Weekly Quizzes Cardiovascular system Flashcards
What is the relationship between arteriole radius and blood flow through the arteriole?
There is a direct relationship to the power of 4 (r^4) between arteriole radius and arteriole blood flow. In other words, if the radius of the arteriole decreases, then the flow in the arteriole decreases to the power of 4
Is preventing the movement of any molecules or ions betweeen the ICF and ECF a function of the cell membrane?
No
Is the following statement true or false? The sinoatrial node generates the normal auto-activity of the heart.
True
Which arteries is normally supplied by the right coronary artery?
The posterior interventricular artery
The preload can be defined as the aortic systolic volume
False
If a person has a resting arterial blood pressure of 160/100, they would have…
(A)Heart failure(B)Third degree heart block(C)Hypotension(D)Hypertension
D Hypertension
Which component of an ECG represents ventricular repolarization?
T wave
What happens in the condition known as complete heart block(or 3rd degree heart block)?
Electrical signals from the SA fail to propagate to the ventricles, so the contraction of the atria is not coordinated with the contraction of the ventricles
True. Heart block refers to problems with propagation of activation through the AV node. It can be 1st degree, 2nd degree or 3rd degree (= complete heart block)
True or false? Capillaries do not have a tunica intima
False
Oedema is likely to occur when the capillary hydrostatic pressure decreases.
False, Oedema is caused when outward forces increase or inward forces decrease. We are looking for the FALSE response, i.e. when outward forces decrease or inward forces increase àdecreased capillary
Typical adult blood volume is approximately
4.5-5 litres
Is the following statement true or false? All blood vessels have a wall that is made up of 3 layers in their wall: the tunica externa, tunica media & tunica intima.
(This is actually a question) This is false. Larger blood vessels have 3 layers (eg veins and arteries) but some smaller vessels, in particular capillaries do not have 3 layers. Capillaries only have a single endothelial layer. Arterioles do not have a well-formed tunica externa, and, small venules may lack a tunica media
Which body compartment has the highest [Na+] ions?
The extracellular fluid
What does the P-wave of the ECG represent?
The P wave represents atrial depolarisation
Which body compartment has the lowest [Na+] ions?
The intracellular fluid
The opening and closing of the atrio ventricular and semilunar valves is driven by contraction and relaxation of the valve
False
Ventricular systole (the contraction of the ventricles) occurs in the interval between which two waves of the ECG?
Ventricular systole is the phase of ventricular contraction. It occurs between the QRS complex and the T wave. This is known as the ST segment.
True or false? The smooth muscle layer is in the tunica media
True
Does the cell membrane have lipid tails on its inner and outer surface?
No
Blood returning to the heart from the pulmonary circuit first enters the
left atrium
Blood supply to the heart comes from _
Coronary Arteries
Is the following statement true or false? The sinoatrial node is just one of numerous areas of the heart that contains autoactive cells?
True. Autoactive cells are located in several other areas including the AV node, the AV bundle, and the Purkinje fibres.
True or false, the structure of the cell membrane makes impossible for any molcule to diffuse through it.
False
True or false? Organs frequently work together to form tissues
False, tissues form organs
Which, if any of the following vessels carries blood with the highest concentration of oxygen? The superior vena cava, the inferior vena cava, the jugular vein, the pulmonary artery, the right pulmonary vein?
The right pulmonary vein is carrying oxygenated blood from the lungs to the left ventricle.
The superior vena cava, inferior vena cava and the jugular vein are all carrying deoxygenated blood back to the right ventricle, & the pulmonary artery is also carrying deoxygenated blood to the lungs (to get oxygenated).
True or false, if channels are present in the cell membrane, molecules and ions can pass through them continually
False
True or false, Negative feedback systems return the controlled variable to the set point after it has been disturbed.
True
True or false? When people are obses, water represents a greater percentage of the total body weight
False
Is the following statement true or false? At end diastolic volume, the ventricle contains its maximum volume of blood.
