WorksheetsHeart structure and function
Total questions: 9
Worksheet time: 2hrs 5mins
Veins are blood vessels containing blood flowing to the heart. While arteries have blood flowing from the heart. The blue is representative of blood vessels containing deoxygenated blood, while the red blood vessels have oxygenated blood fresh from the lungs. Now, let's follow the path of the blood through the heart. The superior vena-cava receives blood from the head, neck, upper limbs and chest. Meanwhile, the inferior vena-cava receives blood from the trunk, viscera, and lower limbs. Both superior and inferior vena-cava end up in the right atrium, one of the four chambers of the heart. The heart not only has four chambers, it also has four valves. The purpose of the valves is to keep blood moving in the right direction and not flow backwards. Blood exits the right atrium through the tricuspid valve so called because it has three flaps, and enters the right ventricle. The blood exits the right ventricle through the pulmonary valve and enters the pulmonary artery. Again, it is an artery because blood is flowing away from the heart, but it is blue because it lacks oxygen. The pulmonary artery then splits into the left and right pulmonary arteries, which go to each respective lung. In the lungs, gas exchange occurs. The blood discards carbon dioxide and picks up oxygen. Now, blood comes back from the lungs through the pulmonary veins, entering the left atrium. Next, the blood is pumped into the left into the left ventricle through the mitral, or bicuspid valve. Finally, the oxygenated blood leaves the left ventricle through the aortic semi-lunar valve, entering the aortic arch. The aorta, which is the largest of all the arteries, distributes the oxygenated blood to the rest of the body. The aortic arch has three major branches, which supply the head and arms with blood. Then, the aorta curls downward from behind the heart, forming the descending aorta, which descends through the chest and continues down through the abdomen. In the abdomen, the descending aorta splits to supply the pelvis and legs with blood. If you liked this video, please like and subscribe. It would help me make more videos. And make sure to comment with any topics you would like me to cover in future videos. Also, it would be really nice if you could support me on Patreon. Thank you!
What type of blood vessels carry blood to the heart?
______ have blood flowing from the heart.
______ blood vessels have oxygenated blood fresh from the lungs.
Which color represents deoxygenated blood in blood vessels?
Which chamber of the heart receives blood from the superior and inferior vena cava?
How many valves does the heart have?
Which valve is located between the right atrium and the right ventricle?
What happens to the blood in the lungs?
Which valve does the oxygenated blood leave the left ventricle through?
What is the largest artery in the body?
How many major branches does the aortic arch have?
Which part of the body does the descending aorta NOT supply with blood?
Veins carry blood __________ the heart.
The __________ valve has three flaps and is located between the right atrium and the right ventricle.
The pulmonary artery carries __________ blood to the lungs.
Oxygenated blood returns to the heart through the __________ veins.
The __________ valve prevents blood from flowing backwards into the left ventricle.
The aorta is the __________ artery in the body.
The descending aorta supplies blood to the __________ and __________.
Arteries carry blood away from the heart. (True/False)
The inferior vena cava receives blood from the head and neck. (True/False)
The inferior vena cava receives blood from the lower parts of the body, not the head and neck.
The left ventricle pumps blood into the pulmonary artery. (True/False)
The left ventricle pumps blood into the aorta, not the pulmonary artery.
Gas exchange in the lungs involves the blood picking up carbon dioxide and releasing oxygen. (True/False)
The aortic arch has four major branches. (True/False)
The aortic arch has three major branches, not four.
The descending aorta continues down through the abdomen. (True/False)
Supporting the video creator on Patreon is a way to help them make more videos. (True/False)
The text describes the cardiac cycle, which is the sequence of events that occur and repeat with every heartbeat. The cycle is divided into two major phases: systole and diastole. Systole refers to ventricular contraction, while diastole refers to ventricular relaxation.
The cardiac cycle begins with the firing of the SA node, which stimulates the atria to depolarize. This is represented by the P-wave on the ECG. Atrial contraction starts shortly after the P-wave begins, and causes the pressure within the atria to increase, forcing blood into the ventricles.
What is the cardiac cycle?
The sequence of events that occur with every heartbeat
The process of blood flow through the heart
The electrical activity of the heart
The function of the heart valves
What does atrial contraction do in the cardiac cycle?
