Unit 5
SBI3U
9.3 The Mammalian Heart - ANSWERS
AMAZING Human Heart Facts:
 Pumps about 70x per minute, 90 000x per day through 160 000 km of blood vessels!
 Pumps in 2 directions at once without ever mixing the blood!
 Has a life expectancy of around 80 years
 Is about the size of your fist
The Flow of Blood
Watch the narrated animation and fill in the answers to discover how blood moves through the heart.
http://www.medtropolis.com/VBody.asp
Blood first enters the RIGHT ATRIUM through two large veins called the SUPERIOR vena cava and the
INFERIOR vena cava. The blood entering the right atrium is low in OXYGEN since it is returning to the heart
after nourishing various body parts with oxygen. The blood then moves from the right atrium into the RIGHT
VENTRICLE through a valve called the TRICUSPID valve. The valve prevents blood from flowing from the
right ventricle back to the right atrium, ensuring a one way flow. When the blood is in the right ventricle,
the heart muscle pumps it the short distance to the lungs. Blood goes through the PULMONARY ARTERIES to
the lungs, getting rid of its carbon dioxide and acquiring new oxygen, and then returns to the heart. The
blood returns to the heart through the PULMONARY VEINS leading to the left atrium. When the left atrial
wall contracts, the blood is pushed through the BICUSPID valve into the left ventricle. The left ventricle
contracts and forces the oxygen-rich blood on its life giving journey throughout the body. The blood goes
through the AORTA a large artery with branches that distribute blood to all parts of the body.
Heart Diagram
http://www.smm.org/heart/heart/in-out.htm  LABELS
http://www.smm.org/heart/lessons/lesson6.htm  FUNCTIONS
Part
1. Aorta
2 Superior Vena
Cava
3. right pulmonary
arteries
4. right pulmonary
veins
5. right atrium
6. tricuspid valve
7. right ventricle
8. inferior vena
cava
9. left pulmonary
arteries
10. left pulmonary
veins
11. left atrium
12. bicuspid valve
13. aortic valve
14. left ventricle
15. descending
aorta
Function
Delivers oxygenated blood to the body from the
left ventricle
Receives deoxygenated blood from the upper part
of the body and delivers to right atrium
Carries deoxygenated blood from the right
ventricle to the lungs
Carries oxygenated blood from the lungs to the left
atrium
Receives deoxygenated blood from vena cava
Prevents backflow of blood between the right
atrium and ventricle
Receives deoxygenated blood from right atrium
Receives deoxygenated blood from the lower part
of the body and delivers to right atrium
Carries deoxygenated blood from the right
ventricle to the lungs
Carries oxygenated blood from the lungs to the left
atrium
receives oxygenated blood from pulmonary veins
Prevents backflow of blood between the left
atrium and ventricle
Prevents backflow of blood between the left
ventricle and aorta
Receives oxygenated blood from left atrium
Delivers oxygenated blood to the body from the
left ventricle
Trace the passage of OXYGENATED
blood with a red arrow.
Trace the passage of
DEOXYGENATED blood with a blue
arrow.