Term
| What is the Mediastinum and what are its borders? |
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Definition
| Space extending from thoracic inlet superiorly to the diaphragm inferiorly...the sternum anteriorly and vertebral column posteriorly |
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Term
| The Mediastinum contains 9 things. What are they? |
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Definition
1. Heart
2. Great Vessels
3. Esophagus
4. Trachea
5. Phrenic nerve
6. Cardiac nerve
7. Thoracic duct
8. Thymus
9. Lymph nodes
The Lungs are not in this space |
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Term
| What occurs during inspiration for a patient with an open pneumothorax? |
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Definition
| Air enters pleural cavity through opening. The negative pressure is lost in the ipsilateral lung allowing it to collapse. Venous return to the heart is reduced and the mediastinum shifts, compressing the opposite lung. |
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Term
| What happens during expiration for a patient with an open pneumothorax? |
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Definition
| The chest wall contracts and the diaphragm rises. The air in the pleural cavity leaves via the wound. The mediastinum shifts to the affected side and mediastinal flutter further impairs venous return by distortion of venae cavae. |
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Term
| Where is the pericardium? |
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Definition
| Located in the middle of the mediastinum. |
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Term
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Definition
| Double walled fibroserous sac surrounding the heart and the roots of the vessels entering and leaving the heart. |
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Term
| What are the three layers of the pericardium? |
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Definition
1. Outer parietal layer - fibrous pericardium
2. Inner parietal layer - serous pericardium
3. Inner visceral layer - serous pericardium |
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Term
| The inner visceral layer of the pericardium is also known as what? |
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Definition
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Term
| What is the pericardial space? |
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Definition
| A potential space between the parietal pericardium and the visceral pericardium |
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Term
| T/F. There is no fluid between the parietal and visceral layers of the pericardium. |
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Definition
| False, serous fluid is in between to allow for a friction-free environment |
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Term
| What nerve innervates the parietal layer of the pericardium? |
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Definition
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Term
| What is pericardial effusion? |
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Definition
| A pathological condition where excess fluid fills the pericardial cavity increasing pressure on the heart and restricts blood flow into right ventricle. |
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Term
| Describe the base of the heart. |
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Definition
| The superior portion of the heart formed by both atria. Found at the 2nd intercostal space in adults. |
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Term
| Where is the apex of the heart found? |
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Definition
| The 5th intercostal space at the midclavicular line. |
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Term
| T/F. About 1/3 of the heart lies to the right of the midline and 2/3 lie to the left. |
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Definition
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Term
| What is the point of maximum impulse? Why is it significant? |
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Definition
| The point where the heart is easiest to visualize and palpate. This point marks the apex. |
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Term
| Which way does the diaphragm rotate the heart during deep inspiration? |
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Definition
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Term
| T/F. Heart disease displaces the PMI medially because of the increased heart mass. |
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Definition
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Term
| What are the layers to the heart? |
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Definition
1. Epicardium aka visceral pericardium
2. Myocardium - contains cardiac muscle tissue
3. Endocardium - innermost layer |
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Term
| Myocardial Cells are unique from other types of muscle cells for what reason? |
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Definition
| They have the intrinsic ability to contract in the absence of stimuli (automaticity) |
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Term
| T/F. Different parts of the heart have different rhythms. |
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Definition
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Term
| T/F. Myocardial cells are not able to transmit nerve impulses. |
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Definition
| False, cardiac cells have conductivity |
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Term
| T/F. Myocardial cells do not undergo mitotic activity and cannot be replaced when injured. |
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Definition
| False, there is some evidence that myocardial cells may regenerate but at a very slow rate. |
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Term
| How are cardiac muscle cells structurally and physiologically different from skeletal and smooth muscle? |
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Definition
| Cardiac muscle cells have intercalated discs which add structure and allow heart to have rhythm. T tubules are bigger in cardiac cells and the cells are also striated. Cardiac cells have more numerous mitochondria. |
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Term
| T/F. Myocardial metabolism is essentially aerobic and can be sustained by a semi-continuous O2 delivery from the coronary arteries. |
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Definition
| False, myocardial metabolism is sustained by a continuous O2 delivery from the coronary arteries |
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Term
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Definition
| It is an appendage of the heart and is a remnant of its development |
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Term
| The right atrium receives blood from where? |
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Definition
| Superior and inferior vena cava and coronary sinus |
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Term
| Most blood flow into the right atrium occurs during inspiration or expiration? |
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Definition
| Inspiration, at this point the pressure in the right atrium is less than the pressure in the sup and inf vena cava allowing for blood flow to occur. |