Decreases pressure in the ventricles
Forces blood into the atria
Increases pressure, forcing blood into the ventricles
Causes blood to flow back into the veins
What are the two main phases of the cardiac cycle?
Systole and Diastole
Atria and Ventricles
Contraction and Relaxation
Inhalation and Exhalation
What initiates the cardiac cycle by stimulating atrial depolarization?
SA node firing
AV node firing
Purkinje fibers firing
Bundle of His firing
What does the P-wave represent on the ECG?
Atrial depolarization
Ventricular repolarization
Ventricular depolarization
Atrial repolarization
What repeats with every heartbeat?
Respiratory cycle
Digestive cycle
Cardiac cycle
Nervous cycle
When does atrial contraction start in the cardiac cycle?
Before the P-wave begins
Shortly after the QRS complex
During the T-wave
At the end of the cardiac cycle
What are the two major phases of the cardiac cycle?
What does systole refer to in the cardiac cycle?
Diastole refers to ventricular __________.
The cardiac cycle begins with the firing of the __________ node.
The depolarization of the atria is represented by the __________ on the ECG.
True or False
Systole refers to ventricular relaxation.
True or False
Atrial contraction starts shortly after the P-wave begins.
What happens after the atria depolarize?
Atrial contraction
What causes the pressure within the atria to increase?
Atrial contraction
The firing of the SA node stimulates the atria to __________.
depolarize
The increase in pressure within the atria forces blood into the __________.
True or False:
The depolarization of the atria is represented by the T-wave on the ECG.
True or False:
Atrial contraction forces blood into the ventricles.
The AV valves open when atrial pressures are higher than ventricular pressures and close when the pressure gradient is reversed. Similarly, the semilunar valves open when ventricular pressures are higher than aortic/pulmonary pressures, and close when the reverse is true.
The cycle then moves into systole, where ventricular depolarization (represented by the QRS complex) begins. The ventricles contract rapidly, building up pressures inside the ventricles. For a moment, the semilunar valves remain closed, and the ventricles contract within a closed space. This phase is referred to as isovolumetric contraction.
What is isovolumetric contraction?
Phase in the cardiac cycle where the ventricles are contracting but no blood is ejected
Phase in the cardiac cycle where the atria are contracting
Phase in the cardiac cycle where the ventricles are relaxing
Phase in the cardiac cycle where the heart is at rest
During which phase do semilunar valves remain closed?
Isovolumetric contraction phase
Rapid ejection phase
Isovolumetric relaxation phase
Rapid filling phase
What phase of the cardiac cycle does ventricular depolarization begin with the QRS complex?
Diastole
Systole
Atrial depolarization
T wave
What happens to the ventricles during isovolumetric contraction?
They relax within a closed space
They expand within an open space
They contract within a closed space
They contract within an open space
What happens when the ventricles contract rapidly?
Blood is pumped out of the heart
The atria contract
The heart rate slows down
The valves close
When do semilunar valves open?
When ventricular pressures are higher than aortic/pulmonary pressures
When aortic/pulmonary pressures are higher than ventricular pressures
When atrial pressures are higher than ventricular pressures
When ventricular pressures are higher than atrial pressures
When do AV valves open and close based on the pressure gradient?
When atrial pressures are higher than ventricular pressures
When ventricular pressures are higher than atrial pressures
When both atrial and ventricular pressures are equal
When there is no pressure gradient
The cardiac cycle refers to the sequence of events that occur and repeat with every heartbeat. It can be divided into two major phases: systole and diastole, each of which subdivides into several smaller phases.
Systole and diastole, when not specified otherwise, refer to ventricular contraction and relaxation, respectively.
Reminders: Blood flows from higher to lower pressure. Contraction increases the pressure within a chamber, while relaxation lowers the pressure. AV valves open when atrial pressures are higher than ventricular pressures and close when the pressure gradient is reversed. Similarly, semilunar valves open when ventricular pressures are higher than aortic/pulmonary pressures, and close when the reverse is true.
What effect does contraction have on chamber pressure?
Increases it
Decreases it
No effect
Stabilizes it
In which direction does blood flow based on pressure differentials?
From lower to higher pressure
From higher to lower pressure
In both directions simultaneously
It depends on the type of blood vessel
When do semilunar valves open?
