Systems Phys final questions

Which set of physiological changes would be expected to occur in response to the decrease in diameter?

Decrease in vascular conductance, capillary filtration, and blood flow

Which mechanism is associated with the 3rd heart sound? A. In rushing of blood into the ventricles as a result of atrial contraction B. Closing of the AV valve C. Closing of the pulmonary valve D. Opening of the AV valve E. In rushing of blood into the ventricles in the early to middle part of diastole

E. In rushing of blood into the ventricles in the early to middle of diastole

Sympathetic stimulation of the heart normally causes which condition? A. ACh release at the sympathetic endings B. Decreased heart rate C. Decreased rate 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

Which phase of the cardiac cycle immediately follows the bringing of the QRS wave? A. Isovolumic relaxation B. Ventricular ejection C. Atrial systole D. Diastasis E. Isovolumic contraction

E. Isovolumic contraction

A 65 YO man has congestive heart failure. He has a cardiac output of 4L/min, arterial pressure of 115/85 mm Hg, and a HR of 90beats/min. Further tests by a cardiologist reveal he has a right atrial pressure of 10mmHg. An increase in which of the following would be expected? A. Plasma colloid osmotic pressure B. Interstitial colloid osmotic pressure C. Arterial pressure D. Cardiac output E. Vena cava hydrostatic pressure

E. Vena cava hydrostatic pressure

Which statement about the results of sympathetic stimulation is most accurate? A. Epicardial flow increases B. Venous resistance decreases C. Arteriolar resistance decreases D. Heart rate decreases E. Venous reservoirs constrict

E. Venous reservoirs constrict

Equation for ejection fraction

EF = SV / EDV

When recording lead I in an ECG, the right arm is the negative electrode and the positive electrode is the A. Left arm B. Left leg C. Right leg D. Left arm and leg

A. Left arm

When recording lead II on an ECG, the negative electrode is the A. Right arm B. Left leg C. Left arm and left leg D. Left leg

A. Right arm

An increase in which of the following would be expected to decrease blood flow in a vessel? A. Pressure gradient across the vessel B. Readies of the vessel C. Plasma colloid osmotic pressure D. Viscosity of the blood E. Plasma sodium concentration

D. Viscosity of the blood

What is the membrane potential (threshold level) at which the SA node discharges? A. -40 mV B. -55 mV C. -65 mV D. -85 mV E. -105 mV

A. -40 mV

If the SA node discharges at 0 sec, when will the action potential normally arrive at the AV node? A. 0.03 sec B. 0.09 sec C. 0.12 sec D. 0.16 sec D. 0.80 sec

A. 0.03 sec

If the SA node discharges at 0 sec, when will the action potential normally arrive at the epicardial surface at the base of the left ventricle? A. 0.22 sec B. 0.18 sec C. 0.16 sec D. 0.12 sec E. 0.09 sec

A. 0.22 sec

If the purkinje fibers, situated distal to the AV junction, became the pacemaker of the heart, what is the expected heart rate? A. 30/min B. 50/min C. 60/min D. 70/min E. 80/min

A. 30/min

Which vasoactive agent is usually the most important controller of coronary blood flow? A. Adenosine B. Bradykinin C. Prostaglandins D. Carbon dioxide E. Potassium ions

A. Adenosine

Which of the following segments of the circulatory system has the highest velocity of blood flow? A. Aorta B. Arteries C. Capillaries D. Venules E. Veins

A. Aorta

If a person has been exercising for 1 hour, which organ will have the smallest decrease in blood flow? A. Brain B. Intestines C. Kidneys D. No exercising skeletal muscle E. Pancreas

A. Brian

At the onset of exercise, the mass sympathetic NS strongly discharges. What would you expect to occur? A. Increased sympathetic impulses to the heart B. Decreases coronary blood flow C. Decreased cerebral blood flow D. Reverse stress relaxation E. Venous dilation

A. Increased sympathetic impulses to the heart

What is the delay between the SA node discharges and arrival of the action potential at the ventricular septum? A. 0.80 sec B. 0.16 sec C. 0.12 sec D. 0.09 sec E. 0.03 sec

B. 0.16 sec

Which of the following is associated with the first heart sound? A. In rushing of blood into the ventricles as a result of atrial contraction B. Closing of the AV valve C. Closing of the pulmonary valve D. Opening of the AV valve E. In rushing of blood into the ventricles in the early to middle part of diastole

B. Closing of the AV valve

Which condition will result in flaccid heart? A. Excess calcium ions in the blood B. Excess K+ ions in the blood C. Excess sodium ions in the blood D. Increased sympathetic stimulation E. Increase NE concentration in the blood

