Physiology I Exam 2 Flashcards
During the conduction of a signal from the SA node to the ventricular fibers, there is a .16 second delay from the initial origin of the signal until onset of ventricular contraction. More than half of this delay occurs in which of the following areas of the transmission pathway? SA Node AV Node SA Fibers Penetrating Bundles
AV Node
In a typical ECG, which of the following waves occurs at the beginning of the contraction of the atria? T R S P Q
P
Which of the following events is generally not seen on a typical ECG? Atrial Depolarization Atrial Repolarization Ventricular Depolarization Ventricular Repolarization
Atrial Repolarization
Which of the following is the direction of bipolar lead III? 0 60 90 120
120
Of the three bipolar leads, which one is connected to both left and right arms? Lead I Lead II Lead III All leads are connected to only one arm each
Lead I
Of the three bipolar leads, which one would have the highest amplitude for the normal QRS wave, and which of the following reasons would explain this high amplitude? Lead I, because it is most perpendicular to the vector for the depolarization wave Lead I because it is most parallel to the vector for the depolarization wave Lead II, because it is most perpendicular to the vector for the depolarization wave Lead II, because it is most parallel to the vector for the depolarization wave
Lead II, because it is most parallel to the vector for the depolarization wave
Which of the following represents the mean electrical axis of the normal ventricles? 59 67 120 157 270
59
Which of the following conditions may result in tachycardia? Toxic conditions of the heart Increased body temperature Sympathetic nerve stimulation All of the above B and C only
All of the above
In the ECG shown below, which of the following heart activities is represented (Lead III)? (ATTACH) Sinus tachycardia Sinus bradycardia Complete AV block Incomplete second degree block with dropped beats
Sinus bradycardia
The electrocardiogram below indicates which of the following conditions? (ATTACH) Tachycardia Bradycardia SA node block AV block
AV block
Circus movement are the basis of heart fibrillation. Which of the following statements is not true? Fibrillation may occur when the refractory period of the muscle is greatly shortened. Fibrillation may occur when the pathway around the circle is too short Fibrillation may occur when the conduction velocity slows down Fibrillation may occur when the heart becomes dilated
Fibrillation may occur when the pathway around the circle is too short
84% of the blood volume is in the systemic circulation. Of this, 64% is in which of the following vessels? Capillaries Systemic Arterioles Veins Arterioles
Veins
Blood flow resistance is inversely (indirectly) proportional to which of the following? Viscosity Vessel Diameter Density Viscosity and Density
Vessel Diameter
If rate of blood flow through the entire circulatory system (= cardiac output) = 100 mL/sec AND the pressure difference from the systemic arteries to the systemic veins = 100 mm Hg; the total peripheral resistance is equal to…? 10 PRU 1 PRU .01 PRU 100,000 PRU
1 PRU
Reynolds number is a measure of which of the following parameters? Tendency for turbulence Blood pressure Conductance Resistance
Tendency for turbulence
Which of the following represents the viscosity of blood with a hematocrit of 38-42? 1.5 3.0 38 42
3.0
Consider the following statements: 1. Veins are about 8 times more distensible than arteries. 2. Vascular compliance is directly proportional to volume increase and indirectly proportional to pressure. Only statement 1 is true Only statement 2 is true Both statements are true Both statements are false
Both statements are true
Which of the following properties is a measure of the ease with which a hollow viscus may be distended? Elastance Compliance Resistance Distensibility
Compliance
Which of the following relationships is correct? The greater the amount of elastic tissue in a blood vessel, the higher the compliance and lower the elastance The greater the amount of elastic tissue in a blood vessel, the higher the compliance and the elastance The greater the amount of the elastic tissue in a blood vessel, the lower the compliance and the elastance The greater amount of elastic tissue in a blood vessel, the lower the compliance and the greater the elastance
The greater amount of elastic tissue in a blood vessel, the lower the compliance and the greater the elastance
High resistance in which of the following groups of vessels results in disappearance in the phasic pressure pattern such as seen in the aorta? Pulmonary arteries Systemic arterioles Systemic veins Pulmonary capillaries
Systemic arterioles
The least amount of damping of the pressure pulses would occur in which of the following components of the circulatory system? Femoral artery Arterioles Capillaries Venules
Femoral Artery
Precapillary sphincters are associated with which of the following types of vessels? Small arteries Arterioles Metarterioles Capillaries
Metarterioles
The forces that determine whether fluid will move out of the blood into the interstitial fluid or in the opposite direction are referred to as Starling Forces. Which of the following forces tends to move fluid inward at the arterial end of the capillary? Capillary hydrostatic pressure Negative interstitial free fluid pressure Plasma colloid osmotic pressure Interstitial fluid colloid osmotic pressure
