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