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Questions and Answers
The left side of the heart is responsible for receiving de-oxygenated blood from the body.
The left side of the heart is responsible for receiving de-oxygenated blood from the body.
False (B)
The pulmonary circuit has a longer pathway and higher pressure compared to the systemic circuit.
The pulmonary circuit has a longer pathway and higher pressure compared to the systemic circuit.
False (B)
Coronary arteries are responsible for supplying blood to the brain.
Coronary arteries are responsible for supplying blood to the brain.
False (B)
At rest, the myocardial cell membrane is more permeable to K+ than to Na+.
At rest, the myocardial cell membrane is more permeable to K+ than to Na+.
The aorta is the main artery that carries oxygen-poor blood away from the heart.
The aorta is the main artery that carries oxygen-poor blood away from the heart.
The coronary circulation is the shortest circulation in the body.
The coronary circulation is the shortest circulation in the body.
Blood flow through the coronary arteries occurs effectively when the ventricles are contracting.
Blood flow through the coronary arteries occurs effectively when the ventricles are contracting.
The Na+ concentration inside the myocardial cells is kept high compared to K+ concentration at rest.
The Na+ concentration inside the myocardial cells is kept high compared to K+ concentration at rest.
The normal resting membrane potential of a ventricular cell is typically between -70 to -80mV.
The normal resting membrane potential of a ventricular cell is typically between -70 to -80mV.
When K+ moves out of the cell, it causes an increase in positive charge inside the cell.
When K+ moves out of the cell, it causes an increase in positive charge inside the cell.
Action potential in myocardial cells can raise the membrane potential to +20mV.
Action potential in myocardial cells can raise the membrane potential to +20mV.
The cardiac cycle consists of only one phase: systole.
The cardiac cycle consists of only one phase: systole.
Stroke volume is defined as the amount of blood ejected from the ventricle in one minute.
Stroke volume is defined as the amount of blood ejected from the ventricle in one minute.
Normal serum potassium levels (K+) range from 3.5 to 5.0 mEq/L.
Normal serum potassium levels (K+) range from 3.5 to 5.0 mEq/L.
The heart's electrical conduction system solely consists of the SA node.
The heart's electrical conduction system solely consists of the SA node.
Preload refers to the amount of blood ejected from the ventricle during a contraction.
Preload refers to the amount of blood ejected from the ventricle during a contraction.
In a normal cardiac cycle, systole is characterized by the filling of the heart chambers.
In a normal cardiac cycle, systole is characterized by the filling of the heart chambers.
The equation for cardiac output is CO = SV + HR.
The equation for cardiac output is CO = SV + HR.
Most volatile anesthetic agents lead to coronary vasoconstriction.
Most volatile anesthetic agents lead to coronary vasoconstriction.
Tamponade refers to significant expansion of the heart due to excess blood in the pericardial sac.
Tamponade refers to significant expansion of the heart due to excess blood in the pericardial sac.
Infective endocarditis involves infective organisms invading the valves and causing vegetation.
Infective endocarditis involves infective organisms invading the valves and causing vegetation.
Regurgitant valves fully close and do not permit backward blood flow.
Regurgitant valves fully close and do not permit backward blood flow.
Cardiomyopathies can result in dilatation or hypertrophy of the myocardium.
Cardiomyopathies can result in dilatation or hypertrophy of the myocardium.
Increase in contractility of the heart primarily affects the preloading of the ventricle.
Increase in contractility of the heart primarily affects the preloading of the ventricle.
Sympathetic nervous system activity leads to a decrease in heart rate.
Sympathetic nervous system activity leads to a decrease in heart rate.
Mean Arterial Pressure (MAP) can be calculated using the formula: Diastolic pressure + 2/3 × Pulse pressure.
Mean Arterial Pressure (MAP) can be calculated using the formula: Diastolic pressure + 2/3 × Pulse pressure.
The renin-angiotensin aldosterone system is activated during an increase in arterial pressure.
