Guyton Test #1 Flashcards
What is the Stroke volume in milliliters?
100 mL
What is the cardiac output of this patient?
8200 mL/min
What is the extent of diastole in the ventricular pressure-volume relationship
From point D and Point B
What is correct about isovolumetric contraction?
Extends from B to C in the ventricular pressure-volume curve
A 47-year-old man has an ejection fraction of 0.32 and an end- diastolic volume of 160 ml. What is (approximately) the value of end-systolic volume?
51 ml
In a resting adult, the typical ventricular ejection fraction has what value?
A) 20%
B) 30%
C) 40%
D) 60%
E) 80%
D) 60%
What happens at the end of ventricular isovolumic relaxation?
A) The A-V valves close
B) The aortic valve opens
C) The aortic valve closes
D) The mitral valve opens
E) The pulmonary valve closes
D) The mitral valve opens
Which event is associated with the first heart sound?
A) Closing of the aortic valve
B) Inrushing of blood into the ventricles during diastole
C) Beginning of diastole
D) Opening of the A-V valves
E) Closing of the A-V valves
E) Closing of the A-V valves
Which condition will result in a dilated, flaccid heart?
A) Excess calcium ions in the blood
B) Excess potassium ions in the blood
C) Excess sodium ions in the blood
D) Increased sympathetic stimulation
E) Increased norepinephrine concentration in the blood
B) Excess potassium ions in the blood
A 25-year-old well-conditioned athlete weighs 80 kg (176 lb). During maximal sympathetic stimulation, what is the plateau level of his cardiac output function curve?
A) 3 l/min
B) 5 l/min
C) 10 l/min
D) 13 l/min
E) 25 l/min
E) 25 l/min
A 25-year-old well-conditioned athlete weighs 80 kg (176 lb).
During maximal sympathetic stimulation, what is the plateau level of his cardiac output function curve?
A) 3 l/min
B) 5 l/min
C) 10 l/min
D) 13 l/min
E) 25 l/min
E) 25 l/min
Which phase of the cardiac cycle follows immediately after the beginning of the QRS wave?
A) Isovolumic relaxation
B) Ventricular ejection
C) Atrial systole
D) Diastasis
E) Isovolumic contraction
E) Isovolumic contraction
Sympathetic stimulation of the heart does which of the following?
A) Releases acetylcholine at the sympathetic endings
B) Decreases sinus nodal discharge rate
C) Decreases excitability of the heart
D) Releases norepinephrine at the sympathetic endings
E) Decreases cardiac contractility
D) Releases norepinephrine at the sympathetic endings
Sympathetic stimulation of the heart normally causes which condition?
A) Acetylcholine release at the sympathetic endings
B) Decreased heart rate
C) Decreased rate of conduction of the cardiac impulse
D) Decreased force of contraction of the atria
E) Increased force of contraction of the ventricles
E) Increased force of contraction of the ventricles
What is correct about the sinus node?
A) Delays the cardiac conduction if sympathetic activity
increases
B) Acts as a pacemaker because the membrane constantly leaks
Na+ from extracellular fluid
C) The constant leak of K+ makes resting potential in the sinus
node gradually rise
D) Feedback from the Purkinje fibers defines the sinus node
discharge
E) The resting membrane potential of the sinus node is +55 to
+60mV
B) Acts as a pacemaker because the membrane constantly leaks
Na+ from extracellular fluid
Listed below are the hydrostatic and oncotic pressures within a microcirculatory bed.
Plasma colloid osmotic pressure = 25 mm Hg Capillary hydrostatic pressure = 25 mm Hg
Venous hydrostatic pressure = 5 mm Hg Arterial pressure = 80 mm Hg
Interstitial fluid hydrostatic pressure = −5 mm Hg Interstitial colloid osmotic pressure = 10 mm Hg Capillary filtration rate = 150 ml/min
What is the capillary filtration coefficient (in ml/min/mm Hg) for this capillary wall?
A) 5
B) 10
C) 15
D) 20
E) 25
B) 10
A healthy 60-year-old woman with a 10-year history of hypertension stands up from a supine position. Which set of cardiovascular changes is most likely to occur in response to standing up from a supine position?
A) Increase, increase, increase
In an experimental study, administration of a drug decreases the diameter of arterioles in the muscle bed of an animal subject.
Which set of physiological changes would be expected to occur in response to the decrease in diameter?
E.) decrease, decrease, decrease
A 60-year-old woman has experienced dizziness for the past 6 months when getting out of bed in the morning and standing up.
Her mean arterial pressure is 103/90 while lying down and 95/60 when standing.
Which set of physiological changes would be expected in response to moving from a supine to an upright position.
G) decrease, increase, increase
A 35-year-old woman visits her family practitioner for an examination.
She has a blood pressure of 160/75 mm Hg and a heart rate of 74 beats/min.
Further tests by a cardiologist reveal that the patient has moderate aortic regurgitation. Which set of changes would be expected in this patient?
A) increase, increase, increase
A healthy 27-year-old female medical student runs a 5K race.
Which set of physiological changes is most likely to occur in this woman’s skeletal muscles during the race?
F) decrease, decrease, increase
Cognitive stimuli such as reading, problem solving, and talking all result in significant increases in cerebral blood flow.
Which set of changes in cerebral tissue concentrations is the most likely explanation for the increase in cerebral blood flow?
B) increase, decrease, increase
Histamine is infused into the brachial artery. Which set of microcirculatory changes would be expected in the infused arm?
A) increase, increase, increase
An increase in shear stress in a blood vessel results in which change?
A) Decreased endothelin production
B) Decreased cyclic guanosine monophosphate production
C) Increased nitric oxide release
D) Increased renin production
E) Decreased prostacyclin production
C) Increased nitric oxide release