Paramedic-cardiology 1
Based off Nancy Caroline's Emergency Care in the streets Chapter 27.
- 1.
The layers of the heart, beginning with the outermost layer, are the
- A.
Epicardium,myocardium,and endocardium
- B.
Endocardium,epicardium, and myocardium
- C.
Myocardium,epicardium, andendocardium
- D.
Epicardium,ednocardium, and myocardium
Correct Answer
A. Epicardium,myocardium,and endocardiumExplanation
The correct answer is epicardium, myocardium, and endocardium. The epicardium is the outermost layer of the heart, also known as the visceral pericardium. It is a protective layer that covers the heart and contains blood vessels and adipose tissue. The myocardium is the middle layer and is composed of cardiac muscle tissue. It is responsible for the contraction of the heart and pumping of blood. The endocardium is the innermost layer and is a thin, smooth layer that lines the chambers of the heart and covers the heart valves. It helps to prevent blood clotting and provides a smooth surface for blood flow.Rate this question:
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- 2.
What prevents the backflow of blood during ventricular contraction
- A.
The aortic valve
- B.
Semilunar valve
- C.
The pulmonic valve
- D.
Atrioventricular valve
Correct Answer
D. Atrioventricular valveExplanation
The atrioventricular valve prevents the backflow of blood during ventricular contraction. This valve is located between the atria and ventricles and closes when the ventricles contract, preventing blood from flowing back into the atria. This ensures that blood is efficiently pumped out of the heart and prevents any regurgitation. The aortic valve, semilunar valve, and pulmonic valve are responsible for preventing backflow of blood in other parts of the heart, but they are not specifically involved in preventing backflow during ventricular contraction.Rate this question:
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- 3.
Approximately 80% of ventricular filling occurs
- A.
During systole
- B.
During diastole
- C.
When the semilunar valves are open
- D.
When the atrioventricular valves close
Correct Answer
B. During diastoleExplanation
During diastole, the ventricles of the heart relax and fill with blood. This is the phase of the cardiac cycle when the atrioventricular valves are open and blood flows from the atria into the ventricles. Approximately 80% of ventricular filling occurs during diastole because this is when the ventricles have the most time to fill with blood before the next contraction (systole) occurs.Rate this question:
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- 4.
Atrial kick is most accurately defined as
- A.
The blood that flows passively into the ventricles
- B.
Pressure on the atrioventricular valves during ventricular contraction
- C.
An attempt of the atria to contract against closed valves
- D.
20% of ventricular filling caused by atrial contraction
Correct Answer
D. 20% of ventricular filling caused by atrial contractionExplanation
Atrial kick refers to the contraction of the atria against closed valves, specifically the mitral valve, during ventricular diastole. This contraction helps to push an additional amount of blood into the ventricles, contributing to ventricular filling. It is estimated that the atrial kick accounts for approximately 20% of the total ventricular filling during each cardiac cycle.Rate this question:
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- 5.
Which of the following statements regarding the right side of the heart is most correct
- A.
It receives blood exclusively from the venae cavae
- B.
The right side of the heart is a low pressure pump
- C.
It pumps against the high resistance of the pulmonary circulation
- D.
The right side of the heart pumps blood through the pulmonary veins
Correct Answer
B. The right side of the heart is a low pressure pumpExplanation
The right side of the heart is a low pressure pump because it receives deoxygenated blood from the body through the venae cavae and pumps it to the lungs for oxygenation. This is in contrast to the left side of the heart, which is a high pressure pump that receives oxygenated blood from the lungs and pumps it to the rest of the body. The right side of the heart has thinner walls and less muscle mass compared to the left side, allowing it to pump blood at a lower pressure.Rate this question:
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- 6.
In contrast to the right side of the heart, the left side of the heart
- A.
Drives blood out of the heart against the relatively high resistance of the systemic circulation
- B.
Is a high-pressure pump that sends blood through the pulmonary circulation and to the lungs
- C.
Is a relatively low pressure pump that must stretcher its walls in order to force blood through the aorta
- D.
Drives blood out of the heart against the relatively low resistance of the pulmonary circulation
Correct Answer
A. Drives blood out of the heart against the relatively high resistance of the systemic circulationExplanation
The left side of the heart drives blood out of the heart against the relatively high resistance of the systemic circulation. This means that the left side of the heart pumps oxygenated blood to the rest of the body, which requires more force due to the resistance in the blood vessels throughout the body. In contrast, the right side of the heart pumps deoxygenated blood to the lungs, which has a lower resistance in the pulmonary circulation.Rate this question:
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- 7.