When atrial pressures are higher than ventricular pressures
When ventricular pressures are higher than aortic/pulmonary pressures
When aortic/pulmonary pressures are higher than ventricular pressures
When ventricular pressures are equal to aortic/pulmonary pressures
When do AV valves open?
When atrial pressures exceed ventricular pressures
When ventricular pressures exceed atrial pressures
During diastole
During systole
What do systole and diastole refer to?
Atrial contraction and relaxation
Ventricular contraction and relaxation
Heart rate and blood pressure
Lung expansion and contraction
What happens when the semilunar valves close?
Blood flows into the ventricles
Blood flows back into the atria
Blood flows into the pulmonary artery and aorta
Blood flows into the coronary arteries
What are the two main phases of the cardiac cycle?
Systole and Diastole
Atria and Ventricles
Pulmonary and Systemic
Contraction and Relaxation
What are the two major phases of the cardiac cycle?
When systole and diastole are not specified, what do they typically refer to?
When do AV valves open in the heart?
Blood flows from __________ to __________ pressure.
Contraction increases the pressure within a chamber, while relaxation __________ the pressure.
AV valves open when atrial pressures are higher than ventricular pressures and close when the pressure gradient is __________.
Semilunar valves open when ventricular pressures are higher than aortic/pulmonary pressures, and close when the reverse is __________.
The cardiac cycle refers to a series of events that happen with every respiration. (True/False)
Diastole is the phase of ventricular relaxation. (True/False)
AV valves open when ventricular pressures are higher than atrial pressures. (True/False)
Semilunar valves close when ventricular pressures are lower than aortic/pulmonary pressures. (True/False)
The cycle is initiated with the firing of the SA node that stimulates the atria to depolarize. This is represented by the P-wave on the ECG. Atrial contraction starts shortly after the P-wave begins, and causes the pressure within the atria to increase, forcing blood into the ventricles. Atrial contraction, however, only accounts for a fraction of ventricular filling, because at this point, the ventricles are already almost full due to passive blood flow down the ventricles through the open AV valves.
As atrial contraction completes, atrial pressure begins to fall, reversing the pressure gradient across the AV valves, causing them to close. The closing of the AV valves produces the first heart sound, S1, and marks the beginning of systole.
What happens when atrial pressure falls during the cardiac cycle?
AV valves open
Semilunar valves close
Ventricular pressure increases
AV valves close
What initiates the cardiac cycle?
SA node firing
AV node firing
Purkinje fibers firing
Bundle of His firing
What does atrial contraction do in the cardiac cycle?
Forces blood into the atria
Forces blood into the ventricles
Causes blood to flow back into the veins
Stops the flow of blood in the heart
What produces the first heart sound, S1?
Opening of AV valves
Closing of AV valves
Opening of semilunar valves
Closing of semilunar valves
What fraction of ventricular filling does atrial contraction account for?
One-third
Half
Two-thirds
All
Why are the ventricles almost full?
Due to active blood flow through AV valves
Due to passive blood flow through AV valves
Due to blood flow through semilunar valves
Due to blood flow through pulmonary arteries
What marks the beginning of systole?
Opening of AV valves
Closing of AV valves
Contraction of ventricles
Relaxation of ventricles
What initiates the cardiac cycle by stimulating the atria to depolarize?
What is represented by the P-wave on an ECG?
What event causes the pressure within the atria to increase, forcing blood into the ventricles?
As atrial contraction completes, atrial pressure begins to fall, causing the pressure gradient across the __________ valves to reverse, leading to their closure.
Atrial contraction only contributes a fraction of __________ filling because the ventricles are already almost full due to passive blood flow through the open AV valves.
The closing of the AV valves produces the first heart sound, __________, marking the beginning of systole.
S4
S3
S1
S2
The firing of the SA node causes the ventricles to depolarize. (True/False)
Atrial pressure falls as atrial contraction completes. (True/False)
The closing of the AV valves marks the beginning of diastole. (True/False)
At this point, ventricular depolarization, represented by the QRS complex, is halfway through, and the ventricles start to contract rapidly building up pressures inside the ventricles. For a moment, however, the semilunar valves remain closed, and the ventricles contract within a closed space.