That is true. End Diastolic Volume refers to the volume of blood in the ventricle at the end of ventricular diastole. Ventricular diastole is the filling stage, during which the ventricle fills with blood
Make up a general rule explaining the distribution of ions in the compartments.
The concentrations of Na and K ions are opposite inthe ICF and ECF - [Na] is high in the ECF and low in the ICF. [K] is low in the ECF and high in the ICF. The Na and K concentrations are always the opposites of each other.
Is the following statement true or false? During ventricular ejection arterial pressure is greater than ventricular pressure.
That is false. During ejection, blood is flowing from the ventricle to the aorta. Because blood flows according to a pressure gradient, from high to low pressure, this means that ventricular pressure must be higher than aortic pressure. Otherwise the blood would flow in the opposite direction. Note: that arterial pressure is very similar to ventricular pressure, but it is slight lower.
The mean arterial pressure (MAP) is important because it represents the driving pressure for blood flow
True. Mean arterial pressure is the average forcethat is exerted on the blood, driving flow. Of course BP fluctuates, but the MAP is useful in working out the average driving force for flow
Is the following statement true of false? The ventricles are filling throughout all of ventricular diastole.
It’s false. Ventricular diastole starts with the closure of the semilunar valves. However, ventricular filling doesn’t start until the AV valves have opened. Therefore, the first part of ventricular diastole is an “isovolumetric” phase, where there is no blood entering (or leaving) the ventricle.
Which part of the heart plays the major role regulating heart rate? (i) the SA node, (ii) the AV node, (iii) the atria, (iv) the ventricles?
(i) The SA node. HR is directly regulated by the time it takes for SA node cells to fire, which is controlled by the sympathetic and parasympathetic nervous systems
Is the cell membrane is made up of a layer of molecules of phosphiolipid
No
All arteries carry oxygenated blood
False
During exercise, whichmajororgans receive an increase in the proportion of cardiac output delivered to it?
skeletal muscle, heart, and skin increased blood flow to skin for heat loss, bloodflow to brain is dependent on neural activity, which would not change in exercise.
Is providing a physical barrier seperating the ICF and the ECF a function of the cell membrane?
Yes
The long plateau phase of the cardiac muscle action potential ceases when movement of sodium ions slows down.
False
Oedema is likely to occur when a subject sits in a stationary position for an extended period of time.
True
Is the following statement true or false? At end of ventricular systole, all of the blood has been ejected from the ventricle.
That is false. The volume of blood in the ventricle at the end of systole (end systolic volume) is the minimum amount of blood in the ventricle but it is not 0 because not all of the blood gets ejected from the ventricle. Typical about 50-60% of the end diastolic volume gets ejects, meaning that about 40-50% remains in the ventricle (about 60 ml).
Is the cell membrane has hydrophilic heads in contact with the ICF and ECF
Yes
Dietary reduction in cholesterol is the preferred treatment for coronary artery disease?
No
True or false? Each ATP molecule is built from 3 molecules of adenosine
False
Which vessels are known as resistance vessels?
Arterioles
What happens in the condition known as complete heart block(or 3rd degree heart block)?
The fibrous skeleton of the heart breaks down, interfering with the passage of blood from the atria to the ventricles
False
From which of the following can you calculate the heart rate?
RR interval
What happens in the condition known as complete heart block(or 3rd degree heart block)?
The mitral valve leaflets calcify and close, preventing blood from being pumped efficiently by the left side of the heart
False
What does the QRS complex of the ECG represent?
The QRS complex represents ventricular depolarisation. Atrial repolarisation occurs simultaneously but because the muscle mass of the atrium is very small it has little impact on the ECG.
The opening and closing of the atrio ventricular and semilunar valves is driven by the direction in movement of blood across the valve
True. Remember that the valves do not actively open or close, they are pushed open or closed by the blood flow
The long plateau phase of the cardiac muscle action potential ceases when calcium channels open.
False
What is the main effect of activation of the parasympathetic nervous system?
A decrease in heart rate
There is minimal innervation to blood vessels by the parasympathetic, so the parasympathetic does not affect TPR. The main effect is to decrease heart rate, not decrease TPR.