The renin-angiotensin aldosterone system is activated during an increase in arterial pressure.
Baroreceptors are primarily responsible for minute-to-minute control of blood pressure.
Baroreceptors are primarily responsible for minute-to-minute control of blood pressure.
Afterload refers to the amount of blood delivered to the ventricle by the atrium.
Afterload refers to the amount of blood delivered to the ventricle by the atrium.
The parasympathetic nervous system decreases conduction times through the AV node.
The parasympathetic nervous system decreases conduction times through the AV node.
Hypotension is associated with increased sodium excretion by the kidneys.
Hypotension is associated with increased sodium excretion by the kidneys.
Contractility, preload, afterload, wall motion abnormalities, and valvular dysfunction are all major factors affecting cardiac stroke volume.
Contractility, preload, afterload, wall motion abnormalities, and valvular dysfunction are all major factors affecting cardiac stroke volume.
Long-term control of arterial blood pressure primarily involves immediate feedback from the baroreceptors.
Long-term control of arterial blood pressure primarily involves immediate feedback from the baroreceptors.
The circulatory system comprises the heart, blood vessels, and lymph.
The circulatory system comprises the heart, blood vessels, and lymph.
The right ventricle of the heart receives deoxygenated blood.
The right ventricle of the heart receives deoxygenated blood.
The pericardium is a very flexible tissue that allows for expansion of the heart.
The pericardium is a very flexible tissue that allows for expansion of the heart.
The aortic valve is located between the left atrium and left ventricle.
The aortic valve is located between the left atrium and left ventricle.
The vascular system includes both the systemic and pulmonary circulation.
The vascular system includes both the systemic and pulmonary circulation.
The left atrium receives oxygenated blood from the superior vena cava.
The left atrium receives oxygenated blood from the superior vena cava.
Capillaries are a component of both the arterial and venous systems.
Capillaries are a component of both the arterial and venous systems.
The tricuspid valve is a one-way valve found between the right atrium and right ventricle.
The tricuspid valve is a one-way valve found between the right atrium and right ventricle.
The epicardium is the innermost layer of the heart wall.
The epicardium is the innermost layer of the heart wall.
The left ventricle pumps deoxygenated blood to the lungs.
The left ventricle pumps deoxygenated blood to the lungs.
The left side of the heart is responsible for pumping deoxygenated blood to the lungs.
The left side of the heart is responsible for pumping deoxygenated blood to the lungs.
The coronary arteries provide continuous blood flow to the myocardium, regardless of the heart's contraction state.
The coronary arteries provide continuous blood flow to the myocardium, regardless of the heart's contraction state.
The right ventricle of the heart has a shorter and lower pressure circulation compared to the left ventricle.
The right ventricle of the heart has a shorter and lower pressure circulation compared to the left ventricle.
At rest, myocardial cells have a higher concentration of K+ inside compared to Na+.
At rest, myocardial cells have a higher concentration of K+ inside compared to Na+.
The aorta carries oxygen-rich blood away from the heart to the lungs.
The aorta carries oxygen-rich blood away from the heart to the lungs.
Stroke volume is defined as the amount of blood ejected from the heart in one contraction.
Stroke volume is defined as the amount of blood ejected from the heart in one contraction.
The Na+ concentration inside myocardial cells increases significantly during resting conditions.
The Na+ concentration inside myocardial cells increases significantly during resting conditions.
The cardiac cycle consists only of the diastole phase.
The cardiac cycle consists only of the diastole phase.
Movement of K+ out of the cell results in a net gain of positive charge inside the cell.
Movement of K+ out of the cell results in a net gain of positive charge inside the cell.
The normal resting membrane potential of a ventricular cell is typically between -80 to -90mV.
The normal resting membrane potential of a ventricular cell is typically between -80 to -90mV.
Cardiac output is defined as the amount of blood ejected from the atrium in one minute.
