PHYSIO-LEC-LE-3-Feed-CSV-2025 Flashcards
- Which of the following statement of the
heart is correct
A. Consist of 2 pumps in parallel
B. Blood flow is bidirectional
C. Systole distends the Aorta
D. Cardiac output is continuous
C. Systole distends the Aorta
- Which of the following blood vessels is
known as the “stopcocks” of the vascular
system?
A. Aorta
B. Vena Cava
C. Small Arteries
D. Capillaries
C. Small Arteries
- Where in the systemic vascular system
will we find the greatest volume of blood?
A. Capillaries
B. Aorta
C. Small Veins
D. Small Arteries
C. Small Veins
- Which of the following statement
regarding the cardiovascular circuit is true?
A. O2-rich blood returns to the heart via the
pulmonary arteries
B. composed of conduits arranged in series
alone
C. total volume of blood is variable
D. capillary blood flow is nonpulsatile
D. capillary blood flow is nonpulsatile
- Which of the following does NOT
describe the blood vessels of the circulatory
system?
A. low frictional resistance in large arteries
B. major pressure drop is across the small
arteries and arterioles
C. direct relationship between blood flow
velocity and cross-sectional area
D. maximal cross-sectional area and
minimal flow rate in the capillaries
C. direct relationship between blood flow
velocity and cross-sectional area
- Which among the estimated extracellular
ion concentrations is normally expected in a
healthy person?
A. Cl- = 145mmol/L
B. Na+ = 145mmol/L
C. K+ = 145mmol/L
D. Ca++ = 145mmol/L
B. Na+ = 145mmol/L
- Which of the following characteristics
describes a fast-response action potential?
A. has phase 1
B. resting potential is less negative
C. RRP extends into phase 4
D. occurs in SA and AV node
A. has phase 1
- Which of the following ions would
determine the membrane potential change
during phase 0 of a fast-response action
potential?
A. Sodium
B. Chloride
C. Calcium
D. Potassium
A. Sodium
- Which of the following is NOT a
characteristic feature of the effective
refractory period?
A. a larger-than-normal depolarization
generates a potential
B. sodium channels are in the inactivated
state
C. prevents a sustained contraction of
cardiac muscle
D. another action potential cannot be
generated
A. a larger-than-normal depolarization
generates a potential
- Which phase of the action potential do
you expect all sodium channels to be
closed?
A. Phase 4
B. Phase 1
C. Phase 2
D. Phase 3
B. Phase 1
- Which of the following correctly
describes a L-type voltage-regulated
calcium channel?
A. the channel is transient
B. activated when membrane voltage
reaches -70 mV
C. enables a long-lasting Calcium
current
D. less abundant in the heart
C. enables a long-lasting Calcium
current
- Which of the following substances would
decrease myocardial contractility
A. isoproterenol
B. norepinephrine
C. acetylcholine
D. catecholamine
C. acetylcholine
- Which of the following ions
counterbalances the influx of Ca++ during
the flat portion of phase 2 on the action
potential?
A. influx of K+
B. influx of Na+
C. efflux of K+
D. efflux of Na+
C. efflux of K+
- Which point in the pressure volume loop
will the aortic valve open?
A. F
B. D
C. A
D. C
B. D
15.Which point in the pressure volume loop depicts isovolumetric relaxation?
A. C to D
B. A to C
C. F to A
D. D to F
C. F to A
16.Which of the following mechanisms is the principal means by which heart rate is controlled?
A. Baroreceptor reflex
B. Bainbridge reflex
C.Chemoreceptors
D.Autonomic nervous system
D.Autonomic nervous system
17.Which of the following mechanisms would explain the increase in myocardial contractility when the heart rate is increased?
A. increasing the storage of Ca2+ by the sarcoplasmic reticulum
B. more Ca2+ ions enter the cell during each action potential
C. increasing entry of more Ca+2 during the plateau
D. inhibiting the Na+-K+ pump
B. more Ca2+ ions enter the cell during each action potential
18.Which of the following metabolites autoregulate blood flow to the brain?
A.CO2
B.O2
C.Lactate
D.Adenosine
A.CO2
19.Which of the following situations demonstrates an increase in myocardial contractility by the Frank-Starling relationship?
A. decreased cardiac output for a given end-systolic volume
B. increased cardiac output for a given end-systolic volume
C. decreased cardiac output for a given end-diastolic volume
D. increased cardiac output for a given end-diastolic volume
D. increased cardiac output for a given end-diastolic volume
20.Which of the following intracellular concentrations of ions is best correlated with myocardial contractility?
A.Mg++
B.Ca++
C.K+
D.Na+
B.Ca++
21.Which of the following term is defined as the ratio of the volume of blood ejected from the left ventricle per beat to the volume of blood in the left ventricle at the end of diastole
A.preload
B.afterload
C.cardiac output
D.ejection fraction
D.ejection fraction
EF = SV/EDV
22.Which of the following mechanism is responsible for the physiologic splitting of the second heart sound?