Plasma colloid osmotic pressure
If mean capillary pressure is 17.3 mm Hg; and negative interstitial free fluid pressure is 3.0 mm Hg; and interstitial fluid colloid osmotic pressure is 8.0 mm Hg; and plasma colloid osmotic pressure is 28.0 mm Hg; what is the total inward force? 17.3 mm Hg 20.3 mm Hg 28.0 mm Hg 28.3 mm Hg
28.0 mm Hg
In any tissue in the body, a rapid increase in arterial pressure causes an immediate rise in blood flow. But within less than a minute, the blood flow in most tissues returns almost to the normal level even though the arterial pressure is kept elevated. This return of flow toward normal is due to which of the following events? Autoregulation of blood flow Tubuloglomerular feedback Sympathetic response Means systemic pressure feedback
Autoregulation of blood flow
Which of the following factors is most responsible for controlling the rate of blood flow to each tissue of the body so that it is precisely controlled in relation to tissue need? Sympathetic System Renin-Aldosterone-Angiotensinogen system Oxygen and accumulation of tissue waste product Constriction of large venous reservoirs
Oxygen and accumulation of tissue waste product
Which of the following substances would not result in vasoconstriction? Epinephrine/Norepinephrine Angiotensin II Nitric Oxide Endothelin
Nitric Oxide
Signals from peripheral barorecptors have which of the following effect(s) on the cardiac centers in the brain stem? Inhibit vasoconstrictor and excite vasodilator centers Inhibit both vasoconstrictor and vasodilator centers Inhibit vasodilator and excite vasoconstrictor centers Excite both vasoconstrictor and vasodilator centers
Inhibit vasoconstrictor and excite vasodilator centers
Which of the following factors results in decreased peripheral resistance (vessel dilation) leading to decreased blood pressure? Increased production of angiotensin II Increased release of thromboxane Increased release of catecholamines Increased atrionatriuretic peptide (ANP)
Increased atrionatriuretic peptide (ANP)
Which of the following factors is related to primary (essential) hypertension? Sedentary life style Pre-eclampsia Renal artery constriction Coarctation of the aorta
Sedentary life style
Characteristics of primary hypertension would not include which of the following? Sympathetic nerve activity Increase in cardiac output Activation of renal-pressure natriuresis mechanism Increased levels of angiotensin II and aldosterone in obese patients
Activation of renal-pressure natriuresis mechanism
Angiotensinogen is converted to angiotensin I by renin. Angiotensin I is then converted to angiotensin II, which then results in an increase in extracellular fluid volume. Angiotensinogen is derived from which of the following sources? Kidney Liver Adrenal Cortex Adrenal Medulla
Liver
Blocking of the renin-angiotensin mechanism would have which of the following effects on arterial pressure? It would have no effect on arterial pressure It would result in sodium and water retention and increased arterial pressure It would result in sodium and water retention and decreased arterial pressure It would result in sodium and water loss and increased arterial pressure It would result in sodium and water loss and decreased arterial pressure
It would result in sodium and water loss and decreased arterial pressure
Using the Fick Principle for calculating the cardiac output, the patient’s oxygen consumption volume could be divided by which of the following? The difference between the oxygen concentration in the systemic arterial blood and the systemic mixed venous blood The difference between the oxygen concentration in the systemic arterial blood and the pulmonary vein The difference between the oxygen concentration in the systemic mixed venous blood and the pulmonary vein The difference between the oxygen concentration in the systemic mixed venous blood and the pulmonary artery
The difference between the oxygen concentration in the systemic arterial blood and the systemic mixed venous blood
Which of the following factors would cause a hypereffective heart? Hypertrophy of the heart Valvular heart disease Inhibition of nervous excitation of the herat Coronary artery blockage
Hypertrophy of the heart
A certain dietary deficiency condition weakens the heart. Under these conditions, if the systemic filling pressure is 11.5, the right atrial pressure is 9 mm Hg, and the cardiac output is 8 L/min, this type of heart failure would be best referred to as which of the following? Low-output cardiac failure Left-right cardiac shunt Right-left cardiac shunt High-output cardiac failure
High-output cardiac failure
Which of the following factors is NOT quantitatively expressed on the venous return curve? Mean systemic filling pressure Right arterial pressure Blood flow resistance between peripheral vessels and right atrium Cardiac output
Cardiac output
An increase in blood volume would have which of the following effects on the cardiac and vascular function curves? A decrease in mean systemic pressure and a shift of the vascular function curve to the right. A decrease in mean systemic pressure and a shift of the vascular function curve to the left. An increase in mean systemic pressure and a shift of the vascular function curve to the right. An increase in mean systemic pressure and a shift of the vascular function curve to the left.
An increase in mean systemic pressure and a shift of the vascular function curve to the right.
