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147 Cards in this Set
- Front
- Back
At rest, the heart of an adult pumps about _____ L/min of blood.
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5.0L/min
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What are the four chambers of the heart called? What two categories are they put into and where are they located?
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Atria - Two Upper chambers, sometimes called auricles
Ventricles - Two Lower chambers 1. Right/Left Atrium 2. Right/Left Ventricle |
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What are the four heart valves and where are they located?
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1. Pulmonary Valve (Right)
2. Right AV Valve (Tricuspid) 3. Aortic Valve (Left) 4. Left AV Valve (Mitral) Located between the atria and the ventricles. |
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The pulmonary valve and the aortic valve are also called the __________ valves because they have 3 cusps which resemble half moons.
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Semilunar
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The heart wall is separated into what three layers? Describe the characteristics of each layer.
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1. Endocardium - a thin layer of endothelium
2. Myocardium - muscle layer (cardiac muscle) 3. Epicardium - thin external layer |
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When a specialized system of nodal tissue generates and conducts impulses through the heart, what happens?
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Rhythmic contractions of the myocardium.
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In the cardiac conduction system, there are four structural and functional portions. What are they? (*Hint - Backup pacemakers in order...)
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1. Sinoatrial node (SA Node/Pacemaker)
2. Atrioventricular node (AV node) 3. Atrioventricular bundle (AV bundle or bundle of HIS) 4. Purkinje fibers |
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True or false. When an impulse is created at the top of the heart, it does NOT travel throughout the entire heart.
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False.
Impulses DO travel throughout the entire heart. |
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What are the characteristics of the Sinoatrial node (SA node)? Where is it located and what is the other name for it?
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'Pacemaker'
Located within the posterior wall of the right atrium. Near opening of superior vena cava. Contracts quicker. Cells here depolarize quicker than any other cell in heart. Rhythmical impulses originate in the SA node and spread through atria. |
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What are the characteristics of the Atrioventricular node (AV node)? Where is it located?
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Located within the lower right interatrial septum.
Impulse is delayed in the AV node for 1/10 sec to allow atria contraction BEFORE ventricular contraction. |
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What are the characteristics of the Atrioventricular bundle (AV bundle or bundle of HIS)? Where is it located?
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Originates in the AV node and divides into "two bundle branches" which then extend down the two sides of the interventricular septum.
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What are the characteristics of the Purkinje fibers. Where are they located?
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Originate from the right and left branches, extending to the papillary muscles and lateral walls of the ventricles.
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True or False. When atria muscles contract, they contract with an impulse.
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True.
Atria muscles DO contract with an impulse. |
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How does an electrocardiogram (EKG) operate?
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Monitors impulses that initiate rhythmical and ventricular contractions throughout the heart.
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Control of the conduction in the heart is an _________ system.
*(Intrinsic or Extrinsic) |
Intrinsic
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True or False. An EKG records electrical impulse and spread.
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True.
An EKG records electrical impulses and spread, not electrical speed or contractions. |
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In the cardiac cycle, there are two main functions (*blood pressure). What are they referred to as, and what are their functions?
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1. Systole
Phase of Contraction Emptying of the atria and ventricles 2. Diastole Phase of Relaxation Filling of the atria and ventricles. |
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During the 'Mid-diastole' process. The _______ and _______ are _______.
The _______ and _______ valves are _____, the ______ and _______ valves are ______. |
1. atria
2. ventricles 3. relaxed 4. tricuspid 5. mitral 6. open 7. aortic 8. pulmonary 9. closed |
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Before the end of the 'Mid-diastole' phase, __to__% of ventricular filling occurs.
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65 to 85%
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In 'Mid-diastole' the blood flows from the atria to the ventricles, it flows ________?
(*Actively or passively) |
Passively.
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During the 'Atrial systole' process. The ________ contract and pump the additional __to__% of the blood into the _________. As the _____ contract, the orifices of the ______ ______ and _________ veins narrow; however, there is some regurgitation of blood into the ______.
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1. atria
2. 20 to 35% 3. ventricles 4. atria 5. venae cavae 6. pulmonary 7. veins |
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Which valves are closed during isovolumetric contraction?