This phase is referred to as isovolumetric contraction, because no blood is ejected and ventricular volume is unchanged. Ventricular ejection starts when ventricular pressures exceed the pressures within the aorta and pulmonary artery; the aortic and pulmonic valves open and blood is ejected out of the ventricles. This is the rapid ejection phase.
Where do the ventricles contract during this phase?
A) In an open space
B) Within a closed space
C) Outside the heart
D) In the atria
What represents ventricular depolarization and signals the start of rapid ventricular contraction?
P wave
T wave
QRS complex
ST segment
What happens to ventricular volume during isovolumetric contraction?
It decreases
It remains unchanged
It increases
It fluctuates
What is this phase known as?
Isovolumetric relaxation phase
Rapid ejection phase
Isovolumetric contraction phase
Ventricular filling phase
What happens to the semilunar valves during the initial contraction phase?
They remain closed
They open
They partially close
They oscillate
When does ventricular ejection begin?
When ventricular pressures exceed those in the atria
When ventricular pressures exceed those in the aorta and pulmonary artery
When ventricular pressures are equal to those in the aorta and pulmonary artery
When ventricular pressures are lower than those in the aorta and pulmonary artery
What do the aortic and pulmonic valves do during ventricular ejection?
Open to allow blood to be ejected out of the ventricles
Close to prevent blood from entering the ventricles
Contract to push blood into the ventricles
Expand to store blood in the ventricles
What represents ventricular depolarization on the ECG?
What phase occurs when the ventricles contract with the semilunar valves closed?
Ventricular depolarization is represented by the __________ on the ECG.
During isovolumetric contraction, the semilunar valves remain __________.
(TRUE/FALSE) During isovolumetric contraction, blood is ejected from the ventricles.
The rapid ejection phase begins when ventricular pressures exceed the pressures within the aorta and pulmonary artery. (True/False)
When do the aortic and pulmonic valves open?
When ventricular pressures exceed the pressures within the aorta and pulmonary artery
What phase is characterized by the ejection of blood from the ventricles?
Rapid ejection phase
During isovolumetric contraction, ventricular volume is __________.
The rapid ejection phase starts when the aortic and __________ valves open.
Ventricular depolarization is represented by the T-wave on the ECG. (True/False)
The ventricles start to contract rapidly during ventricular depolarization. (True/False)
As ventricular repolarization, reflected by the T-wave, begins, ventricular pressure starts to fall and the force of ejection is reduced. When ventricular pressures drop below aortic and pulmonary pressures, the semilunar valves close, marking the end of systole and beginning of diastole. Closure of semilunar valves produces the second heart sound, S2
What produces the second heart sound, S2?
Opening of semilunar valves
Closure of atrioventricular valves
Contraction of the atria
Opening of atrioventricular valves
What happens when ventricular pressures drop below aortic and pulmonary pressures?
Semilunar valves open
Semilunar valves close
Atrioventricular valves open
Atrioventricular valves close
When does ventricular repolarization, reflected by the T-wave, begin?
As ventricular pressure rises
As ventricular pressure falls
During ventricular contraction
During atrial depolarization
What marks the end of systole and beginning of diastole?
Opening of semilunar valves
Closure of atrioventricular valves
Contraction of the atria
Opening of the atrioventricular valves
What happens to the force of ejection when ventricular pressures drop below aortic and pulmonary pressures?
It increases
It remains the same
It is reduced
It fluctuates
What marks the end of systole and the beginning of diastole?
S1
S2
S3
S4
What happens to ventricular pressure as ventricular repolarization begins?
It starts to rise
It remains constant
It starts to fall
It fluctuates
What is reflected by the T-wave on an ECG?
What causes the semilunar valves to close?
Ventricular pressure falling below aortic and pulmonary pressures
As __________ begins, reflected by the T-wave, ventricular pressure starts to fall and the force of ejection is reduced.
ventricular diastole/ repolarization
When ventricular pressures drop below __________ and __________ pressures, the semilunar valves close.
Closure of semilunar valves produces the __________ heart sound, S2.
The T-wave represents the beginning of ventricular contraction. (True/False)
The semilunar valves close when ventricular pressure exceeds aortic and pulmonary pressures. (True/False)
The second heart sound, S2, is produced by the closure of the AV valves. (True/False)
entricular repolarization is reflected by the __________ on the ECG.
