Neat Fact – Your heart beats about 100,000 times in one day and about 35 million times in a
year. During an average lifetime, the human heart will beat more than 2.5 billion times.
Anatomy of the Heart
Chapter Learning Objectives:
1) Describe the location, approximate size, and
function of the heart
2) Describe the protective coverings of the heart
3) Identify the major anatomical structures of the
heart and explain how they function
4) Trace the pathway of blood through the heart
5) Describe cardiac muscle
6) Explain the heart’s pacemaker and the electrical
conductivity of the heart
7) Explain the waves of an ECG
Developed by Stephanie Lanoue for L.I.T. 5/14/2007
Where is Your Heart Located?
2)Put your hand on your heart (keep it there).
Neat Fact: The heart pumps about 1 million barrels of blood during an
average lifetime--that's enough to fill more than 3 super tankers.
How big is your heart?
Neat Fact: On average, your body has about 5 liters of blood
continually traveling through it by way of the circulatory system.
How Would You Describe
the Heart? What Do You
Already Know About It?
Class Activity: Appreciating Your Heart as a
The Heart’s Protective
▪ Do you know that the heart
has 2 protective membranes
Heart enclosed in double-walled sac called
Superficial – fibrous pericardium
Deep – serous pericardium
*between the 2 layers is some fluid
Remember the number…
Next, we are going to learn basic heart anatomy:
▪ 4 chambers
▪ 4 valves
▪ 4 main blood vessels coming into/ exiting the
Orientation of the Heart in
Remember, you are looking at someone else’s chest!
(Speaking of someone else’s chest…heart surgery photos)
Photos from Open Heart Surgery Observations –
Methodist Hospital, Houston, TX
Basic Heart Anatomy
NOTE TO STUDENTS: Label the structures of the heart on your
diagram as I explain them.
NOTE: Atria = plural form of atrium
Heart Anatomy Continued
Valves, flaps of connective tissue between
the atria and ventricles, allow blood to flow
semilunar valve image
mitral valve image
(3 cusps are open)
( 2 cusps)
Neat Fact: Heart sounds (“lub, dub”) are caused by the closing of the
heart valves. The mitral & tricuspid valves make the 1st sound, and the
Chordae tendineae (“heart strings”) attached to ______ and _____ valves.
They anchor valve cusps to the papillary muscles (which play a role in valv
function). Papillary muscles protrude from the ventricle walls.
What is a Heart Attack?
Additional Important Arteries
Coronary circulation is blood provided by the right and left coronary arteries.
anterior interventricular artery (also
known as the left anterior descending marginal artery (supplies myocardium of
which supplies to the interventricular the lateral right side)
septum and anterior walls of both posterior interventricular artery
circumflex artery (supplies left atrium
and posterior walls of left ventricle).
After passing through capillary beds of the myocardium, the blood flows into the
coronary sinus (which empties blood into right atrium). Has 3 tributaries:
______ cardiac vein
______ cardiac vein
_______ cardiac vein
Also, several anterior cardiac veins.
Partner Activity: Blood Flow
Through the Heart
Instructions: Working with a partner, can you describe the
flow of blood through the heart? Start with the right atrium.
List all the major structures along the way (chambers,
valves, and vessels). Refer to the diagram on page 602.
Example: Rt. atrium > ? valve> ?
(chamber) > ? valve up the
pulmonary trunk which divides into
the > ? arteries (which send the
deoxygenated blood into the ? for
O2.) From the lungs back to the
heart along the ? Veins > ?
(chamber) through the ? Valve >?
(chamber) > ? Valve > Aorta > Body
> Venae cavae.
Cardiac muscle – _______, short (fat/ _______)
cells that are interconnected for quicker
communication & conduction of electrical current.
Video footage: http://video.aol.com/video-detail/beating-human-
Know Sequence of Excitation:
1. Sinoatrial node (SAN) or __________ > See animation:
2. _______ventricular node (AVN) > http://www.jdaross.cwc.
3. Atrioventricular bundle (bundle of ___) >
4. Right and Left bundle branches >
5. Purkinje fibers (directly supply the papillary muscles)
___ – initiation of the
heartbeat in the atria
___ – movement of
the electrical current
through the ventricles
__ – recovery phase;
spreads back over the
ventricles in the
Electrocardiogram (ECG) continued
Healthy heart – _____, ______, and timing of waves tend
to be _____________
Unhealthy heart – waves are ______
Examples: an enlarged R wave hints of enlarged
ventricles or a prolonged Q-T interval may reveal
Normal and Abnormal
(a) _______– steady sinus
(b) Non-functional _____
(c) Heart _____ – damage to
the AVN (interferes with the
ventricles receiving pacing
(d) __________ fibrillation
(acute heart attack or
Normal and Abnormal ECG Readings
Arrhythmias – ________ heartbeats caused by
uncoordinated atrial and ventricular contractions
Example: atrial flutter
___________ – rapid and irregular contractions; SAN
looses control of setting the pace; fatal condition
Other Heart Abnormalities
Heart ________ – blood back flowing through a
___________ –abnormally fast heart rate
__________ – heart rate slower than 60 beats per
Congestive heart failure – progressively worsening
condition in which the heart can no longer pump
blood efficiently (heart weakens and enlarges)