Cardiovascular Physiology Review Test Flashcards
A 53 year old woman is found, by arteriography, to have 50% narrowing of her left renal artery. What is the expected change in blood flow through the stenotic artery?
Decrease to 1/16
When a person moves from a supine position to a standing position, which of the following compensatory changes occur?
Increased contractility
At which site is systolic blood pressure the highest?
Renal artery
A persons electrocardiogram (ECG) has no P wave, but has a normal QRS complex and a normal T wave. Therefore, his pace-maker is located in the
Atrioventricular (AV) node
If the ejection fraction increases, there will be a decrease in
end-systolic volume
An electrocardiogram (ECG) on a person shows ventricular extrasystoles. The extra-systolic beat would produce
decreased pulse pressure because stroke volume is decreased
After an extrasystole, the next “normal” ventricular contraction produces
increased pulse pressure because the contractility of the ventricle is increased
An increase in contractility is demonstrated on a Frank-Straling diagram by
increased cardiac-output for a given end-diastolic volume
The tendency for blood flow to be turbulent is increased by
partial occlusion of a blood vessel
Following a sympathectomy, a 66 year old man experiences orthostatic hypotension. The explanation for this occurrence is
a suppressed response of the baroreceptor mechanism
The ventricles are completely depolarized during which isoelectric portion of the electrocardiogram (ECG)?
ST Segment
In which of the following situation’s is pulmonary blood flow greater than aortic blood flow?
Left-to-right ventricular shunt
A 30 year old female patients electrocardiogram (ECG) shows two P waves preceding each QRS complex. This interpretation of this pattern is
decreased conduction through the AV node
An acute decrease in arterial blood pressure elicits which of the following compensatory changes?
Decreased firing rate of the carotid sinus nerve
The tendency for edema to occur will be increased by
increased venous pressure
Inspiration “splits” the second heart sound because
the aortic valve closes before the pulmonic valve
During exercise, total peripheral resistance (TPR) decreases because of the effect of
local metabolites on skeletal muscle arterioles
An increase in arteriolar resistance, without a change in any other component of the cardiovascular system, will produce
an increase in arterial pressure
Which of the following is the result of an inward Na+ current?
upstroke of the action potential in purkinje fibers
The greatest pressure decrease in the circulation occurs across the arterioles because
they have the greatest resistance
pulse pressure is
determined by stroke volume
In the sinoatrial (SA) node, phase 4 depolarization (pacemaker potential) is attributable
an increase in Na+ conductance
Which receptor mediates constriction of arteriolar smooth muscle
a1 receptors
during which phase of the cardiac cycle is the aortic pressure highest?
reduced ventricular ejection
myocardial contractility is best correlated with the intracellular concentration of
Ca2+
Which of the following is an effect of histamine?
vasodilation of the arterioles
Carbon dioxide (CO2) regulates blood flow to which one of the following organs?
brain
cardiac output of the right side of the heart is what percentage of the cardiac output of the left side of the heart
100%
the physiologic function of the relatively slow conduction through the atrioventricular (AV) node is to allow sufficient time for
filling of the ventricles
Blood flow to which organ is controlled primarily by the sympathetic nervous system rather than by local metabolites
skin
which of the following parameters is decreased during moderate exercise
total peripheral resistance (TPR)
when propranolol is administered, blockade of which receptor is responsible for the decrease in cardiac output that occurs?
B1 receptors
During which phase of the cardiac cycle is ventricular volume the slowest?
isovolumetric ventricular relaxation
which of the following changes will cause an increase in myocardial O2 consumption
increased size of heart
which of the following substances crosses capillary walls primarily through water-filled clefts between the endothelia cells
glucose
a 24 year old woman presents to emergency department with severe diarrhea. When she is supine (lying down), her blood pressure is 90/60 mm Hg (decreased) and her heart rate is 100 beats/min (increased). When she is moved to a standing position, her heart rate further increases to 120 beats/min. Which of the following accounts for the further increase in heart rate upon standing
decreased venous return
a 60 year old businessman is evaluated by his physician, who determines that his blood pressure is significantly elevated at 185/130 mm Hg. Laboratory tests reveal an increase in plasma renin activity, plasma aldosterone level, and left renal vein renin level. His right renal vein renin level is decreased. What is the most likely cause of the patients hypertension?
left renal artery stenosis
During which phase of the ventricular action potential is the membrane potential closest to the K+ equilibrium potential?
Phase 4
During which phase of the ventricular action potential is the conductance to Ca2+ highest
phase 2
Which phase of the ventricular action potential coincides with diastole?
Phase 4
Propranolol has which of the following effects
decreases heart rate
Which receptor mediates slowing of the heart
muscarinic receptors
Which of the following agents or changes has a negative inotropic effect on the heart
acetylcholine (ACh)
the low resistance pathways between myocardial cells that allow for the spread of action potentials are the
gap junctions
which agent is releases or secreted after a hemorrhage and causes an increase in renal Na+ reabsorption
aldosterone
during which phase of the cardiac cycle does the mitral valve open
isovolumetric ventricular relaxation
a hospitalized patient has an ejection fraction of 0.4, a heart rate of 95 beats/min, and a cardiac output of 3.5 L/min. What is the patients end-diastolic volume
92 mL