Cardiac output is defined as the amount of blood ejected from the atrium in one minute.
Diastole refers to the contraction of the heart chambers and ejection of blood.
Diastole refers to the contraction of the heart chambers and ejection of blood.
The formula for calculating cardiac output is CO = SV x HR.
The formula for calculating cardiac output is CO = SV x HR.
Normal serum chloride levels (Cl-) range from 135 to 145 mEq/L.
Normal serum chloride levels (Cl-) range from 135 to 145 mEq/L.
Preload is the amount of blood that returns to the atrium.
Preload is the amount of blood that returns to the atrium.
The electrical conduction system of the heart includes the SA node and Purkinje fibers.
The electrical conduction system of the heart includes the SA node and Purkinje fibers.
The resting membrane potential becomes more negative during action potential.
The resting membrane potential becomes more negative during action potential.
Systole occurs during the phase where the heart chambers are filling with blood.
Systole occurs during the phase where the heart chambers are filling with blood.
The heart is divided into an upper atrium and a lower ventricle on each side.
The heart is divided into an upper atrium and a lower ventricle on each side.
The pericardium has a flexible structure that allows significant expansion of the heart.
The pericardium has a flexible structure that allows significant expansion of the heart.
The mitral valve is also referred to as the bicuspid valve.
The mitral valve is also referred to as the bicuspid valve.
Deoxygenated blood from the lungs is received by the right atrium.
Deoxygenated blood from the lungs is received by the right atrium.
The left ventricle pumps oxygenated blood to the pulmonary circulation.
The left ventricle pumps oxygenated blood to the pulmonary circulation.
Valves in the heart prevent backward flow of blood during contraction.
Valves in the heart prevent backward flow of blood during contraction.
Arteries carry blood towards the heart and veins carry blood away from the heart.
Arteries carry blood towards the heart and veins carry blood away from the heart.
Capillaries are the site of gas and nutrient exchange in the circulatory system.
Capillaries are the site of gas and nutrient exchange in the circulatory system.
The vascular system comprises only the systemic circulation.
The vascular system comprises only the systemic circulation.
The right ventricle pumps oxygenated blood to systemic circulation.
The right ventricle pumps oxygenated blood to systemic circulation.
Most volatile anesthetic agents lead to coronary vasodilation.
Most volatile anesthetic agents lead to coronary vasodilation.
Tamponade is characterized by significant compression of the heart due to excess fluid in the pericardial sac.
Tamponade is characterized by significant compression of the heart due to excess fluid in the pericardial sac.
Regurgitant valves are able to close fully and prevent backward blood flow.
Regurgitant valves are able to close fully and prevent backward blood flow.
Infective endocarditis involves infective organisms invading the myocardial layer of the heart.
Infective endocarditis involves infective organisms invading the myocardial layer of the heart.
Cardiomyopathies can result in dilation, hypertrophy, or non-compliance of the myocardium.
Cardiomyopathies can result in dilation, hypertrophy, or non-compliance of the myocardium.
Preload is the resistance to forward blood flow by the vessel walls.
Preload is the resistance to forward blood flow by the vessel walls.
The sympathetic nervous system decreases heart rate and contractility in the ventricles.
The sympathetic nervous system decreases heart rate and contractility in the ventricles.
Mean Arterial Pressure (MAP) can be estimated using the formula MAP = Diastolic pressure + 1/3 × Pulse pressure.
Mean Arterial Pressure (MAP) can be estimated using the formula MAP = Diastolic pressure + 1/3 × Pulse pressure.
The renin-angiotensin aldosterone system is activated during a decrease in arterial pressure.
The renin-angiotensin aldosterone system is activated during a decrease in arterial pressure.
Contractility primarily refers to the ability of the heart to fill with blood during diastole.
Contractility primarily refers to the ability of the heart to fill with blood during diastole.
Baroreceptors are located at the bifurcation of the common carotid arteries and are responsible for sensing changes in blood pressure.