During exercise, total peripheral resistance decreases because of the effect of which of the following? The sympathetic nervous system on splanchnic vessels The parasympathetic nervous system on skeletal muscle arterioles Local metabolites of skeletal muscle arterioles Local metabolites on cerebral arterioles
Local metabolites of skeletal muscle arterioles
When both the mean systemic filling pressure and right atrial pressure are 7, what is the venous return rate? 5.2 LPM 5 LPM 4 LPM 0 LPM
0 LPM
Which of the following would not occur as a result of a mass discharge of the sympathetic system during exercise? Strong contraction of the coronary arteries Increase in the mean systemic filling pressure due to contraction of the muscle walls of veins Increase in heart rate Strong contraction of most peripheral arteries
Strong contraction of the coronary arteries
Which of the following is the primary controller of coronary artery blood flow? Sympathetic innervations Parasympathetic innervations Local muscle metabolism Systemic venous resistance
Local muscle metabolism
Which of the following mechanisms would most likely serve as the major immediate factor in compensating for an acute myocardial infarction? Renal angiotensin system Aldosterone Sympathetic response Intravenous fluid therapy
Sympathetic response
Which of the following pairs of potentially fatal condition may follow severe acute left heart failure? Pulmonary vascular congestion and pulmonary edema Systemic vascular congestion and pulmonary edema Systemic vascular congestion and systemic edema Pulmonary vascular congestion and systemic edema
Pulmonary vascular congestion and pulmonary edema
The second heart sound is due to which of the following events? Closure of atrioventricular valves at onset of ventricular systole Opening of atrioventricular valves at onset of atrial systole Closure of semilunar valves at onset of ventricular diastole Opening of semilunar valves at onset of ventricular diastole
Closure of semilunar valves at onset of ventricular diastole
Compared to non-progressive shock, which one of the following is one of the most important features of progressive shock? Sympathetic reflexes Hemorrhagic in origin Cardiac depression Increased vascular permeability
Hemorrhagic in origin
Spinal anesthesia has which of the following effects on cardiac output and venous return? It decreases venous return but increases cardiac output It decreases venous return and cardiac output It increases venous return but decreases cardiac output It increases venous return and cardiac output
It decreases venous return and cardiac output
Which of the following conditions increases the systemic filling pressure by decreasing vascular compliance? Lying down Renal-angiotensin-aldosterone system Burn trauma Inhibition of the sympathetic system
Lying down
ADH is formed in the supraoptic and paraventricular nuclei. It is secreted by specialized neurons from which of the following areas? Adrenal cortex Adrenal medulla Anterior pituitary Posterior pituitary
Posterior pituitary
Which of the following factors would decrease venous return and increase right atrial pressure? Hemorrhage Vasodilation of arterioles Decreased venous compliance Increased ADH secretion
Hemorrhage
Which of the following substances would result in vasodilation? Epinephrine/Norepinephrine Angiotensin II Nitric Oxide Endothelin
Nitric Oxide
Vascular distensibility is directly proportional to which of the following? Increase in volume Original volume Increase in pressure Original Pressure Increase in volume and pressure
Increase in volume
Which of the following properties is a measure of the ease with which a hollow structure may be distended? Elastance Compliance Resistance Distensibility
Compliance
Which of the following factors affect(s) pulse pressure? Vascular elastance Arterial compliance Stroke Volume All of the above B and C only
B and C only
Which of the following is the most important means for the exchange of substances between the blood and the interstitial fluid? Blood hydrostatic pressure Capillary oncotic pressure Diffusion Interstitial fluid hydrostatic pressuure Osmosis
Diffusion
Baroreceptors are extremely abundant in carotid sinuses and the walls of the aortic arch. Which of the following transmits signals from baroreceptors to cranial nerve IX (glossopharyngeal nerve)? Mueller nerves Hering nerves Starling nerves Purkinje nerves
Hering nerves
Approximately how much of the total cardiac output is received by the kidneys? 25% 50% 75% 100%
25%
Which of the following describes the effects of adding hypertonic sodium chloride to extracellular fluid after osmotic equilibrium is reached? Both extracellular and intracellular volume decrease and osmolarity in both compartments increases The extracellular volume decreases and the intracellular volume increases; osmolarity in both compartments increases The extracellular volume increases and the intracellular volume decreases; osmolarity in both compartments increases Both extracellular and intracellular volume increase and osmolarity in both compartments increases
The extracellular volume increases and the intracellular volume decreases; osmolarity in both compartments increases
The osmolar gap can be determined from the basic metabolic profile and helps to narrow the differential diagnosis. Which of the following can elevate the osmolar gap? Ethanol Glycerol Sucrose Glucose
Ethanol
Which of the following characteristics would be true for cortical nephrons? Glomeruli lie deep in the cortex near the medulla of the kidney and have short loops of Henle Glomeruli lie deep in the cortex near the medulla of the kidney and have long loops of Henle Glomeruli lie in the outer cortex and have short loops of Henle Glomeruli lie in the outer cortex and have long efferent arterioles
Glomeruli lie in the outer cortex and have short loops of Henle
The electrocardiogram below indicates which of the following conditions? Tachycardia Bradycardia SA node block AV node block
Tachycardia
