1. Lecture Notes Functional Anatomy of the Cardiovascular System
Chapter 17
Functional Anatomy of the Cardiovascular System
Copyright © 2007, 1998 by Mosby, Inc., an affiliate of Elsevier Inc.

2. Gross Anatomy of the Heart
Lies in mediastinum behind sternum
Apex points to the left
Point of maximal impact (PMI)
The apical beat
5th Intercostal space
at mid-clavicular line
Causes of PMI shift
Left Sided Pneumothorax
Pg. 301
Concept Question:
A tension pneumothorax of the left lung shifts the PMI in which direction?
ConceptQuestion
17-1
Copyright © 2007, 1998 by Mosby, Inc., an affiliate of Elsevier Inc.

3. Clinical Focus 17-1
32 y.o. man. Severe chest wall injury sustained in automobile accident. Conscious, anxious, c/o dyspnea and chest pain. Distending neck veins, tachycardia; systolic blood pressure of 90mmHg.
Read the discussion (pg. 304)
1. The patient exhibits signs of ________________
2. What is this disease?
3. Cause of distended neck veins?
4. Cause of increased HR?
5. Cause of low systolic pressure?
read the discussion on pg. 304 and answer questions
1. Cardiac Tamponade
2. Fluid enters the pericardial space. Builds up and restricts the ventricle from pumping
3. Blood backs up all the way to the right atrium and causing back up even in the neck veins
4. Cause of increased HR is the bodys attempt to sustain normal cardiac output.
5. In severe tamponade, because there’s so little volume in the ventricle (stroke volume), systolic pressure decreases.

4. Pericardium
Loose-fitting membranous sac Parietal vs. visceral pericardium (epicardium)
Pg. 302
Parietal = outter sac
Visceral (epicardium) = inner
The fluid in between = pericardial fluid… Acts as lubrication allowing for smoother, frictionless movement as the heart beats.

5. Parietal = outter sac
Visceral (epicardium) = inner
The fluid in between = pericardial fluid… Acts as lubrication allowing for smoother, frictionless movement as the heart beats.

6. Copyright © 2007, 1998 by Mosby, Inc., an affiliate of Elsevier Inc.
Anatomy of the Heart
Heart wall
Epicardium, Myocardium, Endocardium
Myocardium =
Heart chambers and valves
2 atria and 2 ventricles
RA receives deoxygenated blood from superior vena cava, inferior vena cava
LA receives oxygenated blood from pulmonary veins
Greater muscle mass than the right ventricle
Myocardium = The heart muscle forming the bulk of the heart wall.
This muscle wraps around the chambers in such a way that contraction ejects blood with great force
Pg. 305
Copyright © 2007, 1998 by Mosby, Inc., an affiliate of Elsevier Inc.

7. Copyright © 2007, 1998 by Mosby, Inc., an affiliate of Elsevier Inc.
Anatomy of the Heart
Fig. 17-3
Copyright © 2007, 1998 by Mosby, Inc., an affiliate of Elsevier Inc. 7

8. Anatomy of the Heart Heart chambers and valves
Atrial-ventricular valves
Tricuspid = Right or Left side?
Mitral = Right or Left side?
PURPOSE = prevent back flow of blood during ventricle contractions
Ventricular outflow pg 302
Right Ventricle Pumps through _________________
Left Ventricle Pumps through __________________
Prevents backflow of blood into the ventricles during ventricle relaxation
ConceptQuestion
17-2
Tricuspid = Right side
Mitral Valve or Bicuspid = Left side
Pg. 302
CONCEPT QUESTION What are the consequences of a mitral valve that leaks or allows backflow of blood during ventricular systole?
Answer: A leaking mitral valve would allow blood to flow backward (regurgitate) into the left atrium with each ventricular contraction, increasing mean left atrial pressure and ultimately pulmonary capillary pressure. High pulmonary capillary pressure could lead to pulmonary edema, which would interfere with pulmonary gas exchange.
PURPOSE = PREVENT BACKFLOW OF BLOOD INTO THE ATRIA DURING VENTRICULAR CONTRACTION
RIGHT VENTRICLE PUMPS THROUGH PULMONARY VALVE (AKA Pulmonary Semilunar Valve)
LEFT VENTRICLE PUMPS THROUGH AORTIC VALVE (AKA Aortic Semilunar Valve)
INTERATRIAL SEPTUM = Tissue that separates the right and left atrium… prevents the right atrium blood from going straight to the left atrium…. The book will say “Prevents mixing of oxygenated and deoxygenated blood.” – pg. 278
INTERVENTRICULAR SEPTUM = Tissue that separates the right and left ventricle… prevents the right ventricle blood from going straight to the left ventricle… The book will say “Prevents mixing of oxygenated and unoxygenated blood.” – pg. 278
Look on previous slide to show the septums.