Is the following statement true or false? Arteries are blood vessels that carry blood that is loaded with oxygen.
It’s false. This is only true of the systemic circulation. The pulmonary circulation pumps deoxygenated blood into the lungs where it can be loaded with oxygen.
True or false? The left AV valve closes during the ejection phase of the heart
True
What is the major function of the Purkinje fibres?
Their major function od Purkinje fibres is to propagate action potentials very rapidly through the ventricles. This lets the ventricle be activated as a single muscle mass. The Purkinje fibre “conduction velocity” – i.e. the rate at which they can propagate action potnetials – is ~2-4 metres per second. The Purkinje fibres are also autoactive, but this is not their major function, and is not usually seen in a normally functioning heart.
The right marginal artery and the posterior interventricular artery are branches of the right coronary artery.
True.
True or false? Some cells in the body use ATP as their source of energy
False, All cells use ATP
The term autorhythmicity refers to the heart’s ability to intrinsically modify its contractility
False
Where is the sinoatrial node located?
In the upper back part of the right atrium
Chemicals released by metabolically active cells will cause what?
Relaxation of smooth muscle in arteriolar wall, increasingblood flow to the cells. This is the way that “local factors” regulate blood flow according to metabolic demand.
True or false? The breakdown of ATP produces ADP and energy
True
Is the following statement true or false? The atria undergo systole during ventricular diastole.
That is true. Atrial systole occurs towards the end of ventricular diastole. Similarly ventricular systole occurs during atrial diastole.
Angioplasty and stenting of the affected artery is the preferred treatment for coronary artery disease?
Yes
Oxygen and Carbon Dioxide are carried across the cell membrane by proteins
False
True or false? The tunica externa plays an important role in anchoring the vessel in place
True
The long plateau phase of the cardiac muscle action potential ceases when there is a decreasein membrane permeability to potassium ions.
False
What is the underlying ionic cause of the plateau phase of the action potential of a cardiac contractile cell?
The combined diffusion of K+ out of the cell and Ca2+ into the cell. For this reason, there is very little net movement of “charge”, and so the membrane potential does not change significantly.
Are the SA node cells cardiac muscle cells or neurons?
They are cardiac muscle cells. They are specialised cardiac muscle cell, different to the “contractile cells”. Their main function is to generate the activity of the heart
The term autorhythmicity refers to the heart’s ability to conduct action potentials along the conduction pathway
False
The right marginal artery and the posterior interventricular artery are branches of the coronary sinus
False
What is the relationship between arteriole radius and arterial blood pressure?
There is an inverse relationship. In other words if the arteriole radius decreases, the arterial pressure will increase. To understand this, consider what happens if the arteriole radius decreases. This will cause blood flow through the arteriole to be reduced. Therefore there is a decrease in blood flow out of the artery (feeding the arteriole). This will lead to an increase in blood volume in the artery (because the heart is still pumping blood into the arteries), and therefore arterial blood pressure will increase.
When viewing a dissected heart, it is easy to visually discern the right and left ventricles by
Noticing the difference inthickness of the left & right ventricle walls. The left ventricle is thicker than the right ventricle because of thegreaterpressurethat it generates.
True or false, Negative feedback systems prevent the controlled variable from changing.
False
True or false? Tissues are unique to individual body systems
False
True or false? Most of the water in the body is located in the extracellular space
False
Is regulating exchange between the ICF and ECF a function of the cell membrane?
Yes
True or false, Facilitated diffusion moves ions against their concentration gradient
False
Injection of clot dissolving drugs like tissue plasminogen activator the preferred treatment for coronary artery disease?
No
Are the Purkinje fibres cardiac muscle cells or neurons?
They are also cardiac muscle cells. They are specialised cardiac muscle cell, different to the “contractile cells”.
True or false? Water makes up a small percentage of the body weight in normal humans
False
The primary site of exchange between blood and interstitial fluid occurs across what type of blood vessel?
capillaries. “Exchange” is movement between the blood and the interstitial fluid (or tissues/cells). This only occurs at capillaries.
