Download Unit2-CardiacVascularSystemInAction

The cardiovascular system in
action
1/Cardiac function and cardiac
output
2/ Cardiac cycle
The cardiovascular system in
action
1/Cardiac function and cardiac
output
2/ Cardiac cycle
• Is there a difference between the volume of
blood pumped by the right and the left
ventricles?
• NO!
• What is the name given to the volume of
blood pumped out of the heart to the body
with each heartbeat?
• Stroke volume
• The volume of blood pumped out of the heart
to the body with each heartbeat
• What is meant by cardiac output?
• It is the volume of blood pumped through each
ventricle (i.e. out of the heart) per minute.
• Cardiac output is determined by the heart rate and
stroke volume.
• How do you work out the cardiac output?
• By multiplying the heart rate by the stroke volume.
• CO = HR X SV
• What are the units of cardiac output?
• Litres/minute
• Check the video
• https://www.youtube.com/watch?v=bUW-2GHfX64
The cardiovascular system in
action
1/Cardiac function and cardiac
output
2/ Cardiac cycle
3/ Cardiac conducting system
• What is responsible for the heart sounds
heard with a stethoscope?
• The opening and closing of the AV and SL
valves
• What is name given to the contraction &
relaxation of heart muscles?
• Contraction is the systole, relaxation is the
diastole
Both sets of chambers
are relaxed and
ventricles fill passively
Atrial systole
Atrial contraction
forces a small volume
of additional blood
into ventricles
Ventrical systole
First phase of ventricular
contraction pushes AV
valves closed but does not
create enough pressure to
open semilunar valves
Ventrical systole
As ventricular pressure
rises and exceeds
pressure in the arteries,
the semilunar valves
open and blood is
ejected
P
P
As ventricles relax,
pressure in ventricles falls,
blood flows back into
cusps of semilunar valves
and snaps them closed.
P
Diastole
P
P
P
P
• What is the function of diastole?
• Blood returning to the atria flows into the ventricles.
• Explain the changes in blood pressure in diastole and
their effect on valves.
• In diastole the higher pressure in the arteries
compared to the pressure in the ventricles closes the
SL valves.
• What is the function of systole?
• Atrial systole transfers the remainder of the blood
through the atrio-ventricular (AV) valves to the
ventricles.
• Ventricular systole closes the AV valves and pumps the
blood out through the semi lunar (SL) valves to the
aorta and pulmonary artery.
Pressure graph
• Watch this video from 12min45s to 15min
• https://www.youtube.com/watch?v=p8Jjn5KdjM
• ECG
• https://www.youtube.com/watch?v=RYZ4daFwMa8
• Blood pressure
https://www.youtube.com/watch?v=-di2R51QcqE
• Blood pressure:
https://www.youtube.com/watch?v=diG519dFVNs
• A stent: https://www.youtube.com/watch?v=S9AqBd4RExk
• Cardiac bypass
• https://www.youtube.com/watch?v=3Nf6Q2skGOM
• Actual video
• https://www.youtube.com/watch?v=h0-nIGQZ2PI
http://news.sky.com/video/1559453/bloodpressure-breakthrough
Video about blood pressure resistance