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All four valves are closed
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What is considered to be an average PULSE PRESSURE?
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40-50 mm Hg
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What happens during Ventricular Systole?
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All four valves closed and pressure builds up and ventricular ejection begins.
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During what part of the cardiac cycle does the first heart sound occur? Why?
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(Lub) The rapid movement of blood during the closing of the AV valves.
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What is the diastolic pressure in the pulmonary artery and the pressure during systole?
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10 mm Hg and 24 mm Hg
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What is the diastolic pressure in the aorta during and pressure in left ventricle during systole?
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80 mm Hg and 120 mm Hg
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What occurs during Early diastole?
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The second heart sound (dub) pulmonary and aortic valves close.
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What is bradycardia?
Tachycardia? |
Bradycardia is a decrease in heart rate to less than 60 beats/minute.
Tachycardia is an increase in heart rate. |
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What is the average heart rate in the S.A node?
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72-75 beats/minute
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What is the heart rate in the A.V node?
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50-60 beats/minute
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What is the heart rate in the ventricles?
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30-40 beats/minute
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What is the maximum sympathetic stimulation in the heart?
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250 beats/minute (increase heart rate).
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Sympathetic control does what and how?
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Increases the rate and force of contraction by increasing permeability of cardiac cells to Na+ and Ca++ (via norepinephrine)
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Parasympathetic increases the permeability of membrane to what?
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K+ (via acetylcholine).
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What is the overall impact of parasympathetic control on the cardiac system?
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It decreases the rate and force of contraction
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Under parasympathetic control, what is the maximum stimulation?
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20-30 beats/minute (Bradycardia)
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What does the term inotropic refer to?
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The strength or force of contraction
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Name four factors that have a positive inotropic effect on the heart?
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Frank Starling's Law of the heart
Catecholamines- epinephrine or norephinephrine, isoproterenol Xanthines- caffeine, theophylline Digitalis- drug used for cardiac failure |
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What does the term chronotropic refer to?
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The rate of contraction (how fast the heart beats)
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What is stroke volume?
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The amount of blood pumped out of each ventricle per beat (about 60 to 80 ml)
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What is the equation that renders cardiac output?
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Stroke volume x heart rate = cardiac output
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What is the Fick Principle?
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CO (Cardiac Output) = oxygen consumption ml/minute
arterial O2 - venous O2 |
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Why is the QRS a greater event than the P or T wave?
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Because the ventricles have more cells than the atria
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What is the normal heart rate?
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60-100 beats/minute
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What is 'Frank Starling's law of the heart'?
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Greater the filling during 'diastole', the greater the force of contraction during 'systole'.
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On an EKG, the first wave is called the ___ wave and is associated with ___________ in the _____.
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1. P wave
2. DE-polarization 3. atria |
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On an EKG, the second wave is called the ___ wave (complex) and is associated with ___________ of the __________.
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1. QRS complex
2. DE-polarization 3. ventricles |
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On an EKG, the third wave is called the ___ wave and is associated with ___________ of the __________.
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1. T wave
2. RE-polorazation 3. ventricles |
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An impulse moving in the heart from a negative (-) to a positive (+) lead shows up as a __________ spike on an EKG.
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POSITIVE
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What is the formation and electrode connectivity in 'Einthoven's Triangle'?
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Left Shoulder
Right Shoulder Left Leg |
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In 'Lead I' where is the positive lead located?
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Left Arm
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In 'Lead II' where is the positive lead located?
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Left Leg
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In 'Lead III' where is the positive lead located?
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Left Leg
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In 'Lead aVR' where are the positive lead located?
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Right Arm
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In 'Lead aVL' where are the positive lead located?
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Left Arm
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In 'Lead aVF' where are the positive lead located?
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Left Leg
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Which of the 6 chest leads are mainly negative and which are mainly positive?
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V1 - V3 = Mainly Negative
V4 - V6 = Mainly Positive |
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Deviations from a normal heart rate or from normal electrical activity are referred to as _________.
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Cardiac arrhythmia.
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What is an ectopoic or abnormal pacemaker?
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Shift of pacemaking function from the SA node to another part of the heart.
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What is ischemia defined as?
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Lack/Restriction of bloodflow.
