Term
| Where is the heart located? |
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Definition
| In the mediastinum-the space all around the heart, excluding the lungs. |
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Term
| Where are the apex and base of the heart located? |
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Definition
| The apex is located at the 5th rib, the base at the 2nd rib. |
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Term
| Name the 3 pericardial layers, from inner to outer. |
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Definition
1. Visceral pericardium/Epicardium
2. Parietal pericardium
3. Pericardial sac (space), which contains pericardial fluid |
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Term
| What is the significance of pericardial fluid in the heart? On average, how many mL do we have? |
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Definition
The fluid, located in the space between the pericardial&visceral membranes, lubricates teh membranes, allowing the heart to beat with minimal friction.
We have 5-30 mL. |
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Term
| How many chambers does the heart have? Name them from top to bottom. |
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Definition
The 2 atria, the upper chambers, are the entrance ways.
The 2 thick ventricles are hollow spaces.
Therefore, there are 4 chambers. |
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Term
| How many types of valves are they? Describe them. |
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Definition
Two.
1. Atrioventricular (AV) valves separate atria from ventricles
2. Semilunar valves separate ventricles from the greater vessels. |
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Term
| Describe the 4 valves of the heart and what category each is in. |
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Definition
1. Bicuspid-left side, AV valve
2. Tricuspid (mitral)-right side, AV valve
3. Pulmonary semilunar-separates right ventricle from pulmonary artery, semilunar valve
4. Aortic semilunar-separates left ventricle from aorta, semilunar valve |
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Term
| What are the 4 great vessels? |
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Definition
1. Superior and inferior vena cava
2. Aorta
3. Pulmonary artery
4. Pulmonary veins |
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Term
| What vessel arrives at the heart? |
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Definition
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Term
| What type of vessel leaves the heart? |
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Definition
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Term
| What separates the right and left ventricles? |
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Definition
| The interventricular septum. |
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Term
| What separates the two atria? |
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Definition
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Term
| What does blood do in the atria and ventricles? |
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Definition
The atria are receiving chambers for blood returning to the heart by way of great veins.
The ventricles are the pumps that eject blood into arteries and keep it flowing through out the body. |
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Term
| Which ventricle pumps blood to the entire body? Where does the other pump blood to? |
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Definition
| The left ventricle is thicker, therefore it can pump blood throughout the body. The right ventricle only pumps blood to the lungs and back. |
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Term
| What do the AV valves do for blood flow? |
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Definition
| They regulate the openings between the atria and ventricles. |
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Term
| What do the semilunar valves do as far as blood flow? |
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Definition
| Regulate the flow of blood from the ventricles into the great arteries. |
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Term
| Which valve controls the opening from the right ventricle to the pulmonary trunk? |
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Definition
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Term
| What does the aortic valve control? |
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Definition
| The opening from the left ventricle into the aorta. |
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Term
| What is the coronary sinus? Where is it located? |
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Definition
| A large transverse vein on the posterior heart. It collects blood from three drainage veins to empty into the right atrium. |
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Term
| What are the trebeculae carnae? What about the chordae tendinae? |
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Definition
Trebeculae carnae form the papillary muscles.
Chordae tendinae attach flaps of the AV valves to those papillary muscles. |
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Term
| What is the inside of the heart lining called? The outer layer? |
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Definition
Outer layer=epicardium (upon the heart)
Myocardium is the thick middle layer, contains trabeculae carnae. |
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Term
| What is a systole and diastole? |
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Definition
A systole is a heart contraction, which expels blood from the chamber.
A diastole is the relaxation of a chamber, which allows the chamber to refill. |
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Term
| What is the 'lub-dub' of the heart? |
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Definition
Lub is the closing of AV valves.
Dub is the closing of Semilunar valves. |
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Term
| Describe the 4 steps of the conduction system. And what is the purpose of the cardiac conduction system? |
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Definition
The purpose of the CCS is to control the route and timing of stimulation to ensure that the heart chambers are coordinated with each other.
(Depolarization stimulates contraction) and begins in:
1. The sinoatrial (SA) node in the right atrium serves as the pacemaker that initiates each heartbeat, and determines the heart rate.
2. The AV node, near the AV valve, acts as an electrical gateway to ventricles. AV node depolarizes.
3. AV bundle (Bundle of His) leaves the AV node and forks into right and left bundle branches, which enter the septum and depolarization descends toward the apex of the heart.
4. Purkinje fibersdistribute electrical excitation to the myocytes of the ventricles. Depolorization spreads up the ventricular walls.
Then the ventricles contract! |
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Term
| What is the average heart rate? |
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Definition
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Term
| Describe the 4 steps of the cardiac cycle. |
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Definition
1. All four chambers relaxed, AV valves open, ventricles filling
2. Atrial systole completes ventricular filling
3. Ventricles contract, AV valves close for the Semilunar valves to open, blood is ejected into arteries
4. Heart returns to initial state of relaxation and refills |
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Term
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Definition
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Term
| What is it called when the myocardium of the atria and ventricles electrically discharges? Recharges? |
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Definition
| Depolarization and polarization. |
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Term
| What is a myocardial infarction? What can cause this? |
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Definition
The sudden death of a patch of tissue deprived of its blood flow.
A fatty deposit or blood clot in a corony artery can cause a MI. |
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Term
| What is tachycardia? Bradycardia? Fibrillation? |
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Definition
Tachycardia=heart rate over 100 bpm.
Bradycardia=heart rate below 60 bpm.
Fibrillation are uncoordinated heart beats. |
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Term
| Define an artery and a vein. |
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Definition
| Arteries/arterioles carry blood away from the heart, while veins/venules return blood to the heart. |
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Term
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Definition
| What transports blood to tissue. |
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Term
| What are the 3 layers of a blood vessel from inner to outer? |
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Definition
Tunica Interna (endothelium)--simple squamous, avoids clots
Tunica Media--smooth muscle, collagen and elastic fibers, allows for vasoconstriction/dilation
Tunica Externa--connective tissue |
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Term
| Why are valves required in veins, but not arteries? |
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Definition
| Valves in the veins serve to keep blood flow in one direction. The arterial system is a pressure driven system, unlike veins, which have low pressure. |
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Term
| Why do arteries have thicker walls than veins? |
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Definition
| Again due to pressure. Blood is pumped directly to arteries, meaning higher pressure. |
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