Question 1

In which of the following conditions would you expect a decreased resistance to venous return?

Accepted Answer

A) Anemia 
B) Increased venous resistance 
C) Increased arteriolar resistance 
D) Increased sympathetic output 
E) Obstruction of veins 
A) Anemia 
B) Increased venous resistance 
C) Increased arteriolar resistance 
D) Increased sympathetic output 
E) Obstruction of veins A

Question 2

For the cardiac output curve defined by the solid line and the venous return curve defined by the dashed line (with equilibrium at point B), what is the resistance to venous return in units of mm Hg/L/min?

Accepted Answer

A) 1.70 
B) 1.40 
C) 1.23 
D) 0.65 
E) 0.35 
A) 1.70 
B) 1.40 
C) 1.23 
D) 0.65 
E) 0.35 D

Question 3

Which of the following will elevate the plateau of the cardiac output curve?

Accepted Answer

A) Surgically opening the thoracic cage 
B) Placing a patient on a mechanical ventilator 
C) Cardiac tamponade 
D) Decreasing parasympathetic stimulation of the heart 
E) Decreasing sympathetic stimulation of the heart 
A) Surgically opening the thoracic cage 
B) Placing a patient on a mechanical ventilator 
C) Cardiac tamponade 
D) Decreasing parasympathetic stimulation of the heart 
E) Decreasing sympathetic stimulation of the heart D

Question 4

Which of the following will usually increase the plateau level of the cardiac output curve?

Accepted Answer

A) Myocarditis 
B) Severe cardiac tamponade 
C) Decreased parasympathetic stimulation of the heart 
D) Myocardial infarction 
E) Mitral stenosis 
A) Myocarditis 
B) Severe cardiac tamponade 
C) Decreased parasympathetic stimulation of the heart 
D) Myocardial infarction 
E) Mitral stenosis

Question 5

A 40-year-old woman is hospitalized with severe anemia. This patient has a cardiac output of 12.5 L/min, oxygen consumption is 250 mL/min, and pulmonary artery oxygen concentration of 160 ml/L. What is the pulmonary vein oxygen concentration (in ml/L)?

Accepted Answer

A) 140 
B) 150 
C) 160 
D) 180 
E) 200 
A) 140 
B) 150 
C) 160 
D) 180 
E) 200

Question 6

Which of the following conditions is normally associated with an increased mean systemic filling pressure?

Accepted Answer

A) Decreased blood volume 
B) Increased venous compliance 
C) Increased arterial compliance 
D) Congestive heart failure 
E) Hypothyroidism 
A) Decreased blood volume 
B) Increased venous compliance 
C) Increased arterial compliance 
D) Congestive heart failure 
E) Hypothyroidism

Question 7

A 60-year-old woman in the intensive care unit has a large arteriovenous fistula. Her cardiac output is 10 L/min, oxygen consumption is 250 mL/min, and pulmonary vein oxygen concentration is 180 ml/L. What is the pulmonary artery oxygen concentration (in ml/L)?

Accepted Answer

A) 145 
B) 155 
C) 165 
D) 185 
E) 205 
A) 145 
B) 155 
C) 165 
D) 185 
E) 205

Question 8

For the following cardiac output and venous return curves defined by the dashed lines (with the equilibrium at B), which of the following is true?

Accepted Answer

A) Mean systemic filling pressure is 7 mm Hg 
B) Right atrial pressure is 0 mm Hg 
C) Resistance to venous return is 1.4 mm Hg/L/min 
D) Pulmonary arterial flow is approximately 7 L/min 
E) Resistance to venous return is 2.8 mm Hg/L/min 
A) Mean systemic filling pressure is 7 mm Hg 
B) Right atrial pressure is 0 mm Hg 
C) Resistance to venous return is 1.4 mm Hg/L/min 
D) Pulmonary arterial flow is approximately 7 L/min 
E) Resistance to venous return is 2.8 mm Hg/L/min

Question 9

Which of the following is normally associated with an increased cardiac output?

Accepted Answer

A) Cardiac tamponade 
B) Increased venous compliance 
C) Moderate anemia 
D) Severe aortic stenosis 
E) Surgically opening the chest 
A) Cardiac tamponade 
B) Increased venous compliance 
C) Moderate anemia 
D) Severe aortic stenosis 
E) Surgically opening the chest

Question 10

Which of the following statements about resistance to venous return (RVR) is true?

Accepted Answer

A) An increase in venous resistance causes an increase in RVR 
B) Increased parasympathetic stimulation causes an increase in RVR 
C) An increase in RVR causes an increase in venous return 
D) Sympathetic inhibition causes an increase in RVR 
E) Changes in arterial resistance have a greater effect on RVR than do equal changes in venous resistance 
A) An increase in venous resistance causes an increase in RVR 
B) Increased parasympathetic stimulation causes an increase in RVR 
C) An increase in RVR causes an increase in venous return 
D) Sympathetic inhibition causes an increase in RVR 
E) Changes in arterial resistance have a greater effect on RVR than do equal changes in venous resistance

Question 11

A patient with a resting cardiac output of 4 L/min is exercised maximally, increasing cardiac output to 8 L/min. What is the cardiac reserve?

Accepted Answer

A) 250% 
B) 200% 
C) 150% 
D) 100% 
E) 50% 
A) 250% 
B) 200% 
C) 150% 
D) 100% 
E) 50%

Question 12

Which of the following normally causes the cardiac output curve to shift to the right along the right atrial pressure axis?