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During an 'Atrial Premature Beat', what happens?
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1. Premature depolarization of SA node / ectopic pacemaker
2. Some P waves are normal / some are abnormal 3. LITTLE clinical significance. May precede a flutter or fibrillation |
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During an 'AV Nodal Premature Beat', what happens?
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1. From ectopic discharge of AV node then proceeds down the Bundle of HIS
2. Normal QRS complex 3. Not proceeded by a P wave |
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During a 'Premature Ventricular Depolarization' (PVD or PVC), what happens?
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1. From ectopic pacemaker in the ventricles
2. No P Wave 3. Wide QRS Complex 4. High Voltage 5. T wave is usually inverted 6. Usually a pause post-PVD 7. May become coupled w/ one or more normal beats. |
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What is the definition of a 'Bigeminy'?
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One normal beat and one PVD beat.
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What is the definition of a 'Trigeminy'?
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Two normal beats and one PVD beat.
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During a 'SA Block,' what happens?
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1. Pacemaker temporarily stops for at LEAST one complete cycle.
2. P waves before and after block are identical |
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During a 'First Degree - Incomplete' 'AV Block', what happens?
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First Degree - Incomplete
1. Prolonged PR interval (0.2-0.3 sec) 2. Can be caused by digitalis or vagal stimulation |
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During a 'Second Degree - Incomplete' Type 1 'AV Block', what happens? What is another name for this arrhythmia?
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1. PR intervals lengthen progressively until a ventricle beat is dropped (6 or 8)
2. Can be caused by digitalis |
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During a 'Type 2' AV Block' arrhythmia, what happens?
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1. Present when it takes 2+ atrial impulses to stimulate ventricles
2. Usually 2:1, 3:1 or 4:1 3. May be caused by myocardial infarction or myocarditis 4. May lead to 3rd degree block |
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During a 'Third Degree' or 'Complete AV Block', what happens?
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1. Occurs when NONE of atrial impulses stimulate AV node.
2. Ventricles are paced independently from the atria 3. Ventricular rate is slower than atrial rate of contraction No impulses from atria make it down. |
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During an 'Atrial Flutter', what happens?
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1. Originates in an atrial pacemaker
2. P waves very rapid/coordinated (Look simliar to each other) 3. 2:1, 3:1, 4:1 |
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During an 'Atrial Fibrillation', what happens?
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1. Caused by many ectopic pacemakers in atria
2. Uncoordinated or irregular P waves |
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During a 'Ventricular Flutter', what happens?
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1. Caused by a single ectopic pacemaker in ventricles
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True or False:
Ventricular Flutter is usually caused by a single ectopic pacemaker. |
TRUE
Only a single ectopic pacemaker. |
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During a 'Ventricular Fibrillation', what happens?
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Caused by man ventricular ectopic pacemakers and causes DEATH
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What is the technical term used for 'Heat Attack'?
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Myocardial Infarction
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What are the three phases that are also referred to as the 'Classical Triad'?
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1. Ischemia
2. Injury 3. Infarction |
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What is the ischemia phase? What does it show up?
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Characterized by a symmetrical inversion of the T wave
Altered repolarization (1st PHASE) |
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What is the injury phase? When does it show up?
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ST elevation = infarction is fresh (acute)
Tissue damage starts to occur (2nd PHASE) |
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What is the 'infarction' phase? When does it occur?
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Significant Q wave - much wider than normal
(3rd PHASE) |
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During a myocardial infarction (heart attack), what is one of the 7 things that may occur
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Cardiac troponins (I and T found in the blood) This coordinates with severity.
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What are the two factors that determine the blood flow through a vessel?
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Pressure / Resistance
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What is the normal pressure of the heart? Where is it usually measured?
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1. 120/80 mm Hg
2. Arteries |
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What is laminar flow?
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The velocity flow is greater at the center of the vessel than along the outer edges.
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The diameter of blood vessels is mainly regulated by the ____________ nervous system.
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1. Autonomic
*However there are other factors that can also influence vascular diameter. |
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There are 2 types of NERVES that affect vascular diameter.