Baroreceptors are located at the bifurcation of the common carotid arteries and are responsible for sensing changes in blood pressure.
Afterload is defined as the efficiency and strength of contraction of the heart muscle.
Afterload is defined as the efficiency and strength of contraction of the heart muscle.
The effect of slower renal mechanisms in blood pressure regulation become noticeable only hours after sustained changes in arterial pressure.
The effect of slower renal mechanisms in blood pressure regulation become noticeable only hours after sustained changes in arterial pressure.
Sustained hypertension leads to the retention of sodium and water by the kidneys.
Sustained hypertension leads to the retention of sodium and water by the kidneys.
Wall motion abnormalities are among the major factors affecting cardiac stroke volume.
Wall motion abnormalities are among the major factors affecting cardiac stroke volume.
The right side of the heart is responsible for pumping oxygenated blood to the lungs.
The right side of the heart is responsible for pumping oxygenated blood to the lungs.
The coronary arteries deliver blood effectively when the heart is contracting.
The coronary arteries deliver blood effectively when the heart is contracting.
The aorta carries oxygen-rich blood away from the heart to the systemic circulation.
The aorta carries oxygen-rich blood away from the heart to the systemic circulation.
The systemic circuit has less resistance to blood flow compared to the pulmonary circuit.
The systemic circuit has less resistance to blood flow compared to the pulmonary circuit.
A membrane-bound Na+-K+ ATPase transports Na+ into the myocardial cells and K+ out of the cell.
A membrane-bound Na+-K+ ATPase transports Na+ into the myocardial cells and K+ out of the cell.
At rest, myocardial cells are more permeable to Na+ than to K+.
At rest, myocardial cells are more permeable to Na+ than to K+.
The left ventricle has a longer pathway and higher pressure than the right ventricle.
The left ventricle has a longer pathway and higher pressure than the right ventricle.
The primary role of the left side of the heart is to receive deoxygenated blood.
The primary role of the left side of the heart is to receive deoxygenated blood.
Volatile anesthetic agents typically promote coronary vasodilation.
Volatile anesthetic agents typically promote coronary vasodilation.
Tamponade refers to the significant reduction of the heart's size due to excess fluid in the pericardial sac.
Tamponade refers to the significant reduction of the heart's size due to excess fluid in the pericardial sac.
Infective Endocarditis involves the invasion of infective organisms into the myocardial layer of the heart.
Infective Endocarditis involves the invasion of infective organisms into the myocardial layer of the heart.
Stenotic heart valves are unable to fully open, which restricts forward blood flow.
Stenotic heart valves are unable to fully open, which restricts forward blood flow.
The presence of vegetation on a heart valve is a characteristic of Rheumatic Heart Disease.
The presence of vegetation on a heart valve is a characteristic of Rheumatic Heart Disease.
The resting membrane potential of a normal ventricular cell is typically between -80 and -90mV.
The resting membrane potential of a normal ventricular cell is typically between -80 and -90mV.
An increase in K+ concentration inside the myocardial cell leads to depolarization.
An increase in K+ concentration inside the myocardial cell leads to depolarization.
The components of the cardiac cycle include diastole, which is the contraction phase.
The components of the cardiac cycle include diastole, which is the contraction phase.
Cardiac output is calculated using the formula CO = SV x HR.
Cardiac output is calculated using the formula CO = SV x HR.
The normal range of serum potassium levels (K+) is 3.0 to 4.5 mEq/L.
The normal range of serum potassium levels (K+) is 3.0 to 4.5 mEq/L.
The Purkinje fibers are part of the heart's electrical conduction system and help conduct impulses rapidly.
The Purkinje fibers are part of the heart's electrical conduction system and help conduct impulses rapidly.
Systole refers to the process where the heart fills with blood.
Systole refers to the process where the heart fills with blood.
Preload is dependent on the amount of blood delivered to the chamber, affected by venous return.
Preload is dependent on the amount of blood delivered to the chamber, affected by venous return.