Which layer of the blood vessel is made up of elastic fibers and muscle, and provides for strength and contractility
- A.
Tunica media
- B.
Tunica intima
- C.
Tunica adventitia
- D.
Arterial lumen
Correct Answer
A. Tunica mediaExplanation
The tunica media is the correct answer because it is the layer of the blood vessel that is made up of elastic fibers and muscle. This layer provides strength and contractility to the blood vessel, allowing it to expand and contract as needed to regulate blood flow. The tunica intima is the innermost layer of the blood vessel, consisting of endothelial cells, while the tunica adventitia is the outermost layer, composed of connective tissue. The arterial lumen refers to the central opening inside the blood vessel.Rate this question:
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- 8.
In contrast to arteries, veins
- A.
Do not contain valves that prevent backflow of blood
- B.
Have less capacity to increase the size of their diameter
- C.
Are more likely to distend when exposed to back pressure
- D.
Operate on the high-pressure side of the circulatory system
Correct Answer
C. Are more likely to distend when exposed to back pressureExplanation
Veins are more likely to distend when exposed to back pressure. This is because veins have thinner walls and less smooth muscle compared to arteries. When there is an increase in pressure within the veins, such as when there is a blockage or when blood flow is impeded, the veins are more likely to stretch and expand. This distension allows the veins to accommodate the increased volume of blood and helps to prevent damage to the vessel walls. In contrast, arteries have thicker walls and more smooth muscle, allowing them to withstand higher pressures without distending.Rate this question:
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- 9.
The amount of blood that is pumped out by either ventricle per minute is called
- A.
Ejection fraction
- B.
Cardiac output
- C.
Stroke volume
- D.
Minute volume
Correct Answer
B. Cardiac outputExplanation
Cardiac output refers to the amount of blood that is pumped out by either ventricle per minute. It is a measure of the overall effectiveness of the heart in delivering oxygenated blood to the body's tissues. It is calculated by multiplying the stroke volume (the amount of blood ejected by each ventricle with each heartbeat) by the heart rate (the number of times the heart beats per minute). Therefore, cardiac output is a crucial parameter in assessing the heart's ability to meet the body's demands for oxygen and nutrients.Rate this question:
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- 10.
With regard to stroke volume, a healthy heart
- A.
Has a relatively fixed stroke volume
- B.
Has an average stroke volume of 40 ml
- C.
Can double stroke volume if demand is high
- D.
Can easily increase stroke volume by 50%
Correct Answer
D. Can easily increase stroke volume by 50%Explanation
A healthy heart has the ability to easily increase its stroke volume by 50%. This means that when the body requires more blood to be pumped, the heart can efficiently adjust and pump out a larger volume of blood per beat. This flexibility allows the heart to meet the increased demands of the body during exercise or times of stress.Rate this question:
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- 11.
Cardiac output in influenced by
- A.
Heart rate
- B.
Stroke volume
- C.
Heart rate and or stroke volume
- D.
Ejection fraction and heart rate
Correct Answer
C. Heart rate and or stroke volumeExplanation
Cardiac output refers to the amount of blood pumped by the heart per minute. It is influenced by two main factors: heart rate and stroke volume. Heart rate refers to the number of times the heart beats per minute, while stroke volume refers to the volume of blood pumped by the heart with each beat. The combination of these two factors determines the overall cardiac output. Therefore, the correct answer is heart rate and/or stroke volume, as both factors play a significant role in influencing cardiac output.Rate this question:
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- 12.
The ability of the heart to vary the degree (force) of its contraction without stretching is called
- A.
Contractility
- B.
Chonotropy
- C.
Automaticity
- D.
Frank-starling effect
Correct Answer
A. ContractilityExplanation
Contractility refers to the ability of the heart to vary the force of its contraction without stretching. This means that the heart can adjust the strength of its contractions to meet the demands of the body, without needing to change its size or stretch. Contractility is an important factor in regulating cardiac output and maintaining proper circulation throughout the body.Rate this question:
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- 13.
Administering a drug that possesses a positive chronotropic effect will have a direct effect on
- A.
Stroke volume
- B.
Blood pressure
- C.
Cardiac output
- D.
The heart rate
Correct Answer
D. The heart rateExplanation
Administering a drug that possesses a positive chronotropic effect means that it will increase the heart rate. This means that the drug will directly affect the heart rate, not stroke volume, blood pressure, or cardiac output.Rate this question:
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- 14.
Changes in cardiac contractility may be induced by medications that have a positive or negative__________effect
- A.
Vasoactive
- B.
Dromotropic
- C.