A. decreased blood flow from an inspiration-induced increase in venous return
B. increased blood flow from an inspiration-induced increase in venous return
C.increased blood flow from an inspiration-induced decrease in venous return
D.decreased blood flow from an inspiration-induced decrease in venous return
B. increased blood flow from an inspiration-induced increase in venous return
23.Which of the following heart sounds is caused by the oscillation of blood and cardiac chambers as a result of atrial contraction?
A.S4
B.S2
C.S1
D.S3
A.S4
24.Which of the following terms is defined as the heart rate that prevails after complete autonomic blockade?
A. normal heart rate
B. resting heart rate
C. extrinsic heart rate
D. intrinsic heart rate
D. intrinsic heart rate
25.Which of the following changes in heart rate during respiration is correct?
A. accelerates during inspiration and decelerates during expiration
B. accelerates during inspiration and expiration
C. decelerates during inspiration and expiration
C. decelerates during inspiration and accelerates during expiration
A. accelerates during inspiration and decelerates during expiration
26.Which of the following mechanisms is responsible for the rhythmic variation in heart rate during respiration?
A. changes in sympathetic activity
B. changes in vagal activity
C. changes in both vagal and sympathetic activity
D. no relationship with vagal or sympathetic activity
B. changes in vagal activity
27.Which of the following effects would occur if the atrial receptor were distended?
A. increase in heart rate, decrease in urine volume
B. decrease in heart rate and urine volume
C. decrease in heart rate, increase in urine volume
D. increase in heart rate and urine volume
D. increase in heart rate and urine volume
28.Which of the following is NOT true of the baroreceptor reflex?
A. change in arterial blood pressure result in an inverse change in heart rate
B. entirely brought about by changes in vagal activity
C. receptors are located in the aortic arch and carotid sinuses
D. prevails over the Bainbridge reflex when blood volume diminishes
B. entirely brought about by changes in vagal activity
29.Which of the following does NOT describe the Bainbridge reflex?
A. IV infusion of blood accelerates heart rate when heart rate is slow
B. heart rate increased when central venous pressure is increased
C. prevails over the baroreceptor when blood volume diminishes
D. abolished by bilateral transection of the vagus nerves
C. prevails over the baroreceptor when blood volume diminishes
30.Which of the following events occurs when the primary mechanism of the chemoreceptor reflex is stimulated?
A. excite medullary vagal center, increase heart rate
B. excite medullary vagal center, decrease heart rate
C. inhibit medullary vagal center, increase heart rate
D. inhibit medullary vagal center, decrease heart rate
B. excite medullary vagal center, decrease heart rate
31.Which of the following substances is considered a vasodilator?
A. Thromboxane A2
B. Nitric Oxide
C.Endothelin
D.Angiotensin II
B. Nitric Oxide
32.Which of the following fetal tissues does NOT receive the most oxygen?
A.legs
B.heart
C.head
D.liver
A.legs
33.Which of the following does NOT describe the blood brain barrier?
A. includes the tight junction proteins and endothelial cytoskeleton
B. does not include the neurovascular unit
C. regulates ion and nutrient transport
D. limits entry of harmful substances
B. does not include the neurovascular unit
34.Which of the following factors does NOT contribute in maintaining the basal vessel tone?
A. presence of Ca++
B. nervous system
C. myogenic response to stretch
D. high PO2 of arterial blood
B. nervous system
35.What is the primary effect of norepinephrine on the vascular beds?
A. low concentrations dilate resistance vessels, high concentrations produce constriction
B. Primary vasodilation
C. high concentrations dilate resistance vessels, low concentration produce constriction
D. primary vasoconstriction
D. primary vasoconstriction
36.Which of the following events would cause the contraction of the vascular smooth muscle when considering the myogenic mechanism?
A. increase in transmural pressure
B. decrease in transmural pressure
C. decrease in metabolic activity
D. increase in metabolic activity
D. increase in metabolic activity
37.Which features of the vagus nerve exert control over the SA and AV node?
A. prolonged latency and rapid decay
B. Brief latency and slow decay
C. Prolonged latency and slow decay
D. Brief latency and rapid decay
D. Brief latency and rapid decay
38.Which of the following compensatory changes should occur when a person moves from a supine position to a standing position?
A. increase sympathetic outflow resulting to increased contractility
B. decreased venous return contributing to decreased cardiac output
C. decrease parasympathetic outflow leading to a decreased heart rate
D. activation of the vasomotor center resulting to decreased TPR
A. increase sympathetic outflow resulting to increased contractility
39.Which of the following mechanisms would explain the fall in arterial pressure upon standing up in an person who has had a sympathectomy?
A. an exaggerated response of the baroreceptor mechanism
B. a suppressed response of the brainbridge reflex
C. an exaggerated response of the brainbridge reflex
D. a suppressed response of the baroreceptor mechanism
A. an exaggerated response of the baroreceptor mechanism
40.Which of the following conditions will increase cardiac output?
A.hypertension
B.severe hypoxemia
C.supraventricular tachycardia
D.normal inspiration
D.normal inspiration