricle into aorta

 General path of deoxygenated blood around the right side of the body  This path would utilize blood entering from the vena cava, then going into the right atrium where it contracts to send the blood down to the right ventricle through the atrioventricular valve  Once enough blood is in the right ventricle it contracts

 This contraction initiates the following: › Closure of atrioventricular valve (prevents backflow into atrium) › Dramatic increase in blood pressure inside the right ventricle which forces open the right semilunar valve so blood can enter pulmonary artery › Due to high pressure, blood leaves through pulmonary artery

 Blood then goes to the lungs where it exchanges CO 2 for O 2 and then returns back to the heart via the pulmonary vein

 General path of oxygenated blood around the left side of the heart and then out to the body  A similar process occurs on the left side (in fact both sides act in unison) so… › Blood accumulates in atrium and then enters the left ventricle via the left av valve › When blood fills left ventricle, it contracts which closes the av. valve, increases blood pressure which opens left semilunar valve, and then blood is forced out of the aorta

 After blood leaves the aorta it takes some path to end up in tissue somewhere in your body  The heart is supplied with blood b/c blood from the aorta can branch into the coronary artery which supplies heart muscle with O 2 rich blood and nutrients  Each complete circuit around the body includes both the pulmonary and systemic routes  Each complete circuit takes no longer than 1-2 minutes *Discovery Education exploration The Beat Goes On *