Transcript 2circulatoryHeart

Systemic circulation:
heart
oxy
artery
arterioles
capillaries (half blue)
venuoles
veins
heart
gas exchange
deoxy
THREE CIRCULATORY SYSTEMS
- overall there are 3 circulatory systems in your
body
1) Systemic
- delivers blood between the heart and body cells
2) Pulmonary
- blood goes to the lungs to be oxygenated
- delivers blood between the heart and the lungs
3) Cardiac
- circulation of blood in the heart
The Heart
CARDIAC CIRCULATION
• the mammalian heart is a double pump,
separated by a wall of muscles called a septum
• each side of the heart is divided into two
chambers: an upper atrium and a lower ventricle
(four chambers in total)
• it is used to push blood through the body and
provides a connection between our pulmonary
and systemic circulatory systems
• it is supplied by blood via the coronary arteries
(come off main aorta)
• http://www.fed.cuhk.edu.hk/~johnson/teac
hing/transport/animations/HyperHeart.swf
Heart Sounds: lubb-dubb
• caused by the closing of the heart valves
1) Diastole
- relaxation of the ventricles, atria fill with blood
2) Systole
- contraction of the ventricles, atrioventricular valves close
(lubb) and blood is pushed through the semilunar
valves, as semilunar valves close you get the dubb
• (if valves don’t close properly, esp. the bicuspid (left),
you get a murmur (soft gurgling as blood comes back to
the atrium from the ventricle
SETTING THE HEART’S TEMPO
• the heart’s tempo or beat rate is set by the sinoatrial
(SA) node
– located where the venae cavae enter the right atrium
– acts as a pacemaker, setting a rhythm to ~70 beats per minute
– from the SA node the contractions travel to the atrioventricular
(AV) node, which sends the contractions through to the walls of
the heart, causing the atria to contract first, and then the
ventricles (using Purkinje fibers)
• seen on an ECG, p.260, dead tissue doesn’t conduct
electrical signals well to you can see where the problem
is
Purkinje fibers
- carry the signal from the AV node to the bottom tip of
the heart, allowing the ventricles to contract
simultaneously
•seen on an ECG, dead tissue doesn’t conduct electrical signals well to
you can see where the problem is
OVERALL CARDIAC CIRCULATION
- deoxygenated blood is collected
from your upper body
through the superior vena
cava
from your lower body
through the inferior vena
cava
right atrium
(through atrioventricular tricuspid valve)
right ventricle
(through semilunar valve)
right pulmonary artery
left pulmonary artery
right lung
left lung
capillaries -> CO2 exchanged for O2 through simple diffusion
pulmonary veins
left atrium
(through atrioventricular bicuspid valve)
left ventricle
(through semilunar valve)
aorta
arteries
veins
arterioles
venules
capillaries (O2 is dropped off, CO2 is picked up)
• Homework:
– P.263 #1,2,3, 5, 6,7