Ch. 14 Pearson Quiz – Flashcards

Arteries are most accurately defined as blood vessels that ________. a) carry highly oxygenated blood b) carry blood away from the heart c) carry deoxygenated blood d) carry blood toward the heart

Which of these is the best definition of an artery? a) A vessel that has a large amount of smooth muscle in its wall. b) A vessel that carries oxygenated blood c) A vessel that carries blood away from the heart d) A vessel that can change its diameter.

Which blood vessels return blood to the heart? a) capillaries b) veins c) atria d) arteries

Why does blood flow through the cardiovascular system? a) Because cells need blood to survive b) So that oxygen and nutrients can get to all parts of the body c) Because the heart establishes a pressure gradient d) Because without blood flow a person could not survive

As blood flows away from the heart, how does overall blood pressure in vessels change? Why? a) Blood pressure decreases, because blood vessels are passive and cannot exert any force on the moving blood. b) Blood pressure increases, because vessel diameter narrows with distance from the heart, which increases the force on the blood. c) Blood pressure decreases, because of the effects of friction between the vessel walls and the moving blood. d) Blood pressure increases. Otherwise the blood would not flow up toward the heart.

Blood flows through a vessel at a particular flow rate and velocity. What happens to the velocity of the blood flow through that vessel after it constricts, narrowing its diameter? You may assume that the flow rate is unchanged. a) Velocity increases. b) Velocity will not change. c) Velocity decreases. d) There is not enough information to answer the question.

Which blood vessels have the lowest blood pressure? a) Venules b) Capillaries c) Veins d) Arteries

Why does the pressure in the arteries and arterioles fall as the blood moves away from the heart? a) Friction causes a loss of energy. b) The arterial vessels get smaller as they get farther from the heart. c) There is less blood in each vessel. d) Heat is lost to the environment.

Which of these would cause an increase in blood flow through a vessel? a) Vasodilation b) Vasoconstriction c) Increased blood viscosity d) Increased vessel length

Which would have the highest flow rate? Tube 1: water flowing in a 4 cm long tube with radius of 4 mm Tube 2: water flowing in a 2 cm long tube with a radius of 8 mm Tube 3: blood flowing in a 4 cm long tube with a radius of 4 mm a) Tube 1 and 2 equally b) Tube 1 c) Tube 3 d) Tube 2

Through which valve must blood pass as it moves from the right atrium to the right ventricle? a) Bicuspid b) Tricuspid c) Aortic d) Mitral

What is the role of heart valves? a) Heart valves ensure one-way flow of blood through the coronary circulation. b) Heart valves ensure one-way flow of blood through the heart chambers. c) Heart valves contain the pacemaker cells, which determine cardiac rhythm. d) Heart valves regulate the volume of blood entering the chambers and are a location where this volume is regulated according to the demands of the body.

Which cells act as the heart's pacemaker? Why are they the pacemaker cells? a) Cells of the SA node are the usual pacemaker, because they are autorhythmic cells and set the pace of the heart rate. b) Cells of the AV node are the usual pacemaker, because they are autorhythmic cells and set the pace of the heart rate. c) Cells of the AV node are the usual pacemaker, because they produce a lower rate of pacemaker potentials than other pacemaker cells. d) Cells of the SA node are the usual pacemaker, because the other cells of the conduction system are incapable of producing pacemaker potentials.

In skeletal muscle cells, action potentials cause the release of calcium from the SR by directly opening SR voltage-gated calcium channels. What causes the release of calcium from the SR in cardiac muscle cells? a) Action potentials destabilize the sarcolemma changing the permeability of the cardiac SR and allowing Ca2+ to leak out. b) ACh from the cardiac neurons bind ACh receptors on the cardiac myocytes and cause Ca2+ to bind troponin. c) The mechanism is the same in cardiac muscle cells. d) Influx of extracellular calcium ions opens ryanodine receptors allowing Ca2+ to flow out of the SR.

The electrocardiogram represents ________. a) the contractile activity of most of the myocardium b) the electrical activity of only the pacemaker cells c) the electrical activity of all of the cardiac muscle cells d) the electrical activity of the nerves that regulate the heart beat

Which two mechanisms influence the force of cardiac contraction? a) End diastolic volume and parasympathetic nervous system stimulation b) Parasympathetic nervous system stimulation and end systolic volume c) End systolic volume and sympathetic nervous system stimulation d) End diastolic volume and sympathetic nervous system stimulation

Action potentials generated by the autorhythmic cells spread to the contractile cells through what structures in the membrane? a) gap junctions b) desmosomes c) intercalated discs d) tight junctions

One of the changes that occurs in the pacemaker potential (unstable resting membrane potential) in the SA node (an autorhythmic cell) is a decreased efflux of what ion? a) sodium b) calcium c) potassium

When threshold is reached at the SA node (an autorhythmic cell), what channels open causing further depolarization of the membrane? a) fast calcium b) slow calcium c) potassium d) fast sodium

Repolarization of an autorhythmic cell is due to the opening of which channels? a) Chemically gated potassium channels b) voltage-gated potassium channels c) chemically gated calcium channels d) voltage-gated sodium channels

In order to cause cardiac muscle contraction, the contractile cells must also depolarize. What causes the depolarization of the contractile cells? a) an unstable resting membrane potential in the contractile cells b) the flow of positive ions from adjacent cells c) the flow of negative ions from adjacent cells

Isovolumetric relaxation and ventricular filling (two phases of the cardiac cycle) take place during __________. a) ventricular systole b) ventricular diastole

Which of the following is correct about the filling of the ventricles? a) The majority of ventricular filling is caused by contraction of the atria. b) Most blood flows passively into the ventricles through open AV valves.

Describe the pressures in the atria and ventricles that would cause the opening of the AV valves. a) Pressure in the ventricles would be greater than in the atria. b) Pressure in the atria would be greater than the pressure in the ventricles. c) Pressures in the atria and ventricles would be equal.

What causes the aortic semilunar valve to close? a) higher ventricular pressure than aortic pressure b) equal ventricular and aortic pressures c) greater pressure in the aorta than in the left ventricle

Put the phases of the cardiac cycle in the correct order, starting after ventricular filling. a) ventricular ejection, ventricular relaxation, isovolumetric contraction b) ventricular ejection, isovolumetric contraction, isovolumetric relaxation c) isovolumetric relaxation, ventricular ejection, isovolumetric contraction d) isovolumetric contraction, ventricular ejection, isovolumetric relaxation

Increased pressure in the ventricles would close what valve(s)? a) AV valves only b) both semilunar and AV valves c) semilunar valves only

The heart is actually (one, two, or three) pumps? a) two pumps b) one pump c) three pumps

Which chamber receives blood from the superior and inferior vena cavae? a) left atrium b) left ventricle c) right ventricle d) right atrium

Which heart chamber receives blood from the pulmonary veins? a) left ventricle b) right atrium c) left atrium d) right ventricle

Which heart chamber pumps unoxygenated blood out the pulmonary trunk? a) left atrium b) right ventricle c) left ventricle d) right atrium

Which chamber pumps oxygenated blood out the aorta to the systemic circuit? a) right atrium b) left atrium c) left ventricle d) right ventricle