Accepted Answer

A) Changing intrapleural pressure to -6 mm Hg 
B) Increasing mean systemic filling pressure 
C) Taking a patient off a mechanical ventilator and allowing normal respiration 
D) Surgically opening the chest 
E) Breathing against a negative pressure 
A) Changing intrapleural pressure to -6 mm Hg 
B) Increasing mean systemic filling pressure 
C) Taking a patient off a mechanical ventilator and allowing normal respiration 
D) Surgically opening the chest 
E) Breathing against a negative pressure

Exam 20: Cardiac Output, Venous Return, and Their Regulation

In which of the following conditions would you expect a decreased resistance to venous return?

For the cardiac output curve defined by the solid line and the venous return curve defined by the dashed line (with equilibrium at point B), what is the resistance to venous return in units of mm Hg/L/min?

Which of the following will elevate the plateau of the cardiac output curve?

Which of the following will usually increase the plateau level of the cardiac output curve?

A 40-year-old woman is hospitalized with severe anemia. This patient has a cardiac output of 12.5 L/min, oxygen consumption is 250 mL/min, and pulmonary artery oxygen concentration of 160 ml/L. What is the pulmonary vein oxygen concentration (in ml/L)?

Which of the following conditions is normally associated with an increased mean systemic filling pressure?

A 60-year-old woman in the intensive care unit has a large arteriovenous fistula. Her cardiac output is 10 L/min, oxygen consumption is 250 mL/min, and pulmonary vein oxygen concentration is 180 ml/L. What is the pulmonary artery oxygen concentration (in ml/L)?

For the following cardiac output and venous return curves defined by the dashed lines (with the equilibrium at B), which of the following is true?

Which of the following is normally associated with an increased cardiac output?

Which of the following statements about resistance to venous return (RVR) is true?

A patient with a resting cardiac output of 4 L/min is exercised maximally, increasing cardiac output to 8 L/min. What is the cardiac reserve?

Which of the following normally causes the cardiac output curve to shift to the right along the right atrial pressure axis?

Functional Organization of the Human Body and Control of the Internal Environment

The Cell and Its Functions

Genetic Control of Protein Synthesis, Cell Function, and Cell Reproduction

Transport of Substances Through Cell Membranes

Membrane Potentials and Action Potentials

Contraction of Skeletal Muscle

Excitation of Skeletal Muscle: Neuromuscular Transmission and Excitation-Contraction Coupling

Excitation and Contraction of Smooth Muscle

Cardiac Muscle; the Heart As a Pump and Function of the Heart Valves

Rhythmical Excitation of the Heart

The Normal Electrocardiogram

Electrocardiographic Interpretation of Cardiac Muscle and Coronary Blood Flow Abnormalities: Vectorial Analysis

Cardiac Arrhythmias and Their Electrocardiographic Interpretation

Overview of the Circulation; Biophysics of Pressure, Flow, and Resistance

Vascular Distensibility and Functions of the Arterial and Venous Systems

The Microcirculation and Lymphatic System: Capillary Fluid Exchange, Interstitial Fluid, and Lymph Flow

Local and Humoral Control of Tissue Blood Flow

Nervous Regulation of the Circulation and Rapid Control of Arterial Pressure

Role of the Kidneys in Long-Term Control of Arterial Pressure and in Hypertension: the Integrated System for Arterial Pressure Regulation

Muscle Blood Flow and Cardiac Output During Exercise; the Coronary Circulation and Ischemic Heart Disease

Cardiac Failure

Heart Valves and Heart Sounds; Valvular and Congenital Heart Defects

Circulatory Shock and Its Treatment

The Body Fluid Compartments: Extracellular and Intracellular Fluids; Edema

Red Blood Cells, Anemia, and Polycythemia

Resistance of the Body to Infection: I Leukocytes, Granulocytes, the Monocyte-Macrophage System, and Inflammation

Resistance of the Body to Infection: Ii Immunity and Allergy

Blood Types; Transfusion; Tissue and Organ Transplantation

Hemostasis and Blood Coagulation

Pulmonary Ventilation

Pulmonary Circulation, Pulmonary Edema, Pleural Fluid

Physical Principles of Gas Exchange; Diffusion of Oxygen and Carbon Dioxide Through the Respiratory Membrane

Transport of Oxygen and Carbon Dioxide in Blood and Tissue Fluids

Regulation of Respiration

Respiratory Insufficiencypathophysiology, Diagnosis, Oxygen Therapy

Aviation, High Altitude, and Space Physiology

Physiology of Deep-Sea Diving and Other Hyperbaric Conditions

Organization of the Nervous System, Basic Functions of Synapses, and Neurotransmitters

Sensory Receptors, Neuronal Circuits for Processing Information

Somatic Sensations: I General Organization, the Tactile and Position Senses

Somatic Sensations: II Pain, Headache, and Thermal Sensations

The Eye: I Optics of Vision

The Eye: II Receptor and Neural Function of the Retina

The Eye: III Central Neurophysiology of Vision

The Sense of Hearing

The Chemical Sensestaste and Smell

Motor Functions of the Spinal Cord; the Cord Reflexes

Cortical and Brain Stem Control of Motor Function

Contributions of the Cerebellum and Basal Ganglia to Overall Motor Control

Cerebral Cortex, Intellectual Functions of the Brain, Learning, and Memory

Behavioral and Motivational Mechanisms of the Brainthe Limbic System and the Hypothalamus

States of Brain Activitysleep, Brain Waves, Epilepsy, Psychoses, and Dementia

The Autonomic Nervous System and the Adrenal Medulla

Cerebral Blood Flow, Cerebrospinal Fluid, and Brain Metabolism

General Principles of Gastrointestinal Functionmotility, Nervous Control, and Blood Circulation

Propulsion and Mixing of Food in the Alimentary Tract

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