The myocardium can be affected by cardiomyopathies, leading to hypertrophy or dilatation.
The myocardium can be affected by cardiomyopathies, leading to hypertrophy or dilatation.
Electrical cells in the heart include the SA node, which generates impulses slowly.
Electrical cells in the heart include the SA node, which generates impulses slowly.
Afterload is determined by the efficiency of contraction in the ventricles.
Afterload is determined by the efficiency of contraction in the ventricles.
The sympathetic nervous system primarily decreases the heart rate.
The sympathetic nervous system primarily decreases the heart rate.
Baroreceptors are sensitive to changes in blood pressure and are located in the aortic arch.
Baroreceptors are sensitive to changes in blood pressure and are located in the aortic arch.
Mean Arterial Pressure (MAP) can be approximated using the formula MAP = Diastolic pressure + 2/3 × Pulse pressure.
Mean Arterial Pressure (MAP) can be approximated using the formula MAP = Diastolic pressure + 2/3 × Pulse pressure.
The renin-angiotensin aldosterone system is activated during a sustained increase in arterial pressure.
The renin-angiotensin aldosterone system is activated during a sustained increase in arterial pressure.
Hypotension results in retention of sodium and water by the kidneys.
Hypotension results in retention of sodium and water by the kidneys.
Contractility mainly affects the afterload of the ventricle.
Contractility mainly affects the afterload of the ventricle.
The effects of the renal mechanism on blood pressure become apparent immediately after changes occur.
The effects of the renal mechanism on blood pressure become apparent immediately after changes occur.
The immediate control of arterial blood pressure is largely maintained by the autonomic nervous system.
The immediate control of arterial blood pressure is largely maintained by the autonomic nervous system.
Systolic pressure is defined as the pressure in the arteries when the heart is at rest.
Systolic pressure is defined as the pressure in the arteries when the heart is at rest.
The pericardial sac can hold 30-50mL of serous fluid to prevent friction during heart contraction.
The pericardial sac can hold 30-50mL of serous fluid to prevent friction during heart contraction.
The right atrium receives oxygenated blood from the pulmonary veins.
The right atrium receives oxygenated blood from the pulmonary veins.
The aortic valve is situated between the right atrium and right ventricle.
The aortic valve is situated between the right atrium and right ventricle.
The left ventricle pumps oxygenated blood to the systemic circulation.
The left ventricle pumps oxygenated blood to the systemic circulation.
Arteries carry blood away from the heart, while veins return blood to the heart.
Arteries carry blood away from the heart, while veins return blood to the heart.
The heart wall consists of three layers: endocardium, myocardium, and pericardium.
The heart wall consists of three layers: endocardium, myocardium, and pericardium.
The tricuspid valve allows blood to flow from the left atrium to the left ventricle.
The tricuspid valve allows blood to flow from the left atrium to the left ventricle.
The right ventricle pumps deoxygenated blood to the lungs through the pulmonary artery.
The right ventricle pumps deoxygenated blood to the lungs through the pulmonary artery.
Capillaries are absent in the venous system.
Capillaries are absent in the venous system.
The pulmonary circulation has a higher blood pressure compared to systemic circulation.
The pulmonary circulation has a higher blood pressure compared to systemic circulation.
Study Notes
Circulation Through the Heart
- Blood flow is divided into two circuits: pulmonary (right side) and systemic (left side).
- Deoxygenated blood from the body enters the right atrium, passes to the right ventricle, and is sent to the lungs via the pulmonary trunk for oxygenation.
- Oxygenated blood returns to the left atrium from the lungs, moves to the left ventricle, and is pumped to the body through the aorta.
- Pulmonary circuit operates at low pressure; systemic circuit encounters five times the resistance and operates at high pressure.
Coronary Circulation
- The coronary arteries, arising from the base of the aorta, supply blood to the heart tissue.
