Chapter 17: Heart Anatomy

questions for pre lecture readings

the heart is located in a subdivision of the thoracic cavity known as the

mediastinum

the heart’s shape is basically a

cone

the heart is about the size of your

fist

the heart’s atria receive blood coming from

veins

which side of the heart functions as the pulmonary pump

right side

the arteries and veins that supply the heart muscle itself form the ___ circulation

coronary

the lumen of the heart’s is lined with

endocardium

the visceral pericardium is part of the

epicardium

the cardiac skeleton is part of the

myocardium

which of the following vessels is not a GREAT vessel

right coronary artery

match each great vessel with the correct description

aorta - systemic artery, attached to left ventricle

pulmonary veins - bring blood from the lungs back to the left atrium

inferior vena cava - drains blood from the lower extremities back to the heart into the right atrium

pulmonary trunk - branches into 2 pulmonary arteries attached to right ventricle

superior vena cava - drains blood from the head and upper extremities back to the heart into the right atrium

the atria receive blood. they can expand as they fill with blood because of muscular pouches called __ which have that name because they resemble the external ear

auricles

the right and left ventricles are divided by a wall called the

interventricular septum

what is the purpose of the valves in the heart

to prevent blood from flowing backward

which valve is also known as the mitral valve

bicuspid valve

select the two arteries of the coronary circulation that are directly connected to the ascending aorta

left coronary artery

right coronary artery

the anterior interventricular artery is a branch of the left coronary artery. where does the posterior interventricular artery come from

it depends on the person

there are three structures that drain into the right atrium. those three structures are the inferior vena cava, the superior vena cava, and the

coronary sinus

slow depolarization in rhythmic cycles is characteristic of __ cells

pacemaker

pacemaker cells do NOT have many __ channels

sodium

the pacemaker cells with the fastest rate of intrinsic depolarization are located in the

SA (sinoatrial) node

an action potential starting at the SA node will spread along atrial conducting fibers until it reaches the __, where there is a short delay. this delay is very important because it allows the atria to finish contracting before the ventricles contract

AV node

99% of cardiac muscle cells are contractile cells. these cells CONTRACT in response to action potentials. these action potentials have a “plateau” phase which is dependent on __ ions

calcium

the ECG (or EKG) measures electrical changes that happen in __ cells

contractile cardiac muscle cells

It is possible to calculate heart rate from the

R-R interval

match the ECG finding with its meaning

T wave - ventricular repolarization

Q -T interval - duration of the entire ventricular action potential

QRS complex - ventricular depolarization

P wave - atrial depolarization

what is the cardiac cycle

the sequence of mechanical events from one heartbeat to the next

blood flows through the heart from high to low, according to the ___ gradient

pressure

as the left ventricle contracts, its pressure rises above the pressures in the left atrium and the aorta. then blood will flow into the aorta. which valves need to be open or closed at this point in the cardiac cycle

aortic valve open; left atrioventricular valve closed

as the left ventricle relaxes, its pressure will fall. when the left ventricle is completely relaxed, which valves will be open or closed

aortic valve closed; left atrioventricular valve open

the sound of vibration of the heart walls due to a closing aortic valve is heard during the __ heart sound

S2

what is the best location to place the stethoscope to hear the sound associated with the aortic valve closing

2nd intercostal space; right sternal border

place the events of the cardiac cycle in order

1. ventricular filling

2. isovolumetric contraction

3. ventricular ejection

4. isovolumetric relaxation

80% of the blood that flows from the atria into the ventricles flow __

passively

match the term with its definition

1. relaxation - diastole

2. contraction - systole

3. amount of blood in the ventricles before contraction - end diastolic volume

4. amount of blood in the ventricles after contraction - end systolic volume

5. no change in blood volume in the ventricle - isovolumetric

6. blood flowing out of the ventricle - ejection

what is considered a normal valve for heart rate

60 to 80 beats per minute

how does the amount of blood pumped by the right ventricle compare to that pumped by the left ventricle

the right ventricle pumps the same amount of blood as the left ventricle

the ejection fraction is the % of blood in the ventricle that is pumped out during systole. what is the normal ejection fraction

65%

match each factor that influences stroke volume with the correct descriptors

1. dependent on how much blood comes into the ventricle before it contracts: preload

2. the degree of cardiac muscle stretch - preload

3. can be changed by various neural and hormonal factors - contractility

4. the intrinsic pumping ability of the heart- contractility

5. determined by blood pressure in the pulmonary and systemic circuits - afterload

6. the amount of force that the ventricles must overcome in order to pump blood out of the heart - afterload

which of the following has a positive chronotropic effect on the heart (as in, it makes the heart beat faster)

thyroid hormone

what effect does a positive chronotropic agent have on cardiac output

cardiac output will increase

what effect will vagus nerve stimulation have on cardiac output

decreased cardiac output due to decreased heart rate

aldosterone and ADH are two hormones that increase blood volume. what effect does increasing blood volume have on cardiac output

increasing cardiac output by increasing preload

why do trained athletes generally have a lower resting heart rate

they have increased stroke volume, which maintains cardiac output

pulmonary congestion and pulmonary edema, from fluid backing up in the lungs, is a common symptom of which type of heart failure

left sided heart failure