Structure of
the heart
the heart
Circulation
The Cardiac
Cycle
Cycle
Sounds/
Regulation
Regulation
Observing/
Analyzing
Analyzing
100
Where is the heart located?
The heart is located in the middle of the chest, under the breast bone. (Misconception: located on the left.)
100
How much blood can the heart pump when the body is resting?
5 Liters in one minute; equal to the total volume of blood in the body.
100
What is the Cardiac Cycle?
Contractions and relaxations of the heart muscles during a complete heartbeat.
100
What causes the familiar lubb-DUBB of the heartbeat?
Closing of the heart valves.
100
In what year did Augustus Waller discover that you could detect the electrical current from the heart from various places on the skin?
1887.
200
What seperates the heart into two parallel pumps?
The septum
200
How many valves ensure that blood flows in only one direction and what are they?
4 valves; semilunar valves and atrioventricular valves.
200
What are the two basic phases?
Diastole and Systole.
200
What instrument do you use to hear the sounds of the heart?
Stethoscope.
200
What is an electrocardiograph and how is it connected to the body?
A device that detects the electrical activity of the heart through electrodes placed on the body’s surface; connected to the body using a number of electrodes, usually 12.
300
Why are the walls of the ventricles thicker than the walls of the atria?
The ventricles have to pump the blood over much longer distances and through capillary networks.
300
What prevents the the valves from opening backwards into the atria during the high pressure caused by the ventricular contraction?
The Chordae Tendineae.
300
Explain what diastole and systole mean?
Diastole: when the ventricles are relaxed and this is when blood fills the ventricles.
Systole: when the ventricles contact and blood is ejected from the ventricles.
300
What is the difference between the skeletal muscle and the heart muscle?
The heart muscle has the unusual ability to contract and relax on its own without stimulation from an external source.
300
What can analysis of an electrocardiogram provide?
Evidence for the presence of abnormal heart conditions.
400
What is the name of the heart's own supply of blood vessels and what does it do?
Coronary blood vessels; provide oxygen and nutrients to the muscle cells of the heart and removes the waste products.
400
Briefly explain how deoxygenated blood travels through the heart and into the body as oxygenated.
Right atrium pumps deoxygenated blood to right ventricle through tricuspid valve.
Right ventricle pumps blood to the lungs through the pulmonary valve.
Left atrium receives oxygenated blood from the lungs and pumps it to the left ventricle through the mitral valve.
Left ventricle pumps blood through the aortic valve out to the rest of the body.
400
In what stage of the cardiac cycle does does the atria contract?
3rd stage.
400
What is the difference between a Sinoatrial node (SA) and a Atrioventricular node (AV)?
Sinoatrial (SA) node: A mass of muscle and nerve cells in the right atrium; initiates the heartbeat and maintains the regular rhythm.
Atrioventricular (AV) node: A mass of conducting cells that transmits the signals from the SA node to the muscles the regular rhythm.
400
What happens during the QRS complex?
Represents ventricular depolarization (and atrial re-polarization) or the journey through the electrical impulse from the AV-Node through the Purkinje network.