SALADIN ANATOMY Chapter 19

The cardiac conduction system does not include

the tendinoous cords

To get from the right atrium to the right ventricle, blood flows through

the tricuspid valve

Assume that one ventricle of a child's heart has an EDV of 90 mL, an ESV of 60 mL, and a cardiac output of 2.55 L/min. What are the child's stroke volume (SV), ejection fraction (EF), and heart rate (HR)?

SV = 30 mL; EF = 33%; HR = 85 bpm

A heart rate of 45 bpm and an absence of P waves suggests

damage to the SA node

There is/are _______ pulmonary vein(s) emptying into the right atrium of the heart

no

The coronary blood vessels are part of the __________ circuit of the circulatory system

systemic

The atria contract during

the PQ segment

Cardiac muscle does not exhibit tetanus because it has

a long absolute refractory period

The blood contained in a ventricle during isovolumetric relaxation is

the end-systolic volume

Drugs that increase the heart rate have a __________ effect

positive chronotropic

The contraction of any heart chamber is called ___________ and its relaxation is called ___________

systole, diastole

The circulatory route from aorta to the the venae cavae is the __________ circuit

systemic

The circumflex artery travels in a groove called the _____________

atrioventricular (coronary) sulcus

The pacemaker potential of the SA node cells results from the slow inflow of __________

Na+

Electrical signals pass quickly from one cardiac myocyte to another through the _____________ of the intercalated discs

gap junctions

Repolarization of the ventricles produces the __________ of the electrocardiogram

T wave

The __________ nerves innervate the heart and tend to reduce the heart rate

vagus

The death of cardiac tissue from lack of blood flow is commonly known as a heart attack, but clinically called _______________

myocardial infarction

Blood in the heart chambers is separated from the myocardium by a thin membrane called the ________________

endocardium

The Frank-Starling law of the heart explains why the _______________ of the left ventricle is the same as that of the right ventricle

cardiac output

atrio-

entryway (atrium)

brady-

slow (bradycardia)

cardio-

heart (cardiology)

corono-

crown (coronary)

lun-

moon (semilunar)

papillo-

nipple (papillary)

semi-

semi (semilunar)

tachy-

fast (tachycardia)

vaso-

vessel (vasomotor)

ventro-

belly (ventricle)

The blood supply to the myocardium is the coronary circulation; everything else is called the systemic circuit

FALSE - The coronary circulation is part of the systemic circuit; the other division is the pulmonary circuit

There are no valves at the point where venous blood flows into the atria

TRUE

No blood can enter the ventricles until the atria contract

FALSE - The first two-thirds of ventricular filling occurs before the atria contract. The atria add only about 31% of the blood that fills the ventricles

The vagus nerves reduce the heart rate but have little effect on the strength of ventricular contraction

TRUE

A high blood CO2 level and low blood pH stimulate an increase in heart rate

TRUE

The first heart sound occurs at the time of the P wave of the electrocardiogram

FALSE - The first heart sound occurs at the time of the QRS complex

If all nerves to the heart were severed, the heart would instantly stop beating

FALSE - The heart has its own internal pacemaker

If the two pulmonary arteries were clamped shut, systemic edema would follow

TRUE

Ventricular cardiocytes have a stable resting membrane potential but myocytes of the SA node do not

TRUE

An electrocardiogram is a tracing of the action potential of a cardiocyte

FALSE - The ECG is a composite record of the electrical activity entire myocardium, not a record from a single myocyte. It looks much different from an action potential