- Blood flow through coronary arteries occurs during diastole when the heart muscles are relaxed, as they are compressed during systole.
Cardiac Physiology
- Myocardial cells maintain a high concentration of potassium (K+) and a low concentration of sodium (Na+).
- Resting membrane potential of cardiac cells is between -80 to -90 mV; action potentials cause depolarization to +20 mV.
- The cardiac cycle consists of diastole (filling) and systole (contraction and blood ejection).
Cardiac Output
- Cardiac output (CO) is defined as the amount of blood ejected by the ventricle per minute, calculated using CO = Stroke Volume (SV) x Heart Rate (HR).
- Stroke volume is influenced by preload (amount of blood delivered to chambers) and afterload (resistance to blood flow).
Electrical Conduction System
- Consists of specialized structures including the SA node, AV node, Bundle of His, and Purkinje fibers, which rapidly generate and conduct electrical impulses.
- The cardiac action potential is characterized by phases: depolarization, early repolarization, plateau, and late rapid repolarization.
Autonomic Nervous System
- Sympathetic nervous system increases heart rate and contractility; it extensively innervates the SA node and ventricular cells.
- Parasympathetic nervous system reduces heart rate and conduction speed through the AV node.
Arterial Blood Pressure Control
- Mean Arterial Pressure (MAP) correlates with systemic vascular resistance and cardiac output, estimated by combining diastolic and systolic pressures.
- Blood pressure is controlled through immediate (autonomic nervous system) and intermediate (renin-angiotensin-aldosterone system) mechanisms.
- Long-term control involves kidney regulation of sodium and water balance to stabilize blood pressure.
Pathophysiology of the Heart
- Pericarditis refers to inflammation of the pericardium; effusion refers to excess fluid in the pericardial sac, which can lead to tamponade (heart compression).
- Myocarditis involves inflammation of the myocardium, while cardiomyopathies can lead to dilatation or non-compliance of the heart muscle.
- Valvular heart disease includes stenosis (restricts forward flow) and regurgitation (backward flow), often resulting in hypertrophy and dilation of cardiac chambers.
Effects of Anesthesia
- Most volatile anesthetics cause coronary vasodilation and lower myocardial metabolic demand, potentially beneficial in cases of myocardial ischemia.
Circulation through the Heart
- Pulmonary Circuit: Right side of the heart; carries deoxygenated blood from body to lungs.
- Systemic Circuit: Left side of the heart; circulates oxygenated blood from lungs to the body.
- Deoxygenated blood returns to the right atrium via superior and inferior venae cavae.
- Oxygen-rich blood flows from the lungs to the left atrium, through the left ventricle, and into the aorta.
- Pulmonary circuit operates at lower pressure with short flow, while systemic circuit has higher pressure and more resistance.
Coronary Circulation
- Supplies blood to the heart muscle, primarily through right and left coronary arteries from the aorta.
- Blood flow to myocardium occurs when the heart is relaxed; it is hindered during ventricular contraction due to compression and aortic valve occlusion.
Cardiac Physiology
- Electrophysiology: Myocardial cells maintain ion gradients; permeable mainly to potassium (K+), less so to sodium (Na+).
- Action potentials trigger depolarization, raising membrane potential to +20mV.
- The cardiac cycle includes diastole (filling) and systole (contraction).
Cardiac Output
- Defined as the volume of blood pumped by the ventricle per minute.
- Formula: Cardiac Output (CO) = Stroke Volume (SV) x Heart Rate (HR).
Stroke Volume Determinants
- Preload: Volume of blood in heart before contraction; influenced by venous return.
- Afterload: Resistance the heart must overcome to eject blood.
- Contractility: Strength of ventricular contraction.
Autonomic Nervous System Influence
- Sympathetic Nervous System: Increases heart rate and contractility, primarily affecting the SA node.
- Parasympathetic Nervous System: Slows heart rate and conduction through the AV node.
Blood Pressure Regulation
- Mean Arterial Pressure (MAP): Related to systemic vascular resistance (SVR) and cardiac output (CO).