What are they and how do they affect vascular diameter? |
Sympathetic:
1. Alpha-adrenergic = (Vasoconstriction) Norep. 2. Beta-adrenergic = (Vasodilation) Norep. 3. Cholinergic = (Vasodilation) Ach Parasympathetic nerves = (Vasodilation) Ach |
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There are 3 HORMONES that affect vascular diameter.
What are they and how do they affect vascular diameter? |
1. Angiotensin II = (Vasoconstriction)
2. ADH = (Vasoconstriction) 3. Histamine = (Vasodilation) |
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Systemic circulation is responsible for __% of the blood volume?
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79% of the blood volume
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Pulmonary circulation is responsible for __% of the blood volume?
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12% of the blood volume
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What percentage of total blood volume is occupied by the heart during diastole?
**Blood volume % depends on cardiac phase |
9% = Heart
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What is the average pressure of the 'arterioles' when blood enters and when it leaves?
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85 - 30 mm Hg
*This is the most important in regulation of blood pressure Gets smaller as it moves into the capillaries (30-10) |
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What is the function of precapillary sphincters?
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Regulate blood flow to capillaries.
Provide intrinsic, loclized regulation of blood flow in capillary beds. |
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Precapillary sphincters have mechanisms that help regulate blood flow in relation to the local tissues' need for oxygen.
What is this ability called? |
Autoregulation
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Water flow across the capillary wall is due to two factors. What are the two factors?
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1. Capillary Hydrostatic Pressure (CP)
2. Osmotic Force (OF) |
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The ability for water to diffuse 'IN' to the vessel is usually caused by what? This ability is also helped by what protein?
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Osmotic Force (OF)
Protein = Albumin |
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Osmotic Force is usually what?
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23 mm Hg
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What is the smallest protein that also helps in water regulation in blood vessels?
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Albumin
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True or False:
Osmotic Force (OF) generally changes, but Capillary Pressure (CP) remains the same. |
FALSE
Osmotic Force (OF) stays the SAME. Capillary Pressure (CP) is DIFFERENT. |
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What is 'Edema'?
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The presence of excess interstitial fluid in the tissues.
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There are 3 main causes of edema. What are they? (All push fluid out)
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1. Increased capillary hydrostatic pressure
2. Decreased plasma protein (mainly albumin) 3. Increased interstitial fluid protein |
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Increased interstitial fluid proteins in the body can cause what to happen?
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Edema
More specifically, 'Pneumonia' |
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What are the 3 factors that can change blood pressure (short term)?
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1. Cardiac Output
2. Peripheral Resistance 3. Total Blood Volume |
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Long term regulation of blood pressure is controlled by what?
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Hormones
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Alcohol acts as a(n) ___________?
(Diuretic/Antidiuretic) |
Diuretic
Alcohol inhibits ADH release Increases urine production Increased urine production aids dumping of alcohol from body. |
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How long does it take the nervous system to regulate blood pressure?
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Seconds
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What organ(s) monitor blood pressure?
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Kidneys
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Where is angiotensinogen made?
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Liver
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The converting enzyme for Angiotensin is stored in what organ?
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Lungs
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The Renin-Angiontensin System regulates blood pressure in 3 ways. What are the 3 ways?
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1. Aldosterone Secretion
2. Increase ADH Release 3. Vasoconstriction of arterioles |
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What is Primary Aldosteronism (Conn's Syndrome)?
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Hypersecretion of aldosterone from the adrenal cortex. Leads to:
Hypertension Increased extracellular fluid volume Hypernatremia Potassium Depletion |
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What do ACE inhibitors do?
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Block the converting enzyme from binding to Angiotensin I so that no Angiotensin II is created.
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What are the characteristics of 'Hypovolemic shock'?
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Reduced blood volume
Caused by hemorrhage/dehydration/ or loss of fluid from burns Symptoms: Low B.P. Rapid Pulse Cold Clammy Skin Little Urine Formation Increased Respiration Rate Intense Thirst |
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What are the characteristics of 'Anaphylactic shock'?
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Rapid drop in B.P.
Result from severe allergic reaction Histamine causes vasodilation and thus a drop in B.P. |
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What are the characteristics of 'Neurogenic shock'?
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Spinal cord damage causes decreased sympathetic activity.
