Exam 19-20 practice

1. Venoconstriction increases which of the following?

-blood pressure within the vein -blood flow within the vein -return of blood to the heart

1. Prevents backflow into the left ventricle.

Aortic semilunar valve

1. Site where resistance to blood flow is greatest.

Arterioles

1. Death of heart muscle cells.

Cardiac infarction

1. _____ is the amount of blood that collects in a ventricle during diastole (filling of ventricles)

EDV

1. Arterial blood supply to heart muscle is continuous whether the heart is in systole or diastole.

False

Arterial pressure in the pulmonary circulation is much higher than in the systemic circulation because of its proximity to the heart.

False

1. Site where the velocity of blood flow is fastest.

Large arteries

1. Prevents backflow into the right ventricle.

Pulmonary semilunar valve

1. Which component of the heart conduction system would have the slowest rate of firing?

Purkinje fibers

1. EDV - ESV =

SV

1. Endothelial cells line the interior of blood vessels and the heart.

TRUE

1. Prevents backflow into the right atrium.

Tricuspid valve

1. Which of the following would NOT result in the dilation of the feeder arterioles and opening of the precapillary sphincters in systemic capillary beds?

a local increase in pH (acidic waste)

1. Renin stimulates the release of angiotensin which stimulates the release of which hormone?

aldosterone

1. The plateau portion of the action potential in contractile cardiac muscle cells is due to:

an influx of calcium ions.

1. Which of the following is NOT part of the intrinsic conduction system of the heart?

atrioventricular (AV) valve

1. During the isovolumetric relaxation phase of the cardiac cycle, _______.

atrioventricular, aortic, and pulmonary valves are closed

1. When the left ventricle contracts, the _____ valve closes and the _____ valve is pushed open.

bicuspid; aortic

1. During the period of ventricular filling, ________.

blood flows mostly passively from the atria through the atrioventricular (AV) valves into the ventricles

1. Renin and angiontensin regulate

blood pressure

Site where exchanges of food and gases are made.

capillaries

1. The volume of blood ejected by each ventricle in one minute is called

cardiac output

1. The autorhythmicity of the heart's conductive cells is due to a pacemaker potential generated by:

constant slow leak of Na+ ions

Forcefulness of heartbeat

contractility

1. The source of blood carried to capillaries in the myocardium would be the ________.

coronary arteries

1. If cardiac muscle is deprived of its normal blood supply, damage would primarily result from ________.

decreased delivery of oxygen

1. Vasoconstriction of arteries ______ blood flow

decreases

1. Vasoconstriction of veins ______ resistance

decreases

relaxation of muscle

diastole

1. Blood flow is ________ proportional to the difference in blood pressure. Blood flow is ________ proportional to the total peripheral resistance.

directly; inversely

1. Your heart seems to "pound" after you hear a sudden, loud noise. This increased contractility is:

due to norepinephrine causing threshold to be reached more quickly

1. Autonomic regulation of heart rate is via two reflex centers found in the pons.

false

1. Heart tissue is supplied with nutrients primarily by diffusion from the heart chambers through the myocardium.

false

1. Sympathetic stimulation reduces heart rate.

false

1. A condition of rapid and irregular or out-of-phase contraction of ventricular heart muscle cells.

fibrillation

1. Which is most responsible for the synchronized contraction of cardiac muscle tissue?

gap junctions

1. Cardiac output is determined by __________.

heart rate & stroke volume

Slight vasoconstriction in an arteriole prompts a

huge increase in resistance

1. At the arterial end of the capillary bed, ____ forces dominate and fluid moves ____.

hydrostatic, out

1. Vasoconstriction of arteries ______ blood pressure

increases

1. Vasoconstriction of veins ______ blood pressure

increases

1. Osmotic pressure, created by large nondiffusible particles in the blood, tends to draw water _____ capillaries.

into

1. Initiates impulses (pacemaker) and distributes impulses throughout the heart so that it depolarizes and contracts in an orderly, sequential manner.

intrinsic conduction system

1. Vessels that carry blood away from the heart and are named by the organs they distribute to are _________.

muscular arteries

1. Which type of blood vessel has the largest amount of fibrous tissues?

muscular arteries

1. The hypoxia and tissue death caused by a blockage in coronary circulation is best described as:

myocardial infarction

1. Which portion of the ECG corresponds to repolarization of the atria?

none of the above: atrial repolarization is masked by ventricular depolarization

1. Which is NOT a factor that affects stroke volume?

pacemaker potential

1. the degree to which heart muscle cells are stretched before they contract

preload

1. Afterload is

pressure due to the volume of blood returning to the ventricle

1. Which is NOT a vessel that brings blood directly into the right atrium?

pulmonary vein

1. Isovolumetric contraction ________.

refers to the short period during ventricular systole when the ventricles are completely closed chambers

1. The ________________ is the pacemaker that initiates each heartbeat.

sinoatrial (SA) node

1. The turbulent sounds of a heart murmur due to stenosis is because

stiff valves slow movement of blood between chambers

Of the following cardiovascular components, which contains the majority of the body's blood volume at any one time?

systemic veins & venules

contraction of the muscle

systole

1. Acetylcholine (ACh) reduces heart rate.

true

1. An increase in blood viscosity will cause an increase in peripheral resistance.

true

1. Hydrostatic pressure is greater than osmotic pressure at the arterial end of capillary beds, while osmotic pressure is greater at the venule end. If these conditions are not maintained, edema is one possible result.

true

1. The adjustment of blood flow to each tissue in proportion to its requirements at any point in time is termed autoregulation.

true

1. The left side of the heart pumps the same volume of blood as the right.

true

1. The myocardium receives its blood supply from the coronary arteries.

true

1. Histologically, the ________ is squamous epithelium supported by a sparse connective tissue layer.

tunica intima

1. A decrease in O2 level in skeletal muscle would initiate an autoregulatory mechanism that would stimulate __________ in the arterioles & precapillary sphincters supplying the muscle.

vasodilation

An increasing lumen diameter is termed

vasodilation

1. Most blood at any given time is in the:

veins

1. Which of the following does NOT contribute to venous blood pressure?

venous anastomoses

1. The correct sequence of (ventricular) events of the cardiac cycle is

ventricular filling &γτ; isovolumetric contraction &γτ; ventricular ejection &γτ; isovolumetric relaxation

1. Ventricular relaxation immediately follows ________.

ventricular repolarization