Closure of the semilunar valves produces the __________ heart sound.
During ventricular repolarization, ventricular pressure starts to fall. (True/False)
The second heart sound, S2, is produced by the opening of the semilunar valves. (True/False)
When do the semilunar valves close?
When ventricular pressures drop below aortic and pulmonary pressures
What phase begins with the closure of the semilunar valves?
Diastole
When ventricular pressures drop below aortic and pulmonary pressures, the __________ valves close.
The second heart sound, S2, marks the end of __________.
The T-wave on the ECG represents ventricular depolarization. (True/False)
Closure of the semilunar valves marks the beginning of diastole. (True/False)
False.
The first part of diastole is again isovolumetric, as the ventricles relax with all valves closed. Ventricular pressure drops rapidly but their volumes remain unchanged. Meanwhile, the atria are being filled with blood and atrial pressures rise slowly.
Ventricular filling starts when ventricular pressures drop below atrial pressures, causing the AV valve to open, allowing blood to flow down the ventricles passively. The atria contract to finish the filling phase and the cycle repeats itself.
What initiates ventricular filling?
When ventricular pressures drop below atrial pressures
When atrial pressures drop below ventricular pressures
When ventricular pressures exceed atrial pressures
When atrial pressures exceed ventricular pressures
What happens as atrial pressures rise slowly?
A. The atria are emptied of blood
B. The atria are filled with blood
C. The ventricles contract
D. The heart rate decreases
What did Atria contract to complete?
Filling phase
Emptying phase
Resting phase
Contracting phase
What process repeats itself?
Systole
Diastole
Cardiac cycle
Respiration
What is the first part of diastole?
Isovolumetric with all valves closed
Isovolumetric with all valves open
Ejection phase with all valves closed
Rapid filling phase with all valves open
What happens to ventricular pressure while volumes remain unchanged?
It increases rapidly
It drops rapidly
It remains constant
It fluctuates
What does the AV valve do during the diastole process?
Opens to allow passive blood flow into the ventricles
Closes to prevent blood backflow into the atria
Contracts to push blood out of the ventricles
Regulates blood flow into the atria
What is the first part of diastole characterized by?
Isovolumetric relaxation
When do the AV valves open during the cardiac cycle?
The first part of diastole is again isovolumetric, as the ventricles relax with all valves __________.
Ventricular pressure drops rapidly but their volumes remain __________.
Meanwhile, the atria are being filled with blood and atrial pressures rise __________.
slowly due to the increase in blood volume within the atria
Ventricular filling starts when ventricular pressures drop below atrial pressures, causing the AV valve to __________, allowing blood to flow down the ventricles passively.
The atria contract to finish the filling phase and the cycle __________ itself.
The first part of diastole involves the ventricles contracting with all valves closed. (True/False)
Ventricular filling occurs when ventricular pressures are higher than atrial pressures. (True/False)
Atrial pressures rise slowly as the atria are being filled with blood during diastole. (True/False)
The cardiac cycle repeats itself after the atria contract to finish the filling phase. (True/False)
As ventricular repolarization, reflected by the T-wave, begins, ventricular pressure starts to fall and the force of ejection is reduced. When ventricular pressures drop below aortic and pulmonary pressures, the semilunar valves close, marking the end of systole and beginning of diastole. Closure of semilunar valves produces the second heart sound, S2.
The first part of diastole is again isovolumetric, as the ventricles relax with all valves closed. Ventricular pressure drops rapidly but their volumes remain unchanged. Meanwhile, the atria are being filled with blood and atrial pressures rise slowly.
Ventricular filling starts when ventricular pressures drop below atrial pressures, causing the AV valve to open, allowing blood to flow down the ventricles passively. The atria contract to finish the filling phase and the cycle repeats itself.
When do semilunar valves close?
When ventricular pressures drop below aortic and pulmonary pressures
When ventricular pressures exceed aortic and pulmonary pressures
At the beginning of systole
During diastole
What is the first part of diastole characterized by as ventricles relax?
Isovolumetric with all valves closed
Rapid filling of the ventricles
Atrial contraction
Ventricular ejection
What produces the second heart sound, S2?
