The Heart

Question 1

Blood from the Upper extremity

Answer 1

SVC

Question 2

Blood from Lower extremity

Answer 2

IVC (exception azygous vein drains lumbars into SVC)

Question 3

how much of the blood from the right atrium passively flows into the Right ventricle

Answer 3

80%, other 20% needs atrial contraction

Question 4

what happens at the p-wave

Answer 4

starts at SA node in Crista terminalis of R atrium. Tricuspid closes after P-wave. Impulse travels to AV node

Question 5

what is the P-R interval

Answer 5

AV nodal delay. SA node impulse to AV node and delayed

Question 6

what happens at the R ventricle

Answer 6

Tricuspid closes=>ventricle contracts=isovolumetric contraction. Ventricular depolarization=QRS complex

Question 7

what happens with the pulmonary artery

Answer 7

mid-systole (halfway through)=enough pressure to blow open pulmonic semilunar valve. Blood exits via pulmonary a. to lungs. pulmonary a carries DE-oxygenated blood. (only other artery with de-O2=umbilical artery in fetus)

Question 8

how is blood oxygenated

Answer 8

bohr effect- 4 O2/molecule hemoglobin, 97% hemoglobin saturated with O2, decreased CO2, deceased H, decreased temp

Question 9

how does blood exit the lung?

Answer 9

via pulmonary vein into L atrium. Highest O2 in body. pulmonary vein carries oxygenated blood (also umbilical vein in fetus)

Question 10

how blood from the left atrium flows passively into left ventricle

Answer 10

80%, other 20% needs P-wave

Question 11

what happens at the left ventricle

Answer 11

Mitral closes=>isovolumic contraction=>builds tension

midsystole=>aortic valves open=>blood rushes into aorta=> circulation