Practice Questions Phys 11-20

Through action of beta1 receptors, this part of the ANS will increase HR, conduction velocity, and contractility

Which of the following mechanisms is responsible for increasing the rate of relaxation of heart muscle?

Cardiac glycosides have positive ionotropic effects by inhibitng the Na/K ATPase pump. Ultimately, this inhibition will

Conduction time through the AV node is included in the

Blood is distributed unevenly to tissues based on ____ demand

Stroke volume generally equals

During which phase of the ventricular action potential, phase 0 or 4, is inward current greater than outward current

Which of the following produce(s) an increase in contractility:

In phase 0 of an action potential of the heart, this event occurs

The QRS complex of an ECG represents

Baroreceptors are pressure sensors located in the walls of the carotid sinus and aortic arch. Function is to

During ventricular filling, lV pressure increases dramatically as blood enters from the left atrium

Among the responses that occur following hemorrhage, which of the following increases:

During which portion of the cardiac cycle is the mitral valve closed?

The P wave of an ECG represents

For most species, aortic pressure averages ____ and right atrial pressure averages ____

Activation of the SNS will cause vasoconstriction of vascular smooth muscle via these receptors

Blood vessel A has an area of 1cm; blood vessel B has an area of 10cm. If blood flow is equal, which velocity is higher?

If there is an increased rate of phase 4 depolarization and hyperpolarization of the threshold potential this occurs:

The unstressed volume is the volume of blood in the arteris, while stressed volume is the volume of blood in the veins

Frank-Starling Law says that when all other factors remain constant, increase in CO will increase in response to EDV

If afterload increases, aortic pressure ____, stroke volume/cardiac output ____, and EDV ____

The most important mechanism controlling the following circulations is local metabolic control:

Starling's Law of the capillary (old) states that:

An AP in the heart has 5 phases. In phase 2, this ion enters the cell and is responsible for the plateau of the AP

Increased activity of the SNS increases the stroke volume; this is a result of the action of the SNS on which cell?

This ion is the main contributor to the resting membrane potential in cardiac cells

The increase in HR in response to greater sympathetic stimulation is related to

This hormone is an important indicator of early heart failure; released by the atria due to increased atrial pressure

The SNS will have all of the following effects on the cardiovascular system except:

On an ECG, ventricular arrhythmias would be indicated by a prolonged

Blood flow to the heart itself is maximal during

During this refractory period, a stimulus may locally excite tissue, but conduction of AP can't occur

While there is inward current of Na+ in the SA and AV nodes during depolarization, the most important current in AP is

Aldosterone secretion will increase when

The wave for this event is usually very small and buried in the QRS complex

The primary force causing fluid movement (filtration) out of the capillaries is

What are the units of hemodynamic resistance?

RBC are smaller in size than the diameter of capillaries and are able to easily flow through them

The effect of preload on the ventricular cycle is a(n) ____ in EDV due to a(n) ____ in venous return

The volume ejected during a single heart beat (stroke volume) and number of beats per minute (HR) will determine

The valve located between the right atrium and right ventricle is the ____ valve

The majority of blood volume (60%+) exists in which vessels at any given time?

During ventricular ejection, ventricular pressure must become higher than aortic pressure then all blood is ejected

When the left ventricle contracts, blood moves into the ____ artery

As this vessel decreases in diameter, it becomes sensitive to low O2 levels and will constrict to shunt blood to lungs

The Reynolds number predicts the ____ of blood

During this refractory period, even a large stimulus cannot cause another AP

In this cardiac tissue, there is no plateau during an action potential:

The difference in systolic and diastollic blood pressure determines:

If tension in the ventricular wall increases, myocardial oxygen consumption increases

In laminar blood flow, flow near the wall of the vessel is stationary and velocity near the center of vessel is highest

What is the name of the volume contained in the left ventricle immediately before it contracts?

As HR increases, intracellular Ca2+ concentrations increase due to more Ca2+ entering cell and more AP per unit time

During disease, these vital organs (vessel-rich tissues) receive preferential blood flow:

Which of the following actions will slow the heart?

Which of the following are mediated by an increase in intracellular Ca2+:

If blood volume decreases, this hormone would be released

The amount of blood flowing out the right ventricle is identical to the amount of blood flowing out the left ventricle

During isovolumetric contraction of the left ventricle, pressure increases and

During Excitation-Contraction coupling, intracellular Ca2+ rises and triggers more release of Ca2+ from the SR via

A contraction in the heart occurs from

The T wave of an ECG represents

Veins have a large capacitance (compliance), which means as pressure increases, volume in veins will

Which of the following circulations receives the highest percentage of cardiac output?

Which portion of the cardiac cycle has the lower ventricular volume?

In the myogenic mechanism of autoregulation, according to Law of LaPlace, does an increase in pressure lead to

If the rate of venous return to the heart is increases, each of the following events will occur except:

Resistances in parallel will ____ overall resistance

According to the ventricular pressure-volume loop, increase in afterload produces an increase in:

In the revised law, how does interstitial fluid move back into the general circulation?

The valve located between the left atrium and left ventricle is the ____ valve

When a person moves quickly from a lying to a standing position, which of the following decreases?

The main pacemaker in the heart is the:

When the left ventricle contracts and the mitral valve closes, this coincides with

As the radius of a blood vessel increases in size, resistance in that vessel will:

According to the cardiac and vascular function curves, an increase in TPR leads to _ venous return and _ cardiac output

During breathing, it is possible for the pressure in the right atrium to become negative

During exercise, which of the following decrease?

Revised version of Starling's Law of the capillary states that

By the cardiac and vascular function curves, an increase in blood volume leads to ___ right atrial pressure and ___ CO

Which situation is associated with the higher efficiency of myocardial oxygen consumption

As the left ventricle contracts, first 1/3 of aorta expands; as LV relexes, expansion will contract to ensure blood flow

Which vessels are the major resistance vessels and are subject to neurochemical regulation?

Muscarinic receptors are used in the ____ nervous system

The rate-limiting step in conducting actionpotentials through the heart is:

Two vessels that supply blood to the heart are the:

Which term best applies to the ARP of the ventricular action potential:

Higher Ca+ concentrations within a myocardial cell correlate with

Which of the following will decrease cardiac output?