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What are the characteristics of 'Cardiogenic shock'?
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Inadequate circulation of blood in body tissues due to cardiac failure.
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Hypertension causes __% of all deaths.
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12%
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What are the two types of hypertension?
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1. Primary (Essential)
2. Secondary |
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What is the most common type of hypertension? Percent?
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Primary (Essential) 90%
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What are some of the characteristics/factors of primary (essential) hypertension?
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1. No cause can be determined
2. Occurs 25-50 years of age 3. More common in females and blacks |
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What is the definition of secondary hypertension?
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Results from clearly DEFINABLE causes. (Structural/Phsyiological)
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What percentage of the high blood pressure population has secondary hypertension?
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10%
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What mechanisms of secondary hypertension are involved in 'Renal Artery Disease'? What system is involved?
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Kidneys
Decreased urine formation Secretion of vasoactive chemicals |
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What examples of secondary hypertension are involved with the endocrine system?
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1. Conn's Syndrome
2. Adrenal Medulla Tumor |
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What are the results of having a tumor on the adrenal medulla and blood pressure?
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Increased Blood Pressure
Excess Catecholamines created Increased cardiac output and total peripheral resistance |
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What causes the first heart sound, "lub"?
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The two AV (tricuspid and meitral) valves closing in ventricular systole
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What is the diastolic pressure in the pulmonary artery?
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10 mm Hg
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What is the diastolic pressure in the aorta?
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80 mm Hg
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After Ventricular Systole, and under normal resting conditions, the pressure reaches ___ mm Hg on the right side and ____ mm Hg on the left side.
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1. 24 mm Hg
2. 120 mm Hg |
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How much blood remains in either ventricle at the end of ventricular systole?
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50 ml- the end systolic volume
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True or false: The valves make the "lub" "dub" heart sounds.
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FALSE! The turbulence of the moving blood makes the noise, not the valves.
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When does the second heart sound "dub" take place and what makes the noise?
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During early diastole, when the semilunar (pulmonary and aortic) valves close.
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What is the correct order of cardiac impulse conduction?
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SA node, Atrium AV node, bundle of HIS, purkinje fibers, ventricle
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What percent of ventricle filling takes place during MID-DIASTOLE?
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65-80%
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What causes the 'lub' heart sound?
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Closure of the TWO AV valves
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What pressure is reached int he right ventricle under normal conditions?
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24 mm Hg
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Cardiac output is measured by what TWO factors?
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Stroke Volume x Heart Rate
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True or False
A shift of the pacemaker function from the SA node to another part of the heart is called an 'ECTOPIC' pacemaker. |
TRUE
Ectopic = ABNORMAL Any pacemaker not started from the SA node is 'ectopic' |
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Histamine causes what to occur?
|
VASODILATION
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Precapillary sphincters regulate blood flow in relation to what?
|
Local tissues need for oxygen
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In the Cardiac Conduction System, what exchange of ions takes place during the SA node firing? (Four steps).
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1-Funny Channels open Na+ moves in K+ stops moving out (depolarization half way to threshold)
2- T-type Ca+ channels open (depolarize until threshold) 3- L-type Ca+ channels open reaches membrane potential of zero (depolarization). 4- Opening of K+ channels allowing K+ out (re-polarization). |
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Chest Leads V1 and V2 show most of which region of the heart?
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Right Ventricle
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Chest Leads V3 and V4 show most of which region of the heart?
|
Intraventricular Septum
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Chest Leads V5 and V6 show most of which region of the heart?
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Left Ventricle
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Short term regulation of blood pressure is taken care of by what two parts of the Nervous system? Where are they located?
|
Cardioinhibitory center and Vasomotor Center
Located in the medulla |
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Vasomotor Center stimulates which part of the CNS? What causes this stimulation?
|
Sympathetic. (increase in HR, C.O. and Vasoconstriction)
Carotid sinuses (Receive stimulus from vagus and glossopharyngeal nerves) |
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Cardioinhibitory Center stimulates which part of the CNS?
What causes this stimulation? |
Parasympathetic (decrease in HR, C.O. and Vasodialation).
Carotid bodies recognize lowering levels of O2 and increasing levels of H+ |