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Term
| T/F. There is no functional valve at the vena cava and this can lead to systemic congestion. |
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Definition
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Term
| What is the normal filling pressure of the right atrium? |
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Definition
| 0-8 mmHg = central venous pressure |
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Term
| The right ventricle receives blood from where? |
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Definition
| Blood comes from right atrium through the tricuspid valve |
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Term
| Blood from the right ventricle leaves via what valve? |
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Definition
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Term
| T/F. The right ventricle works just as hard as the left ventricle in terms of stroke work. |
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Definition
| False, the right ventricle generates less than 1/4th the stroke work of left ventricle. The force needed to pump blood into the lungs is not near as high as it needs to be to pump blood to the whole body. |
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Term
| The left atrium receives blood from where? |
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Definition
| The right and left pulmonary veins |
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Term
| What is the name of the valve that prevents blood from back flowing into the lungs from the left atrium? |
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Definition
| There is no valve. Atrial muscle surrounds the pulmonary veins and this reduces backflow of blood during atrial systole. |
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Term
| How thick are the walls of the left ventricle compared to the right ventricle? |
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Definition
| 2-3x greater thickness compared to the right |
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Term
| Blood in the left ventricle is received from where? |
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Definition
| The left atrium through the mitral valve |
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Term
| Blood leaving the left ventricle goes through what valve? |
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Definition
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Term
| What is the ventricular septum? |
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Definition
| A thick muscular area that separates the ventricles and provides stability during contractions. Sometimes considered part of the spine of the heart |
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Term
| What is the purpose of the heart valves? |
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Definition
| To ensure unidirectional blood flow through the heart |
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Term
| Atrioventricular valves could prolapse into atria if it were not for these structures. |
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Definition
| Papillary muscles and their extensions that anchor the AV valves, the chordae tendineae |
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Term
| The Atrioventricular valve on the right side of the heart is? |
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Definition
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Term
| The Atrioventricular valve on the left side of the heart is? |
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Definition
| The bicuspid or mitral valve |
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Term
| What is the purpose of the Semilunar valves? |
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Definition
| To prevent backflow of blood from aorta and pulmonary artieries into the ventricles during diastole |
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Term
| What is valve stenosis and what is its significance? |
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Definition
| Thickening of the valves which can impede blood flow |
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Term
| What is valve regurgitation? |
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Definition
| A cardiac pathology that results in retrograde flow |
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Term
| T/F. Neither valve stenosis nor regurgitation will limit a patient's ability to exercise. |
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Definition
| False, both of these can lead to exercise intolerance |
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Term
| Where is the SA node located? |
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Definition
| The posterior wall of the right atrium near entrance of the superior vena cava |
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Term
| What is the intrinsic rate of the SA node? |
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Definition
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Term
| What is the regular course of conduction through the heart? |
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Definition
| SA node > AV node or junction > Bundle of His > right and left bundle branches > Purkinje fibers |
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Term
| Where is the AV node located? |
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Definition
| Floor of the right atrium near coronary sinus |
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Term
| What is the intrinsic rate of the AV node? |
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Definition
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Term
| What is the intrinsic rate of ventricle cells? |
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Definition
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Term
| What is the intrinsic rate of atrial cells? |
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Definition
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Term
| How much of a delay is there through the AV node and why is this important? |
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Definition
| Approximately .04 seconds and this is important to allow for more venticular filling/ greater stroke volume |
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Term
| Stimulation of the Sympathetic pathway has what 4 results? |
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Definition
1. Causes acceleration of the discharge rate in the SA node
2. Causes increase in AV node conduction
3. Causes increase in the contractile force of both atrial and ventricular muscles
4. Causes coronary artery vasodilation |
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Term
| Stimulating the Parasympathetic system via vagal nerve results in what 5 things? |
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Definition
1. Cardiac slowing
2. Decreased AV nodal conduction
3. Decreased force of heart contraction
4. Decreased myocardial metabolism
5. Causes coronary artery vasocontriction |
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Term
| What is the period of time between successive heartbeats? |
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Definition
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Term
| What is ejection fraction and what are its norm values? |
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Definition
| The percentage of end diastolic volume ejected during systole. Normally 60-70% |