- Immediate Control: Managed by the autonomic nervous system via baroreceptors sensing blood pressure changes.
- Intermediate and Long-term Control: Involves renal mechanisms, altering body sodium and water balance to stabilize pressure.
Effects of Anesthetic Agents
- Most volatile anesthetics cause coronary vasodilation, reducing myocardial oxygen demand.
- Beneficial during myocardial ischemia and infarction events.
Pathophysiology Overview
- Pericardial Disease: Inflammation (pericarditis), fluid accumulation (effusion), and heart compression (tamponade).
- Myocardial Disease: Inflammation (myocarditis) and various cardiomyopathies affecting myocardial function.
- Valvular Disease: Stenosis (restricted blood flow) and regurgitation (backward blood flow), leading to hypertrophy and dilation of heart chambers.
- Infective Endocarditis: Invasion by pathogens leading to valvular vegetations and scarring from rheumatic fever.
Circulation through the Heart
- Pulmonary Circuit: Right side of the heart; carries deoxygenated blood from body to lungs.
- Systemic Circuit: Left side of the heart; circulates oxygenated blood from lungs to the body.
- Deoxygenated blood returns to the right atrium via superior and inferior venae cavae.
- Oxygen-rich blood flows from the lungs to the left atrium, through the left ventricle, and into the aorta.
- Pulmonary circuit operates at lower pressure with short flow, while systemic circuit has higher pressure and more resistance.
Coronary Circulation
- Supplies blood to the heart muscle, primarily through right and left coronary arteries from the aorta.
- Blood flow to myocardium occurs when the heart is relaxed; it is hindered during ventricular contraction due to compression and aortic valve occlusion.
Cardiac Physiology
- Electrophysiology: Myocardial cells maintain ion gradients; permeable mainly to potassium (K+), less so to sodium (Na+).
- Action potentials trigger depolarization, raising membrane potential to +20mV.
- The cardiac cycle includes diastole (filling) and systole (contraction).
Cardiac Output
- Defined as the volume of blood pumped by the ventricle per minute.
- Formula: Cardiac Output (CO) = Stroke Volume (SV) x Heart Rate (HR).
Stroke Volume Determinants
- Preload: Volume of blood in heart before contraction; influenced by venous return.
- Afterload: Resistance the heart must overcome to eject blood.
- Contractility: Strength of ventricular contraction.
Autonomic Nervous System Influence
- Sympathetic Nervous System: Increases heart rate and contractility, primarily affecting the SA node.
- Parasympathetic Nervous System: Slows heart rate and conduction through the AV node.
Blood Pressure Regulation
- Mean Arterial Pressure (MAP): Related to systemic vascular resistance (SVR) and cardiac output (CO).
- Immediate Control: Managed by the autonomic nervous system via baroreceptors sensing blood pressure changes.
- Intermediate and Long-term Control: Involves renal mechanisms, altering body sodium and water balance to stabilize pressure.
Effects of Anesthetic Agents
- Most volatile anesthetics cause coronary vasodilation, reducing myocardial oxygen demand.
- Beneficial during myocardial ischemia and infarction events.
Pathophysiology Overview
- Pericardial Disease: Inflammation (pericarditis), fluid accumulation (effusion), and heart compression (tamponade).
- Myocardial Disease: Inflammation (myocarditis) and various cardiomyopathies affecting myocardial function.
- Valvular Disease: Stenosis (restricted blood flow) and regurgitation (backward blood flow), leading to hypertrophy and dilation of heart chambers.
- Infective Endocarditis: Invasion by pathogens leading to valvular vegetations and scarring from rheumatic fever.
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Test your knowledge on the heart's circulation system, focusing on both the pulmonary and systemic pathways. This quiz covers the flow of blood through the right and left sides of the heart, as well as gas exchange processes. Understand how oxygen and carbon dioxide are transported in the body!
