Flashcards in Exam II Questions Deck (78):
You are placing leads on a patient in order to measure EKG. In order to get the highest level of EKG activity, how should the leads be placed?
Parallel to the control lead.
During pathological tachycardia, body temperature and sympathetic stimulation are increased. What feature of the heart DECREASES during pathological tachycardia?
During endogenous tachycardia, stoke volume does not fall even though filling time is reduced. Why does this occur?
There is sympathetic stimulation, which increases the strength of contractions.
Stokes-Adam syndrome is a disease that occurs from which type of heart abnormality?
complete AV block.
The velocity of blood flow through the capillaries is relatively low. What feature of capillaries causes such a low velocity?
Capillaries have a large cross-sectional area; (V = F/A).
In artherosclerosis, resistance is greatly increased due to a blockage in blood vessels. What property of blood vessels will be directly affected?
Capacitance; it is inversely proportional to resistance.
A vessel with high capacitance will have a low ____.
True or false: rate of blood flow is not controlled by local tissue needs.
What is the total resistance in blood vessels?
When conducting a cardiac experiment, you note that veins have a relatively high compliance. Based on this observation, do the veins have a low or high amount of elastic fibers?
You take a pulse pressure reading from a 15 year old patient. They have a high pulse pressure. What does this tell you about the compliance of their arteries?
They are highly compliant (PP = SV/AC)
You are studying arterial pressure in dogs and wish to calculate the mean arterial pressure. What equation would be useful for doing so?
Mean arterial pressure = diastolic + 1/3PP.
What is the most important determinant of resistance in a vessel?
After a large amount of angiotensin has been released into the blood stream, how will autoregulation affect blood pressure?
sympathetic innervation will cause an increase in pressure, but blood flow does not necessarily increase by as much.
What is the most important factor in vasomotion?
the concentration of oxygen in tissues.
What is the definition of compliance?
The ease with which a hollow viscus may be distended.
What is the definition of elastance?
The ease with which a hollow viscus may be recoiled.
After a long day, you decide to lie down. How wil lying down affect venous return?
It will increase (increased volume and pressure).
Aortic valve stenosis involves a decrease the diameter of a vessel. How does this affect pulse pressure?
Pulse pressure decreases.
Patent ductus arteriosus is what kind of shunt?
left-to-right shunt. It decreases pulse pressure.
How does autoregulation affect pulse pressure?
It decreases pulse pressure.
According to the vasodilator theory, an increase in metabolism results in what?
decreased oxygen in the tissues, which causes vasodilation.
According to the metabolic theory, an increase in oxygen to the tissues results in what?
inactivation of vasoregulatiors.
How does the brain attempt to autoregulate blood flow?
By dilating blood vessels, which washes out carbon dioxide.
You encounter a patient who has decreased nitric oxide levels. How will this affect vessel constriction/dilation?
The vessels will not be able to dilate as well because nitric oxide is responsible for dilating blood vessels.
Damaged blood vessels release what protein, and what does the protein do?
Endothelin; it causes vasoconstriction.
You encounter a patient in the ER that is suffering a heart attack. What are some factors that would increase vasodilation in the patient's blood vessels?
Adenosine, bradykinins, histamine, potassium, prostacyclin/prostagalandins.
You are hiking and see a bear, which subsequently tries to attack you. What hormones will you most likely release, and how will they affect your vessels?
Epinephrine/norepinephine; they will cause vasoconstriction.
Does continual firing of nervous signals result in vasoconstriction or vasodilation?
What is a term for the partial contraction of blood vessels?
In a cardiac experiment, Herring's nerve is abnormal in a cat that you are studying. What region of the brain will be affected?
Sensory area (medulla); constriction and vasodilation will be affected.
You encounter a patient that has baroreceptors that have an abnormally high level of activity. How will heart rate be affected?
Heart rate will be low due to vasodilation caused by the baroreceptors.
What two cranial nerves are responsible for vasoconstriction/vasodilation?
Vagus nerve and glossopharyngeal nerve.
You encounter a patient who smokes, has diabetes, and lives a sedentary lifestyle. They most likely experience what type of hypertension?
You encunter a patient that has renal abnormalities, as well as valvular disease and hypertension. What type of hypetension do they most likely have?
You encounter a patient who has hyperthryoidism and hypertension. What type of hypertension do they most likely suffer from?
You administer adenosine to a patient who is suffering from a heart attack, which decreases their heart rate. How will cardiac output be affected?
Cardiac output will decrease.
In a patient experiencing cardiac fibrillation, contractility of the heat is significantly decreased. How does this affect cardiac output?
Cardiac output is significantly decreased.