Inotropic
- D.
Chronotropic
Correct Answer
C. InotropicExplanation
Changes in cardiac contractility may be induced by medications that have a positive or negative inotropic effect. Inotropic agents directly affect the force of myocardial contraction. Positive inotropic agents increase contractility, while negative inotropic agents decrease contractility. These medications can be used to treat conditions such as heart failure or arrhythmias, where there is a need to enhance or reduce the strength of cardiac contractions. Therefore, the term "inotropic" is the correct answer as it specifically refers to the effect on cardiac contractility.Rate this question:
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- 15.
Automaticity is most accurately defined as the ability of the heart to
- A.
Generate an electrical impulse from the same site every time
- B.
Spontaneously conduct an electrical impulse between cardiac cells
- C.
Generate its own electrical impulses without stimulation from nerves
- D.
Increas or decrease its heart rate based on the body's metabolic need
Correct Answer
C. Generate its own electrical impulses without stimulation from nervesExplanation
Automaticity refers to the ability of the heart to generate its own electrical impulses without the need for stimulation from nerves. This means that the heart can initiate and regulate its own electrical activity, allowing it to maintain a regular heartbeat even in the absence of external signals. This is an important characteristic of the heart's electrical system, as it ensures that the heart can continue to beat rhythmically and effectively without relying on external factors.Rate this question:
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- 16.
Which of the following statements regarding the sinoatrial node is most correct
- A.
The SA node is the dominant cardiac pacemaker in healthy patients
- B.
The SA node is a backup cardiac pacemaker in healthy patients
- C.
The SA node is located in the superior aspect of the right ventricle
- D.
Impulses generated by the SA node travel through the right atrium only
Correct Answer
A. The SA node is the dominant cardiac pacemaker in healthy patientsExplanation
The SA node, located in the right atrium of the heart, is indeed the primary pacemaker that initiates electrical impulses responsible for cardiac contraction. It sets the pace for the heart's rhythm under normal conditions. Therefore, the statement that the SA node is the dominant cardiac pacemaker in healthy patients is most accurate.Rate this question:
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- 17.
The atrioventricular junction
- A.
Includes the AV node but not the bundle of His
- B.
Is the dominant and fastest pacemaker of the heart
- C.
Reveives its blood supply from the circumflex artery
- D.
Is composed of the AV node and the bundle of His
Correct Answer
D. Is composed of the AV node and the bundle of HisExplanation
The correct answer is "is composed of the AV node and the bundle of His." The atrioventricular junction refers to the area in the heart where electrical signals are transmitted from the atria to the ventricles. It includes both the AV node and the bundle of His. The AV node is responsible for delaying the electrical signal before it is transmitted to the ventricles, allowing for proper coordination of atrial and ventricular contractions. The bundle of His then carries the signal down the septum of the heart, allowing for synchronized contraction of the ventricles.Rate this question:
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- 18.
An electrical impulse is slightly delayed at the AV node so that the
- A.
Bundle of His can depolarize fully
- B.
Ventricles can contract completely
- C.
Primary cardiac pacemaker can reset
- D.
Atria can empty into the ventricles
Correct Answer
D. Atria can empty into the ventriclesExplanation
The electrical impulse is slightly delayed at the AV node to allow time for the atria to contract and empty their blood into the ventricles. This delay ensures that the ventricles are filled with blood before they contract, maximizing the efficiency of the heart's pumping action.Rate this question:
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- 19.
The effect on the velocity of electrical conduction is referred to as the _________effect
- A.
Inotropic
- B.
Dromotropic
- C.
Chronotropic
- D.
Conductivity
Correct Answer
B. DromotropicExplanation
The effect on the velocity of electrical conduction is referred to as the dromotropic effect.Rate this question:
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- 20.
Thousands of fibrils that are distributed thoughout the ventricles, which represent the end of the cardiac conduction system, are called the
- A.
Bundle branches
- B.
Internodal pathways
- C.
Pukinje fibers
- D.
Cardiac myocytes
Correct Answer
C. Pukinje fibersExplanation
The correct answer is Purkinje fibers. Purkinje fibers are thousands of specialized cardiac muscle fibers that are located in the ventricles of the heart. They are responsible for the rapid conduction of electrical impulses, allowing for coordinated and efficient contraction of the ventricles. This ensures that blood is effectively pumped out of the heart to the rest of the body. The other options mentioned (bundle branches, internodal pathways, and cardiac myocytes) are also components of the cardiac conduction system, but they do not specifically represent the fibrils distributed throughout the ventricles like Purkinje fibers do.Rate this question:
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- 21.