Opening of semilunar valves
Closure of atrioventricular valves
Contraction of the atria
Relaxation of the ventricles
What happens to atrial pressures as the atria are filled with blood during ventricular relaxation?
They remain constant
They decrease rapidly
They rise slowly
They fluctuate irregularly
What initiates ventricular filling?
Atrial pressures dropping below ventricular pressures
AV valve closing
Contraction of the ventricles
Opening of the semilunar valves
What do the atria contract to complete before the cycle repeats itself?
Ventricular relaxation phase
Atrial contraction phase
Ventricular filling phase
Ventricular ejection phase
What happens to ventricular pressure during ventricular repolarization?
Increases
Remains constant
Falls
Fluctuates
What reflects ventricular repolarization on the ECG?
What marks the end of systole and the beginning of diastole?
Closure of semilunar valves
Ventricular repolarization is reflected by the __________ on the ECG.
Closure of the semilunar valves produces the __________ heart sound.
During ventricular repolarization, ventricular pressure starts to fall. (Ture/False)
The second heart sound, S2, is produced by the opening of the semilunar valves. (True/False)
When do the semilunar valves close?
When ventricular pressures drop below aortic and pulmonary pressures
What phase begins with the closure of the semilunar valves?
Diastole
When ventricular pressures drop below aortic and pulmonary pressures, the __________ valves close.
The second heart sound, S2, marks the end of __________.
The T-wave on the ECG represents ventricular depolarization. (True/False)
Closure of the semilunar valves marks the beginning of diastole. (True/False)
What marks the end of systole and the beginning of diastole?
What is produced by the closure of the semilunar valves?
As ventricular repolarization, reflected by the __________, begins, ventricular pressure starts to fall and the force of ejection is reduced.
When ventricular pressures drop below __________ and __________ pressures, the __________ valves close.
Closure of __________ valves produces the __________ heart sound, S2.
Ventricular repolarization is reflected by the QRS complex on the ECG. (True/False)
The closure of the semilunar valves marks the end of systole. (True/False)
The second heart sound, S2, is produced by the closure of the AV valves. (True/False)
What phase of diastole is characterized by the ventricles relaxing with all valves closed?
During the first part of diastole, what happens to ventricular pressure and volume?
The first part of diastole is again __________, as the ventricles relax with all valves closed.
Ventricular pressure __________ rapidly but their volumes remain __________.
Meanwhile, the atria are being filled with blood and atrial pressures __________ slowly.
During isovolumetric relaxation, the ventricles contract with all valves closed. (True/False)
Ventricular volume increases during the first part of diastole. (True/False)
What happens to ventricular pressure during the first part of diastole?
Atrial pressures rise slowly as the atria fill with blood during diastole. (True/False)
During the first part of diastole, the ventricles are:
The first part of diastole is __________, as the ventricles relax with all valves closed.
During the first part of diastole, ventricular volumes remain __________.
During the first part of diastole, the atria are being filled with blood. (True/False)
Atrial pressures drop rapidly during the first part of diastole. (True/False)
What happens to atrial pressures during the first part of diastole?
During the first part of diastole, what is the state of the heart valves?
During the first part of diastole, atrial pressures __________ slowly.
The first part of diastole is called __________ relaxation.
isovolumetric
Ventricular volumes increase rapidly during the first part of diastole. (True/False)
Atrial pressures rise slowly during the first part of diastole. (True/False)
When does ventricular filling start?
What causes the AV valve to open during ventricular filling?
Ventricular filling starts when ventricular pressures drop below __________ pressures.
Blood flows down to the ventricles __________ when the AV valve opens.
passively
The atria contract to finish the filling phase of the ventricles. (True/False)
Ventricular filling begins when atrial pressures drop below ventricular pressures. (True/False)
What is the primary action of the atria to complete the ventricular filling phase?
What happens to the cycle after the atria contract to finish the filling phase?
It repeats itself
The atria __________ to finish the filling phase of the ventricles.
After the filling phase is completed, the cardiac cycle __________ itself.
repeats
Blood flows passively into the ventricles after the AV valve opens. (True/False)
The cardiac cycle stops after the atria contract to finish the filling phase. (True/False)