Given the following information, calculate the net filtration pressure. Capillary hydrostaticpressure = 25 mm Hg, interstitial fluid hydrostatic pressure = 5 mm Hg, capillary colloid osmotic pressure = 15 mm Hg, and interstitial fluid colloid osmotic pressure = 5 mm Hg.?
10 mm Hg, favouring filtration
outward forces are capillary hydrostatic pressure and interstitial fluid colloid osmotic pressure (25+5) –inward forces are interstitial fluid hydrostaticpressure and plasma colloid osmotic pressure (5+15) à30-20 = +10. When the sign is positive (“+”) then the fluid flow is outwards.
The circumflex artery is a branch of the
left coronary artery
The preload can be defined as the atrial volume
False
A combination of moderate exercise and dietary changes is the preferred treatment for coronary artery disease?
No
Which body compartment has the highest [K+] ions?
The intracellular fluid
Oxygen and Carbon Dioxide move through the cell membrane by the process of passive diffusion
Correct
The opening and closing of the atrio ventricular and semilunar valves is driven by contraction of the papillary muscles attached to the valves
False
True or false? The external elastic membrane is located in the tunica media or arteries
True
The preload can be definedas the end-systolic volume
False
Oxygen and Carbon Dioxide move through the cell membrane from areas of lower to higher concerntration
False
True or false, negative feedback systems prevent to set point from changing.
False
What is the normal duration of a contractile cell action potential?
about 250 ms, or 0.25 sec. This is very long !!
Is the following statement true or false? The right side of the heart acts as the pump for the pulmonary circulation.
It’s true. The right side of the heart is the pump for the pulmonary circulation. It receives blood that has delivered oxygen to the tissues (& collected CO2) and then pumps it into the lungs where it can be re-oxygenated and carbon dioxide removed.
Is enabling communication between the cell and the enviroment a function of the cell membrane?
Yes
True or false? Energy is released when phosphate molecules are attached to adenosine
False, Energy is released when phosphate is released from adenosine
The right marginal artery and the posterior interventricular artery are branches of the left coronary artery
False
The term autorhythmicity refers to the heart’s ability to generate its own contraction
True. Also known as auto-activity and pacemaker activity
The chordae tendineae are connected to
The papillary muscle
The cell membrane contains few protein molecules inserted in it
No
What is the function of arterial anastomoses in the coronary circulation?
They are a connection between 2 or more arteries. Their function is to provide an area with blood from 2 different arteries. In effect they are a back up in case one artery gets blocked (eg with atherosclerosis).
All arteries have high blood pressure
False
What does the T wave of the ECG represent?
The T wave represents ventricular repolarisation
During exercise increased muscle contraction increases venous return to the heart. What effect does this have on cardiac output?
An increase in venous return produces an increase in end-diastolic volume (pre-load). This produced an increase in stroke volume and therefore an increase in cardiac output
The total cross-sectional area is greatest in which blood vessel type?
Capillaries, At each branching point in the circulation, the “daughter” vessels have a smaller individual cross-sectional area, but a greater total cross-sectional area than the “mother vessel”.
Calculate the mean arterial pressure if systolic pressure is 125 and diastolic pressure is 83 mmHg
MAP = DBP + [(SBP-DBP)/3]. = 83 + (125-83)/3 = 97 mmHg
Only large arteries are lined with endothelium
False
What is the name of the protective sac that surrounds the heart?
The pericardium
Name the inner layer of the serous pericardium
The visceral pericardium
The opening and closing of the atrio ventricular and semilunar valves is driven by contraction of the ventricle and atria that pull the valves into place
False
What is the main role of the AV node?
To slow down the propagation of action potentials into the ventricles. This allows the atria to complete their contraction before the ventricles start contracting.
The first heart sound is heard when the ventricles contract.
True Think of it in this way: 1stheart sound occurs when the ventricles contract, the 2ndheart sound occurs when the ventricles relax.