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Term
| What increases/decreases ejection fraction? |
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Definition
| Exercise increases and pathology decreases |
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Term
| What event has to occur in order ventricular filling to begin? |
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Definition
| Ventricular pressure has to fall below atrial pressure and then the AV valves open and fill |
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Term
| What marks the end of ventricular filling? |
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Definition
| The initiation of the cardiac cycle causing atrial contraction ends ventricular filling but not before pushing a little more blood into the ventricles and this is called the atrial kick |
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Term
| The aortic sinuses give rise to two arteries. Which are they? |
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Definition
| The left and right coronary arteries |
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Term
| The left coronary artery has two branches. What are they? |
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Definition
| The left anterior descending artery and the left circumflex artery |
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Term
| The left circumflex artery supplies what part of the heart? |
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Definition
Left atrium and lateral/posterior walls of left ventricle
In 45% of people the SA Node is supplied and in 10% of people the AV node is supplied |
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Term
| The left anterior descending artery supplies what area of the heart? |
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Definition
| Anterior wall of the left ventricle |
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Term
| A block in the left coronary artery is referred to as...? |
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Definition
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Term
| The right coronary artery supplies what? |
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Definition
Generally the right atrium, the right ventricle and the inferior wall of the left ventricle
In 55% of people the SA Node is supplied and in 90% of people the AV node is supplied |
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Term
| How is coronary dominance determined? |
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Definition
Which artery supplies the AV node determines
35-40% of people have mixed blood supply to AV node |
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Term
| What veins return blood to the right atrium? |
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Definition
1. Thebesian veins
2. Anterior cardiac veins
3. Coronary sinus |
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Term
| What happens when the myocardium has inadequate blood flow? |
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Definition
| Cell death, less contractility, Angina, MI |
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Term
| On average how much blood is ejected from the heart per minute? |
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Definition
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Term
| Cardiac output = stroke volume x heart rate. What is stroke volume? |
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Definition
| Average volume of blood ejected per heart beat |
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Term
| What is Frank-Starling Law of the heart? |
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Definition
| The more the heart muscle is stretched when an increased volume of blood fills the ventricles, the more vigorous its contraction will be, resulting in a greater volume of blood pumped out of the heart |
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Term
| Preload depends on what 5 things? |
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Definition
1. Venous return
2. Blood volume
3. Left atrial contraction
4. Heart rate
5. Central venous pressure |
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Term
| T/F. The heart can be overstretched. |
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Definition
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Term
| Resistance to ejection during ventricular systole is determined by what 4 things? |
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Definition
1. Distensibility of the aorta
2. Vascular resistance
3. Patency of the aortic valve
4. Viscosity of the blood |
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Term
| What extrinsic factors affect stroke volume? |
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Definition
1. Norepinephrine
2. Sympathetic nerves firing
3. Medications such as digitalis, amiodirone, and isoproterenol |
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Term
| Compare a inotropic effect to a chronotropic effect |
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Definition
Inotropic effects impact contractility
Chronotropic effects impact timing |
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Term
| T/F. Meds such as barbiturates, calcium antagonists and anesthetic agents provide a positive inotropic effect because they increase the contractility of the heart. |
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Definition
| False, these drugs provide a negative inotropic effect and decrease the contractility of the heart |
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Term
| T/F. Catecholamines such as epinephrine work slower than the sympathetic nervous system. |
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Definition
| True, catecholamines take about 5-10 minutes to kick in |
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Term
| T/F. If blood pressure increases then the sympathetic system kicks in to decrease the rate and force of the cardiac contraction. |
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Definition
| False, the parasympathetic system kicks in to decrease rate and force of cardiac contraction as well as inhibiting the sympathetic system and decreasing peripheral resistance |
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Term
| Baroreceptors are the main mechanism for controlling HR but where are they located? |
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Definition
| Walls of aortic arch and carotid bodies |
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Term
| T/F. There is an indirect relationship between body temp and HR. |
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Definition
| False, its a direct relationship. The higher the body temp the higher the HR |
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Term
| Chemoreceptors are located in the carotid body and are sensitive to what blood chemicals? |
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Definition
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Term
| T/F. Cardiovascular Disease is the 2nd leading cause of death right behind cancer. |
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Definition
| False, Cardiovascular disease is the leading cause |
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Term
| The most prevalent forms of CVD include Coronary Artery Disease, Rheumatic heart disease and what other two conditions? |
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Definition
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