B. Excess K+ ions in blood

At the onset of exercise, what normally occurs? A. Decreased cerebral blood flow B. Increased venous constriction C. Decreased mean systemic filling pressure D. Decreased coronary blood flow E. Increased parasympathetics impulses to the heart

B. Increases venous constriction

When recording lead II in an ECG, the right arm is the negative electrode and the positive electrode is the A. Left arm B. Left leg C. Right leg D. Left arm and left leg E. Right arm and left leg

B. Left leg

Which statement about cardiac muscle is most accurate? A. The t-tubules of cardiac muscle can store much less calcium than the t-tubules in skeletal muscle B. The strength and contraction of cardiac muscle depends on the amount of calcium surrounding cardiac myocytes C. In cardiac muscle, the initiation of the AP causes can immediate opening of slow calcium channels D. Cardiac muscle depolarization is caused by opening of sodium channels E. Mucopolysaccharides inside the t tubules bind chloride ions

B. The strength and contraction of cardiac muscle depends on the amount of calcium surrounding cardiac myocytes

Which of the following structures will have the slowest rate of conduction of the cardiac action potential? A. Atrial muscle B. Anterior intermodal pathway C. AV bundle fibers D. Purkinje fibers E. Ventricular muscle

C. AV bundle fibers

Which of the following vessels has the greatest total cross-sectional area in the circulatory system? A. Aorta B. Small arteries C. Capillaries D. Venules E. Vena cava

C. Capillaries

Which event normally occurs during exercise? A. Arteriolar dilation in non-existing muscle B. Decreased sympathetic output C. Venoconstriction D. Decreased release of epinephrine by the adrenals E. Decreased release of NE by the adrenals

C. Venoconstriction

Equation for cardiac output

CO = SV x HR

Which best explains how sympathetic stimulation effects the heart? A. The permeability of the SA node to sodium decreases B. The permeability of the AV node to sodium decreases C. The permeability of the SA node to potassium increases D. There is an increased rate of upward drift of the resting membrane potential of the SA node E. The permeability of the cardiac muscle to calcium decreases

D. There is an increased rate of upward drift of the resting membrane potential of the SA node

If the SA node discharges at 0 seconds, when will the action potential normally arrive at the AV bundle (bundle of his)? A. 0.22 sec B. 0.18 sec C. 0.16 sec D. 0.12 sec E. 0.09 sec

D. 0.12 sec

What is the normal time delay of the cardiac impulse in the AV node + bundle? A. 0.22 sec B. 0.18 sec C. 0.16 sec D. 0.13 sec E. 0.09 sec

D. 0.13 sec

In which phase of ventricular muscle action potential is K+ permeability is the highest? A. 0 B. 1 C. 2 D. 3 E. 4

D. 3

Which condition at the AV node will cause heart rate to decrease? A. Increased sodium permeability B. Decreased ACh level C. Increased NE level D. Increased potassium permeability E. Increased calcium permeability

D. Increased K+ permeability

Which condition at the SA node will cause heart rate to decrease? A. Increased NE level B. Increased sodium permeability C. Increased calcium permeability D. Increased potassium permeability E. Decreased ACh level

D. Increased K+ permeability

Which condition at the AV node will cause a decrease in heart rate? A. Increased sodium permeability B. Decreased ACh levels C. Increased NE levels D. Increased potassium permeability E. Increased calcium permeability

D. Increased potassium permeability

What happens at the end of isovolumic relaxation? A. The AV valve close B. The aortic valve opens C. The aortic valve opens D. The mitral valve opens E. The pulmonary valve closes

D. Mitral and tricuspid valve open

Sympathetic of the heart does what? A. Releases ACh at the sympathetic endings B. Decreases sinus nodal discharge rate C. Decreases excitability of the heart D. Releases NE at the sympathetic endings E. Decreases cardiac contractility

D. Releases NE at sympathetic endings

The tendency for turbulent flow is greatest in which of the following? A. Arterioles B. Capillaries C. Small arterioles D. Aorta

D. Small arterioles

What is the normal QT interval? A. 0.03 sec B. 0.13 sec C. 0.16 sec D. 0.20 sec E. 0.35 sec

E. 0.35 sec

A 25 year old athlete weighs 80 kg. 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

The diameter of a arteriole is increased in a muscle bed. A decrease in which of the following would be expected? A. Capillary filtration rate B. Vascular conductance C. Capillary blood flow D. Capillary hydrostatic pressure E. Arteriolar resistance

E. Arteriolar resistance

Which of the following would cause the heart to go into spastic contraction? A. increased body temperature B. Increased sympathetic activity C. Decreased extracellular fluid potassium ions D. excess extracellular fluid potassium ions E. Excess extracellular fluid calcium ions

E. Excess extracellular fluid calcium ions

What changes would be expected in response to a hemorrhage?

Increased heart rate, sympathetic nerve activity, and total peripheral resistance