Homework #1 – The Cardiovascular System: The Heart
Which of the following is false with regard to a serous membrane? (A) it is always wet, (B) it forms a two layer “sack” around some organs, (C) it includes endothelium, (D) its primary function is reducing friction, (E) none of the above, these are all true.
When the digestive physiologist Pavlov rang a bell, he could get a dog to salivate because he had trained the dog that following the bell, food would be delivered. This action can be described as an example of a(n): (A) extrinsic control of a negative feedback mechanism, (B) extrinsic control of a feedforward mechanism , (C) intrinsic control of a negative feedback mechanism, (D) intrinsic control of a feedforward mechanism, (E) intrinsic control of a positive feedback mechanism.
True or False. The lamina propria is simply the name for the areolar connective tissue found in mucous membranes.
The majority of the heart’s wall is composed of a layer of cardiac muscle called the:
(A) pericardium, (B) mesometrium, (C) mesocardium, (D) myocardium, (E) epicardium
Which of the following is false with regard to the internal lining of the heart chambers?
(A) it is classified as a mucous membrane, (B) it is most superficially lined with simple squamous epithelial cells, (C) it is known as the endocardium, (D) its most superficial lining is known as the endothelium, (E) none of the above, these are all true with regard to the internal lining of the heart.
True or False. Overall, arteries and veins are differentiated by the fact that arteries carry oxygenated blood whereas veins carry deoxygenated blood.
True or False. Blood ejected from the left ventricle is bound for the lungs.
The bicuspid valve is also known as: (list all that apply) (A) the right atrioventricular valve, (B) the pulmonary valve, (C) a semilunar valve, (D) the mitral valve, (E) the left atrioventricular valve.
The blood pressure in the pulmonary trunk is _?_ that in the aorta.
(A) less than, (B) more than, (C) the same as, (D) highly variable and can’t be compared to ________ True or False. The volume of blood ejected by the left ventricle should be the same as the volume ejected by the right ventricle.
The chordae tendineae: (A) form the structural supports for the interventricular septum, (B) help keep the ventricles from collapsing, (C) are attached to papillary muscles, (D) conduct electrical impulses to the ventricles, (E) keeps the electrical impulses of the atria separate from that of the ventricles.
If the aortic valve in the heart was damaged, such that it failed to close properly:
(A) blood would accumulate in the left ventricle, (B) there would be a back flow of blood into the
right ventricle, (C) the blood pressure of the aorta would be increased, (D) blood pressure would increase in the lungs, (E) the right side of the heart would enlarge.
The action potential of contractile cardiac muscle fibers lasts approximately as long as:
(A) an autorhythmic cardiac muscle fiber’s action potential, (B) a contractile cardiac muscle fiber contraction, (C) a neuron’s action potential, (D) all of the above, (E) none of the above.
Approximately what percentage of cardiac muscle fibers can produce their own action potentials, i.e., are autorhythmic fibers? (A) 100%, (B) 50%, (C) 10%, (D) 1%, (E) none of the above, no cardiac muscle fibers are autorhythmic.
Starting from a point within the right brachial (arm) vein, a red blood cell will travel through the following vessels and chambers, in what order? (not all components are listed)
(A) left atrium, (B) superior vena cava, (C) right ventricle, (D) pulmonary vein, (E) aorta
The sinoatrial node, without external stimuli, will fire at a rate of approximately _?_ beats per minute. (A) 120, (B) 100, (C) 60-80, (D) 40, (E) 0, there is no beating without external stimuli
Place the following electrical conducting tissues of the heart in the correct order.
(A) atrioventricular node, (B) Purkinje fibers, (C) bundle branches, (D) bundle of His, (E) sinoatrial node.
True or False. The valve between the inferior and superior venae cavae and the atrium closes during atrial contraction.
In a normal functioning heart the atria contract _?_ the ventricles contract.
(A) at a faster rate than, (B) at a slower rate than, (C) at the same frequency as,
(D) at the same time as, (E) C & D
With regard to the heart sounds, the “lub” (1st sound) is produced by the ______, and the “dup” (2nd sound) is produced by the _______.
(A) vacuum created by ejecting the blood, (B) opening of the semilunar valves, (C) closing of pulmonary and aortic valves, (D) closing of the atrioventricular valves, (E) contraction of the aorta.
Label the deviations on the ECG below and place the following labels (the letters) at their appropriate locations along the ECG (show whether the following “items” are at a pt. or over a range).
(A) dup (2nd heart sound), (B) passive ventricular filling, (C) isovolumetric (ventricular) contraction, (D) the opening of semilunar valves, (E) the closing of atrioventricular valves
If scar tissue blocks the electrical conduction between the sinoatrial node and atrioventricular node, the ventricles will: (A) contract at a faster rate than the atria, (B) contract in synchrony with the atria, (C) contract less frequently than the atria, (D) will not contract.
Which of the following is not true of cardiac muscle?
(A) the cells have 1 or 2 nuclei, (B) the cells are connected by intercalated discs, (C) it is striated,
(D) the cells are interconnected by many gap junctions, (E) all of the above are true of cardiac muscle
The hole connecting the right and left atria in utero (during fetal development) is called the:
(A) atrial foramen, (B) papillary foramen, (C) foramen pulmonar, (D) foramen ovale, (E) anus foramis
What are the two equations for determining stroke volume? (hint, see next question)
What equation have we learned for determining cardiac output?
What is the stroke volume of a patient with an end systolic volume of 70 mL and an end diastolic volume of 142 mL? include units. (show your equation below)
What is the average stroke volume of a patient with a cardiac output of 4.9 L/min and a heart rate of 70 beats/min? include units. (show your equation below)
What is the cardiac output of a patient with a stroke volume of 75 mL and a heart rate of 85 beats/min? include units. (show your equation below)
According to the Frank-Starling law, when the heart receives a greater blood volume: (A) it will pump weakly to continue to produce the original stroke volume, (B) it will pump at the original strength to increase stroke volume, (C) it will increase the strength of the pump and increase stroke volume, (D) none of the above, the heart can not suddenly receive a greater blood volume.
True or False. High systemic levels of epinephrine lead to a large increase in cardiac output by speeding up the heart rate and increasing stroke volume by improving myocardial contractility and by enlarging the end diastolic volume through higher venous return.
Insert typical, healthy approximate values for the following characteristics (assume ~150 lb, 25 y.o.) include units.
Stroke Volumerest _______________ COrest _______________ COmax ________________
Heart Raterest ______________ HRmax ________________ Blood Volume ______________