When you are hiking in the desert, you see a rattlesnake and your blood pressure significantly increases. This short-term increased is caused by activation of what system?
sympathetic nervous system.
Long term control of arterial pressure is maintained by what system?
the kidneys (natriuresis, diuresis).
When dissecting a cadaver in the laboratory, you detect an atheroma in a patient. The atheroma was derived from what precursor?
An inflammatory response, which created fatty streaks.
Artherosclerosis is caused by what factors?
high cholesterol, hypertension, smoking and diabetes.
What is metabolic syndrome associated with?
A resistance to insulin.
A patient has a kidney disorder that causes decreased release of renin. How will this affect the patient's blood pressure?
Blood pressure will be decreased because there is less activation of angiotensin II, which causes vasoconstriction and increase in blood pressure.
A patient has a liver disorder in which high levels of angiotensin are released. How will this affect a patient's blood pressure?
Blood pressure may be high, as angiotensin causes vasoconstriction.
What is the Fick equation for blood flow?
O2 consumption/([O2]v - [O2]a)
You are studying the kidney in a dog and inject a large amount of ADH in the dog's bloodstream. How will blood pressure be affected?
Blood pressure will increase because ADH causes increased retention of water.
You encounter a patient in the ER who has a blockage in an artery. How is their cardiac output affected?
cardiac output decreases.
You encounter a patient who suffers from myocarditis. How is their cardiac output affected?
Cardiac output decreases.
You treat a patient who is a well-trained athlete. Are they more likely to have a hypereffective heart or a hypoeffective hear?
You are studying the cardiovascular system and decide to inhibit sympathetic nerve stimulation in a subject. How will this affect the heart?
The heart will become hypoeffective.
What is mean systemic filling pressure?
Pressure when the heart is not pumping.
When the arterial system contains 700 mL of blood, meean arterial pressure is 100 mm Hg. When the system contains 400 mL of blood, the mean arterial pressure drops to 0 mm Hg. The veins do not experience such a drop. Why does this occur?
Veins are more compliant than arteries.
An increase in right atrial pressure has what affects on volume and compliance?
volume is increased and compliance is decreased.
A decrease in right atrial pressure causes what to happen to volume and compliance?
volume decreases and compliance increases.
A marathon runner has high metabolism during a race. How does this affect blood flow?
Blood flow increases in direct proportion to oxygen consumption.
You are examining pulse pressure diagrams. How is the flow during systole and diastole?
During systole, flow is low. During diastole, flow is high.
You encounter a patient in the ER with a coronary occlusion. How is their cardiac output affected?
cardiac output is decreased.
You encounter a patient in the ER who is experiencing a heart attack. What will the heart do in order to increase cardiac output to normal (5 L/min)?
Right atrial pressure will increase.
During compensated heart failure, what is significantly decreased?
In a pulmonary edema, fluid from the pulmonary system accumulates and flows into what area?
What occurs during an AV fistula?
There is increased venous return of blood to the heart.
During cardiac failure, what three mechanisms are used to return heart rate to normal?
baroreceptor, chemoreceptor and CNS ischemic response.
How does the sympathetic system affect damaged musculature during cardiac failure?
It strengthens the heart and allows for more contractility.
Although baroreceptors decrease cardiac output and pressure during cardiac shock, what function do they have in increasing output during cardiac shock?
They increase venous constriction and heart activity.
What role do baroreceptors play in shock?
They increase sympathetic stimulation, especially when pressure is below 50 mm Hg.
During moderate shock, there is an expected increase in what hormones?
renin and angiotensin.
A patient that undergoes anaesthesia has undergone shock that is unrelated to vessel activity. What kind of shock are they experiencing?
You encounter a patient in the ER whose heart rate is gradually decreasing without any improvement. What type of shock are they most likely experiencing?
You perform surgery on a patient with cardiac issues. As you perform surgery, you notice they have an ischemia in the AV node and there is also inflammation. What type of heart abnormality do they most likely have?
You encounter a patient who has used a high amount of diuretics. What ion will be low in their plasma, and how will the brain be affected?
sodium; the brain will start to swell.
In patients who experience hypernatremia, how is the sodium concentration affected?
Sodium concentration in the plasma is increased.
A patient who is experiencing hypernatremia usually experiences what symptoms?
increased thirst and desire for salty foods.
Excessive capillary filtration can causes fluid fromt he plasma to interstitial spaces. This is what type of edema?
What is the normal value for am osmolar gap?
You encounter a drunk patient in the ER and perform a blood test on them. How is their osmolar gap affected?
It will increase.
The amounts of ECF in interstitial spaces is affected by what two factors?
hydrostatic and colloid forces across the capillary membrane.