9. Clinical Focus 17-3 Mitral Valve Stenosis
Person with Severe Mitral Valve Stenosis requires oxygen and shows signs of pulmonary edema.
What is Pulmonary Edema?
What is the connection of a cardiac problem leading to a pulmonary problem?
Mitral Valve Stenosis is a condition characterized by a narrowed, stiff mitral valve. The narrowed valve created high resistance to blood flow. It can back up into the pulmonary capillaries and can leak into the lungs.

10. Clinical Focus 17-2 Ventricular Septal Defect (VSD)
What is it?
Mixing of blood from the two chambers
Treatment?
If patient is symptomatic (SOB), it will need surgical correction.
What is it? Mixing of blood from the two chambers
Treatment? If patient is symptomatic (SOB), it will need surgical correction.

11. Coronary Circulation
Though the heart pumps blood, it also receives oxygenated blood to sustain itself
Coronary arteries
Left and right coronaries
1. Right coronary is the dominant blood supplier
2. Originate immediately above aortic semilunar valve
3. “The heart relies almost exclusively on the two main coronary arteries.” pg 305
In the heart, there is a lack of collateral circulation if…
1. If blood flow is blocked = ischemia (tissue hypoxia) and central chest pain (angina pectoris)
2. Myocardial infarction (MI) = heart muscle tissue death
MONA – Morphine, Oxygen, Nitroglycerin(vasodilator), Asprin (prevent blood clot)
Left and right coronaries
1. Right coronary is the dominant blood supplier
2. Originate immediately above aortic semilunar valve
3. “The heart relies almost exclusively on the two main coronary arteries.”
In the heart, there is a lack of collateral circulation
If blood flow is blocked = ischemia (tissue hypoxia) and central chest pain (angina pectoris)
Myocardial infarction (MI) = heart muscle tissue death
This is why we used to give MONA…
Morphine – Pain
Oxygen – Hypoxia
Nitroglycerin – Vasodilator
Aspirin – Prevention of blood clot formation

12. Angina Pectoris pg 306 Aka Chest Pain
Caused by: Coronary artery disease
The pain is often felt beneath the sternum, in the left arm, and in the neck
“About 35% of all deaths in the United States are caused by coronary artery disease” (CAD) pg. 306
Aka Chest Pain
Caused by Coronary artery occlusion leading to Myocardial Ischemia

13. Coronary Circulation pg 307
Coronary veins
Flow parallel to arteries
Empty into right atrium (coronary sinus)
Oxygen requirement and blood flow
O2 extraction ≈70% (compare to 25% whole body)
 during exercise =  coronary flow
O2 need governs coronary blood flow
Tachycardia is a response by the heart that it needs more oxygen
During exercise, because the heart can’t extract more oxygen from the supply it’s getting… It needs to increase the blood flow by increasing the heart rate and get oxygen more quickly.
If you give the patient oxygen, the heart rate will come back down.
During exercise, because the heart can’t extract more oxygen from the supply it’s getting… It needs to increase the blood flow by increasing the heart rate and get oxygen more quickly.
If you give the patient oxygen, the heart rate will come back down.
Copyright © 2007, 1998 by Mosby, Inc., an affiliate of Elsevier Inc.

14. Cardiac Conduction System pg 309
Specialized cardiac muscle tissue (not neurons)
Atria contract at last second (“atrial kick”) to complete ventricular filling
Conduction
Sinoatrial node (SA node) – Initiates Electrical Impulses. Travel down to the AV Node.
Atrioventricular node (AV node) - Triggers initial contraction of ventricles. Trigger travels down the AV bundle.
AV bundle aka “bundle of His”. The AV Bundle triggers down the right and left bundle branches.
Bundle branches terminate into the Purkinje fibers
Purkinje fibers carry the electrical signal to the ventricles (apex of the heart).
Ventricles receive signal and contract.