What are the 2 main branches of the left coronary artery?
The anterior interventricular artery and the circumflex artery
True or false, Molecules and ions can only cross the cell membrane of lower to areas of higher concentration.
False
A body system frequently contains several organs
True
True or false, Negative feedback systems prevent the controlled variable from moving away from the set point.
False
What is the equation relating mean arterial pressure, cardiac output and total peripheral resistance?
Mean Arterial Pressure = Cardiac Output x Total Peripheral Resistance (MAP=CO x TPR)
Why is the SA node called the natural pacemaker of the heart?
Because the autoactive cells in the SA node discharge at a faster rate than anywhere else in the heart, and so they control the normal heart rate.
The preload can be defined as the end-diastolic volume
True, Sometimes it is defined as end-diastolic pressure. This is because it is easier to measure pressure than volume, and there is a strong correlation between pressure and volume.
The term autorhythmicity refers to the heart’s ability to act as a functional syncytium
False
True or false? The left and right AV valve close at the same time.
True
All arteries directblood flow away from the heart
True
True or false, There is no movement at all of ions through channels when there is no concerntation gradient
False
True or false, Facilitated diffusion is the process by which carriers assist thje moment molecules through the cell membrane
True
During which phase of the cardiac cycle are all four heart valves open?
None, In isovolumetric contractionall 4 valves are closed, but there is never a circumstance when all 4 are open.
True or false? Extracellular fluid is made up of the interstitial fluid and the plasma
True
What causes the rapid depolarization phase of a contractile cell action potential?
sodium movement into the cell
The action potential is caused by Nainflux+in contractile cell, and Ca2+influxin nodal (pacemaker) cell.
Is the following statement true or false? The mediastinum contains only the heart and the great vessels.
No this is false. The mediastinum is the cavity in the thorax in which the heart sits, but other structures are also present, including, for example, the trachea, the primary bronchi, and the oesophagus.
Atrial systole (the contraction of the atria) occurs in the interval between which two waves of the ECG?
Atrial systole is the phase of atrial contraction. It occurs between the P-wave in the QRS complex. This is known as the PR segment.
Where in the vascular system is the greatest resistance to blood flow?
In the arterioles
Define the terms preload and afterload.
Preload: the amount of stretch on the ventricle at the end of ventricular filling – equivalent to end-diastolic ventricular volume. This stretches the sarcomeres and causes an increase in the force of contraction.
Increasing preload increases stroke volume
Afterload: the pressure the ventricle must push against to eject blood during. This is the diastolic aortic blood pressure.
Increasing afterload decrease stroke volume
Organelles are formed by groups of cells preforming similiar functions
False,
True or false, All water movement through the cell membrane occurs through aquaporins
false
The aortic valve opens during
Ventricular systole
True or false: The right coronary artery arises from the pulmonary trunk and the left coronary artery from the aorta.
False. Both coronary arteries arise from the aorta. They are carrying oxygenated blood to the heat muscle.
Oxygen and Carbon Dioxide move through the cell membrane by active transport
False
True or false? The chordae tendine help to maintain the structural integrity of the pulmonary valve.
False
True or false, Movement of ions against their concerntration gradient occurs by active transport
True
The long plateau phase of the cardiac muscle action potential ceases when there is a decrease in the amount of calcium diffusing across the membrane.
True. The plateau is caused by balance between potassium efflux and calcium influx.At endthe end of the plateau, K+ion movement increases and Ca2+ion movement ceases.
What happens in the condition known as complete heart block(or 3rd degree heart block)?
Coronary arteries are blocked by plaques, preventing blood and oxygen from reaching the myocardial contractile cells
False
The right marginal artery and the posterior interventricular artery are branches of the circumflex artery
false
True or false? The chordae tendinae are pulled tight during the ejection phase of the heart.
True
In the circulatory system, the largest pressure drop occurs across which blood vessels?
arterioles because arterioles have the greatest resistance to flow, the most energy loss will occur here, leading to the greatest drop in pressure.