The sinoatrial node
- A.
Cannot depolarize faster than 100 times/min
- B.
Will normally outpace any slower conduction tissue
- C.
Functions as the heart's secondary pacemaker
- D.
Has an intrinsic firing rate of 40-60 beats per minute
Correct Answer
B. Will normally outpace any slower conduction tissueExplanation
The sinoatrial node is often referred to as the natural pacemaker of the heart. It is responsible for initiating the electrical signals that regulate the heartbeat. The statement "will normally outpace any slower conduction tissue" means that the sinoatrial node has the ability to generate electrical impulses at a faster rate than any other tissue in the heart. This ensures that the heart beats in a coordinated and efficient manner, with the sinoatrial node setting the pace for the rest of the heart.Rate this question:
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- 22.
The P wave represents
- A.
SA nodal discharge
- B.
Atrial depolarization
- C.
A depaly at the AV node
- D.
Contraction of the atria
Correct Answer
B. Atrial depolarizationExplanation
The correct answer is atrial depolarization. The P wave on an electrocardiogram (ECG) represents the electrical depolarization of the atria, which leads to their contraction. It is the first wave in the ECG and indicates the initiation of the cardiac cycle. The SA node, also known as the sinoatrial node, is responsible for initiating the electrical impulses that result in atrial depolarization. Therefore, the P wave represents the atrial depolarization that is initiated by the SA nodal discharge.Rate this question:
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- 23.
The brief pause between the P wave and the QRS complex represents
- A.
Depolarization of the inferior part of the atria
- B.
The period of time when the atria are repolarizing
- C.
Full dispersal of electricity throughout both atria
- D.
A momentary conduction delay at the AV junction
Correct Answer
D. A momentary conduction delay at the AV junctionExplanation
The brief pause between the P wave and the QRS complex represents a momentary conduction delay at the AV junction. This delay allows for the atria to fully contract and empty their blood into the ventricles before the ventricles contract. It is necessary to ensure efficient and coordinated contraction of the heart chambers.Rate this question:
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- 24.
Which of the following ECG waveforms represents ventricular depolarization
- A.
T waves
- B.
ST segment
- C.
QRS complex
- D.
U wave
Correct Answer
C. QRS complexExplanation
The QRS complex represents ventricular depolarization. It is a waveform on an ECG that represents the electrical activity associated with the contraction of the ventricles. The QRS complex consists of three main components: the Q wave, the R wave, and the S wave. This waveform is important in diagnosing and evaluating various cardiac conditions. The T waves represent ventricular repolarization, the ST segment represents the period between ventricular depolarization and repolarization, and the U wave is a small waveform that can sometimes be seen after the T wave and represents repolarization of the papillary muscles.Rate this question:
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- 25.
Stimulation of the parasympathetic nervous system causes all of the following effects, except
- A.
Negative inotropy
- B.
Increased salsivation
- C.
Dilation of the pupils
- D.
Negative chronotropy
Correct Answer
C. Dilation of the pupilsExplanation
Stimulation of the parasympathetic nervous system causes various effects on the body, including negative inotropy (reduced force of heart contractions), increased salivation, and negative chronotropy (slowed heart rate). However, dilation of the pupils is not a direct effect of parasympathetic stimulation. Instead, pupil constriction (miosis) is associated with parasympathetic activation. Therefore, the correct answer is dilation of the pupils.Rate this question:
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- 26.
A physiologic effect of the sympathetic nervous stimulation includes
- A.
Dilation of the bronchioles
- B.
Decreased conduction velocity
- C.
A negative dromotropic effect
- D.
Dilation of the blood vessels
Correct Answer
A. Dilation of the bronchiolesExplanation
Sympathetic nervous stimulation causes the dilation of the bronchioles. This is because the sympathetic nervous system is responsible for the "fight or flight" response, which prepares the body for intense physical activity. Dilation of the bronchioles allows for increased airflow to the lungs, enabling more oxygen to be delivered to the muscles. This physiological effect helps to enhance performance and increase oxygenation during times of stress or exercise.Rate this question:
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- 27.
Which of the following chemicals or drugs can cause an increase in heart rate
- A.
Norepinephrine
- B.
Cholinesterase
- C.
Atenolol and neostigmine
- D.
Atropine and epinephrine
Correct Answer
D. Atropine and epinephrineExplanation
Atropine and epinephrine can cause an increase in heart rate. Atropine is an anticholinergic drug that blocks the action of acetylcholine, a neurotransmitter that slows down the heart rate. By blocking this action, atropine increases heart rate. Epinephrine, also known as adrenaline, is a hormone that stimulates the sympathetic nervous system. It increases heart rate by binding to beta-adrenergic receptors in the heart, leading to an increase in the strength and rate of contractions. Therefore, both atropine and epinephrine can cause an increase in heart rate.Rate this question:
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- 28.