15. Systole vs. Diastole Diastole Systole Ventricle is relaxed and
Ventricle contracts
and ejects blood
Diastole
Ventricle is relaxed and
fills with blood
PAGE 308
A. = Diastole
B. = Systole
Note what happens in diastole.
The tricuspid and mitral valve are open. The pulmonary and aortic valves are closed.
Note what happens in systole.
The tricuspid and mitral valve are closed. The pulmonary and aortic valves are open.
Copyright © 2007, 1998 by Mosby, Inc., an affiliate of Elsevier Inc. 15

16. Example
In the _____________ phase, the mitral valve and tricuspid valve is open, but the semilunar valves remain closed.
A. Aortic
B. Diastolic
C. Systolic
D. Anacrotic
B. Diastolic

17. Example
In the ______________ phase, the mitral valve and tricuspid valve remain closed, but the semilunar valves open.
A. Aortic
B. Diastolic
C. Systolic
D. Anacrotic
C. Systolic

18. Cardiac Conduction System
Time
“Stalls” for
From SA to AV = 0.03 seconds
At the AV Node, STALLS FOR 0.13 seconds
AV Node to Purkinje Fibers = 0.03 seconds
TOTAL TIME = 0.19 seconds.
Time
Fig
Total Time From Electrical Signal To Ventricular Contraction = 18

19. Cardiac Cycle Cardiac Cycle refers to a complete pumping cycle
Contraction (systole) and relaxation (diastole)
Beginning of Systole to the end of diastole = 0.8 seconds
Ventricular filling PRELOAD
80% passive + 20% atrial “kick”
80% is blood flowing from atria into ventricle
At the last moment, the atria kicks 20% more blood into the ventricle to get the ventricle ready to pump
Ventricular emptying (contraction) AFTERLOAD
Closure of the AV valves (1st heart sound)
Isovolumetric contraction (all valves closed)
Resistance to ejection = afterload pg 316
PRELOAD refers to the ventricle filling up.
Afterload begins immediately once the ventricles have been filled… In after load, there is still no physical ejection of the blood… Here’s what happens in the Afterload phase…
Then the valves close… With the valves closed, there is a contraction… This is known as the isovolumetric contraction… The blood isn’t ejected yet because the valves are closed..
Then the pulmonary and aortic valves open up… The resistance during the ejection of blood is known as the afterload.

20. Volume of blood during cardiac cycle
Ventricular filling PRELOAD
120 mL of blood total in this phase
“End-Diastolic” Volume
Ventricular emptying (contraction) AFTER LOAD
Normal amount of blood that is ejected = Stroke volume = 70 mL
How much is left in the ventricle?
50mL
= “End-Systolic” Volume (Not the same as stroke volume)
Cycle repeats itself and the ventricle is filled back up to 120mL in the preload phase.
If 70mL out of 120mL is ejected, what’s the percentage of ejected blood?
Next slide talks about ejection fraction… Percentage is 58 or about 60%. 20

21. … this is known as… EJECTION FRACTION
Ejection fraction… Percentage is 58 or about 60%. (Normal ≈ 60%.)
A low ejection fraction =
Indicates = Less than 50%
indicates poor contractility and pumping failure
On the flip side, during exercise, the ejection fraction may increase up to 90% pg 316
Low ejection fraction = Less than 50%
It indicates poor contractility and pumping failure
On the flip side, during exercise, the ejection fraction may increase up to 90%

22. From Previous Slide Two ways to calculate Stroke Volume
Ventricular emptying (contraction) AFTER LOAD
Normal amount of blood that is ejected = Stroke volume = 70 mL
How much is left in the ventricle?
50mL
= “End-Systolic” Volume (Not the same as stroke volume)
Two ways to calculate Stroke Volume
1. Cardiac Output(mL) / HR
2. Preload – Afterload

23. Determining Stroke Volume
Cardiac Output(mL) / HR
Example:
C.O = 5L/min
HR = 80/min
S.V. = ____ mL
C.O. = 3 L/min
HR = 120/min
S.V. = ______ mL

24. Determining Stroke Volume
The following information is obtained:
HR 120/min
Preload volume 120mL
Afterload Volume 80mL
B/P 109/75mmHg
What is the stroke volume?
A. 210mL
B. 90mL
C. 50mL
D. 40mL Preload – Afterload (D)
Preload – Afterload
D. 40mL

25. Summary Which of the following is known as end-diastolic volume?
A. Afterload
B. Stroke Volume
C. Preload
D. Diastole
Go back 5 slides ago
C. Preload
Go back 5 slides ago
Diastolic is the resting phase… So it’s filling up until you have a maximal amount of volume filling the ventricles during the non-kicking phase… This is pre-load…
And then of course, I could ask:
Which of the following is known as end-systolic volume…. ANSWER: After load
Ventricular emptying (contraction) AFTER LOAD
Amount of blood that is ejected = Stroke volume = 70 mL

26. Regulation of Pumping Activity
Normally, the blood that comes in (Right Atrium) is pumped out (Left Ventricle) at the same rate
The heart has the ability to adapt to inflow changes
“Frank-Starling Mechanism”
The heart may lose its ability to adapt is the left ventricle’s muscle has been over stretched
Left Ventricle Fails
Blood backs up
Congestive Heart Failure pg 314