Cardiac Cycle, Output and

Sounds of the Heart

By: Cara Amundson, Trey Osterholt, Mohammad Ahmed, Abby Lathrop

• Cardiac muscle: The type of muscle that is found in the walls of the heart. Cardiac muscle is striated but branched, unlike the straight-shaped striated skeletal muscle cells.

• Cardiac Cycle: The rhythmic contraction (systole) and relaxation (diastole) of the chambers of the heart that corresponds to one heartbeat.• One cardiac cycle is completed when

the heart fills with blood and the blood is pumped out of the heart

• cardiac output (CO): the effective volume of blood expelled by either ventricle of the heart per unit of time (usually per minute).

• Diastole: The phase of the heartbeat when the heart muscle relaxes and allows the chambers to fill with blood.

• Systole: The phase of the heartbeat when the heart muscle contracts and pumps blood from the chambers into the arteries.

Heart Sounds

• The normal heart sound is typically described as "lub-dub.”

• The sounds of the heart are only from the valves closing, not opening

• The sounds are also amplified by the chest, making them more audible.

• http://www.youtube.com/watch?v=-4kGMI-qQ3I

The “Lub”

• The "lub" is the first heart sound

• The "lub" sound is usually softer and longer than the "dub”

• The "lub" is the sound of the tricuspid and mitral valves closing.

The Dub

• The "DUB" is the sound of the aortic and pulmonary valves closing.

• The "dub" sound is shorter and louder than the "lub" sound.

• http://www.youtube.com/watch?v=qYBtchCqPao• http://depts.washington.edu/physdx/heart/demo.html

Stroke Volume

• Stroke Volume: The amount of blood pumped out of one ventricle of the heart as the result of a single contraction.

• A measure of the effectiveness of ventricular contraction. • Measured in millimeters (ml)

Cardiac Output

• cardiac output (CO): the effective volume of blood expelled by either ventricle of the heart per unit of time (usually per minute).

• Cardiac Output in mL/min = heart rate (beats/min) X stroke volume (mL/beat)

• An average person has a resting heart rate of 70 beats/minute and a resting stroke volume of 70 mL/beat. The cardiac output for this person at rest is:

• Cardiac Output = 70 (beats/min) X 70 (mL/beat) = 4900 mL/minute.

Works Cited

• Web MD• http://biology.about.com/od/anatomy/ss/cardiac_cycle.htm• Thefreedictionary.com• Biologydictionary.com• Youtube.com• http://www.google.com/imgres?q=diastole&um=1&safe=active&sa=N&rls=com.microsoft:en-

us:IE-SearchBox&hl=en&biw=1366&bih=600&tbm=isch&tbnid=iTXot679tbx7wM:&imgrefurl=http://www.rnceus.com/hemo/bloodflo.htm&docid=Gdgg9UCkw0-7xM&imgurl=http://www.rnceus.com/hemo/Images/systole.gif&w=337&h=286&ei=w9t2UZSsEaqp2QXI5oCYBA&zoom=1&iact=rc&dur=171&page=1&tbnh=148&tbnw=174&start=0&ndsp=22&ved=1t:429,r:8,s:0,i:109&tx=72&ty=93

• http://www.biosbcc.net/doohan/sample/htm/COandMAPhtm.htm• http://www.google.com/imgres?

q=cardiac+output&um=1&safe=active&sa=N&rls=com.microsoft:en-us:IE-SearchBox&hl=en&biw=1366&bih=600&tbm=isch&tbnid=swsK25wbREdgjM:&imgrefurl=http://www.learnhemodynamics.com/hemo/contract.htm&docid=9mxM08QihhD5jM&imgurl=http://www.learnhemodynamics.com/hemo/images/BABYPROP.jpg&w=520&h=364&ei=Edx2UbnQDcKW2QW0wYGgAg&zoom=1&iact=rc&page=1&tbnh=139&tbnw=218&start=0&ndsp=19&ved=1t:429,r:9,s:0,i:112&tx=186&ty=125

• https://en.wikipedia.org/wiki/Heart_sounds