Stimulation of alpha and beta receports affects the
- A.
Heart only
- B.
Heart and blood vessels
- C.
Blood vessels and the lungs
- D.
Heart, lungs, and blood vessels
Correct Answer
D. Heart, lungs, and blood vesselsExplanation
Stimulation of alpha and beta receptors affects the heart, lungs, and blood vessels. Alpha receptors are found in the smooth muscles of blood vessels, and their stimulation causes vasoconstriction, leading to increased blood pressure. Beta receptors are found in the heart, lungs, and blood vessels. Stimulation of beta-1 receptors in the heart increases heart rate and contractility, while stimulation of beta-2 receptors in the lungs causes bronchodilation. Overall, the stimulation of both alpha and beta receptors affects the cardiovascular system by regulating blood pressure, heart rate, and lung function.Rate this question:
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- 29.
Vasoconstriction occurs following stimulation of
- A.
Beta 1 receptors
- B.
Beta 2 receptors
- C.
Alpha receptors
- D.
Alpha and beta receptors
Correct Answer
C. Alpha receptorsExplanation
Stimulation of alpha receptors causes vasoconstriction. Alpha receptors are found in smooth muscle cells of blood vessels and when activated, they cause the contraction of these muscles, leading to a decrease in the diameter of the blood vessels. This results in increased vascular resistance and a decrease in blood flow. Therefore, the correct answer is alpha receptors.Rate this question:
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- 30.
Drugs that have alpha or beta sympathetic properties are called
- A.
Vagolytics
- B.
Sympathomimetics
- C.
Parasympatholytics
- D.
Adrenergic blockers
Correct Answer
B. SympathomimeticsExplanation
Drugs that have alpha or beta sympathetic properties are called sympathomimetics. These drugs mimic the effects of the sympathetic nervous system, which is responsible for the "fight or flight" response. By activating alpha or beta receptors, sympathomimetics can increase heart rate, blood pressure, and bronchodilation. They are commonly used to treat conditions such as asthma, hypotension, and cardiac arrest.Rate this question:
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- 31.
A pure alpha agent
- A.
Causes marked vasoconstriction
- B.
Has a direct effect on the heart rate
- C.
Causes moderate bronchoconstriction
- D.
Decreases the blood pressure by dilating the blood vessels
Correct Answer
A. Causes marked vasoconstrictionExplanation
A pure alpha agent refers to a medication or substance that specifically targets alpha receptors in the body. Alpha receptors are found primarily in blood vessels, and when stimulated, they cause vasoconstriction, which is the narrowing of blood vessels. This leads to an increase in blood pressure. Therefore, a pure alpha agent would cause marked vasoconstriction, explaining why the correct answer is "causes marked vasoconstriction."Rate this question:
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- 32.
Which of the following drugs possesses beta-2 specific properties
- A.
Dopamine
- B.
Levophed
- C.
Albuterol
- D.
Epinephrine
Correct Answer
C. AlbuterolExplanation
Albuterol possesses beta-2 specific properties. Beta-2 specific drugs primarily target the beta-2 adrenergic receptors found in the smooth muscles of the bronchioles, leading to bronchodilation. Albuterol is a commonly used bronchodilator that acts selectively on these receptors, relaxing the smooth muscles and improving airflow in conditions like asthma and chronic obstructive pulmonary disease (COPD). Dopamine, levophed, and epinephrine do not possess beta-2 specific properties and have different mechanisms of action.Rate this question:
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- 33.
When auscultating the lungs of a patient with early pulmonary edema, you will most likely hear
- A.
Inspiratory rhonchi to the bilateral apices of the lungs
- B.
Crackles in the bases of the lungs at the end of inspiration
- C.
Faintrhonchi to all lung fields on inspiration and expiration
- D.
Wheezing during inspiration
Correct Answer
B. Crackles in the bases of the lungs at the end of inspirationExplanation
When auscultating the lungs of a patient with early pulmonary edema, crackles in the bases of the lungs at the end of inspiration are most likely to be heard. Pulmonary edema is the accumulation of fluid in the lungs, and crackles are abnormal lung sounds caused by the movement of air through fluid-filled airways or collapsed airways opening up. The crackles are typically heard at the bases of the lungs because fluid tends to accumulate in the dependent areas.Rate this question:
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